Retirement and Postemployment Benefits (Defined Benefits) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Coal Industry Retiree Health Benefit Act of 1992 [Abstract]
Coal Industry Retiree Health Benefit Act of 1992, net recorded liability	$ 6
Coal Industry Retiree Health Benefit Act of 1992, estimated amount future benefit payments	67
Coal Industry Retiree Health Benefit Act of 1992, assets in VEBA trust	31
Coal Industry Retiree Health Benefit Act of 1992, assets in Black Lung Trust	30
Significant Specific Multiemployer Plan [Member]
Multiemployer Plans (Numeric) [Abstract]
Multiemployer Plan, period contributions	5		4		5
Number of subsidiaries whose contributions, on a combined basis, exceeded 5% of a specific plan's contributions	3
Threshold, as a percentage, of contributions to a specific plan that if exceeded require disclosure	5.00%
All Multiemployer Plans [Member]
Multiemployer Plans (Numeric) [Abstract]
Multiemployer Plan, number of plans	70
Pension Plans	36		26		29
Other Postretirement Medical Plans	31		23		25
Total Contributions	67		49		54
Pension Benefits - US [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	95		64		60
Interest cost	217		159		145
Expected return on plan assets	(245)		(184)		(169)
Amortization of: [Abstract]
Transition (asset) obligation	0		0		(5)
Prior service cost	24		21		19
Actuarial (gain) loss	30		8		3
Net periodic defined benefit costs (credits) prior to termination benefits	121		68		53
Settlement charges	0		0		2	[1]
Termination benefits	0		0		9	[2]
Net periodic defined benefit costs (credits)	121		68		64
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Settlements	0		0		(2)
Current year net (gain) loss	117		142		102
Current year prior service costs (credit)	8		0		1
Amortization of: [Abstract]
Transition asset (obligation)	0		0		5
Prior service cost	(24)		(21)		(19)
Actuarial (gain) loss	(30)		(7)		(3)
Acquisition of regulatory assets/liabilities: [Abstract]
Transition asset (obligation)	0		0		0
Prior service cost	0		31		0
Actuarial (gain) loss	0		303		0
Total recognized in OCI and regulatory assets/liabilities	71	[3]	448	[3]	84	[3]
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	192		516		148
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI	47		84		51
Regulatory assets	24		364		33
Total recognized in OCI and regulatory assets/liabilities	71	[3]	448	[3]	84	[3]
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Transition obligation	0
Prior service cost	24
Actuarial (gain) loss	42
Total	66
Amortization from Balance Sheet: [Abstract]
AOCI	27
Regulatory assets/liabilities	39
Total	66
Net Periodic Defined Benefit Costs Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs charged to operating expense, excluding amounts charged to construction and other non-expense accounts	98		59		56
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	5.06%		5.42%		6.00%
Benefit obligations valuation rate of compensation increase	4.02%		4.88%		4.75%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate	5.42%		5.96%		6.50%
Net periodic benefit costs rate of compensation increase	4.88%		4.79%		4.75%
Net periodic benefit costs expected return on plan assets	7.25%	[4]	7.96%	[4]	8.00%	[4]
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	4,007		2,460
Service cost	95		64		60
Interest cost	217		159		145
Participant contributions	0		0
Plan amendments	8		0
Actuarial (gain) loss	220		222
Acquisitions	0		1,231	[5]
Settlements	0		0
Termination benefits	0		0
Actual expenses paid	0		(2)
Gross benefits paid	(166)		(127)
Federal subsidy	0		0
Currency conversion	0		0
Benefit Obligation, end of period	4,381		4,007		2,460
Change in Plan Assets [Roll Forward]
Balance at beginning of period	2,819		1,772
Actual return on plan assets	349		263
Employer contributions	470		148
Participant contributions	0		0
Acquisitions	0		765	[5]
Settlements	0		0
Actual expenses paid	(1)		(2)
Gross benefits paid	(166)		(127)
Currency conversion	0		0
Balance at end of period	3,471		2,819		1,772
Funded Status, end of period	(910)		(1,188)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Current liability	(29)		(10)
Noncurrent liability	(881)		(1,178)
Amounts recognized in AOCI and regulatory asets/liabilities (pre-tax): [Abstract]
Transition (asset) obligation	0		0
Prior service cost (credit)	115		131
Net actuarial loss	922		836
Total	1,037	[6]	967	[6]
Total accumulated benefit obligation for defined benefit pension plans	3,949		3,564
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	481		431
