Summary of Significant Accounting Policies - Computation of Income Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Numerator:
(Loss) income from continuing operations																	$ (1,753)	$ 5,253	$ 8,196
Loss from discontinued operations, net of tax																	(1,666)	(8,826)	(4,393)
Net (loss) income	(973)	[1]	(608)	[2]	(399)	[3]	(1,438)		(6,527)		686	[4]	3,393		(1,125)	[5]	(3,419)	(3,573)	3,803
Less: Accrued dividend on Series B mandatorily redeemable convertible preferred stock plus an 8% non-cumulative dividend on Series A and Series C mandatorily redeemable convertible preferred stock																	0	294	3,523
Less: Allocation of net income to participating preferred shares																	0	0	167
Numerator for basic calculation																	(3,419)	(3,867)	113
Undistributed earnings re-allocated to common stockholders																	0	0	13
Numerator for diluted calculation																	$ (3,419)	$ (3,867)	$ 126
Denominator:
Denominator for basic calculation, weighted average number of common shares outstanding																	24,722	22,297	7,558
Dilutive effect of stock options, restricted stock units and warrants using the treasury stock method																	0	1,578	1,587
Denominator for diluted calculation																	24,722	23,875	9,145
Net (loss) income per share – basic
Continuing operations																	$ (0.07)	$ 0.23	$ 0.59
Discontinued operations, net of tax																	$ (0.07)	$ (0.40)	$ (0.58)
Net (loss) income per share attributable to common stockholders (in dollars per share)	$ (0.04)	[1],[6]	$ (0.02)	[2],[6]	$ (0.02)	[3],[6]	$ (0.06)	[6]	$ (0.27)	[6]	$ 0.03	[4],[6]	$ 0.14	[6]	$ (0.08)	[5],[6]	$ (0.14)	$ (0.17)	$ 0.01
Net (loss) income per share – diluted
Continuing operations																	$ (0.07)	$ 0.23	$ 0.59
Discontinued operations, net of tax																	$ (0.07)	$ (0.40)	$ (0.58)
Net (loss) income per share attributable to common stockholders (in dollars per share)	$ (0.04)	[1],[6]	$ (0.02)	[2],[6]	$ (0.02)	[3],[6]	$ (0.06)	[6]	$ (0.27)	[6]	$ 0.03	[4],[6]	$ 0.13	[6]	$ (0.08)	[5],[6]	$ (0.14)	$ (0.17)	$ 0.01

[1] During the fourth quarter of 2012, the Company recorded correcting entries to reduce revenue by $87 thousand for the correction of immaterial errors in deferred revenue balances, to reduce stock-based compensation expense by $106 thousand for the correction of immaterial errors in additional paid-in capital, to increase royalty expenses by $39 thousand for the correction of immaterial errors in accrued royalties and to increase sales tax expense by $106 thousand for the correction of immaterial errors in other assets.

[2] During the third quarter of 2012, the Company recorded a correcting entry to reduce stock-based compensation expense by $32 thousand for the correction of immaterial errors in additional paid-in capital for the three months ended September 30, 2012.

[3] During the second quarter of 2012, the Company recorded correcting entries to increase operating expenses by $51 thousand for the correction of immaterial errors in accrued expenses in the three months ended June 30, 2012.

[4] During the third quarter of 2011, the Company recorded correcting entries to increase royalty and consulting expenses by $127 thousand for the correction of immaterial errors in capitalization of costs related to internal use software.

[5] During the first quarter of 2011, the Company recorded correcting entries to increase consulting expenses by $36 thousand for the correction of immaterial errors in accrued expenses and to increase revenue by $88 thousand for the correction of immaterial errors in deferred revenue.

[6] Net (loss) income per share for the four quarters of each fiscal year may not sum to the total for the fiscal year because of the different number of shares outstanding during each period.