Share-Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended											1 Months Ended		12 Months Ended											12 Months Ended				12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 $ 0.00 - $2.48 [Member]	Dec. 31, 2012 $ 2.48 - $4.97 [Member]	Dec. 31, 2012 $ 4.97 - $7.46 [Member]	Dec. 31, 2012 $ 7.46 - $9.95 [Member]	Dec. 31, 2012 $ 9.95 - $12.44 [Member]	Dec. 31, 2012 $ 14.92 - $17.41 [Member]	Dec. 31, 2012 $ 17.41 - $19.90 [Member]	Dec. 31, 2012 Employee Plan [Member]	Jun. 30, 2011 2005 Equity Incentive Plan [Member]	Dec. 31, 2012 2005 Equity Incentive Plan [Member]	Dec. 31, 2012 2005 Equity Incentive Plan [Member] Minimum [Member]	Dec. 31, 2012 2005 Equity Incentive Plan [Member] Maximum [Member]	Dec. 31, 2012 1998 Director Stock Option Plan [Member]	Dec. 31, 2012 Employee Stock Purchase Plan [Member]	Dec. 31, 2011 Employee Stock Purchase Plan [Member]	Dec. 31, 2010 Employee Stock Purchase Plan [Member]	Dec. 31, 2012 Stock Options [Member]	Dec. 31, 2011 Stock Options [Member]	Dec. 31, 2010 Stock Options [Member]	Dec. 31, 2012 Stock Options [Member] 1996 Employee Stock Option Plan [Member]	Dec. 31, 2012 Stock Options [Member] 1998 Director Stock Option Plan [Member]	Dec. 31, 2012 Restricted Stock [Member]	Dec. 31, 2012 Non statutory stock options [Member]	Dec. 31, 2012 Non statutory stock options [Member] 2005 Equity Incentive Plan [Member]	Dec. 31, 2012 Incentive stock options [Member] 2005 Equity Incentive Plan [Member]	Dec. 31, 2012 Professional Services [Member]	Dec. 31, 2011 Professional Services [Member]	Dec. 31, 2010 Professional Services [Member]	Dec. 31, 2012 Maintenance [Member]	Dec. 31, 2011 Maintenance [Member]	Dec. 31, 2010 Maintenance [Member]	Dec. 31, 2012 Sales and Marketing [Member]	Dec. 31, 2011 Sales and Marketing [Member]	Dec. 31, 2010 Sales and Marketing [Member]	Dec. 31, 2012 Product Research and Development [Member]	Dec. 31, 2011 Product Research and Development [Member]	Dec. 31, 2010 Product Research and Development [Member]	Dec. 31, 2012 General and Administrative [Member]	Dec. 31, 2011 General and Administrative [Member]	Dec. 31, 2010 General and Administrative [Member]
Employee Service Share Based Compensation, Allocation Of Recognized Period Costs [Line Items]
Share-based compensation expense, net of tax	$ 5,786	$ 3,908	$ 2,623														$ 0												$ 90	$ 45	$ 69	$ 40	$ 186	$ 96	$ 1,805	$ 1,460	$ 442	$ 451	$ 36	$ 231	$ 3,400	$ 2,181	$ 1,785
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock award plans											4					1
Additional shares authorized (in shares)												3,000,000
Number of shares of common stock authorized for issuance (in shares)													16,500,000										3,265,826	300,000				5,000,000
Vesting period														3 years	4 years
Options outstanding (in shares)																				12,172,452	9,191,034	7,959,110				30,411	12,142,041
Assumptions used to estimate the fair value of stock option awards [Abstract]
Dividend yield (in hundredths)	0.00%	0.00%	0.00%
Expected volatility (in hundredths)	65.00%	100.00%	100.00%
Risk-free interest rate, minimum (in hundredths)	0.30%	0.60%	0.80%
Risk-free interest rate, maximum (in hundredths)	0.80%	1.80%	2.10%
Expected term (in years)	3 years	4 years	4 years
Weighted-average grant date fair value (in dollars per share)	$ 3.51	$ 3.37	$ 1.97																						$ 3.62
Unrecognized compensation cost related to stock options																				15,553
Weighted-average period over which compensation cost to be recognized																				2 years 9 months 18 days