Regulatory assets/liabilities	556		536
Total	1,037	[6]	967	[6]
Pension Benefits - UK [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	44		17		9
Interest cost	282		151		156
Expected return on plan assets	(338)		(202)		(189)
Amortization of: [Abstract]
Transition (asset) obligation	0		0		0
Prior service cost	4		4		4
Actuarial (gain) loss	57		48		2
Net periodic defined benefit costs (credits) prior to termination benefits	49		18		(18)
Settlement charges	0		0		0
Termination benefits	50	[2]	0		0
Net periodic defined benefit costs (credits)	99		18		(18)
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Settlements	0		0		0
Current year net (gain) loss	152		17		403
Current year prior service costs (credit)	0		0		0
Amortization of: [Abstract]
Transition asset (obligation)	0		0		0
Prior service cost	(4)		(4)		(4)
Actuarial (gain) loss	(57)		(48)		(2)
Acquisition of regulatory assets/liabilities: [Abstract]
Transition asset (obligation)	0		0		0
Prior service cost	0		0		0
Actuarial (gain) loss	0		0		0
Total recognized in OCI and regulatory assets/liabilities	91	[7]	(35)	[7]	397	[7]
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	190	[7]	(17)	[7]	379	[7]
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
Total recognized in OCI and regulatory assets/liabilities	91	[7]	(35)	[7]	397	[7]
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Transition obligation	0
Prior service cost	4
Actuarial (gain) loss	79
Total	83
Amortization from Balance Sheet: [Abstract]
AOCI	83
Regulatory assets/liabilities	0
Total	83
Net Periodic Defined Benefit Costs Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs charged to operating expense, excluding amounts charged to construction and other non-expense accounts	82		16		(17)
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	5.24%		5.54%		5.55%
Benefit obligations valuation rate of compensation increase	4.00%		4.00%		4.00%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate	5.59%		5.59%		7.47%
Net periodic benefit costs rate of compensation increase	3.75%		4.00%		4.00%
Net periodic benefit costs expected return on plan assets	7.04%	[4]	7.91%	[4]	7.90%	[4]
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	2,841		2,933
Service cost	44		17		9
Interest cost	282		151		156
Participant contributions	11		6
Plan amendments	0		0
Actuarial (gain) loss	257		37
Acquisitions	3,501	[5]	0
Settlements	0		0
Termination benefits	50		0
Actual expenses paid	0		0
Gross benefits paid	(309)		(152)
Federal subsidy	0		0
Currency conversion	(39)		(151)
Benefit Obligation, end of period	6,638		2,841		2,933
Change in Plan Assets [Roll Forward]
Balance at beginning of period	2,524		2,331
Actual return on plan assets	444		228
Employer contributions	164		231
Participant contributions	(11)		(6)
Acquisitions	3,567	[5]	0
Settlements	0		0
Gross benefits paid	(309)		(152)
Currency conversion	(50)		(120)
Balance at end of period	6,351		2,524		2,331
Funded Status, end of period	(287)		(317)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Noncurrent asset	130
Current liability	0		0
Noncurrent liability	(417)		(317)
Amounts recognized in AOCI and regulatory asets/liabilities (pre-tax): [Abstract]
Transition (asset) obligation	0		0
Prior service cost (credit)	3		7
Net actuarial loss	1,191		1,097
Total	1,194	[7]	1,104	[7]
Total accumulated benefit obligation for defined benefit pension plans	6,144		2,646
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
Total	1,194	[7]	1,104	[7]
Pension Benefits - UK [Member] | PPL WEM [Member]
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, end of period	3,600
Change in Plan Assets [Roll Forward]
Balance at end of period	3,700
Amounts recognized in AOCI and regulatory asets/liabilities (pre-tax): [Abstract]
Total accumulated benefit obligation for defined benefit pension plans	3,300
Pension Benefits - UK [Member] | PPL WW [Member]
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, end of period	3,000		2,800
Change in Plan Assets [Roll Forward]
Balance at end of period	2,600		2,500
Amounts recognized in AOCI and regulatory asets/liabilities (pre-tax): [Abstract]
Total accumulated benefit obligation for defined benefit pension plans	2,800		2,600
Other Postretirement Benefits - US [Member]
Net Periodic Defined Benefit Costs (Credits): [ Abstract]
Service cost	12		8		6
Interest cost	33		28		29
Expected return on plan assets	(23)		(20)		(18)
Amortization of: [Abstract]
Transition (asset) obligation	2		5		9
Prior service cost	0		4		9
