Goodwill and Other Intangible Assets (Details) (USD $)							3 Months Ended
	Apr. 01, 2012	Dec. 31, 2011	Apr. 01, 2012 Patents & Trademarks [Member]	Dec. 31, 2011 Patents & Trademarks [Member]	Apr. 01, 2012 Customer Lists [Member]	Dec. 31, 2011 Customer Lists [Member]	Apr. 01, 2012 Customer Contracts [Member]	Apr. 01, 2012 Acquired Finite-Lived Intangible Assets [Member] Y
Goodwill [Abstract]
Goodwill	$ 65,788,000	$ 64,671,000
Finite-lived intangible assets [Abstract]
Weighted average amortization period for acquired intangible assets subject to amortization								15
Finite-lived intangible assets, gross, non-current							600,000
Number of PCC satellite facilities							7
Finite-lived intangible assets, gross, current							500,000
Amortization expense							200,000
Estimated amortization expense, 2012							200,000	600,000
Estimated amortization expense, 2013							400,000	600,000
Estimated amortization expense, 2014							400,000	600,000
Estimated amortization expense, 2015							100,000	600,000
Estimated amortization expense, 2016								600,000
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	8,900,000	8,900,000	6,200,000	6,200,000	2,700,000	2,700,000
Accumulated amortization	$ 5,300,000	$ 5,500,000	$ 3,900,000	$ 4,000,000	$ 1,400,000	$ 1,500,000