Earnings Per Share (Details) - USD ($) $ / shares in Units, $ 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	$ 14,085	$ 14,717	$ 30,036	$ 38,728
Basic weighted average shares (in shares)	52,238,796	52,566,619	52,315,719	52,586,429
Effect of dilutive stock options and restricted stock (in shares)	388,745	447,650	399,671	516,979
Diluted weighted average shares (in shares)	52,627,541	53,014,269	52,715,390	53,103,408
Basic (usd per share)	$ 0.27	$ 0.28	$ 0.57	$ 0.74
Diluted (usd per share)	$ 0.27	$ 0.28	$ 0.57	$ 0.73
Anti-dilutive shares (in shares)	1,950,343	842,631	1,929,453	795,678