Derivative Financial Instruments Offsetting Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Offsetting Assets [Line Items]
Derivative asset, fair value	$ 83,265	$ 33,398
Derivative, Collateral, Obligation to Return Securities	373	202
Derivative, Collateral, Obligation to Return Cash	(18)	0
Net Amount	82,874	33,196
Derivative liability, gross liability	83,331	33,117
Derivative liability, Collateral, Right to Reclaim Securities	(373)	(202)
Derivative liability, Collateral, Right to Reclaim Cash	(82,510)	(31,130)
Derivative liability, Net Amount	448	1,785
Interest Rate Swap [Member]
Offsetting Assets [Line Items]
Derivative asset, fair value	82,888	32,970
Derivative, Collateral, Obligation to Return Securities	14	55
Derivative, Collateral, Obligation to Return Cash	0	0
Net Amount	82,874	32,915
Derivative liability, gross liability	82,888	32,970
Derivative liability, Collateral, Right to Reclaim Securities	(14)	(55)
Derivative liability, Collateral, Right to Reclaim Cash	(82,510)	(31,130)
Derivative liability, Net Amount	364	1,785
Foreign Exchange Contract [Member]
Offsetting Assets [Line Items]
Derivative asset, fair value	377	428
Derivative, Collateral, Obligation to Return Securities	359	147
Derivative, Collateral, Obligation to Return Cash	(18)	0
Net Amount	0	281
Derivative liability, gross liability	443	147
Derivative liability, Collateral, Right to Reclaim Securities	(359)	(147)
Derivative liability, Collateral, Right to Reclaim Cash	0	0
Derivative liability, Net Amount	$ 84	$ 0