Loans, Lending Commitments and Related Allowance for Credit Losses - Past Due Loans Held for Investment before Allowance (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 194,215	$ 174,956
Past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	197	209
Corporate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	6,739	5,567
Corporate | Past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	47	0
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	50,449	44,251
Residential real estate | Past due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 150	$ 209