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Amount of increase in allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), from recovery.

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Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Fair Value Measurements (Details) - USD ($)	3 Months Ended		6 Months Ended
Fair Value Measurements (Details) - USD ($)	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability	$ 0		$ 0		$ 0
Payment of contingent consideration	1,039,000		1,039,000	$ 0
Operating lease asset impairment charges	2,534,000		2,534,000	0
Intangible asset impairment charges	19,571,000	$ 0	19,571,000	0
Reclassification of credit loss on investments	85,000	0	(75,000)	0
Gross credit losses recorded	0	0	160,000	0
Gross recoveries	85,000	$ 0	85,000	$ 0
Other Income (Expense)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value adjustment	114,000
Restructuring Charges
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Operating lease asset impairment charges			2,534,000
Chiaro Technologies LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration, Liability					$ 1,153,000
GVi Ventures, Inc. [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low	2,500,000		2,500,000
Minimum \| GVi Ventures, Inc. [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low	$ 0		$ 0