Net Income (Loss) Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Anti-dilutive securities excluded from the computation of diluted net income (loss) per share
Anti-dilutive securities (in shares)	3,186	2,776	3,357	2,776
Components of basic and diluted net loss per share
Net income (loss)	$ 3,319	$ (19,562)	$ (9,097)	$ (41,857)
Weighted average common shares outstanding	21,370	21,167	21,359	21,156
Effect of dilutive securities:
Stock options and restricted stock units (in shares)	279
Shares used in calculating dilutive net income (loss) per share (in shares)	21,649	21,167	21,359	21,156
Net income (loss) per share:
Basic (in dollars per share)	$ 0.16	$ (0.92)	$ (0.43)	$ (1.98)
Diluted (in dollars per share)	$ 0.15	$ (0.92)	$ (0.43)	$ (1.98)
Options to purchase shares of common stock
Anti-dilutive securities excluded from the computation of diluted net income (loss) per share
Anti-dilutive securities (in shares)	3,044	2,127	2,873	2,127
Shares of common stock issuable upon the vesting of restricted stock units
Anti-dilutive securities excluded from the computation of diluted net income (loss) per share
Anti-dilutive securities (in shares)	142	649	484	649