Retirement and Postemployment Benefits (Plan Assets and Expected Cash Flows) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended						12 Months Ended		12 Months Ended							12 Months Ended																																																							12 Months Ended								12 Months Ended								12 Months Ended																															12 Months Ended																																																12 Months Ended																	12 Months Ended													12 Months Ended										12 Months Ended			12 Months Ended																																																																						12 Months Ended																		12 Months Ended				12 Months Ended			12 Months Ended											12 Months Ended								12 Months Ended								12 Months Ended								12 Months Ended								12 Months Ended								12 Months Ended								12 Months Ended								12 Months Ended																																12 Months Ended				12 Months Ended										12 Months Ended								12 Months Ended				12 Months Ended										12 Months Ended							12 Months Ended							12 Months Ended																																							12 Months Ended								12 Months Ended																																																							12 Months Ended								12 Months Ended								12 Months Ended																															12 Months Ended																																																12 Months Ended																	12 Months Ended													12 Months Ended										12 Months Ended										12 Months Ended					12 Months Ended							12 Months Ended																												12 Months Ended				12 Months Ended				12 Months Ended												12 Months Ended																								12 Months Ended									12 Months Ended													12 Months Ended										12 Months Ended			12 Months Ended																																																																						12 Months Ended																		12 Months Ended				12 Months Ended			12 Months Ended										12 Months Ended				12 Months Ended										12 Months Ended							12 Months Ended							12 Months Ended																																					12 Months Ended								12 Months Ended																												12 Months Ended				12 Months Ended				12 Months Ended																12 Months Ended																								12 Months Ended									12 Months Ended													12 Months Ended										12 Months Ended			12 Months Ended																																																																						12 Months Ended																		12 Months Ended				12 Months Ended			12 Months Ended
	Dec. 31, 2012 Pension Benefits - US [Member]	Dec. 31, 2011 Pension Benefits - US [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Integer		Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Receivables [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Receivables [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Payables [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Payables [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member]		Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Equity Securities [Member]		Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Equity Securities [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Debt Securities [Member]		Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Debt Securities [Member]		Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Alternative Investments [Member]		Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Alternative Investments [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member]		Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Debt Securities [Member]		Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Debt Securities [Member]		Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Derivatives [Member]		Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Derivatives [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Master Trust [Member] Liquidity Portfolio [Member]		Dec. 31, 2011 Pension Benefits - US [Member] Master Trust [Member] Liquidity Portfolio [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Pension Benefits - 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US [Member] US Commingled Money Market Funds Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 Other Postretirement Benefits - US [Member] US Commingled Money Market Funds Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Other Postretirement Benefits - US [Member] Debt Securities [Member]		Dec. 31, 2011 Other Postretirement Benefits - US [Member] Debt Securities [Member]		Dec. 31, 2012 Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member]	Dec. 31, 2011 Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member]	Dec. 31, 2012 Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Other Postretirement Benefits - 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US [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2012 Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2011 Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2012 Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2011 Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2012 Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2011 Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2012 Other Postretirement Benefits - US [Member] Account 401 H [Member]	Dec. 31, 2011 Other Postretirement Benefits - US [Member] Account 401 H [Member]	Dec. 31, 2012 Other Postretirement Benefits - US [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2011 Other Postretirement Benefits - US [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2012 Other Postretirement Benefits - US [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2011 Other Postretirement Benefits - US [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2012 Other Postretirement Benefits - US [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2011 Other Postretirement Benefits - US [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member]	Dec. 31, 2010 PPL Energy Supply LLC [Member] Pension Benefits - US [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Integer		Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member]		Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Equity Securities [Member]		Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Equity Securities [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Debt Securities [Member]		Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Debt Securities [Member]		Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Alternative Investments [Member]		Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Alternative Investments [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member]		Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Debt Securities [Member]		Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Debt Securities [Member]		Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Derivatives [Member]		Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Derivatives [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Liquidity Portfolio [Member]		Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Liquidity Portfolio [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Pension Benefits - UK [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Pension Benefits - UK [Member]	Dec. 31, 2010 PPL Energy Supply LLC [Member] Pension Benefits - UK [Member]	Dec. 31, 2012 PPL Energy Supply LLC [Member] Other Postretirement Benefits - US [Member]	Dec. 31, 2011 PPL Energy Supply LLC [Member] Other Postretirement Benefits - US [Member]	Dec. 31, 2010 PPL Energy Supply LLC [Member] Other Postretirement Benefits - US [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Commodities Alternative Investments [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Commodities Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Commodities Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Commodities Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Integer		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Equity Securities [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Equity Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Debt Securities [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Debt Securities [Member]		Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Alternative Investments [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Alternative Investments [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Debt Securities [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Debt Securities [Member]		Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Derivatives [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Derivatives [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Liquidity Portfolio [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Master Trust [Member] Liquidity Portfolio [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Growth Portfolio [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Growth Portfolio [Member] Equity Securities [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Growth Portfolio [Member] Debt Securities [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Immunizing Portfolio [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Immunizing Portfolio [Member] Debt Securities [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Liquidity Portfolio [Member]		Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Cash And Cash Equivalents [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Cash And Cash Equivalents [Member]		Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Equity Securities [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Equity Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Debt Equity Securities [Member] Integer	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Money Market Funds Equity Securities [Member] Integer	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Money Market Funds Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Money Market Funds Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Money Market Funds Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Money Market Funds Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Money Market Funds Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] US Commingled Money Market Funds Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Debt Securities [Member]		Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Debt Securities [Member]		Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Municipalities Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Receivables [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Receivables [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Receivables [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Receivables [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Receivables [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Receivables [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Receivables [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Receivables [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Account 401 H [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Account 401 H [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2012 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2011 LG And E And KU Energy LLC [Member] Other Postretirement Benefits - US [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Integer		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Level 1 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Cash And Cash Equivalents [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Small Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] International Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] US Treasury And US Government Sponsored Agency Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Residential - Commercial Backed Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Corporate Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Other Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] International Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Commodities Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Real Estate Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Private Equity Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Hedge Fund Of Funds Alternative Investments [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Other Derivatives [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Interest Rate Swaps Derivatives [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Receivables [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Payables [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Insurance Contracts [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Equity Securities [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Equity Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Debt Securities [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Debt Securities [Member]		Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Alternative Investments [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Growth Portfolio [Member] Alternative Investments [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Debt Securities [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Debt Securities [Member]		Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Derivatives [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Immunizing Portfolio [Member] Derivatives [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Liquidity Portfolio [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Master Trust [Member] Liquidity Portfolio [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 1 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 3 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 1 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 3 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Cash And Cash Equivalents [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Large Cap Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Commingled Debt Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member] Level 1 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member] Level 3 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] International Equity Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] US Treasury Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member] Level 1 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member] Level 3 