Contracts-In-Process And Long-Term Receivables (Schedule Of Receipts For Long Term Receivables) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Long Term Receivables Collection Schedule [Line Items]
Financing Receivables excluding unbilled Contracts In Process	$ 377,525
Less, current portion included in contracts-in-process	(14,837)
Long-term receivables	362,688	319,426
2012 [Member]
Long Term Receivables Collection Schedule [Line Items]
Financing Receivables excluding unbilled Contracts In Process	14,837
2013 [Member]
Long Term Receivables Collection Schedule [Line Items]
Financing Receivables excluding unbilled Contracts In Process	16,145
2014 [Member]
Long Term Receivables Collection Schedule [Line Items]
Financing Receivables excluding unbilled Contracts In Process	17,487
2015 [Member]
Long Term Receivables Collection Schedule [Line Items]
Financing Receivables excluding unbilled Contracts In Process	19,046
2016 [Member]
Long Term Receivables Collection Schedule [Line Items]
Financing Receivables excluding unbilled Contracts In Process	20,600
Thereafter [Member]
Long Term Receivables Collection Schedule [Line Items]
Financing Receivables excluding unbilled Contracts In Process	$ 289,410