Equity - Accumulated Other Comprehensive Gain (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	$ 19,835	$ 15,869	$ 15,826	$ 15,539
Other comprehensive income (loss), net of tax	(74)	(6)	(172)	(19)
Balance, end of period	19,826	15,807	19,826	15,807
Unrealized loss from equity method investment, tax expense (benefit)	1	0	(3)	0
Unrealized loss on derivatives qualifying as cash flow hedges, taxes	(23)	(3)	(49)	(8)
Reclassification to net income of losses on cash flow hedges, taxes	(2)	0	(6)	1
Change in revaluation of defined benefit plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(12)	(12)	(12)	(12)
Other comprehensive income (loss), net of tax	0	0	0	0
Balance, end of period	(12)	(12)	(12)	(12)
Loss on nonqualified pension plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(20)	(7)	(20)	(7)
Other comprehensive income (loss), net of tax	0	0	0	0
Balance, end of period	(20)	(7)	(20)	(7)
Unrealized loss from equity method investment, net of income tax expense (benefit)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(3)	0	0	0
Other comprehensive income (loss), net of tax	(6)	0	(9)	0
Balance, end of period	(9)	0	(9)	0
Unrealized gain during period on derivatives qualifying as cash flow hedges, net of income tax benefit
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(135)	(29)	(35)	(13)
Other comprehensive income (loss), net of tax	(73)	(15)	(173)	(31)
Balance, end of period	(208)	(44)	(208)	(44)
Reclassification to net income of (gains) losses on cash flow hedges, net of income tax (benefit) expense
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(39)	(60)	(44)	(63)
Other comprehensive income (loss), net of tax	5	9	10	12
Balance, end of period	(34)	(51)	(34)	(51)
(Loss) Gain on derivatives qualifying as cash flow hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(174)	(89)	(79)	(76)
Other comprehensive income (loss), net of tax	(68)	(6)	(163)	(19)
Balance, end of period	(242)	(95)	(242)	(95)
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(209)	(108)	(111)	(95)
Other comprehensive income (loss), net of tax	(74)	(6)	(172)	(19)
Balance, end of period	$ (283)	$ (114)	$ (283)	$ (114)