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Corporate Debt Securities [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member] Level 1 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member] Level 3 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Return Swaps Derivatives [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member] Level 1 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Insurance Contracts [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Total Trust Assets Not Including 401 H Assets [Member] Level 3 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member] Level 1 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member] Level 2 [Member]	Dec. 31, 2012 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Account 401 H [Member] Level 3 [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Growth Portfolio [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Growth Portfolio [Member] Equity Securities [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Growth Portfolio [Member] Debt Securities [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Immunizing Portfolio [Member]	Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Immunizing Portfolio [Member] Debt Securities [Member]		Dec. 31, 2011 Louisville Gas And Electric Co [Member] Pension Benefits - US [Member] Louiville Gas Electric And Kentucky Energy Pension Trust [Member] Liquidity Portfolio [Member]
Information About Plan Assets (Numeric) [Abstract]
Value of plan U.S. pension trust assets that relate to PPL subsidiary																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																													$ 149																																																																																																																																																																																																																				$ 1,100																																																																																																																																																																																																																																																																																													$ 287																																																																																																																						$ 256
Undivided interest percentage in each asset category that PPL subsidiary holds																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																													4.00%																																																																																																																																																																																																																				26.00%																																																																																																																																																																																																																																																																																													7.00%																																																																																																																						26.00%
Assumptions Used in Calculations (Numeric) [Abstract]
Weighted average coupon for debt securities held									3.49%																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																				3.49%																																																																																																																																																																																																																				3.49%																																																																																																																																																																																																																																																																																													3.49%
Weighted average duration for debt securities held (in years)									21																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																				21																																																																																																																																																																																																																				21																																																																																																																																																																																																																																																																																													21
The limited lives of four partnership of private equity investments (in years)									10																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																				10																																																																																																																																																																																																																				10																																																																																																																																																																																																																																																																																													10
The limited lives of fifth partnership of private equity investments (in years)									15																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																				15																																																																																																																																																																																																																				15																																																																																																																																																																																																																																																																																													15
The amount of potential liability that maybe required to be funded by the master trust during life of the partnership									73																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																				73																																																																																																																																																																																																																				73																																																																																																																																																																																																																																																																																													73
The number of days notice required to redeem shares in hedge fund investments									90																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																				90																																																																																																																																																																																																																				90																																																																																																																																																																																																																																																																																													90
