Segment Information (Details) (USD $)	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012		Dec. 31, 2012
Segment Reporting Information [Line Items]
Revenues	$ 333,081,000		$ 371,268,000		$ 667,894,000		$ 709,298,000
Operating income (loss)	26,306,000		26,092,000		57,413,000		49,939,000
Identifiable assets	1,241,892,000				1,241,892,000				1,211,454,000	[1]
Capital expenditures	11,436,000		19,946,000		19,833,000		31,740,000
Depreciation and amortization	10,434,000		9,337,000		20,258,000		18,356,000
Intersegment revenues	11,400,000		18,100,000		24,900,000		32,500,000
Launch Vehicles [Member]
Segment Reporting Information [Line Items]
Revenues	134,027,000		126,340,000		268,319,000		252,462,000
Operating income (loss)	10,521,000		8,072,000		22,554,000		16,988,000
Identifiable assets	208,593,000				208,593,000				206,194,000	[1]
Capital expenditures	2,976,000		12,268,000		4,673,000		19,519,000
Depreciation and amortization	4,618,000		3,898,000		8,877,000		7,631,000
Intersegment revenues	10,300,000		16,400,000		22,000,000		29,000,000
Satelites and Space Systems [Member]
Segment Reporting Information [Line Items]
Revenues	93,828,000		130,114,000		194,611,000		241,397,000
Operating income (loss)	10,637,000		10,572,000		21,475,000		17,949,000
Identifiable assets	269,546,000				269,546,000				278,008,000	[1]
Capital expenditures	5,337,000		4,603,000		10,373,000		6,889,000
Depreciation and amortization	2,074,000		2,165,000		4,232,000		4,129,000
Intersegment revenues	900,000		1,400,000		2,300,000		3,100,000
Advanced Space Programs [Member]
Segment Reporting Information [Line Items]
Revenues	116,620,000		132,947,000		229,879,000		247,910,000
Operating income (loss)	5,148,000		9,539,000		13,384,000		17,093,000
Identifiable assets	455,511,000				455,511,000				390,059,000	[1]
Capital expenditures	1,311,000		1,442,000		2,762,000		3,416,000
Depreciation and amortization	2,179,000		1,690,000		4,035,000		3,453,000
Intersegment revenues	200,000		300,000		600,000		400,000
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues	(11,394,000)	[2]	(18,133,000)	[2]	(24,915,000)	[2]	(32,471,000)	[2]
Operating income (loss)	0		(2,091,000)	[3]	0		(2,091,000)	[3]
Identifiable assets	308,242,000				308,242,000				337,193,000	[1]
Capital expenditures	1,812,000		1,633,000		2,025,000		1,916,000
Depreciation and amortization	$ 1,563,000		$ 1,584,000		$ 3,114,000		$ 3,143,000

[1] As of December 31, 2012.

[2] Corporate and other revenues are comprised solely of the elimination of intersegment revenues summarized as follows (in millions): Quarters Ended June 30, Six Months Ended June 30, 2013 2012 2013 2012 Launch Vehicles $10.3 $16.4 $22.0 $29.0 Satellites and Space Systems 0.9 1.4 2.3 3.1 Advanced Space Programs 0.2 0.3 0.6 0.4 Total intersegment revenues $11.4 $18.1 $24.9 $32.5

[3] The corporate and other operating loss in 2012 is comprised solely of professional fees and other costs related to a potential acquisition that was not consummated.