Off-Balance Sheet Arrangements, Guarantees and Other Commitments - Commitments to Extend Credit (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Other Commitments [Line Items]
Commitments to extend credit	$ 44,016	$ 31,982
Allowance for unfunded credit commitments	422	448	$ 305	$ 282
Unfunded credit commitments
Other Commitments [Line Items]
Allowance for unfunded credit commitments	171	121	$ 68	$ 55
Loan commitments
Other Commitments [Line Items]
Commitments to extend credit	40,327	28,975
Standby letters of credit
Other Commitments [Line Items]
Commitments to extend credit	3,612	3,003
Commercial letters of credit
Other Commitments [Line Items]
Commitments to extend credit	$ 77	$ 4