Number of Options [Abstract]
Options outstanding (in shares)																				9,191,034	7,959,110					30,411	12,142,041
Options granted (in shares)																				4,960,038	2,134,786				505,038
Options exercised (in shares)	(190,269)	(295,500)																		(695,307)	(295,500)
Options forfeited and expired (in shares)																				(1,283,313)	(607,362)
Options outstanding (in shares)																				12,172,452	9,191,034	7,959,110				30,411	12,142,041
Options exercisable (in shares)																				5,545,382	4,215,920	2,795,937
Weighted-Average Exercise Price [Abstract]
Options outstanding (in dollars per share)																				$ 3.14	$ 2.94
Options granted (in dollars per share)																				$ 5.03	$ 4.96
Options exercised (in dollars per share)																				$ 3.62	$ 2.95
Options forfeited and expired (in dollars per share)																				$ 5.60	$ 6.91
Options outstanding (in dollars per share)																				$ 3.63	$ 3.14	$ 2.94
Options exercisable (in dollars per share)																				$ 2.50	$ 2.78	$ 3.75
Weighted-Average Remaining Contractual Term (In Years) [Abstract]
Options outstanding																				4 years 1 month 6 days	5 years 2 months 12 days	5 years 6 months
Options outstanding																				4 years 1 month 6 days	5 years 2 months 12 days	5 years 6 months
Options exercisable																				3 years 4 months 24 days	4 years 7 months 6 days	4 years 9 months 18 days
Aggregate Intrinsic Value [Abstract]
Options outstanding																				17,860	10,720
Options outstanding																				3,767	17,860	10,720
Options exercisable																				3,765	10,381	4,226
Proceeds from stock options exercised																									688
Fair value of stock awards vested [Abstract]
Total fair value of stock options vested	8,380	6,719	4,585
Total fair value of restricted stock awards vested	1,591	0	613
Summary of stock options outstanding by exercise price range [Abstract]
Options outstanding - Range of exercise prices, Minimum (in dollars per share)				$ 0.00	$ 2.48	$ 4.97	$ 7.46	$ 9.95	$ 14.92	$ 17.41
Options outstanding - Range of exercise prices, Maximum (in dollars per share)				$ 2.48	$ 4.97	$ 7.46	$ 9.95	$ 12.44	$ 17.41	$ 19.90
Options outstanding - Number of shares (in shares)	12,172,452			2,670,000	5,990,240	3,449,164	10,000	1,694	21,354	30,000
Options outstanding - Weighted-average remaining contractual life in years	4 years 1 month 6 days			3 years 2 months 12 days	4 years 2 months 12 days	4 years 9 months 18 days	4 months 24 days	4 years 3 months 18 days	1 year 3 months 18 days	2 years 4 months 24 days
Options outstanding - Weighted-average exercise price (in dollars per share)	$ 3.63			$ 1.06	$ 3.24	$ 6.06	$ 9.78	$ 10.81	$ 16.22	$ 17.50
Options exercisable - Number of shares (in shares)	5,545,382			2,657,500	2,359,927	464,907	10,000	1,694	21,354	30,000
Options exercisable - Weighted-average exercise price (in dollars per share)	$ 1.51			$ 0.64	$ 2.11	$ 3.16	$ 4.03	$ 3.29	$ 6.17	$ 1.80
Maximum number of shares to be purchase specified as percentage of eligible compensation (in hundredths)																	10.00%
Percentage of discount from the market price at the end of each calendar quarter (in hundredths)																	5.00%
Share-based compensation expense	5,786	3,908	2,623														0												90	45	69	40	186	96	1,805	1,460	442	451	36	231	3,400	2,181	1,785
Amount contributed by employee under employee stock purchase plan	$ 353	$ 294	$ 160														$ 353	$ 294	$ 160