Loans - Wholesale Loan Portfolio, Loans Secured by Real Estate (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 1,084,850	$ 1,089,598	$ 1,018,397
Wholesale
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 604,324	$ 603,670	$ 569,953
% of criticized to total retained loans secured by real estate	2.89%	2.60%
% of criticized nonaccrual loans to total retained loans secured by real estate	0.37%	0.33%
Wholesale | Criticized nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 2,211	$ 1,963
Wholesale | Secured by real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 127,389	$ 126,732
% of criticized to total retained loans secured by real estate	3.56%	3.08%
% of criticized nonaccrual loans to total retained loans secured by real estate	0.27%	0.19%
Wholesale | Secured by real estate | Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 4,538	$ 3,908
% of criticized to total retained loans secured by real estate	3.56%	3.08%
Wholesale | Secured by real estate | Criticized nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 338	$ 246
% of criticized nonaccrual loans to total retained loans secured by real estate	0.27%	0.19%
Wholesale | Secured by real estate | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 79,374	$ 79,139
Wholesale | Secured by real estate | Multifamily | Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 2,212	$ 1,916
% of criticized to total retained loans secured by real estate	2.79%	2.42%
Wholesale | Secured by real estate | Multifamily | Criticized nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 60	$ 51
% of criticized nonaccrual loans to total retained loans secured by real estate	0.08%	0.06%
Wholesale | Secured by real estate | Other commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 48,015	$ 47,593
Wholesale | Secured by real estate | Other commercial | Criticized
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 2,326	$ 1,992
% of criticized to total retained loans secured by real estate	4.84%	4.19%
Wholesale | Secured by real estate | Other commercial | Criticized nonaccrual
Accounts, Notes, Loans and Financing Receivable [Line Items]
Retained loans	$ 278	$ 195
% of criticized nonaccrual loans to total retained loans secured by real estate	0.58%	0.41%