Nature of Operations and Basis of Presentation (Details) $ in Thousands		12 Months Ended
	Dec. 31, 2006 employee	Dec. 31, 2015 USD ($) plan segment	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)
Nature of Operations [Line Items]
Number of business segments | segment		1
Amortized cost		$ 147,967	$ 142,461
Loans placed on nonaccrual, period of delinquency		90 days
Change to accrual status, minimum repayment performance		6 months
Uncollectible loan criteria, period of unpaid scheduled payments		4 months
Allowance of loan losses		$ 15,195	20,345	$ 26,785	$ 29,314
Number of quarters associated with losses		24 months
Number of quarters for look back period		60 months
Comprehensive income (loss)		$ 3,650	160,588	(18,765)
Deferred income tax related to the components of other comprehensive loss		$ 2,000	6,300	10,800
Number of SERP plans | plan		3
Employer matching contribution percentage		50.00%
Percentage of pay deferred by employee eligible for employer matching contributions		6.00%
Matching and discretionary contributions		$ 700	600	500
Number of new employees covered | employee	0
Pension costs		$ 400	100	300
Number of SERPs terminated | plan		3
Buildings and Improvements [Member] | Minimum [Member]
Nature of Operations [Line Items]
Estimated useful lives of premises and equipment		10 years
Buildings and Improvements [Member] | Maximum [Member]
Nature of Operations [Line Items]
Estimated useful lives of premises and equipment		50 years
Furniture and Equipment [Member] | Minimum [Member]
Nature of Operations [Line Items]
Estimated useful lives of premises and equipment		3 years
Furniture and Equipment [Member] | Maximum [Member]
Nature of Operations [Line Items]
Estimated useful lives of premises and equipment		10 years
Core Deposits [Member] | Minimum [Member]
Nature of Operations [Line Items]
Estimated useful lives of intangible assets		8 years
Core Deposits [Member] | Maximum [Member]
Nature of Operations [Line Items]
Estimated useful lives of intangible assets		10 years
Granite Corp. [Member]
Nature of Operations [Line Items]
Allowance of loan losses		$ 2,800	3,200
Accretable yield		$ 7,000	$ 9,600	$ 16,000