Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data	Sep. 30, 2011	Dec. 31, 2010
Consolidated Balance Sheets
Convertible senior notes, debt discount (in dollars)	$ 0	$ 141
Redeemable common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Redeemable common stock, Outstanding shares	0	46
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, Authorized shares	5,000	5,000
Preferred stock, Issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, Authorized shares	100,000	100,000
Common stock, Issued shares	26,237	25,877
Common stock, Outstanding shares	23,277	23,015
Treasury stock, Shares at cost	2,960	2,862