Loans and Allowance for Loan Losses (Purchased Loans with Deteriorated Credit Quality) (Details) - Granite Corp [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities [Roll Forward]
Balance, beginning of period	$ 84,627	$ 109,262	$ 87,564	$ 122,842
Accretion	(1,319)	(1,841)	(2,725)	(3,889)
Payments received	(12,650)	(8,522)	(16,993)	(23,376)
Foreclosed and transferred to OREO	(698)	(466)	(698)	(1,240)
Subtotal before allowance	72,598	102,115	72,598	102,115
Allowance for credit losses					$ (2,754)	$ (3,181)
Net carrying amount, end of period					69,844	98,934
Deteriorated Loans Acquired, Accretable Yield Movement Schedule [Roll Forward]
Balance, beginning of period	14,215	20,925	15,623	24,898
Accretion	(1,319)	(1,841)	(2,725)	(3,889)
Increase (Decrease) in future accretion	(1)	1,716	(3)	(209)
Subtotal before allowance	14,215	20,925	15,623	24,898	$ 12,895	$ 20,800
Net carrying amount, end of period	$ 12,895	$ 20,800	$ 12,895	$ 20,800