Stock-Based Compensation (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 Y	Dec. 31, 2010	Dec. 31, 2009
Stock-Based Compensation Expense
Stock-based employee compensation expense	$ 19,138,000	$ 18,430,000	$ 18,162,000
Tax effect on stock-based employee compensation	(7,472,000)	(8,160,000)	(7,222,000)
Effect on net income, net of tax	11,666,000	10,270,000	11,144,000
Capitalized stock-based compensation expense	233,000	94,000	228,000
Total unrecognized compensation cost	33,700,000
Weighted average period for recognition of compensation cost (in years)	2.3
Continuing operations
Stock-Based Compensation Expense
Effect on net income, net of tax	11,666,000	10,270,000	10,940,000
Discontinued operation
Stock-Based Compensation Expense
Effect on net income, net of tax			204,000
Options, SARs & ESPP
Stock-Based Compensation Expense
Stock-based employee compensation expense	10,973,000	12,080,000	10,386,000
Tax effect on stock-based employee compensation	(4,303,000)	(5,592,000)	(4,091,000)
Effect on net income, net of tax	6,670,000	6,488,000	6,371,000
Options, SARs & ESPP | Continuing operations
Stock-Based Compensation Expense
Effect on net income, net of tax	6,670,000	6,488,000	6,295,000
Options, SARs & ESPP | Discontinued operation
Stock-Based Compensation Expense
Effect on net income, net of tax			76,000
RSU
Stock-Based Compensation Expense
Stock-based employee compensation expense	8,165,000	6,350,000	7,776,000
Tax effect on stock-based employee compensation	(3,169,000)	(2,568,000)	(3,131,000)
Effect on net income, net of tax	4,996,000	3,782,000	4,773,000
RSU | Continuing operations
Stock-Based Compensation Expense
Effect on net income, net of tax	4,996,000	3,782,000	4,645,000
RSU | Discontinued operation
Stock-Based Compensation Expense
Effect on net income, net of tax			128,000
Total cost of revenues
Stock-Based Compensation Expense
Stock-based employee compensation expense	3,468,000	2,915,000	2,966,000
Total cost of revenues | Options, SARs & ESPP
Stock-Based Compensation Expense
Stock-based employee compensation expense	1,858,000	1,870,000	1,784,000
Total cost of revenues | RSU
Stock-Based Compensation Expense
Stock-based employee compensation expense	1,610,000	1,045,000	1,182,000
Cost of recurring revenues
Stock-Based Compensation Expense
Stock-based employee compensation expense	2,154,000	1,774,000	1,697,000
Cost of recurring revenues | Options, SARs & ESPP
Stock-Based Compensation Expense
Stock-based employee compensation expense	1,105,000	1,066,000	985,000
Cost of recurring revenues | RSU
Stock-Based Compensation Expense
Stock-based employee compensation expense	1,049,000	708,000	712,000
Cost of non-recurring revenues
Stock-Based Compensation Expense
Stock-based employee compensation expense	1,314,000	1,141,000	1,269,000
Cost of non-recurring revenues | Options, SARs & ESPP
Stock-Based Compensation Expense
Stock-based employee compensation expense	753,000	804,000	799,000
Cost of non-recurring revenues | RSU
Stock-Based Compensation Expense
Stock-based employee compensation expense	561,000	337,000	470,000
Total operating expenses
Stock-Based Compensation Expense
Stock-based employee compensation expense	15,670,000	15,515,000	15,196,000
Total operating expenses | Options, SARs & ESPP
Stock-Based Compensation Expense
Stock-based employee compensation expense	9,115,000	10,210,000	8,602,000
Total operating expenses | RSU
Stock-Based Compensation Expense
Stock-based employee compensation expense	6,555,000	5,305,000	6,594,000
Sales and marketing
Stock-Based Compensation Expense
Stock-based employee compensation expense	6,305,000	5,866,000	5,390,000
Sales and marketing | Options, SARs & ESPP
Stock-Based Compensation Expense
Stock-based employee compensation expense	4,324,000	4,141,000	3,274,000
Sales and marketing | RSU
Stock-Based Compensation Expense
Stock-based employee compensation expense	1,981,000	1,725,000	2,116,000
Product development
Stock-Based Compensation Expense
Stock-based employee compensation expense	5,138,000	5,200,000	4,857,000
Product development | Options, SARs & ESPP
Stock-Based Compensation Expense
Stock-based employee compensation expense	2,348,000	2,856,000	2,148,000
Product development | RSU
Stock-Based Compensation Expense
Stock-based employee compensation expense	2,790,000	2,344,000	2,709,000
General and administrative
Stock-Based Compensation Expense
Stock-based employee compensation expense	4,227,000	4,449,000	4,949,000
General and administrative | Options, SARs & ESPP
Stock-Based Compensation Expense
Stock-based employee compensation expense	2,443,000	3,213,000	3,180,000
General and administrative | RSU
Stock-Based Compensation Expense
Stock-based employee compensation expense	$ 1,784,000	$ 1,236,000	$ 1,769,000