Variable Interest Entities - Assets and Liabilities of Consolidated VIEs (Details) $ in Millions	Dec. 31, 2018 USD ($) investment	Dec. 31, 2017 USD ($)
Consolidated Assets
Interest Bearing Deposits in Banks	$ 6,289	$ 1,335
Loans Held for Investment, Net	86,033	79,538
Other assets	9,620	9,410
Total Assets		0
Consolidated Liabilities
Other liabilities	2,048	2,143
Consolidated VIEs
Consolidated Assets
Interest Bearing Deposits in Banks	0	1
Loans Held for Investment, Net	570	583
Other assets	165	226
Total Assets	735	810
Consolidated Liabilities
Other liabilities	17	24
Total Liabilities	17	24
Consolidated VIEs | LIHC investments
Consolidated Assets
Interest Bearing Deposits in Banks	0	0
Loans and Leases Receivable, Net of Deferred Income	0	0
Other assets	43	68
Total Assets	43	68
Consolidated Liabilities
Other liabilities	0	0
Total Liabilities	$ 0	0
Number of LIHC investment fund | investment	2
Consolidated VIEs | Leasing investments
Consolidated Assets
Interest Bearing Deposits in Banks	$ 0	1
Loans and Leases Receivable, Net of Deferred Income	570	583
Other assets	122	158
Total Assets	692	742
Consolidated Liabilities
Other liabilities	17	24
Total Liabilities	$ 17	$ 24