Variable Interest Entities - Consolidated VIEs (Details) $ in Millions	Mar. 31, 2019 USD ($) investment	Dec. 31, 2018 USD ($)
Variable Interest Entities
Interest bearing deposits in banks	$ 7,003	$ 6,289
Consolidated Assets
Other Assets	9,378	9,620
Consolidated Liabilities
Other Liabilities	3,339	2,048
Consolidated VIEs
Variable Interest Entities
Interest bearing deposits in banks	0	0
Consolidated Assets
Loans Held for Investment, Net	490	570
Other Assets	159	165
Total Assets	649	735
Consolidated Liabilities
Other Liabilities	17	17
Total Liabilities	17	17
Consolidated VIEs | LIHC investments
Variable Interest Entities
Interest bearing deposits in banks	0	0
Consolidated Assets
Loans Held for Investment, Net	0	0
Other Assets	38	43
Total Assets	38	43
Consolidated Liabilities
Other Liabilities	0	0
Total Liabilities	$ 0	0
Number of LIHC investment fund | investment	2
Consolidated VIEs | Leasing investments
Variable Interest Entities
Interest bearing deposits in banks	$ 0	0
Consolidated Assets
Loans Held for Investment, Net	490	570
Other Assets	121	122
Total Assets	611	692
Consolidated Liabilities
Other Liabilities	17	17
Total Liabilities	$ 17	$ 17