Goodwill and Other Intangible Assets (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 Y	Dec. 31, 2010	Dec. 31, 2009
Goodwill [Abstract]
Goodwill	$ 64,671,000	$ 67,156,000
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	8,900,000	8,900,000
Accumulated amortization	5,500,000	4,700,000
Patents & Trademarks [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	6,200,000	6,200,000
Accumulated amortization	4,000,000	3,500,000
Customer Lists [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,700,000	2,700,000
Accumulated amortization	1,500,000	1,200,000
Acquired Finite-Lived Intangible Assets [Member]
Finite-lived intangible assets [Abstract]
Weighted average amortization period for acquired intangible assets subject to amortization (in years)	15
Amortization expense	800,000	500,000	900,000
Estimated amortization expense, 2012	600,000
Estimated amortization expense, 2013	600,000
Estimated amortization expense, 2014	600,000
Estimated amortization expense, 2015	600,000
Estimated amortization expense, 2016	600,000
Customer Contracts [Member]
Finite-lived intangible assets [Abstract]
Amortization expense	700,000	1,000,000	1,500,000
Estimated amortization expense, 2013	400,000
Estimated amortization expense, 2014	400,000
Estimated amortization expense, 2015	400,000
Estimated amortization expense, 2016	100,000
Finite-lived intangible assets, gross, non-current	900,000
Number of PCC satellite facilities	7
Finite-lived intangible assets, gross, current	$ 400,000