Number of months from date of purchase that investment must mature																																																																																																																																																																																																																																																																																																																																																																																																																																																							13							13																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																												13							13
Fund management expects to outperform this percentage of ex-Japan Index returns																																																																																																																																																																																																																																																																																																																																			50.00%
Fund management expects to outperform this percentage of Japan Index returns																																																																																																																																																																																																																																																																																																																																			50.00%
Actual Allocation by Plan Asset (Details) [Abstract]
Percentage of trust assets									100.00%	[1]	100.00%																																																																																																																																																																												58.00%	[1]	57.00%	31.00%	[1]	31.00%	18.00%	[1],[2]	17.00%	[2]	9.00%	[1]	9.00%	41.00%	[1]	41.00%	40.00%	[1],[2]	40.00%	[2]	1.00%	[1]	1.00%	1.00%	[1]	2.00%	100.00%																																																																																								54.00%	33.00%	21.00%	[1]	34.00%	34.00%	[1],[2]	12.00%	[2]	100.00%	100.00%								0.00%	5.00%							6.00%	14.00%							14.00%	5.00%							0.00%	5.00%							0.00%	5.00%							3.00%	2.00%							2.00%	1.00%							18.00%	0.00%																															51.00%	[3]	56.00%	[3]	6.00%	7.00%									100.00%	100.00%							3.00%	[4]	6.00%	[4]	46.00%	41.00%																							51.00%	[5]	53.00%	[5]																																					100.00%	[1]	100.00%																																																																																																																																																																												58.00%	[1]	57.00%	31.00%	[1]	31.00%	18.00%	[1],[2]	17.00%	[2]	9.00%	[1]	9.00%	41.00%	[1]	41.00%	40.00%	[1],[2]	40.00%	[2]	1.00%	[1]	1.00%	1.00%	[1]	2.00%													100.00%	[1]	100.00%																																																																																						58.00%	[1]	57.00%	31.00%	[1]	31.00%	18.00%	[1],[2]	17.00%	[2]	9.00%	[1]	9.00%	41.00%	[1]	41.00%	40.00%	[1],[2]	40.00%	[2]	1.00%	[1]	1.00%	1.00%	[1]	2.00%	100.00%																																																																																								54.00%	33.00%	21.00%	[1]	34.00%	34.00%	[1],[2]	12.00%	[2]	100.00%	100.00%							3.00%	[4]	6.00%	[4]	46.00%	41.00%																							51.00%	[5]	53.00%	[5]																																			100.00%	[1]	100.00%																																																																																										58.00%	[1]	57.00%	31.00%	[1]	31.00%	18.00%	[1],[2]	17.00%	[2]	9.00%	[1]	9.00%	41.00%	[1]	41.00%	40.00%	[1],[2]	40.00%	[2]	1.00%	[1]	1.00%	1.00%	[1]	2.00%	100.00%																																																																																								54.00%	33.00%	21.00%	[1]	34.00%	34.00%	[1],[2]	12.00%	[2]
Target Allocations (Details ) [Abstract]
Target asset allocation									100.00%																																																																																																																																																																														56.00%													42.00%										2.00%			100.00%																																																																																								59.00%				38.00%			3.00%	[2]	100.00%																	6.00%								4.00%								3.00%								5.00%								5.00%								1.00%								18.00%																																52.00%	[3]			6.00%										100.00%								5.00%	[4]			45.00%																								50.00%	[5]																																							100.00%																																																																																																																																																																														56.00%													42.00%										2.00%															100.00%																																																																																								56.00%													42.00%										2.00%			100.00%																																																																																								59.00%				38.00%			3.00%	[2]	100.00%								5.00%	[4]			45.00%																								50.00%	[5]																																					100.00%																																																																																												56.00%													42.00%										2.00%			100.00%																																																																																								59.00%				38.00%			3.00%	[2]
Target asset allocation - PPL Plans									100.00%																																																																																																																																																																														55.00%													43.00%										2.00%																																																																																																																																																																																																																																																																																															100.00%																																																																																																																																																																														55.00%													43.00%										2.00%
Target asset allocation - LKE Plans									100.00%																																																																																																																																																																														59.00%													38.00%										3.00%																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																			100.00%																																																																																								59.00%													38.00%										3.00%																																																																																																																																																																														100.00%																																																																																												59.00%													38.00%										3.00%
Defined benefit plan fair value of plan assets (Details) [Abstract]
