Contracts-In-Process And Long-Term Receivables (Credit Quality Of Financing Receivables) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Schedule Of Credit Rating Of Financing Receivables [Line Items]
Financing receivables	$ 417,496	$ 383,155
Rating Categories, A/BBB [Member]
Schedule Of Credit Rating Of Financing Receivables [Line Items]
Financing receivables	41,607	37,303
Rating Categories, BB/B [Member]
Schedule Of Credit Rating Of Financing Receivables [Line Items]
Financing receivables	246,373	225,533
Rating Categories, B/CCC [Member]
Schedule Of Credit Rating Of Financing Receivables [Line Items]
Financing receivables	94,156	80,222
Rating Categories, Customers In Bankruptcy [Member]
Schedule Of Credit Rating Of Financing Receivables [Line Items]
Financing receivables	39,307	39,376
Rating Categories, Other [Member]
Schedule Of Credit Rating Of Financing Receivables [Line Items]
Financing receivables	$ (3,947)	$ 721