CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Tax expense (benefit) on cash flow hedges reclassified from AOCI to net income	$ 1	$ 2	$ 3	$ 5
Tax expense (benefit) of unrealized gains/losses on available for sale securities still held	3	(1)	6	(3)
Tax expense (benefit) on available for sale securities reclassified from AOCI to net income	(1)	1	1	(1)
Tax expense (benefit) of defined benefit pension and other benefits plans	(1)	0	(16)	(1)
Tax expense (benefit) of defined benefit pension and other benefits plans reclassified from AOCI to net income	0	(1)	(1)	(1)
Tax expense (benefit) of other comprehensive income (loss) related to equity method investees	1	(1)	(1)	1
AOCI Impacts of NEP Deconsolidation, tax				$ 15