Share-Based Compensation (Schedule Of Selected Financial Impact Of Share-Based Compensation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Income tax benefit resulting from share-based compensation arrangements	$ (5,584)	$ (5,403)	$ (5,245)
Net impact of share-based compensation on net income	10,990	10,519	10,251
Cost Of Revenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	1,841	1,770	1,439
Operating Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	14,733	14,152	14,057
Total Share-Based Compensation Expense Included In Consolidated Statements Of Income [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 16,574	$ 15,922	$ 15,496