Allowance for Credit Losses - Allowance for Credit Losses and Liability for Off-balance Sheet Credit Exposures (Details) - USD ($) $ in Millions	Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019	Dec. 31, 2018
Credit Loss [Abstract]
Loans	$ 447	[1]	$ 1,015	[1]	$ 637	$ 541
Securities held-to-maturity	1		2
Other financial assets measured at amortized cost	1		2
Securities available-for-sale	1		1
Total allowance for credit losses	450		1,020
Liability for off-balance sheet credit exposures	$ 103		$ 237		$ 104	$ 96

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at December 31, 2021 and 2020. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 27, "Variable Interest Entities," for additional information. At December 31,20212020(in millions)AssetsLoans$46 $10 Other assets55 79 Total assets$101 $89 LiabilitiesInterest, taxes and other liabilities$9 $10 Total liabilities$9 $10