Loans - Wholesale Loan Portfolio - Real Estate Class of Loans (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 832,792	$ 747,508	$ 724,177
Wholesale
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 357,050	$ 324,502	$ 308,263
% of criticized to total real estate retained loans	2.06%	1.45%
% of criticized nonaccrual to total real estate retained loans	0.28%	0.18%
Wholesale | Total real estate loans
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 92,820	$ 79,113
% of criticized to total real estate retained loans	1.60%	1.98%
% of criticized nonaccrual to total real estate retained loans	0.25%	0.32%
Wholesale | Multifamily
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 60,290	$ 51,049
% of criticized to total real estate retained loans	0.86%	1.28%
% of criticized nonaccrual to total real estate retained loans	0.14%	0.25%
Wholesale | Commercial lessors
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 20,062	$ 17,438
% of criticized to total real estate retained loans	4.21%	4.82%
% of criticized nonaccrual to total real estate retained loans	0.50%	0.63%
Wholesale | Commercial construction and development
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 4,920	$ 4,264
% of criticized to total real estate retained loans	0.87%	0.98%
% of criticized nonaccrual to total real estate retained loans	0.02%	0.00%
Wholesale | Other
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 7,548	$ 6,362
% of criticized to total real estate retained loans	0.99%	0.49%
% of criticized nonaccrual to total real estate retained loans	0.60%	0.27%
Wholesale | Criticized | Total real estate loans
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 1,482	$ 1,566
Wholesale | Criticized | Multifamily
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	520	652
Wholesale | Criticized | Commercial lessors
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	844	841
Wholesale | Criticized | Commercial construction and development
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	43	42
Wholesale | Criticized | Other
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	75	31
Wholesale | Criticized nonaccrual
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	988	599
Wholesale | Criticized nonaccrual | Total real estate loans
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	231	253
Wholesale | Criticized nonaccrual | Multifamily
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	85	126
Wholesale | Criticized nonaccrual | Commercial lessors
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	100	110
Wholesale | Criticized nonaccrual | Commercial construction and development
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	1	0
Wholesale | Criticized nonaccrual | Other
Loans and Leases Receivable Disclosure [Line Items]
Total retained loans	$ 45	$ 17