Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended			3 Months Ended				9 Months Ended
	Jul. 16, 2014	Jun. 05, 2014	May 21, 2013	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Earnings Per Share [Abstract]
Net income				$ 12,440		$ 10,522		$ 33,625		$ 29,781
Basic weighted average shares (in shares)				54,905,288	[1]	55,113,393	[1]	54,851,911	[1]	55,128,986	[1]
Effect of dilutive stock options and restricted stock (in shares)				578,755	[1]	412,949	[1]	571,383	[1]	433,677	[1]
Diluted weighted average shares (in shares)				55,484,043	[1]	55,526,342	[1]	55,423,294	[1]	55,562,663	[1]
Basic (usd per share)				$ 0.23	[1]	$ 0.19	[1]	$ 0.61	[1]	$ 0.54	[1]
Diluted (usd per share)				$ 0.22	[1]	$ 0.19	[1]	$ 0.61	[1]	$ 0.54	[1]
Anti-dilutive shares (in shares)				29,132	[1]	37,350	[1]	22,676	[1]	266,270	[1]
Stock split, conversion ratio	1.5	1.5	1.5

[1] Reflects three-for-two stock split effective July 16, 2014