Segment and Related Information (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2015		Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014	Dec. 31, 2014
Income Statement Data
Revenues		$ 1,781		$ 1,849	$ 4,011		$ 4,027
Net Income (Loss)		(757)		229	(110)		545
Balance Sheet Data
Assets		38,244			38,244			$ 48,864
United Kingdom Regulated [Member]
Income Statement Data
Revenues		587		672	1,284		1,320
Net Income (Loss)	[1]	190		187	565		393
Balance Sheet Data
Assets		15,973			15,973			16,005
Kentucky Regulated [Member]
Income Statement Data
Revenues		714		722	1,613		1,656
Net Income (Loss)		47		58	156		165
Balance Sheet Data
Assets		13,314			13,314			13,062
Pennsylvania Regulated [Member]
Income Statement Data
Revenues		476		448	1,106		1,039
Net Income (Loss)		49		52	136		137
Balance Sheet Data
Assets		8,171			8,171			7,785
Corporate And Other [Member]
Income Statement Data
Revenues		4		7	8		12
Net Income (Loss)		(36)	[2]	(67)	(55)	[2]	(76)
Balance Sheet Data
Assets	[3]	786			786			1,095
Discontinued Operations [Member]
Income Statement Data
Net Income (Loss)	[4]	(1,007)		$ (1)	(912)		$ (74)
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 to prepare the new Talen Energy organization for the June 1, 2015 spinoff and 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 transaction s.

[4] See Note 8 for additional information.