Stock-Based Compensation (Details 2) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock-Based Compensation Expense
Stock-based employee compensation expense	$ 8,391,000	$ 5,371,000	$ 40,597,000	$ 15,344,000
Tax effect on stock-based compensation expense	(2,938,000)	(2,154,000)	(16,100,000)	(5,983,000)
Total unrecognized compensation cost	56,700,000		56,700,000
Weighted average period for recognition of compensation cost			2 years 8 months 12 days
Continuing operations
Stock-Based Compensation Expense
Effect on net income, net of tax	5,453,000	3,217,000	24,497,000	9,361,000
Total cost of revenues
Stock-Based Compensation Expense
Stock-based employee compensation expense	1,431,000	946,000	5,337,000	2,736,000
Cost of recurring revenues
Stock-Based Compensation Expense
Stock-based employee compensation expense	853,000	615,000	2,647,000	1,810,000
Cost of non-recurring revenues
Stock-Based Compensation Expense
Stock-based employee compensation expense	578,000	331,000	2,690,000	926,000
Total operating expenses
Stock-Based Compensation Expense
Stock-based employee compensation expense	6,960,000	4,425,000	35,260,000	12,608,000
Sales and marketing
Stock-Based Compensation Expense
Stock-based employee compensation expense	2,874,000	1,877,000	10,920,000	5,263,000
Product development
Stock-Based Compensation Expense
Stock-based employee compensation expense	2,083,000	1,440,000	6,941,000	4,338,000
General and administrative
Stock-Based Compensation Expense
Stock-based employee compensation expense	$ 2,003,000	$ 1,108,000	$ 17,399,000	$ 3,007,000