Share-Based Compensation (Details) (USD $) In Thousands, except Share data in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 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	$ 4,482	$ 3,292	$ 10,055	$ 6,569
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	174	163	341	277
Cost of consulting services [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	519	330	1,183	778
Product development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	544	173	1,236	506
Sales and marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	1,419	884	2,860	1,750
General and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 1,826	$ 1,742	$ 4,435	$ 3,258