Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets
Allowance for loan losses	$ 5,534	$ 5,343
Employee benefits	2,911	2,972
Accrued expenses and other	6,831	7,299
Non-U.S. operations	5,368	5,365
Tax attribute carryforwards	2,155	2,602
Gross deferred tax assets	22,799	23,581
Valuation allowance	(785)	(735)
Deferred tax assets, net of valuation allowance	22,014	22,846
Deferred tax liabilities
Depreciation and amortization	3,294	3,167
Mortgage servicing rights, net of hedges	4,807	4,968
Leasing transactions	4,053	3,042
Non-U.S. operations	4,572	4,285
Other, net	5,493	4,419
Gross deferred tax liabilities	22,219	19,881
Net deferred tax (liabilities)/assets	(205)
Net deferred tax (liabilities)/assets		$ 2,965
U.S. federal
Deferred tax liabilities
NOL carryforwards	3,800
Non-U.S.
Deferred tax liabilities
NOL carryforwards	142
Tax credit carryforwards	$ 776