Share-Based Compensation (Compensation Expense Recognized In The Condensed Consolidated Statements Of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amounts charged against earnings, before income tax benefit	$ 54,091	$ 38,200	$ 101,926	$ 73,587
Amount of related income tax benefit recognized in earnings	10,191	8,191	20,447	14,634
Stock option and non-vested share compensation expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amounts charged against earnings, before income tax benefit	53,941	37,549	101,891	72,580
Associate stock purchase plan expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amounts charged against earnings, before income tax benefit	1,613	1,727	3,161	2,828
Amounts capitalized in software development costs, net of amortization
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amounts charged against earnings, before income tax benefit	$ (1,463)	$ (1,076)	$ (3,126)	$ (1,821)