Stock-based Compensation (Details) (USD $)	12 Months Ended									10 Months Ended		12 Months Ended		10 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Stock option	Dec. 31, 2011 Stock option	Dec. 31, 2010 Stock option	Dec. 31, 2012 Stock option Non-employee awards to board members	Dec. 31, 2011 Stock option Non-employee awards to board members	Dec. 31, 2010 Stock option Non-employee awards to board members	Nov. 06, 2011 Stock option Stock option / 2003 Incentive Plan	Nov. 06, 2011 Stock option Stock option / 2003 Incentive Plan Minimum	Dec. 31, 2012 Stock option Stock option / 2003 Incentive Plan Minimum	Dec. 31, 2012 Stock option Stock option / 2011 Incentive Plan	Nov. 06, 2011 Stock option Stock option / 2011 Incentive Plan Minimum	Dec. 31, 2012 Stock option Stock option / 2011 Incentive Plan Minimum
Stock-based Compensation
Number of shares of common stock authorized for issuance	4,671,000									2,016,000			2,655,000
Options outstanding (in shares)				3,899,000	3,950,000
Number of shares available for grant	79,000
Exercise price of options as percentage of fair value of common stock on the date of grant											100.00%	100.00%		100.00%	100.00%
Exercise price of options as percentage of fair value of common stock on the date of grant in case of options granted to stockholder owning in excess of 10% of Company's common stock											110.00%	110.00%		110.00%	110.00%
Percentage of ownership required in entity's common stock for specified exercise price											10.00%			10.00%	10.00%
Exercise period										10 years			10 years
Exercise period in case of stock options granted to stockholder owning in excess of 10% of the company's common stock										5 years			5 years
Award vesting period										4 years			4 years
Weighted-average assumptions used in estimation of grant date fair values
Expected term				6 years 3 months	6 years 3 months	6 years 3 months
Volatility (as a percent)				60.00%	60.00%	58.00%
Expected dividend yield (as a percent)				0.00%	0.00%	0.00%
Risk-free interest rates (as a percent)				1.10%	1.35%	1.92%
Summary of stock option activity - Shares
Options outstanding at the beginning of the period (in shares)				3,950,000
Granted (in shares)				218,000				317,000	258,000
Exercised (in shares)				(222,000)
Cancelled (in shares)				(47,000)
Options outstanding at the end of the period (in shares)				3,899,000	3,950,000
Options exercisable at the end of the period (in shares)				1,652,000
Options vested and expected to vest at the end of the period (in shares)				3,729,000
Summary of stock option activity - Weighted-Average Exercise Price (in dollars per share)
Options outstanding at the beginning of the period (in dollars per share)				$ 2.94
Granted (in dollars per share)				$ 4.22
Exercised (in dollars per share)				$ 1.26
Cancelled (in dollars per share)				$ 3.70
Options outstanding at the end of the period (in dollars per share)				$ 3.10	$ 2.94
Options exercisable at the end of the period (in dollars per share)				$ 2.31
Options vested and expected to vest at the end of the period (in dollars per share)				$ 3.07
Weighted-Average Contractual Life (In Years)
Options outstanding at the end of the period				8 years 25 days
Options exercisable at the end of the period				6 years 10 months 24 days
Options vested and expected to vest at the end of the period				8 years 11 days
Aggregate Intrinsic Value
Options outstanding at the end of the period (in dollars)				$ 8,578,000
Options exercisable at the end of the period (in dollars)				4,942,000
Options vested and expected to vest at the end of the period (in dollars)				8,317,000
Additional disclosures
Weighted-average grant-date fair value (in dollars per share)				$ 2.36	$ 2.07	$ 0.60
Total grant date fair value of stock options vested				1,500,000	400,000
Aggregate intrinsic value of options vested during the period				900,000	200,000
Stock-based compensation expense	$ 1,795,000	$ 304,000	$ 134,000				$ 483,000	$ 131,000	$ 34,000