Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Consolidated Balance Sheets [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 571	$ 262
Cumulative convertible preferred stock at accreted value, par value	$ 0.0001	$ 0.0001
Cumulative convertible preferred stock, shares authorized	100,000	100,000
Cumulative convertible preferred stock, shares issued	0	11,205
Cumulative convertible preferred stock, shares outstanding	0	11,205
Cumulative convertible preferred stock, liquidation preference	$ 1,000	$ 1,000
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	80,000,000	80,000,000
Common stock, shares issued	51,957,652	36,753,891
Common stock, shares outstanding	49,153,495	35,327,893
Treasury stock, shares	1,358,299	565,199