Summary Of Major Accounting Policies - Percentage-of-Completion (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule Temporary Differences Using Percentage of Completion [Line Items]
Revenue Recognition, Multiple-deliverable Arrangements, Percentage of Revenue Accounted Under the Percentage of Completion Method	11.00%
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	$ 181,286	$ 271,233
Billed Contracts Receivable	(177,915)	(252,745)
Costs in Excess of Billings on Uncompleted Contracts or Programs	3,371	18,488
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	(55,803)	(42,952)
Billed Contracts Receivable	108,244	78,876
Billings in Excess of Cost	$ 52,441	$ 35,924