Earnings per Share - Basic and Diluted Earnings Per Share (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
Earnings Per Share, Basic and Diluted [Abstract]
Numerator for basic and diluted earnings per share—income available to common shareholders	$ 6,466	$ 5,080	$ 12,582	$ 10,806
Denominator for basic earnings per share—weighted-average shares outstanding	19,675	16,243	19,812	16,250
Effect of dilutive securities—employee stock options and awards	98	86	99	86
Denominator for diluted earnings per share—adjusted weighted-average shares outstanding	19,773	16,329	19,911	16,336
Basic earnings per share	$ 0.33	$ 0.31	$ 0.64	$ 0.67
Diluted earnings per share	$ 0.33	$ 0.31	$ 0.63	$ 0.66
Average anti-dilutive options and awards excluded from computation of diluted earnings per share	507	521	489	502