Derivative Financial Instruments Fair Value Gains and Losses on Derivative Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Derivative [Line Items]
Net fair value gains (losses) on derivative financial instruments	$ (381)	$ 967	$ (160)	$ 2,886
Interest rate lock with customers [Member]
Derivative [Line Items]
Net fair value gains (losses) on derivative financial instruments	512	(1,287)	1,744	(165)
Forward Commitments [Member]
Derivative [Line Items]
Net fair value gains (losses) on derivative financial instruments	(906)	2,291	(2,012)	2,845
Interest Rate Swap with Customer [Member]
Derivative [Line Items]
Net fair value gains (losses) on derivative financial instruments	20,569	(9,839)	50,000	(435)
Interest Rate Swap with Counterparty [Member]
Derivative [Line Items]
Net fair value gains (losses) on derivative financial instruments	(20,569)	9,839	(50,000)	435
Foreign Exchange Contracts With Customer [Member]
Derivative [Line Items]
Net fair value gains (losses) on derivative financial instruments	81	(748)	455	(181)
Foreign Exchange Contracts With Correspondent Banks [Member]
Derivative [Line Items]
Net fair value gains (losses) on derivative financial instruments	$ (68)	$ 711	$ (347)	$ 387