Basis Of Presentation And Significant Accounting Policies (Schedule Of Revenue Earned On Contracts In Excess Of Billings And Deferred Revenue) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Deferred Revenue Arrangement [Line Items]
Revenue earned on contracts in excess of billings	$ 75,204	$ 64,679
Deferred revenue (current)	288,900	228,606
Prepayments and billings in excess of revenue earned on contracts in progress (long-term)	18,891	6,451
Total deferred revenue	307,791	235,057
Contracts In Progress For Software And Services [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue (current)	180,123	129,602
Contracts In Progress For Support And Maintenance [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue (current)	$ 108,777	$ 99,004