Actuarial (gain) loss	6		6		2
Net periodic defined benefit costs (credits) prior to termination benefits	30		31		37
Settlement charges	0		0		0
Termination benefits	0		0		0
Net periodic defined benefit costs (credits)	30		31		37
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross: [Abstract]
Settlements	0		0		0
Current year net (gain) loss	(9)		20		32
Current year prior service costs (credit)	10		(71)		(4)
Amortization of: [Abstract]
Transition asset (obligation)	(2)		(5)		(9)
Prior service cost	0		(4)		(8)
Actuarial (gain) loss	(6)		(6)		(2)
Acquisition of regulatory assets/liabilities: [Abstract]
Transition asset (obligation)	0		4		0
Prior service cost	0		6		0
Actuarial (gain) loss	0		(2)		0
Total recognized in OCI and regulatory assets/liabilities	(7)	[3]	(58)	[3]	9	[3]
Total recognized in net periodic benefit costs, OCI and regulatory assets/liabilities	23		(27)		46
Other Changes in Plan Assets and Benefit Obligations Recognized in OCI and Regulatory Assets/Liabilities - Gross (Details) [Abstract]
OCI	(6)		(40)		6
Regulatory assets	(1)		(18)		3
Total recognized in OCI and regulatory assets/liabilities	(7)	[3]	(58)	[3]	9	[3]
Estimated Amounts to be Amortized From AOCI and Regulatory Assets into Net Periodic Benefit Costs in the Next Fiscal Period (Details) [Abstract]
Transition obligation	2
Prior service cost	1
Actuarial (gain) loss	4
Total	7
Amortization from Balance Sheet: [Abstract]
AOCI	2
Regulatory assets/liabilities	5
Total	7
Net Periodic Defined Benefit Costs Charged to Operating Expense, Excluding Amounts Charged to Construction and Other Non-expense Accounts (Details) [Abstract]
Net periodic defined benefit costs charged to operating expense, excluding amounts charged to construction and other non-expense accounts	24		27		31
Weighted Average Assumptions Used in the Valuation of the Benefit Obligations (Details) [Abstract]
Benefit obligations valuation discount rate	4.80%		5.14%		5.81%
Benefit obligations valuation rate of compensation increase	4.00%		4.90%		4.75%
Weighted Average Assumptions Used to Determine the Net Periodic Benefit Costs (Details) [Abstract]
Net periodic benefit costs discount rate	5.14%		5.47%		6.45%
Net periodic benefit costs rate of compensation increase	4.90%		4.78%		4.75%
Net periodic benefit costs expected return on plan assets	6.57%	[4]	6.90%	[4]	7.00%	[4]
Assumed Health Care Cost Trend Rates (Details) [Abstract]
Health care cost trend rate assumed for next year, obligations	8.50%		9.00%		8.00%
Health care cost trend rate assumed for next year, cost	9.00%		8.00%		8.40%
Rate to which the cost trend rate is assumed to decline, obligations	5.50%		5.50%		5.50%
Rate to which the cost trend rate is assumed to decline,cost	5.50%		5.50%		5.50%
Year that the rate reaches the ultimate trend rate, obligations	2019		2019		2016
Year that the rate reaches the ultimate trend rate, cost	2019		2016		2014
Effect of One Percentage Point Change in Assumed Health Care Costs Trend Rate (Details) [Abstract]
Effect on accumulated postretirement benefit obligation of a one percentage point increase	8
Effect on accumulated postretirement benefit obligation of a one percentage point decrease	(8)
Change in Benefit Obligation [Roll Forward]
Benefit Obligation, beginning of period	667		498
Service cost	12		8		6
Interest cost	33		28		29
Participant contributions	5		7
Plan amendments	10		(71)
Actuarial (gain) loss	6		32
Acquisitions	0		206	[5]
Settlements	0		0
Termination benefits	0		0
Actual expenses paid	0		0
Gross benefits paid	(47)		(44)
Federal subsidy	1		3
Currency conversion	0		0
Benefit Obligation, end of period	687		667		498
Change in Plan Assets [Roll Forward]
Balance at beginning of period	360		301
Actual return on plan assets	38		33
Employer contributions	33		17
Participant contributions	(5)		(7)
Acquisitions	0		42	[5]
Settlements	0		0
Gross benefits paid	(45)		(40)
Currency conversion	0		0
Balance at end of period	391		360		301
Funded Status, end of period	(296)		(307)
Amounts recognized in the Balance Sheets consist of: [Abstract]
Current liability	(1)		(2)
Noncurrent liability	(295)		(305)
Amounts recognized in AOCI and regulatory asets/liabilities (pre-tax): [Abstract]
Transition (asset) obligation	2		4
Prior service cost (credit)	(5)		(16)
Net actuarial loss	97		112
Total	94	[6]	100	[6]
Changes in Plan Assets and Benefit Obligations Recognized in AOCI and Regulatory Assets/Liabilities by Type (Details) [Abstract]
AOCI	56		53
Regulatory assets/liabilities	38		47
Total	$ 94	[6]	$ 100	[6]

