Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Earnings (Loss) Per Share [Abstract]
Net income (loss)	$ 3,651	$ (638)
Weighted average shares outstanding: [Abstract]
Basic (in shares)	47,519	48,864
Effect of dilutive securities: [Abstract]
Stock options and employee stock purchase plan shares (in shares)	1,079	0
Diluted (in shares)	48,598	48,864
Basic (in dollars per share)	$ 0.08	$ (0.01)
Diluted (in dollars per share)	$ 0.08	$ (0.01)
Anti-dilutive stock options excluded from diluted earnings per share computations (in shares)	1,199	5,252