Revenues and Receivables (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contract Receivable Retainage, Due after One Year	$ 2.1
Percentage Of Revenues From U S Government	99.20%	98.70%	98.30%
Percentage Of Receivable Not Collected Within One Year From Sales To U s Government	93.60%

Amounts due that have been withheld by the contracting party against the reporting company's performance under the contract. These amounts will be collected upon complying with certain contractual terms or satisfaction and release by the contracting party. It is expected that such amounts will be collected more than one year from the balance sheet date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Subparagraph c(4)

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.3(c)(4))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 910

-SubTopic 310

-Section 50

-Paragraph 4

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6471494&loc=d3e49370-109356

Name:	us-gaap_ContractReceivableRetainageDueAfterOneYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant