Variable Interest Entities - Consolidated VIEs (Details) $ in Millions	Mar. 31, 2020 USD ($) investment	Dec. 31, 2019 USD ($)	Mar. 31, 2019 USD ($)
Variable Interest Entities
Interest bearing deposits in banks	$ 9,830	$ 7,184
Consolidated Assets
Other Assets	11,791	10,200
Total assets	165,696	170,810	$ 170,707
Consolidated Liabilities
Other Liabilities	3,317	2,837
Total liabilities	149,164	154,443
Consolidated VIEs
Consolidated Assets
Loans Held for Investment, Net	339	349
Other Assets	210	213
Total assets	549	562
Consolidated Liabilities
Other Liabilities	44	45
Total liabilities	44	45
Consolidated VIEs | LIHC investments
Consolidated Assets
Loans Held for Investment, Net	0	0
Other Assets	94	96
Total assets	94	96
Consolidated Liabilities
Other Liabilities	36	36
Total liabilities	$ 36	36
Number of LIHC investment fund | investment	2
Consolidated VIEs | Leasing investments
Consolidated Assets
Loans Held for Investment, Net	$ 339	349
Other Assets	116	117
Total assets	455	466
Consolidated Liabilities
Other Liabilities	8	9
Total liabilities	$ 8	$ 9