Fair value at end of period	3,939.0	3,471.0	1,230.0	1,213.0	2,567.0	2,160.0	98.0	142.0	3,939.0			1,230.0	963.0	2,567.0	1,512.0	142.0	84.0	78.0	84.0	78.0					558.0	371.0	206.0	247.0	352.0	124.0			124.0	112.0	124.0	112.0					676.0	458.0	56.0		620.0	458.0			557.0	299.0	184.0	102.0	373.0	197.0			704.0	515.0	634.0	443.0	70.0	72.0			12.0	9.0			11.0	9.0	1.0		874.0	446.0			847.0	439.0	27.0	7.0	24.0	10.0			23.0	10.0	1.0	7.0	6.0			7.0	6.0			59.0				59.0				93.0	85.0			93.0	85.0			75.0	45.0					75.0	45.0	125.0	92.0			125.0	92.0			2.0	5.0			2.0	5.0			36.0	20.0			36.0	20.0			55.0	50.0	29.0	31.0	26.0	19.0			(66.0)	(48.0)	(55.0)	(40.0)	(11.0)	(8.0)			42.0						42.0	4,041.0	2,553.0	1,262.0	973.0	2,633.0	1,528.0	146.0	52.0	(102.0)	(26.0)	(32.0)	(10.0)	(66.0)	(16.0)	(4.0)																												944.0			250.0		648.0		46.0		122.0		122.0						220.0				220.0				65.0				65.0				106.0		44.0		62.0				97.0		97.0						342.0				342.0				4.0				4.0				46.0					46.0			1,002.0		263.0		693.0		46.0		(58.0)		(13.0)		(45.0)												6,911.0	6,351.0		957.0	313.0	5,954.0	6,038.0			14.0		14.0	313.0					440.0		223.0		217.0	921.0			956.0		720.0		236.0	313.0								312.0								335.0			231.0				231.0	116.0			127.0				127.0	31.0			1,220.0				1,220.0	25.0			593.0	699.0			593.0	699.0			1,664.0	2,109.0			1,664.0	2,109.0			1,243.0	744.0			1,243.0	744.0									423.0	433.0			423.0	433.0			421.0	391.0	45.0	23.0	372.0	368.0	4.0								145.0	126.0			145.0	126.0			119.0			119.0	121.0			13.0	13.0			20.0							41.0	40.0			41.0	40.0			1.0				1.0				319.0	307.0	13.0		306.0	307.0			102.0	84.0	32.0	23.0	66.0	61.0	4.0		149.0	132.0	106.0		3,939.0			1,230.0	963.0	2,567.0	1,512.0	142.0	84.0	78.0	84.0	78.0					558.0	371.0	206.0	247.0	352.0	124.0			124.0	112.0	124.0	112.0					676.0	458.0	56.0		620.0	458.0			557.0	299.0	184.0	102.0	373.0	197.0			704.0	515.0	634.0	443.0	70.0	72.0			12.0	9.0			11.0	9.0	1.0		874.0	446.0			847.0	439.0	27.0	7.0	24.0	10.0			23.0	10.0	1.0	7.0	6.0			7.0	6.0			59.0				59.0				93.0	85.0			93.0	85.0			75.0	45.0					75.0	45.0	125.0	92.0			125.0	92.0			2.0	5.0			2.0	5.0			36.0	20.0			36.0	20.0			55.0	50.0	29.0	31.0	26.0	19.0			(66.0)	(48.0)	(55.0)	(40.0)	(11.0)	(8.0)			42.0						42.0	4,041.0	2,553.0	1,262.0	973.0	2,633.0	1,528.0	146.0	52.0	(102.0)	(26.0)	(32.0)	(10.0)	(66.0)	(16.0)	(4.0)																														2,524.0						59.0		59.0		3,939.0			1,230.0	1,213.0	2,567.0	2,160.0	142.0	84.0	84.0			558.0	206.0	352.0		124.0	124.0			676.0	56.0	620.0		557.0	184.0	373.0		704.0	634.0	70.0		12.0		11.0	1.0	874.0		847.0	27.0	24.0		23.0	1.0	7.0		7.0		93.0		93.0		75.0			75.0	125.0		125.0		2.0		2.0		36.0		36.0		55.0	29.0	26.0		(66.0)	(55.0)	(11.0)		42.0			42.0	4,041.0	1,262.0	2,633.0	146.0	(102.0)	(32.0)	(66.0)	(4.0)																											944.0			250.0		648.0		46.0		122.0		122.0						220.0				220.0				65.0				65.0				106.0		44.0		62.0				97.0		97.0						342.0				342.0				4.0				4.0				46.0					46.0			1,002.0		263.0		693.0		46.0		(58.0)		(13.0)		(45.0)														45.0	23.0	372.0	368.0	4.0								145.0	126.0			145.0	126.0			119.0			119.0	121.0			13.0	13.0			20.0							41.0	40.0			41.0	40.0			1.0				1.0				319.0	307.0	13.0		306.0	307.0			102.0	84.0	32.0	23.0	66.0	61.0	4.0				3,939.0			1,230.0	1,213.0	2,567.0	2,160.0	142.0	84.0	84.0			558.0	206.0	352.0		124.0	124.0			676.0	56.0	620.0		557.0	184.0	373.0		704.0	634.0	70.0		12.0		11.0	1.0	874.0		847.0	27.0	24.0		23.0	1.0	7.0		7.0		59.0		59.0		93.0		93.0		75.0			75.0	125.0		125.0		2.0		2.0		36.0		36.0		55.0	29.0	26.0		(66.0)	(55.0)	(11.0)		42.0			42.0	4,041.0	1,262.0	2,633.0	146.0	(102.0)	(32.0)	(66.0)	(4.0)																											944.0			250.0		648.0		46.0		122.0		122.0						220.0				220.0				65.0				65.0				106.0		44.0		62.0				97.0		97.0						342.0				342.0				4.0				4.0				46.0					46.0			1,002.0		263.0		693.0		46.0		(58.0)		(13.0)		(45.0)
Change in Plan Assets [Roll Forward]
Balance at beginning of period	3,471.0	2,819.0	1,230.0	1,213.0	2,567.0	2,160.0	63.0	142.0	2,527.0			1,230.0	963.0	2,567.0	1,512.0	52.0	84.0	78.0	84.0	78.0					558.0	371.0	206.0	247.0	352.0	124.0			124.0	112.0	124.0	112.0					676.0	458.0	56.0		620.0	458.0			557.0	299.0	184.0	102.0	373.0	197.0			704.0	515.0	634.0	443.0	70.0	72.0			12.0	9.0			11.0	9.0			874.0	446.0			847.0	439.0	7.0	6.0	24.0	10.0			23.0	10.0		7.0	6.0			7.0	6.0			59.0				59.0				93.0	85.0			93.0	85.0			75.0	45.0					45.0	10.0	125.0	92.0			125.0	92.0			2.0	5.0			2.0	5.0			36.0	20.0			36.0	20.0			55.0	50.0	29.0	31.0	26.0	19.0			(66.0)	(48.0)	(55.0)	(40.0)	(11.0)	(8.0)			42.0							4,041.0	2,553.0	1,262.0	973.0	2,633.0	1,528.0	146.0	52.0	(102.0)	(26.0)	(32.0)	(10.0)	(66.0)	(16.0)	(4.0)																															250.0		648.0		46.0		122.0		122.0						220.0				220.0				65.0				65.0				106.0		44.0		62.0				97.0		97.0						342.0				342.0				4.0				4.0				46.0					47.0			1,002.0		263.0		693.0		46.0		(58.0)		(13.0)		(45.0)												6,351.0	2,524.0		957.0	313.0	5,954.0	6,038.0			313.0		14.0	313.0					921.0		223.0		217.0	921.0			313.0		720.0		236.0	313.0			312.0					312.0			335.0					335.0			116.0				231.0	116.0			31.0				127.0	31.0			25.0				1,220.0	25.0			593.0	699.0			593.0	699.0			1,664.0	2,109.0			1,664.0	2,109.0			1,243.0	744.0			1,243.0	744.0									423.0	433.0			423.0	433.0			391.0	360.0	45.0	23.0	372.0	368.0	4.0								145.0	126.0			145.0	126.0			121.0			119.0	121.0			20.0	13.0			20.0							41.0	40.0			41.0	40.0			1.0				1.0				319.0	307.0	13.0		306.0	307.0			102.0	84.0	32.0	23.0	66.0	61.0	4.0		149.0	132.0	106.0	63.0	2,527.0			1,230.0	963.0	2,567.0	1,512.0	52.0	84.0	78.0	84.0	78.0					558.0	371.0	206.0	247.0	352.0	124.0			124.0	112.0	124.0	112.0					676.0	458.0	56.0		620.0	458.0			557.0	299.0	184.0	102.0	373.0	197.0			704.0	515.0	634.0	443.0	70.0	72.0			12.0	9.0			11.0	9.0			874.0	446.0			847.0	439.0	7.0	6.0	24.0	10.0			23.0	10.0		7.0	6.0			7.0	6.0			59.0				59.0				93.0	85.0			93.0	85.0			75.0	45.0					45.0	10.0	125.0	92.0			125.0	92.0			2.0	5.0			2.0	5.0			36.0	20.0			36.0	20.0			55.0	50.0	29.0	31.0	26.0	19.0			(66.0)	(48.0)	(55.0)	(40.0)	(11.0)	(8.0)			42.0							4,041.0	2,553.0	1,262.0	973.0	2,633.0	1,528.0	146.0	52.0	(102.0)	(26.0)	(32.0)	(10.0)	(66.0)	(16.0)	(4.0)																														2,524.0					63.0	59.0		59.0					1,230.0	1,213.0	2,567.0	2,160.0	98.0	84.0	84.0			558.0	206.0	352.0		124.0	124.0			676.0	56.0	620.0		557.0	184.0	373.0		704.0	634.0	70.0		12.0		11.0		874.0		847.0		24.0		23.0		7.0		7.0		93.0		93.0		75.0				125.0		125.0		2.0		2.0		36.0		36.0		55.0	29.0	26.0		(66.0)	(55.0)	(11.0)		42.0				4,041.0	1,262.0	2,633.0	146.0	(102.0)	(32.0)	(66.0)	(4.0)																														250.0		648.0		46.0		122.0		122.0						220.0				220.0				65.0				65.0				106.0		44.0		62.0				97.0		97.0						342.0				342.0				4.0				4.0				46.0					47.0			1,002.0		263.0		693.0		46.0		(58.0)		(13.0)		(45.0)														45.0	23.0	372.0	368.0	4.0								145.0	126.0			145.0	126.0			121.0			119.0	121.0			20.0	13.0			20.0							41.0	40.0			41.0	40.0			1.0				1.0				319.0	307.0	13.0		306.0	307.0			102.0	84.0	32.0	23.0	66.0	61.0	4.0			63.0				1,230.0	1,213.0	2,567.0	2,160.0	98.0	84.0	84.0			558.0	206.0	352.0		124.0	124.0			676.0	56.0	620.0		557.0	184.0	373.0		704.0	634.0	70.0		12.0		11.0		874.0		847.0		24.0		23.0		7.0		7.0		59.0		59.0		93.0		93.0		75.0				125.0		125.0		2.0		2.0		36.0		36.0		55.0	29.0	26.0		(66.0)	(55.0)	(11.0)		42.0				4,041.0	1,262.0	2,633.0	146.0	(102.0)	(32.0)	(66.0)	(4.0)																														250.0		648.0		46.0		122.0		122.0						220.0				220.0				65.0				65.0				106.0		44.0		62.0				97.0		97.0						342.0				342.0				4.0				4.0				46.0					47.0			1,002.0		263.0		693.0		46.0		(58.0)		(13.0)		(45.0)
