Earnings per Share - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share, Basic and Diluted [Abstract]
Net income	$ 7,528	$ 6,235	$ 20,110	$ 17,041
Net income allocated to unvested restricted stock	(66)	(64)	(177)	(193)
Net income allocated to common shares	$ 7,462	$ 6,171	$ 19,933	$ 16,848
Denominator for basic earnings per share—weighted-average shares outstanding	19,337	16,059	19,537	16,058
Effect of dilutive securities—employee stock options	31	23	28	22
Denominator for diluted earnings per share—adjusted weighted-average shares outstanding	19,368	16,082	19,565	16,080
Basic earnings per share	$ 0.39	$ 0.38	$ 1.02	$ 1.05
Diluted earnings per share	$ 0.39	$ 0.38	$ 1.02	$ 1.05
Average anti-dilutive options and awards excluded from computation of diluted earnings per share	565	554	550	563