Accumulated Other Comprehensive Income (Loss) (After-tax Changes by Component) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	$ (2,728)	$ (2,274)
Amounts arising during the period	(384)	(56)
Reclassifications from accumulated other comprehensive income	(47)	19
Net other comprehensive income during the period	(431)	(37)
Balance at end of period	(3,159)	(2,311)
Foreign Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(520)	(286)
Amounts arising during the period	(464)	(66)
Reclassifications from accumulated other comprehensive income	0	0
Net other comprehensive income during the period	(464)	(66)
Balance at end of period	(984)	(352)
Available For Sale Securities Unrealized Gains (Losses) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	0	201
Amounts arising during the period	0	5
Reclassifications from accumulated other comprehensive income	0	(1)
Net other comprehensive income during the period	0	4
Balance at end of period	0	205
Qualifying Derivatives Unrealized Gains (Losses) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(7)	20
Amounts arising during the period	80	6
Reclassifications from accumulated other comprehensive income	(78)	(17)
Net other comprehensive income during the period	2	(11)
Balance at end of period	(5)	9
Equity Investees Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	0	1
Amounts arising during the period	0	0
Reclassifications from accumulated other comprehensive income	0	(1)
Net other comprehensive income during the period	0	(1)
Balance at end of period	0	0
Defined Benefit Plans Prior Service Costs [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(6)	3
Amounts arising during the period	0	0
Reclassifications from accumulated other comprehensive income	0	0
Net other comprehensive income during the period	0	0
Balance at end of period	(6)	3
Defined Benefit Plans Actuarial Gain (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance at beginning of period	(2,195)	(2,213)
Amounts arising during the period	0	(1)
Reclassifications from accumulated other comprehensive income	31	38
Net other comprehensive income during the period	31	37
Balance at end of period	(2,164)	$ (2,176)
LG And E And KU Energy LLC [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Net other comprehensive income during the period	$ 1