Net Income Per Common Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Disclosure Calculation Of Net Income Per Common Share [Abstract]
Net income	$ 11,142	$ 12,089	$ 29,052	$ 34,809
Basic:
Basic weighted average EPS shares	25,074	24,979	25,045	24,952
Basic net income per share	$ 0.44	$ 0.48	$ 1.16	$ 1.40
Diluted:
Basic weighted average EPS shares	25,074	24,979	25,045	24,952
Dilutive common stock equivalents	78	92	90	97
Dilutive EPS shares	25,152	25,071	25,135	25,049
Diluted net income per share	$ 0.44	$ 0.48	$ 1.16	$ 1.39
Anti-dilutive shares	64	146	59	195