Segment and Related Information (Details) - USD ($) $ in Millions		3 Months Ended			9 Months Ended
		Sep. 30, 2015		Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014	Dec. 31, 2014
Income Statement Data
Revenues		$ 1,878		$ 1,879	$ 5,889		$ 5,906
Net Income		393		497	283		1,042
Balance Sheet Data
Assets		39,246			39,246			$ 48,864
United Kingdom Regulated [Member]
Income Statement Data
Revenues		552		644	1,836		1,964
Net Income	[1]	249		295	814		688
Balance Sheet Data
Assets		16,382			16,382			16,005
Kentucky Regulated [Member]
Income Statement Data
Revenues		801		753	2,414		2,409
Net Income		111		82	267		247
Balance Sheet Data
Assets		14,043			14,043			13,062
Pennsylvania Regulated [Member]
Income Statement Data
Revenues		519		477	1,625		1,516
Net Income		55		57	191		194
Balance Sheet Data
Assets		8,305			8,305			7,785
Corporate And Other [Member]
Income Statement Data
Revenues		6		5	14		17
Net Income		(19)	[2]	(24)	(74)	[2]	(100)
Balance Sheet Data
Assets	[3]	516			516			1,095
Discontinued Operations [Member]
Income Statement Data
Net Income	[4]	(3)		$ 87	(915)		$ 13
Balance Sheet Data
Assets		$ 0			$ 0			$ 10,917	[4]

[1] Includes unrealized gains and losses from economic activity . See Note 14 for additional information.

[2] 2015 includes transition costs related to the formation of the Talen Energy organization and to reconfigure the remaining PPL Services functions. See Note 8 for additional information.

[3] Primarily consists of unallocated items, including cash, PP&E and the elimination of inter-segment transactions.

[4] See Note 8 for additional information.