Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Unaffiliated Third Party Entity [Member]
Accounts Receivable (Numeric) [Abstract]
Purchases of accounts receivable	$ 276	$ 253	$ 607	$ 614
PPL Electric Utilities Corp [Member] | Unaffiliated Third Party Entity [Member]
Accounts Receivable (Numeric) [Abstract]
Purchases of accounts receivable	276	253	607	614
PPL Electric Utilities Corp [Member] | PPL EnergyPlus [Member]
Accounts Receivable (Numeric) [Abstract]
Purchases of accounts receivable	$ 53	$ 79	$ 146	$ 184
WPD [Member]
Depreciation (Numeric) [Abstract]
Weighted average useful life	69 years		69 years
Decrease in depreciation expense from change in weighted average useful lives	$ 22		$ 42
Decrease in depreciation expense from change in weighted average useful lives, after-tax	$ 17		$ 33
Decrease in depreciation expense from change in weighted average useful lives, per share	$ 0.03		$ 0.05
WPD [Member] | Previously Reported [Member]
Depreciation (Numeric) [Abstract]
Weighted average useful life					55 years