Regulatory Capital Matters (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Total risk-based capital ratio, Amount [Abstract]
Actual Amount	$ 210,545	$ 198,392
For capital adequacy purposes	86,856	80,463
Total risk-based capital ratio, Minimum ratio [Abstract]
Actual Ratio (in hundredths)	19.39%	19.73%
For capital adequacy purposes (in hundredths)	8.00%	8.00%
Tier 1 risk-based capital ratio, Amount [Abstract]
Actual Amount	196,889	185,741
For capital adequacy purposes	43,428	40,231
Tier 1 risk-based capital ratio, Minimum Ratio [Abstract]
Actual Ratio (in hundredths)	18.13%	18.47%
For capital adequacy purposes (in hundredths)	4.00%	4.00%
Tier 1 leverage ratio, Amount [Abstract]
Actual Amount	196,889	185,741
For capital adequacy purposes, Amount	66,858	66,546
Tier 1 leverage ratio, Minimum ratio [Abstract]
Actual Ratio (in hundredths)	11.78%	11.16%
For capital adequacy purposes (in hundredths)	4.00%	4.00%
Whidbey Island Bank [Member]
Total risk-based capital ratio, Amount [Abstract]
Actual Amount	203,471	191,816
For capital adequacy purposes	86,715	80,366
To be well-capitalized under prompt corrective action provisions	108,393	100,458
Total risk-based capital ratio, Minimum ratio [Abstract]
Actual Ratio (in hundredths)	18.77%	19.09%
For capital adequacy purposes (in hundredths)	8.00%	8.00%
To be well-capitalized under prompt corrective action provisions (in hundredths)	10.00%	10.00%
Tier 1 risk-based capital ratio, Amount [Abstract]
Actual Amount	189,837	179,180
For capital adequacy purposes	43,357	40,183
To be well-capitalized under prompt corrective action provisions	65,036	60,275
Tier 1 risk-based capital ratio, Minimum Ratio [Abstract]
Actual Ratio (in hundredths)	17.51%	17.84%
For capital adequacy purposes (in hundredths)	4.00%	4.00%
To be well-capitalized under prompt corrective action provisions (in hundredths)	6.00%	6.00%
Tier 1 leverage ratio, Amount [Abstract]
Actual Amount	189,837	179,180
For capital adequacy purposes, Amount	66,820	66,542
To be well-capitalized under prompt corrective action provisions, Amount	$ 83,525	$ 83,178
Tier 1 leverage ratio, Minimum ratio [Abstract]
Actual Ratio (in hundredths)	11.36%	10.77%
For capital adequacy purposes (in hundredths)	4.00%	4.00%
To be well-capitalized under prompt corrective action provisions (in hundredths)	5.00%	5.00%