Parent Company (Details 1) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Cash and cash equivalents	$ 27,445	$ 32,927	$ 25,208	$ 23,239
Investment securities	4,647	3,159	3,157
Accounts receivable, less reserves	55,320	53,526
Premises and equipment, less accumulated depreciation	4,416	4,329
Other assets	10,471	9,746
Total assets	188,602	181,196	159,000
Liabilities and Shareholders' Equity
Long-term debt	58,423	55,804
Total liabilities	166,312	162,935
Shareholders' Equity
Preferred shares	0	0
Common shares	170	172
Additional paid-in capital	12,218	12,210
Retained earnings	12,499	8,307
Accumulated other comprehensive loss	(2,597)	(2,428)
Total shareholders' equity	22,290	18,261	20,523	20,673
Total liabilities and shareholders' equity	188,602	181,196
Parent Company Details (Textuals) [Abstract]
Premises and equipment, accumulated depreciation	6,015	5,455
Parent Company [Member]
Assets
Cash and cash equivalents	3,287	4,726	$ 5,229	$ 6,400
Equity in net assets of subsidiaries and affiliates	22,298	18,225
Loans to subsidiaries and affiliates	17,945	11,664
Due from subsidiaries and affiliates	1,783	1,962
Other assets	297	361
Total assets	45,610	36,938
Liabilities and Shareholders' Equity
Accounts payable and other liabilities	1,961	3,076
Due to subsidiaries and affiliates	577	175
Short-term debt of subsidiaries and affiliates	2,591	2,731
Long-term debt	18,191	12,695
Total liabilities	23,320	18,677
Shareholders' Equity
Total shareholders' equity	22,290	18,261
Total liabilities and shareholders' equity	$ 45,610	$ 36,938