Amount of cash paid to acquire the entity.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 51

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph f(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

Commitments and Contingencies (Details) (USD $)	9 Months Ended
Commitments and Contingencies (Details) (USD $)	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Apr. 02, 2010 Spacecraft Development and Manufacturing Business [Member]
Research and development expenses [Abstract]
Research and development costs reported as allowable expenses	$ 29,600,000	$ 24,200,000
Research and development allowable costs reported as allowable expenses inception to date	183,000,000
Other Contingencies [Abstract]
Amount of cash paid to acquire certain assets and liabilities				55,000,000
Receivables	$ 495,007,000		$ 333,467,000