Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator:
Net income	$ 5,414	$ 3,112	$ 13,249	$ 9,717
Less: Net income allocated to unvested participating securities	99	46	244	144
Net income available to common stockholders	$ 5,315	$ 3,066	$ 13,005	$ 9,573
Denominator:
Denominator for basic earnings per share - weighted average shares	5,755	5,724	5,753	5,708
Effect of dilutive securities:
Common stock equivalents	9	28	9	41
Denominator for diluted earnings per share - adjusted weighted-average shares and assumed conversions	5,764	5,752	5,762	5,749
Basic earnings per share	$ 0.92	$ 0.54	$ 2.26	$ 1.68
Diluted earnings per share	$ 0.92	$ 0.53	$ 2.26	$ 1.67