Accumulated Other Comprehensive Income (Loss) (After-tax Changes by Component) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	$ (3,778)	$ (2,728)	$ (2,274)
Amounts arising during the period	151	(1,080)	(575)
Reclassifications from AOCI	205	30	145
Net OCI during the period	356	(1,050)	(430)
Distribution of PPL Energy Supply			(24)
Balance at end of period	(3,422)	(3,778)	(2,728)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(1,627)	(520)	(286)
Amounts arising during the period	538	(1,107)	(234)
Reclassifications from AOCI	0	0	0
Net OCI during the period	538	(1,107)	(234)
Distribution of PPL Energy Supply			0
Balance at end of period	(1,089)	(1,627)	(520)
Available For Sale Securities Unrealized Gains (Losses) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	0	0	201
Amounts arising during the period	0	0	8
Reclassifications from AOCI	0	0	(2)
Net OCI during the period	0	0	6
Distribution of PPL Energy Supply			(207)
Balance at end of period	0	0	0
Qualifying Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(7)	(7)	20
Amounts arising during the period	(79)	91	26
Reclassifications from AOCI	73	(91)	2
Net OCI during the period	(6)	0	28
Distribution of PPL Energy Supply			(55)
Balance at end of period	(13)	(7)	(7)
Equity Investees AOCI [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(1)	0	1
Amounts arising during the period	0	0	0
Reclassifications from AOCI	1	(1)	(1)
Net OCI during the period	1	(1)	(1)
Distribution of PPL Energy Supply			0
Balance at end of period	0	(1)	0
Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(8)	(6)	3
Amounts arising during the period	0	(3)	(9)
Reclassifications from AOCI	1	1	0
Net OCI during the period	1	(2)	(9)
Distribution of PPL Energy Supply			0
Balance at end of period	(7)	(8)	(6)
Defined Benefit Plans Actuarial Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(2,135)	(2,195)	(2,213)
Amounts arising during the period	(308)	(61)	(366)
Reclassifications from AOCI	130	121	146
Net OCI during the period	(178)	60	(220)
Distribution of PPL Energy Supply			238
Balance at end of period	(2,313)	(2,135)	(2,195)
LG And E And KU Energy LLC [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(70)	(46)	(45)
Amounts arising during the period	(25)	(27)	(7)
Reclassifications from AOCI	7	3	6
Net OCI during the period	(18)	(24)	(1)
Balance at end of period	(88)	(70)	(46)
LG And E And KU Energy LLC [Member] | Equity Investees AOCI [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(1)	0	0
Amounts arising during the period	0	0	0
Reclassifications from AOCI	1	(1)	0
Net OCI during the period	1	(1)	0
Balance at end of period	0	(1)	0
LG And E And KU Energy LLC [Member] | Prior Service Costs [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at beginning of period	(8)	(10)	(8)
Amounts arising during the period	(2)	0	(3)
Reclassifications from AOCI	1	2	1
Net OCI during the period	(1)	2	(2)
Balance at end of period	(9)	(8)	(10)
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	(61)	(36)	(37)
Amounts arising during the period	(23)	(27)	(4)
Reclassifications from AOCI	5	2	5
Net OCI during the period	(18)	(25)	1
Balance at end of period	$ (79)	$ (61)	$ (36)