Summary of Significant Accounting Policies (Details) (USD $)	9 Months Ended	12 Months Ended
	Sep. 30, 2010	Dec. 31, 2012 condition branch_office	Dec. 31, 2011	Dec. 31, 2010
Accounting Policies [Abstract]
Total assets		$ 972,139,000	$ 934,218,000
Number of conditions that must be met for a modified loan to be considered a TDR		2
Period when collection of all or a portion of contractual interest on a loan has become doubtful		90 days
Percent of goodwill balance determined to be impaired				100.00%
Goodwill impairment	11,700,000	0	0	11,662,000
Goodwill				$ 0
Entity Information [Line Items]
Number of branch offices		19
Northern Idaho
Entity Information [Line Items]
Number of branch offices		8
Southwestern Idaho
Entity Information [Line Items]
Number of branch offices		5
Southcentral Idaho
Entity Information [Line Items]
Number of branch offices		3
Eastern Washington
Entity Information [Line Items]
Number of branch offices		2
Eastern Oregon
Entity Information [Line Items]
Number of branch offices		1