Stockholders' Equity - Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Before Tax
Net unrealized gains (losses) on securities available for sale	$ (4,287)	$ (1,512)
Net unrealized gains (losses) on hedging relationships	(1,593)	(766)
Foreign currency translation adjustments	10	13
Other	0	(1)
Other comprehensive income (loss), before tax	(5,870)	(2,266)
Provision (Benefit)
Net unrealized gains (losses) on securities available for sale	(1,034)	(364)
Net unrealized gains (losses) on hedging relationships	(384)	(185)
Foreign currency translation adjustments	15	(6)
Other	0	0
Other comprehensive income (loss), provision (benefit)	(1,403)	(555)
After Tax
Net unrealized gains (losses) on securities available for sale	(3,253)	(1,148)
Net unrealized gains (losses) on hedging relationships	(1,209)	(581)
Foreign currency translation adjustments	(5)	19
Other	0	(1)
Other comprehensive loss, net of tax	$ (4,467)	$ (1,711)