Actual return on plan assets relating to assets still held at the reporting date							7									14																																																															1	(4)																																						10	8																																															3																																																																																																																	3																																																																																																																																																																																																																					7								14																																																															1	(4)																																						10	8																																															3																																																		7												14																																1																10																								3																																																																																																																																																																																																													7								14																																1																				10																								3																																																																																																									3
Actual return on plan assets relating to assets sold during the period																2																																																															2																																																																																																																																																																																																																																																																																																																																																																																																																																					2																																																															2																																																																																																																																																					2																																2																																																																																																																																																																																																																																																													2																																2
Acquisition of LKE																																																																																																																																																																																																																																																																																																																			3,567	[6]
Purchases, sales and settlements							28									35																																																							1								21	5																																						20	27																																															(7)																																																																																																																	(4)																																																																																																																																																																																																																					28								35																																																							1								21	5																																						20	27																																															(7)																																																		28												35																												1				21																20																								(7)																																																																																																									(4)																																																																																																				28								35																												1				21																				20																								(7)
Transfers from level 2 to level 3																1																																																																							1																																																																																																																																																																																																																																																																																																																																																																																																																													1																																																																							1																																																																																																																																													1																																				1																																																																																																																																																																																																																																																									1																																				1
Transfers from level 3 to level 2																(4)																																																															(4)																																																																																																																																																																																																																																																																																																																																																																																																																																					(4)																																																															(4)																																																																																																																																																					(4)																																(4)																																																																																																																																																																																																																																																													(4)																																(4)
Balance at end of period	3,939.0	3,471.0	1,230.0	1,213.0	2,567.0	2,160.0	98.0	142.0	3,939.0			1,230.0	963.0	2,567.0	1,512.0	142.0	84.0	78.0	84.0	78.0					558.0	371.0	206.0	247.0	352.0	124.0			124.0	112.0	124.0	112.0					676.0	458.0	56.0		620.0	458.0			557.0	299.0	184.0	102.0	373.0	197.0			704.0	515.0	634.0	443.0	70.0	72.0			12.0	9.0			11.0	9.0	1.0		874.0	446.0			847.0	439.0	27.0	7.0	24.0	10.0			23.0	10.0	1.0	7.0	6.0			7.0	6.0			59.0				59.0				93.0	85.0			93.0	85.0			75.0	45.0					75.0	45.0	125.0	92.0			125.0	92.0			2.0	5.0			2.0	5.0			36.0	20.0			36.0	20.0			55.0	50.0	29.0	31.0	26.0	19.0			(66.0)	(48.0)	(55.0)	(40.0)	(11.0)	(8.0)			42.0						42.0	4,041.0	2,553.0	1,262.0	973.0	2,633.0	1,528.0	146.0	52.0	(102.0)	(26.0)	(32.0)	(10.0)	(66.0)	(16.0)	(4.0)																												944.0			250.0		648.0		46.0		122.0		122.0						220.0				220.0				65.0				65.0				106.0		44.0		62.0				97.0		97.0						342.0				342.0				4.0				4.0				46.0					46.0			1,002.0		263.0		693.0		46.0		(58.0)		(13.0)		(45.0)												6,911.0	6,351.0		957.0	313.0	5,954.0	6,038.0			14.0		14.0	313.0					440.0		223.0		217.0	921.0			956.0		720.0		236.0	313.0								312.0								335.0			231.0				231.0	116.0			127.0				127.0	31.0			1,220.0				1,220.0	25.0			593.0	699.0			593.0	699.0			1,664.0	2,109.0			1,664.0	2,109.0			1,243.0	