Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]
Net income	$ 4,188	$ 3,440
Weighted average shares outstanding: [Abstract]
Basic (in shares)	45,178	46,385
Effect of dilutive securities: [Abstract]
Stock options and employee stock purchase plan (in shares)	1,197	1,195
Diluted (in shares)	46,375	47,580
Basic (in dollars per share)	$ 0.09	$ 0.07
Diluted (in dollars per share)	$ 0.09	$ 0.07
Anti-dilutive stock options excluded from diluted earnings per share computations (in shares)	169	3