Share-Based Compensation (Details) (USD $) In Thousands, except Share data in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Vesting Period			vest 50% upon the date of issuance with one-half of the remaining 50% vesting on each of the next two anniversaries of the initial vest date
Stock-based compensation	$ 3,019	$ 2,265	$ 13,073	$ 8,834
2011 Performance Programs [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Number of shares authorized (in shares)	0.7		0.7
Cost of maintenance services [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	168	126	509	403
Cost of consulting services [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	526	401	1,708	1,179
Product development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	437	204	1,673	710
Sales and marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	611	542	3,471	2,292
General and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 1,277	$ 992	$ 5,712	$ 4,250