744.0			1,243.0	744.0									423.0	433.0			423.0	433.0			421.0	391.0	45.0	23.0	372.0	368.0	4.0								145.0	126.0			145.0	126.0			119.0			119.0	121.0			13.0	13.0			20.0							41.0	40.0			41.0	40.0			1.0				1.0				319.0	307.0	13.0		306.0	307.0			102.0	84.0	32.0	23.0	66.0	61.0	4.0		149.0	132.0	106.0		3,939.0			1,230.0	963.0	2,567.0	1,512.0	142.0	84.0	78.0	84.0	78.0					558.0	371.0	206.0	247.0	352.0	124.0			124.0	112.0	124.0	112.0					676.0	458.0	56.0		620.0	458.0			557.0	299.0	184.0	102.0	373.0	197.0			704.0	515.0	634.0	443.0	70.0	72.0			12.0	9.0			11.0	9.0	1.0		874.0	446.0			847.0	439.0	27.0	7.0	24.0	10.0			23.0	10.0	1.0	7.0	6.0			7.0	6.0			59.0				59.0				93.0	85.0			93.0	85.0			75.0	45.0					75.0	45.0	125.0	92.0			125.0	92.0			2.0	5.0			2.0	5.0			36.0	20.0			36.0	20.0			55.0	50.0	29.0	31.0	26.0	19.0			(66.0)	(48.0)	(55.0)	(40.0)	(11.0)	(8.0)			42.0						42.0	4,041.0	2,553.0	1,262.0	973.0	2,633.0	1,528.0	146.0	52.0	(102.0)	(26.0)	(32.0)	(10.0)	(66.0)	(16.0)	(4.0)																														2,524.0						59.0		59.0		3,939.0			1,230.0	1,213.0	2,567.0	2,160.0	142.0	84.0	84.0			558.0	206.0	352.0		124.0	124.0			676.0	56.0	620.0		557.0	184.0	373.0		704.0	634.0	70.0		12.0		11.0	1.0	874.0		847.0	27.0	24.0		23.0	1.0	7.0		7.0		93.0		93.0		75.0			75.0	125.0		125.0		2.0		2.0		36.0		36.0		55.0	29.0	26.0		(66.0)	(55.0)	(11.0)		42.0			42.0	4,041.0	1,262.0	2,633.0	146.0	(102.0)	(32.0)	(66.0)	(4.0)																											944.0			250.0		648.0		46.0		122.0		122.0						220.0				220.0				65.0				65.0				106.0		44.0		62.0				97.0		97.0						342.0				342.0				4.0				4.0				46.0					46.0			1,002.0		263.0		693.0		46.0		(58.0)		(13.0)		(45.0)														45.0	23.0	372.0	368.0	4.0								145.0	126.0			145.0	126.0			119.0			119.0	121.0			13.0	13.0			20.0							41.0	40.0			41.0	40.0			1.0				1.0				319.0	307.0	13.0		306.0	307.0			102.0	84.0	32.0	23.0	66.0	61.0	4.0				3,939.0			1,230.0	1,213.0	2,567.0	2,160.0	142.0	84.0	84.0			558.0	206.0	352.0		124.0	124.0			676.0	56.0	620.0		557.0	184.0	373.0		704.0	634.0	70.0		12.0		11.0	1.0	874.0		847.0	27.0	24.0		23.0	1.0	7.0		7.0		59.0		59.0		93.0		93.0		75.0			75.0	125.0		125.0		2.0		2.0		36.0		36.0		55.0	29.0	26.0		(66.0)	(55.0)	(11.0)		42.0			42.0	4,041.0	1,262.0	2,633.0	146.0	(102.0)	(32.0)	(66.0)	(4.0)																											944.0			250.0		648.0		46.0		122.0		122.0						220.0				220.0				65.0				65.0				106.0		44.0		62.0				97.0		97.0						342.0				342.0				4.0				4.0				46.0					46.0			1,002.0		263.0		693.0		46.0		(58.0)		(13.0)		(45.0)
Defined Benefit Plan Estimated Future Employer Contributions (Numeric) [Abstract]
Amount to be contributed to plan in the next fiscal year	394																																																																																																																																																																																																																																																																																																																	136																																																																																																															24																																																																																																																																																																																																																																																																																										150																																																																																																																																																																																																																									12																																																																								11
Expected amount of benefit payments in the next period for non-qualified plans	7																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																										3
Recurrence of formal actuarial valuations (in years)																																																																																																																																																																																																																																																																																																																		3
Percentage of deficit funding requirements permitted to recover in rates																																																																																																																																																																																																																																																																																																																		75.00%
Estimated Future Benefit Payments (Details) [Abstract]
2013	196																																																																																																																																																																																																																																																																																																																	379																																																																																																															49																																																																								4																																																																																																																																																																																																															1			55																																																																																																																																																																																																																									13																																																																								15
2014	206																																																																																																																																																																																																																																																																																																																	385																																																																																																															53																																																																								5																																																																																																																																																																																																															2			55																																																																																																																																																																																																																									13																																																																								15
2015	219																																																																																																																																																																																																																																																																																																																	393																																																																																																															55																																																																								6																																																																																																																																																																																																															2			58																																																																																																																																																																																																																									14																																																																								15
