Business and Summary of Significant Accounting Policies (Details) (USD $) Share data in Thousands, except Per Share data, unless otherwise specified	3 Months Ended										12 Months Ended
	Dec. 31, 2011		Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010		Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Numerator
Net income	$ 17,369,000		$ 16,473,000	$ 21,217,000	$ 12,335,000	$ 21,227,000	[1]	$ 10,629,000	$ 6,345,000	$ 9,268,000	$ 67,394,000		$ 47,469,000		$ 36,607,000
Percentage allocated to shareholders (in hundredths)											99.10%	[2]	99.00%	[2]	98.80%	[2]
Numerator for basic and diluted earnings per share											66,787,000		46,994,000		36,168,000
Denominator
Denominator for basic earnings per share - weighted-average shares outstanding (in shares)											58,531		57,683		56,787
Dilutive effect of stock options and restricted stock units (in shares)											596		652		709
Denominator for diluted earnings per share (in shares)											59,127		58,335		57,496
Per share income
Basic (in dollars per share)	$ 0.29		$ 0.28	$ 0.36	$ 0.21	$ 0.36		$ 0.18	$ 0.11	$ 0.16	$ 1.14		$ 0.81		$ 0.64
Diluted (in dollars per share)	$ 0.29		$ 0.28	$ 0.36	$ 0.21	$ 0.36		$ 0.18	$ 0.11	$ 0.16	$ 1.13		$ 0.81		$ 0.63
Basic weighted-average shares outstanding (in shares)											58,531		57,683		56,787
Basic weighted-average shares outstanding and unvested restricted stock units expected to vest (in shares)											59,078		58,254		57,494
Percentage allocated to shareholders (in hundredths)											99.10%	[2]	99.00%	[2]	98.80%	[2]
Research and development [Abstract]
Deferred revenue and customer advances	104,970,000					112,182,000					104,970,000		112,182,000
Research and development expenses											102,751,000		122,270,000		109,754,000
Insurance Recoveries											17,800,000		0		5,300,000
COTS Agreement - Cost-Sharing Arrangement Terms with NASA [Member]
Research and development [Abstract]
Aggregate cash milestone payments to partially fund project costs	288,000,000										288,000,000
Estimated total project costs	465,000,000										465,000,000
Deferred revenue and customer advances	6,200,000					25,200,000					6,200,000		25,200,000
Research and development costs incurred											158,800,000	[3]	136,500,000	[3]	96,600,000	[3]
Less amounts funded by NASA											(108,000,000)		(69,100,000)		(60,600,000)
Net research and development expenses											50,800,000		67,400,000		36,000,000
Research and development costs incurred, inception to date	417,900,000	[3]									417,900,000	[3]
Less amounts funded by NASA, inception to date	(260,300,000)										(260,300,000)
Net research and development expenses, inception to date	157,600,000										157,600,000
Antares Development Program [Member]
Research and development [Abstract]
Net research and development expenses, inception to date	192,200,000										192,200,000
Research and development expenses											$ 34,300,000		$ 48,300,000		$ 66,500,000
Buildings [Member]
Property, Plant and Equipment [Line Items]
Useful life (in years)											20
Machinery, Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Useful life, minimum (in years)											3
Useful life, maximum (in years)											12
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Useful life, description											Shorter of estimated useful life or lease term

[1] Includes a reduction in income tax expense resulting from the reinstatement of the Federal research and development tax credit that increased net income by $7.4 million.

[2] Basic weighted-average shares outstanding Years Ended December 31, 2011 2010 2009 58,531 57,683 56,787 Basic weighted-average shares outstanding and unvested restricted stock units expected to vest Years Ended December 31, 2011 2010 2009 59,078 58,254 57,494 Percentage allocated to shareholders Years Ended December 31,2011 2010 2009 99.1% 99.0% 98.8%

[3] Includes associated general and administrative expenses.