Contracts-In-Process And Long-Term Receivables (Credit Quality Of Financing Receivables) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Schedule Of Credit Rating Of Financing Receivables [Line Items]
Financing receivables	$ 441,353	$ 417,496
Rating Categories, A/BBB [Member]
Schedule Of Credit Rating Of Financing Receivables [Line Items]
Financing receivables	61,153	41,607
Rating Categories, BB/B [Member]
Schedule Of Credit Rating Of Financing Receivables [Line Items]
Financing receivables	281,366	246,373
Rating Categories, B/CCC [Member]
Schedule Of Credit Rating Of Financing Receivables [Line Items]
Financing receivables	98,559	94,156
Rating Categories, Customers In Bankruptcy [Member]
Schedule Of Credit Rating Of Financing Receivables [Line Items]
Financing receivables		39,307
Rating Categories, Other [Member]
Schedule Of Credit Rating Of Financing Receivables [Line Items]
Financing receivables	$ 275	$ (3,947)