Share-Based Compensation (Summary Of Share-Based Compensation Expense Related To Share-Based Awards) (Details) (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]
Total share-based compensation expense	$ 6,253	$ 6,132	$ 5,045
Tax benefit	(1,545)	(1,475)	(1,233)
Net decrease in net income	4,708	4,657	3,812
Cost Of Software Services, Maintenance And Subscriptions [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation expense	871	739	540
Selling, General And Administrative Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation expense	$ 5,382	$ 5,393	$ 4,505