Summary Of Major Accounting Policies - Percentage-of-Completion (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Schedule Temporary Differences Using Percentage of Completion [Line Items]
Revenue Recognition, Multiple-deliverable Arrangements, Percentage of Revenue Accounted Under the Percentage of Completion Method	16.00%
Contract in Unbilled Receivable Position [Member]
Schedule Temporary Differences Using Percentage of Completion [Line Items]
Fixed-price Contract, Percentage of Completion, Revenue Recognized to Date	$ 271,233	$ 262,602
Billed Contracts Receivable	(252,745)	(238,473)
Costs in Excess of Billings on Uncompleted Contracts or Programs	18,488	24,129
Contracts in Unearned Revenue Position [Member]
Schedule Temporary Differences Using Percentage of Completion [Line Items]
Fixed-price Contract, Percentage of Completion, Revenue Recognized to Date	(42,952)	(45,144)
Billed Contracts Receivable	78,876	90,315
Billings in Excess of Cost	$ 35,924	$ 45,171