Net Income Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Net income	$ 9,269	$ 8,526	$ 27,225	$ 26,259
Basic weighted-average common shares outstanding (in shares)	38,342	37,393	38,155	37,174
Effect of dilutive stock options (in shares)	31	318	70	371
Effect of dilutive restricted stock (in shares)	1,029	1,410	1,242	1,426
Diluted weighted-average common shares outstanding (in shares)	39,402	39,121	39,467	38,971
Basic income per common share (in dollars per share)	$ 0.24	$ 0.23	$ 0.71	$ 0.71
Diluted income per common share (in dollars per share)	$ 0.24	$ 0.22	$ 0.69	$ 0.67
Antidilutive securities excluded from diluted income per common share (in shares)	355	322	346	378