Share-Based Compensation (Details 5) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation (in dollars)	$ 13,016	$ 11,494	$ 8,095
Cost of maintenance services [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense ( in dollars)	492	482	590
Cost of consulting services [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense ( in dollars)	1,767	1,565	1,107
Product development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense ( in dollars)	1,637	1,149	721
Sales and marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense ( in dollars)	3,123	2,628	2,188
General and Administrative Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense ( in dollars)	$ 5,997	$ 5,670	$ 3,489