Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Numerator:
Net income	$ 4,474	$ 4,777	$ 6,605	$ 7,216
Less: Net income allocated to unvested participating securities	68	41	100	62
Net income available to common stockholders	$ 4,406	$ 4,736	$ 6,505	$ 7,154
Denominator:
Denominator for basic earnings per share— weighted average shares	5,712	5,699	5,711	5,695
Effect of dilutive securities:
Common stock equivalents	45	55	48	60
Denominator for diluted earnings per share — adjusted weighted-average shares and assumed conversions	5,757	5,754	5,759	5,755
Basic earnings per share:	$ 0.77	$ 0.83	$ 1.14	$ 1.26
Diluted earnings per share:	$ 0.77	$ 0.82	$ 1.13	$ 1.24