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, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Deterioarted Loans Acquired Movement Schedule [Roll Forward]
Subtotal before allowance	$ 109,262	$ 149,033	$ 122,842
Accretion	1,841	2,415	3,889	$ 5,079
Reclassifications of loans and adjustments			0	(4,180)
Reclassifications of loans and adjustments	0	0
Payment received	(8,522)	(9,524)	(23,376)	(20,605)
Foreclosed and transferred to OREO	(466)	0	(1,240)	(22)
Subtotal before allowance	102,115	141,924	102,115	141,924
Subtotal before provision	(3,181)	(4,123)	(3,181)	(4,123)
Balance, end of period	98,934	137,801	98,934	137,801
Deteriorated Loans Acquired, Accretable Yield Movement Schedule [Roll Forward]
Future accretion balance, beginning of period	20,925	28,327	24,898	29,987
Accretion	(1,841)	(2,415)	(3,889)	(5,079)
Increase in future accretion	1,716	1,852	(209)	2,856
Future accretion balance, end of period	$ 20,800	$ 27,764	$ 20,800	$ 27,764