Accumulated Other Comprehensive Income (Loss) (After-tax Changes by Component) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	$ (2,284)	$ (1,398)	$ (2,274)	$ (1,565)
Amounts arising during the period	33	(55)	(36)	43
Reclassifications from accumulated other comprehensive income	45	15	128	84
Net other comprehensive income during the period	78	(40)	92	127
Distribution of PPL Energy Supply			(24)
Balance at end of period	(2,206)	(1,438)	(2,206)	(1,438)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(435)	117	(286)	(11)
Amounts arising during the period	52	(48)	(97)	80
Reclassifications from accumulated other comprehensive income	0	0	0	0
Net other comprehensive income during the period	52	(48)	(97)	80
Distribution of PPL Energy Supply			0
Balance at end of period	(383)	69	(383)	69
Available For Sale Securities Unrealized Gains (Losses) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	0	190	202	173
Amounts arising during the period	0	(1)	7	18
Reclassifications from accumulated other comprehensive income	0	(3)	(2)	(5)
Net other comprehensive income during the period	0	(4)	5	13
Distribution of PPL Energy Supply			(207)
Balance at end of period	0	186	0	186
Qualifying Derivatives Unrealized Gains (Losses) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	2	61	20	94
Amounts arising during the period	(19)	(5)	8	(52)
Reclassifications from accumulated other comprehensive income	10	(12)	20	2
Net other comprehensive income during the period	(9)	(17)	28	(50)
Distribution of PPL Energy Supply			(55)
Balance at end of period	(7)	44	(7)	44
Equity Investees Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	0	1	1	1
Amounts arising during the period	0	0	0	0
Reclassifications from accumulated other comprehensive income	0	0	(1)	0
Net other comprehensive income during the period	0	0	(1)	0
Distribution of PPL Energy Supply			0
Balance at end of period	0	1	0	1
Defined Benefit Plans Prior Service Costs [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(3)	(4)	3	(6)
Amounts arising during the period	0	0	(6)	0
Reclassifications from accumulated other comprehensive income	0	1	0	3
Net other comprehensive income during the period	0	1	(6)	3
Distribution of PPL Energy Supply			0
Balance at end of period	(3)	(3)	(3)	(3)
Defined Benefit Plans Actuarial Gain (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(1,849)	(1,764)	(2,215)	(1,817)
Amounts arising during the period	0	(1)	52	(3)
Reclassifications from accumulated other comprehensive income	35	29	111	84
Net other comprehensive income during the period	35	28	163	81
Distribution of PPL Energy Supply			238
Balance at end of period	(1,814)	(1,736)	(1,814)	(1,736)
Defined Benefit Plans Transition Assset Obligation [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	1	1	1	1
Amounts arising during the period	0	0	0	0
Reclassifications from accumulated other comprehensive income	0	0	0	0
Net other comprehensive income during the period	0	0	0	0
Distribution of PPL Energy Supply			0
Balance at end of period	1	1	1	1
LG And E And KU Energy LLC [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(52)	10	(45)	13
Amounts arising during the period	0	0	(8)	(2)
Reclassifications from accumulated other comprehensive income	1		2	(1)
Net other comprehensive income during the period	1	0	(6)	(3)
Balance at end of period	(51)	10	(51)	10
LG And E And KU Energy LLC [Member] | Equity Investees Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(1)	0	0	1
Amounts arising during the period	0	0	0	0
Reclassifications from accumulated other comprehensive income	0		(1)	(1)
Net other comprehensive income during the period	0	0	(1)	(1)
Balance at end of period	(1)	0	(1)	0
LG And E And KU Energy LLC [Member] | Defined Benefit Plans Prior Service Costs [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(7)	(2)	(8)	(2)
Amounts arising during the period	0	0	0	0
Reclassifications from accumulated other comprehensive income	0		1	0
Net other comprehensive income during the period	0	0	1	0
Balance at end of period	(7)	(2)	(7)	(2)
LG And E And KU Energy LLC [Member] | Defined Benefit Plans Actuarial Gain (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(44)	12	(37)	14
Amounts arising during the period	0	0	(8)	(2)
Reclassifications from accumulated other comprehensive income	1		2	0
Net other comprehensive income during the period	1	0	(6)	(2)
Balance at end of period	(43)	12	(43)	12
LG And E And KU Energy LLC [Member] | Defined Benefit Plans Transition Assset Obligation [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	0	0	0	0
Amounts arising during the period	0	0	0	0
Reclassifications from accumulated other comprehensive income	0		0
Net other comprehensive income during the period	0	0	0	0
Balance at end of period	$ 0	$ 0	$ 0	$ 0