(Accumulated Amortization of Intangible Assets Schedule) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 96,561	$ 96,561	$ 96,561
Finite-Lived Intangible Assets, Accumulated Amortization	(40,541)	(35,933)	(30,737)
Finite-Lived Intangible Assets, Net	56,020	60,628	65,824
Core Deposits
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	82,323	82,323	82,323
Finite-Lived Intangible Assets, Accumulated Amortization	(32,083)	(28,304)	(24,150)
Finite-Lived Intangible Assets, Net	50,240	54,019	58,173
Lease Agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	238	238	238
Finite-Lived Intangible Assets, Accumulated Amortization	(229)	(212)	(194)
Finite-Lived Intangible Assets, Net	9	26	44
Customer Relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	14,000	14,000	14,000
Finite-Lived Intangible Assets, Accumulated Amortization	(8,229)	(7,417)	(6,393)
Finite-Lived Intangible Assets, Net	$ 5,771	$ 6,583	$ 7,607