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Investment Securities - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Accrued interest receivables on investment securities	$ 120			$ 120		$ 82
Impairment losses	0	$ 0	$ 7	0	$ 7
Securities with a fair value, pledged as collateral	10,200			10,200		11,200
Investment Holdings [Line Items]
Unrealized losses	3,332			3,332		144
Non-rated Securities
Investment Holdings [Line Items]
Unrealized losses	$ 34			$ 34		$ 2