Segment Information (Details) (USD $)	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 323,285,000		$ 334,813,000
Operating income (loss)	22,983,000		31,107,000
Identifiable assets	1,233,831,000				1,284,761,000	[1]
Capital expenditures	8,443,000		8,397,000
Depreciation and amortization	10,471,000		9,824,000
Intersegment revenues	4,100,000		13,500,000
Launch Vehicles [Member]
Segment Reporting Information [Line Items]
Revenues	137,241,000		134,292,000
Operating income (loss)	11,739,000		12,033,000
Identifiable assets	198,110,000				195,294,000	[1]
Capital expenditures	3,135,000		1,697,000
Depreciation and amortization	4,389,000		4,259,000
Intersegment revenues	3,000,000		11,700,000
Satelites and Space Systems [Member]
Segment Reporting Information [Line Items]
Revenues	82,790,000		100,783,000
Operating income (loss)	3,298,000		10,838,000
Identifiable assets	273,323,000				288,343,000	[1]
Capital expenditures	4,070,000		5,036,000
Depreciation and amortization	2,031,000		2,158,000
Intersegment revenues	900,000		1,400,000
Advanced Space Programs [Member]
Segment Reporting Information [Line Items]
Revenues	107,313,000		113,259,000
Operating income (loss)	7,946,000		8,236,000
Identifiable assets	324,531,000				448,015,000	[1]
Capital expenditures	578,000		1,451,000
Depreciation and amortization	2,461,000		1,856,000
Intersegment revenues	200,000		400,000
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues	(4,059,000)	[2]	(13,521,000)	[2]
Operating income (loss)	0		0
Identifiable assets	437,867,000				353,109,000	[1]
Capital expenditures	660,000		213,000
Depreciation and amortization	$ 1,590,000		$ 1,551,000

[1] As of December 31, 2013.

[2] Corporate and other revenues are comprised solely of the elimination of intersegment revenues. Intersegment revenues are summarized as follows (in millions): Quarters Ended March 31, 2014 2013 Launch Vehicles $3.0 $11.7 Satellites and Space Systems $0.9 $1.4 Advanced Space Programs $0.2 $0.4 Total intersegment revenues $4.1 $13.5