Derivative Financial Instruments Offsetting Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Offsetting Assets [Line Items]
Derivative asset, fair value	$ 81,007	$ 33,398
Derivative, Collateral, Obligation to Return Securities	77	202
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	80,930	33,196
Derivative liability, gross liability	81,339	33,117
Derivative liability, Collateral, Right to Reclaim Securities	(77)	(202)
Derivative liability, Collateral, Right to Reclaim Cash	(81,190)	(31,130)
Derivative liability, Net Amount	72	1,785
Interest Rate Swap [Member]
Offsetting Assets [Line Items]
Derivative asset, fair value	80,948	32,970
Derivative, Collateral, Obligation to Return Securities	18	55
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	80,930	32,915
Derivative liability, gross liability	80,948	32,970
Derivative liability, Collateral, Right to Reclaim Securities	(18)	(55)
Derivative liability, Collateral, Right to Reclaim Cash	(80,930)	(31,130)
Derivative liability, Net Amount	0	1,785
Foreign Exchange Contract [Member]
Offsetting Assets [Line Items]
Derivative asset, fair value	59	428
Derivative, Collateral, Obligation to Return Securities	59	147
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	0	281
Derivative liability, gross liability	391	147
Derivative liability, Collateral, Right to Reclaim Securities	(59)	(147)
Derivative liability, Collateral, Right to Reclaim Cash	(260)	0
Derivative liability, Net Amount	$ 72	$ 0