Assets & Liability Derivative Positions & the Potential Effect of Netting Arrangements - Current Quarter (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Offsetting Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 47,582	$ 23,072
Derivative Asset, Collateral, Obligation to Return Cash, Offset	0	0
Derivative Asset	47,582	23,072
Derivative, Collateral, Obligation to Return Securities	0	2
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	47,582	23,070
Derivative Liability, Fair Value, Gross Liability	190,374	160,270
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative Liability	190,374	160,270
Derivative, Collateral, Right to Reclaim Securities	0	2
Derivative, Collateral, Right to Reclaim Cash	189,627	159,692
Derivative Liability, Fair Value, Amount Offset Against Collateral	747	576
Interest rate swaps
Offsetting Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability	3,188	3,273
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative Liability	3,188	3,273
Derivative, Collateral, Right to Reclaim Securities	0	0
Derivative, Collateral, Right to Reclaim Cash	3,188	3,273
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	0
Loan level swaps
Offsetting Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	46,820	22,470
Derivative Asset, Collateral, Obligation to Return Cash, Offset	0	0
Derivative Asset	46,820	22,470
Derivative, Collateral, Obligation to Return Securities	0	2
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	46,820	22,468
Derivative Liability, Fair Value, Gross Liability	46,723	22,465
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative Liability	46,723	22,465
Derivative, Collateral, Right to Reclaim Securities	0	2
Derivative, Collateral, Right to Reclaim Cash	46,723	22,461
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	2
Customer foreign exchange contracts
Offsetting Liabilities [Line Items]
Derivative Asset, Fair Value, Gross Asset	762	602
Derivative Asset, Collateral, Obligation to Return Cash, Offset	0	0
Derivative Asset	762	602
Derivative, Collateral, Obligation to Return Securities	0	0
Derivative, Collateral, Obligation to Return Cash	0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral	762	602
Derivative Liability, Fair Value, Gross Liability	747	574
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative Liability	747	574
Derivative, Collateral, Right to Reclaim Securities	0	0
Derivative, Collateral, Right to Reclaim Cash	0	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	747	574
Customer repurchase agreements and other short-term borrowings(c)
Offsetting Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability	139,716	133,958
Derivative Liability, Collateral, Right to Reclaim Cash, Offset	0	0
Derivative Liability	139,716	133,958
Derivative, Collateral, Right to Reclaim Securities	0	0
Derivative, Collateral, Right to Reclaim Cash	139,716	133,958
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	0
Other Liabilities [Member]
Offsetting Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 50,658	$ 26,313