Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Net income	$ 11,130	$ 11,363	$ 19,529	$ 21,185
Basic weighted average shares (in shares)	54,208,362	55,004,175	54,205,657	55,036,281
Effect of dilutive stock options and restricted stock (in shares)	461,401	564,037	508,947	567,698
Diluted weighted average shares (in shares)	54,669,763	55,568,212	54,714,604	55,603,979
Basic (usd per share)	$ 0.21	$ 0.21	$ 0.36	$ 0.38
Diluted (usd per share)	$ 0.20	$ 0.20	$ 0.36	$ 0.38
Anti-dilutive shares (in shares)	145,136	18,445	134,625	19,448