[1] Includes the settlement of the pension plan of PPL's former mining subsidiary, PA Mines, LLC in 2009.

[2] Related to the 2011 WPD Midlands separations in the U.K. and a 2009 U.S. cost reduction initiative.

[3] For PPL's U.S. pension benefits, the amounts recognized in OCI for 2011, 2010 and 2009 were $47 million, $84 million and $51 million. The amounts recognized in regulatory assets/liabilities for 2011, 2010 and 2009 were $24 million, $364 million and $33 million. In total, the amounts recognized in either OCI or regulatory assets/liabilities for 2011, 2010 and 2009 were $71 million, $448 million and $84 million.         For other postretirement benefits, the amounts recognized in OCI for 2011, 2010 and 2009 were $(6) million, $(40) million and $6 million. The amounts recognized in regulatory assets/liabilities for 2011, 2010 and 2009 were $(1) million, $(18) million and $3 million. In total, the amounts recognized in either OCI or regulatory assets/liabilities for 2011, 2010 and 2009 were $(7) million, $(58) million and $9 million.

[4] The expected long-term rates of return for PPL, PPL Energy Supply, LKE and LG&E's U.S. pension and other postretirement benefits have been developed using a best-estimate of expected returns, volatilities and correlations for each asset class. The best estimates are based on historical performance, future expectations and periodic portfolio rebalancing among the diversified asset classes. PPL management corroborates these rates with expected long-term rates of return calculated by its independent actuary, who uses a building block approach that begins with a risk-free rate of return with factors being added such as inflation, duration, credit spreads and equity risk. Each plan's specific asset allocation is also considered in developing a reasonable return assumption.         The expected long-term rates of return for PPL's U.K. pension plans have been developed by PPL management with assistance from an independent actuary using a best estimate of expected returns, volatilities and correlations for each asset class. The best estimates are based on historical performance, future expectations and periodic portfolio rebalancing among the diversified asset classes.

[5] Includes the pension and other postretirement medical plans of LKE, which were acquired in 2010, and the pension plan of WPD Midlands, which was acquired in 2011. See Note 10 for additional information.

[6] For PPL's U.S. pension benefits, the amounts recognized in AOCI for 2011 and 2010 were $481 million, $431 million. The amounts recognized in regulatory assets/liabilities for 2011 and 2010 were $556 million and $536 million. In total, the amounts recognized in either OCI or regulatory assets/liabilities for 2011 and 2010 were $1,037 million and $967 million.         For other postretirement benefits, the amounts recognized in AOCI for 2011 and 2010 were $56 million and $53 million. The amounts recognized in regulatory assets/liabilities for 2011 and 2010 were $38 million and $47 million. In total, the amounts recognized in either OCI or regulatory assets/liabilities for 2011 and 2010 were $94 million and $100 million.

[7] WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP. As a result, WPD does not record regulatory assets/liabilities.