Segment and Related Information (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Income Statement Data [Abstract]
Revenues		$ 1,785	$ 1,781	$ 3,796	$ 4,011
Net income		483	(757)	964	(110)
Balance Sheet Data [Abstract]
Assets		39,528		39,528		$ 39,301
United Kingdom Regulated [Member]
Income Statement Data [Abstract]
Revenues		563	587	1,158	1,284
Net income	[1]	345	190	634	565
Balance Sheet Data [Abstract]
Assets	[2]	16,371		16,371		16,669
Segment (Numeric) [Abstract]
Net property, plant and equipment not subject to accounting for the effects of certain types of regulation		12,100		12,100		12,200
Kentucky Regulated [Member]
Income Statement Data [Abstract]
Revenues		721	714	1,547	1,613
Net income		76	47	188	156
Balance Sheet Data [Abstract]
Assets		13,886		13,886		13,756
Pennsylvania Regulated [Member]
Income Statement Data [Abstract]
Revenues		495	476	1,080	1,106
Net income		78	49	172	136
Balance Sheet Data [Abstract]
Assets		8,825		8,825		8,511
Corporate And Other [Member]
Income Statement Data [Abstract]
Revenues		6	4	11	8
Net income	[3]	(16)	(36)	(30)	(55)
Balance Sheet Data [Abstract]
Assets	[4]	446		446		$ 365
Discontinued Operations [Member]
Income Statement Data [Abstract]
Net income	[5]	$ 0	$ (1,007)	$ 0	$ (912)

[1] Includes unrealized gains and losses from hedging foreign-currency related economic activity. See Note 14 for additional information.

[2] Includes $12.1 billion and $12.2 billion of net PP&E as of June 30, 2016 and December 31, 2015. WPD is not subject to accounting for the effects of certain types of regulation as prescribed by GAAP.

[3] 2015 includes transition costs to prepare the Talen Energy organization for the June 1, 2015 spinoff and reconfigure the remaining PPL Services functions. See Note 8 for additional information.

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

[5] See Note 8 for additional information.