Parent Company Financial Information - Parent Company Condensed Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Cash and due from banks	$ 2,753	$ 2,243
Interest-bearing deposits with banks	984	343
Restricted cash	107	370
AFS securities at fair value	25,038	24,547
HTM securities, Amortized Cost	20,552	23,027
Other assets	13,875	14,235
Total assets	225,697	221,642
Liabilities and Shareholders' Equity
Short-term borrowings	5,178	4,938
Long-term debt	23,709	23,648
Accounts payable and other liabilities	5,433	5,990
Total liabilities	195,519	191,947
Total shareholders' equity	30,178	29,695	$ 29,926	$ 27,340
Total liabilities and shareholders' equity	225,697	221,642
Parent Company
Assets
Cash and due from banks	130	13
Interest-bearing deposits with banks	7,029	6,301
Restricted cash	73	64
AFS securities at fair value	132	133
HTM securities, Amortized Cost	0	1
Advances to / receivables from subsidiaries:	7,097	6,118
Investment in subsidiaries:	29,567	29,219
Other assets	52	66
Total assets	44,080	41,915
Liabilities and Shareholders' Equity
Short-term borrowings	2	7
Long-term debt	13,709	12,042
Accounts payable and other liabilities	191	171
Total liabilities	13,902	12,220
Total shareholders' equity	30,178	29,695
Total liabilities and shareholders' equity	44,080	41,915
Parent Company | Banking
Assets
Advances to / receivables from subsidiaries:	2,608	2,454
Investment in subsidiaries:	28,070	27,846
Parent Company | Nonbank
Assets
Advances to / receivables from subsidiaries:	4,489	3,664
Investment in subsidiaries:	$ 1,497	$ 1,373