Variable Interest Entities (Details 2) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Unconsolidated Assets
Interest bearing deposits in banks	$ 3,091		$ 3,844
Securities available for sale (includes $173 at March 31, 2017 and $148 at December 31, 2016 pledged as collateral that may be repledged)	14,925		14,141
Other Assets	8,927		8,496
Unconsolidated Liabilities
Other liabilities	2,383		2,520
Unconsolidated VIEs
Unconsolidated Assets
Interest bearing deposits in banks	1		1
Securities available for sale (includes $173 at March 31, 2017 and $148 at December 31, 2016 pledged as collateral that may be repledged)	37		37
Loans Held for Investment	251		239
Other Assets	2,835		2,941
Total Assets	3,124		3,218
Unconsolidated Liabilities
Other liabilities	454		447
Total Liabilities	454		447
Maximum Exposure to Loss	3,171		3,271
Unconsolidated VIEs | LIHC investments
Variable Interest Entities
Liabilities Assumed	19	$ 37
Unconsolidated Assets
Interest bearing deposits in banks	0		0
Securities available for sale (includes $173 at March 31, 2017 and $148 at December 31, 2016 pledged as collateral that may be repledged)	25		25
Loans Held for Investment	199		168
Other Assets	1,148		1,164
Total Assets	1,372		1,357
Unconsolidated Liabilities
Other liabilities	388		381
Total Liabilities	388		381
Maximum Exposure to Loss	1,372		1,357
Unconsolidated VIEs | Leasing Investments
Unconsolidated Assets
Interest bearing deposits in banks	1		1
Securities available for sale (includes $173 at March 31, 2017 and $148 at December 31, 2016 pledged as collateral that may be repledged)	12		12
Loans Held for Investment	28		47
Other Assets	1,662		1,751
Total Assets	1,703		1,811
Unconsolidated Liabilities
Other liabilities	66		66
Total Liabilities	66		66
Maximum Exposure to Loss	1,723		1,833
Unconsolidated VIEs | Other investments
Unconsolidated Assets
Interest bearing deposits in banks	0		0
Securities available for sale (includes $173 at March 31, 2017 and $148 at December 31, 2016 pledged as collateral that may be repledged)	0		0
Loans Held for Investment	24		24
Other Assets	25		26
Total Assets	49		50
Unconsolidated Liabilities
Other liabilities	0		0
Total Liabilities	0		0
Maximum Exposure to Loss	$ 76		$ 81