Loans - Wholesale Loan Portfolio, Real Estate Class of Loans (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 1,052,390	$ 1,010,206	$ 963,665
Wholesale
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 584,265	$ 560,354	$ 524,855
% of criticized to total retained loans secured by real estate	2.50%	2.39%
% of criticized nonaccrual loans to total retained loans secured by real estate	0.36%	0.37%
Wholesale | Criticized nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 2,083	$ 2,054
Wholesale | Secured by real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 123,448	$ 118,835
% of criticized to total retained loans secured by real estate	3.14%	3.34%
% of criticized nonaccrual loans to total retained loans secured by real estate	0.27%	0.27%
Wholesale | Secured by real estate | Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 3,874	$ 3,971
% of criticized to total retained loans secured by real estate	3.14%	3.34%
Wholesale | Secured by real estate | Criticized nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 328	$ 326
% of criticized nonaccrual loans to total retained loans secured by real estate	0.27%	0.27%
Wholesale | Secured by real estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 77,370	$ 73,801
Wholesale | Secured by real estate | Multifamily | Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 1,714	$ 1,671
% of criticized to total retained loans secured by real estate	2.22%	2.26%
Wholesale | Secured by real estate | Multifamily | Criticized nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 75	$ 91
% of criticized nonaccrual loans to total retained loans secured by real estate	0.10%	0.12%
Wholesale | Secured by real estate | Other commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 46,078	$ 45,034
Wholesale | Secured by real estate | Other commercial | Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 2,160	$ 2,300
% of criticized to total retained loans secured by real estate	4.69%	5.11%
Wholesale | Secured by real estate | Other commercial | Criticized nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 253	$ 235
% of criticized nonaccrual loans to total retained loans secured by real estate	0.55%	0.52%
Wholesale | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 159,475	$ 145,691
% of criticized to total retained loans secured by real estate	5.62%	5.40%
% of criticized nonaccrual loans to total retained loans secured by real estate	0.62%	0.67%
Wholesale | Commercial and industrial | Criticized nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 986	$ 969
Wholesale | Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 301,342	$ 295,828
% of criticized to total retained loans secured by real estate	0.60%	0.52%
% of criticized nonaccrual loans to total retained loans secured by real estate	0.26%	0.26%
Wholesale | Other | Criticized nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 769	$ 759