Summary of Basis of Presentation and Recent Accounting Standards - Components of Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	$ 19,123	$ 14,145
Other comprehensive income	103	(160)
Balance at end of period	18,863	17,075
Unrealized Gains on Available-for-Sale Debt Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(362)
Other comprehensive income	95
Balance at end of period	(267)
Net Unrealized Gains on Derivatives Designated As Hedging Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(8)
Other comprehensive income	8
Balance at end of period	0
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(370)	(24)
Other comprehensive income	103	(160)
Balance at end of period	$ (267)	$ (184)