Property And Equipment, Net (Components Of Property And Equipment, Net) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Property And Equipment, Net [Abstract]
Capitalized software development	$ 473,916,000	$ 387,228,000
Computer equipment	157,219,000	121,792,000
Furniture and other equipment	98,631,000	78,809,000
Leasehold improvements	85,735,000	64,154,000
Total property and equipment, gross	815,501,000	651,983,000
Less: accumulated depreciation	(552,241,000)	(434,296,000)
Projects in progress	57,022,000	28,630,000
Property and equipment, net	320,282,000	246,317,000
Capitalized software development costs, net of accumulated amortization	184,000,000	133,000,000
Amortization of capitalized software development costs	$ 73,000,000	$ 61,000,000	$ 57,000,000