Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Outstanding equity awards not included in the calculation of diluted net loss per share:
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period			(50,000)	(27,000)
Shares Paid for Tax Withholding for Share Based Compensation			(151,000)	(431,000)
Stock options
Outstanding equity awards not included in the calculation of diluted net loss per share:
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	4,457,057	10,724,690	9,167,615	10,724,690
Range of exercise prices, lower limit	$ 1.74	$ 0.47	$ 1.26	$ 0.47
Range of exercise prices, upper limit	$ 16.36	$ 16.36	$ 16.36	$ 16.36
Unvested restricted stock awards
Outstanding equity awards not included in the calculation of diluted net loss per share:
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	112,977	884,391	279,415	884,391
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross			30,000	844,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period			(25,000)	(447,000)
Warrant
Outstanding equity awards not included in the calculation of diluted net loss per share:
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	1,602,489	1,602,489	1,602,489
Warrants, exercise price	$ 0.00	$ 2.40	$ 2.40	$ 2.40
2000ESPP
Outstanding equity awards not included in the calculation of diluted net loss per share:
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			809,000	675,000