Stockholders' Equity and EPS - Activity Related to Net Gains on Cash Flow Hedges in AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cash flow hedge gains expected to reclassified out of AOCI over next 12 months	$ 52
Balance, beginning of period, net of tax	16,609	$ 8,433
Balance, end of period, net of tax	16,360	10,121
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period, net of tax	83	130
Net realized (gain) loss reclassified to net income, net of tax	(11)	(12)
Balance, end of period, net of tax	$ 72	$ 118