Goodwill and Other Intangible Assets (Details) (USD $)							3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Patents & Trademarks [Member]	Dec. 31, 2012 Patents & Trademarks [Member]	Mar. 31, 2013 Customer Lists [Member]	Dec. 31, 2012 Customer Lists [Member]	Mar. 31, 2013 Customer Contracts [Member]	Mar. 31, 2013 Acquired Finite-Lived Intangible Assets [Member]
Goodwill [Abstract]
Goodwill	$ 65,081,000	$ 65,829,000
Finite-lived intangible assets [Abstract]
Weighted average amortization period for acquired intangible assets subject to amortization								15
Finite-lived intangible assets, gross, non-current							500,000
Number of PCC satellite facilities							7
Finite-lived intangible assets, gross, current							400,000
Amortization expense							100,000
Estimated amortization expense, 2013							300,000	600,000
Estimated amortization expense, 2014							400,000	400,000
Estimated amortization expense, 2015							100,000	400,000
Estimated amortization expense, 2016								400,000
Estimated amortization expense, 2017								400,000
Estimated amortization expense, 2018								400,000
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	8,900,000	8,900,000	6,000,000	6,000,000	2,900,000	2,900,000
Accumulated amortization	$ 5,900,000	$ 5,800,000	$ 3,500,000	$ 3,400,000	$ 2,400,000	$ 2,400,000