2016	232																																																																																																																																																																																																																																																																																																																	400																																																																																																															58																																																																								6																																																																																																																																																																																																															2			60																																																																																																																																																																																																																									14																																																																								16
2017	249																																																																																																																																																																																																																																																																																																																	406																																																																																																															60																																																																								7																																																																																																																																																																																																															2			65																																																																																																																																																																																																																									14																																																																								16
2018-2022	1,475																																																																																																																																																																																																																																																																																																																	2,141																																																																																																															333																																																																								48																																																																																																																																																																																																															12			399																																																																																																																																																																																																																									77																																																																								95
Expected Federal Subsidy (Details) [Abstract]
Federal subsidy 2013																																																																																																																																																																																																																																																																																																																																																																																																																																	1																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																			1
Federal subsidy 2014																																																																																																																																																																																																																																																																																																																																																																																																																																	1
Federal subsidy 2015																																																																																																																																																																																																																																																																																																																																																																																																																																	1																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																			1
Federal subsidy 2016																																																																																																																																																																																																																																																																																																																																																																																																																																	1
Federal subsidy 2017																																																																																																																																																																																																																																																																																																																																																																																																																																	1																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																			1
Federal subsidy 2018-2022																																																																																																																																																																																																																																																																																																																																																																																																																																	$ 3																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																																			$ 2

[1] Allocations exclude consideration of cash for the WKE Bargaining Employees' Retirement Plan and a guaranteed annuity contract held by the LG&E and KU Retirement Plan.

[2] Includes commingled debt funds, which PPL treats as debt securities for asset allocation purposes.

[3] Includes commingled debt funds.

[4] Includes commingled money market fund.

[5] At December 31, 2012 and December 31, 2011, includes $428 million and $416 million of PP&E, consisting primarily of "Generation," including leasehold improvements, and $10 million and $11 million of "Other intangibles" from the consolidation of a VIE that is the owner/lessor of the Lower Mt. Bethel plant. See Note 22 for additional information.

[6] Includes the pension plans of WPD Midlands, which was acquired in 2011. See Note 10 for additional information.