Loans and Allowance for Loan Losses (Purchased Loans with Deteriorated Credit Quality) (Details) - Granite Corp [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Deteriorated Loans Acquired, Accretable Yield Movement Schedule [Roll Forward]
Beginning balance, Carrying Amount	$ 102,115	$ 141,924	$ 122,842	$ 161,652
Beginning balance, Future Accretion	20,800	27,764	24,898	29,987
Accretion	(1,634)	(2,323)	(5,523)	(7,402)
Increase in future accretion	(393)	1,495	(602)	4,351
Reclassifications of loans and adjustments	0	0	0	(4,180)
Payment received	(11,072)	(13,253)	(34,448)	(33,858)
Foreclosed and transferred to OREO	0	(329)	(1,240)	(351)
Subtotal before allowance, Carrying Amount	92,677	130,665	92,677	130,665
Subtotal before allowance, Future Accretion	20,800	27,764	24,898	29,987	$ 18,773	$ 26,936
Allowance for credit losses					(3,190)	(3,923)
Net carrying amount, end of period, Carrying Amount					$ 89,487	$ 126,742
Net carrying amount, end of period, Future Accretion	$ 18,773	$ 26,936	$ 18,773	$ 26,936