Variable Interest Entities (Details 2) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Unconsolidated Assets
Interest bearing deposits in banks	$ 2,470		$ 3,844
Securities available for sale (includes $190 at June 30, 2017 and $148 at December 31, 2016 pledged as collateral that may be repledged)	16,169		14,141
Other Assets	8,119		8,496
Unconsolidated Liabilities
Other liabilities	2,551		2,520
Unconsolidated VIEs
Unconsolidated Assets
Interest bearing deposits in banks	1		1
Securities available for sale (includes $190 at June 30, 2017 and $148 at December 31, 2016 pledged as collateral that may be repledged)	40		37
Loans Held for Investment	231		239
Other Assets	2,746		2,941
Total Assets	3,018		3,218
Unconsolidated Liabilities
Other liabilities	356		447
Total Liabilities	356		447
Maximum Exposure to Loss	3,075		3,271
Unconsolidated VIEs | LIHC investments
Variable Interest Entities
Liabilities Assumed	18	$ 48
Unconsolidated Assets
Interest bearing deposits in banks	0		0
Securities available for sale (includes $190 at June 30, 2017 and $148 at December 31, 2016 pledged as collateral that may be repledged)	29		25
Loans Held for Investment	180		168
Other Assets	1,111		1,164
Total Assets	1,320		1,357
Unconsolidated Liabilities
Other liabilities	292		381
Total Liabilities	292		381
Maximum Exposure to Loss	1,320		1,357
Unconsolidated VIEs | Leasing Investments
Unconsolidated Assets
Interest bearing deposits in banks	1		1
Securities available for sale (includes $190 at June 30, 2017 and $148 at December 31, 2016 pledged as collateral that may be repledged)	11		12
Loans Held for Investment	27		47
Other Assets	1,608		1,751
Total Assets	1,647		1,811
Unconsolidated Liabilities
Other liabilities	64		66
Total Liabilities	64		66
Maximum Exposure to Loss	1,667		1,833
Unconsolidated VIEs | Other investments
Unconsolidated Assets
Interest bearing deposits in banks	0		0
Securities available for sale (includes $190 at June 30, 2017 and $148 at December 31, 2016 pledged as collateral that may be repledged)	0		0
Loans Held for Investment	24		24
Other Assets	27		26
Total Assets	51		50
Unconsolidated Liabilities
Other liabilities	0		0
Total Liabilities	0		0
Maximum Exposure to Loss	$ 88		$ 81