Revenue - Additional Information (Detail)	12 Months Ended
	Dec. 28, 2019 USD ($) Installment	Dec. 29, 2018 USD ($)
Revenue From Contract With Customers [Line Items]
Revenue remaining performance obligation	$ 92,400,000
Revenue performance obligation, description of timing	We expect to recognize approximately 62% of our remaining performance obligations as revenue in 2020, 20% in 2021, 13% in 2022 and 5% in 2023.
TFE
Revenue From Contract With Customers [Line Items]
Contract liabilities	$ 4,327,000	$ 14,947,000
Revenue remaining performance obligation	$ 21,400,000
TFE | Accounts Receivable, Unbilled
Revenue From Contract With Customers [Line Items]
Number of installments | Installment	3
Change in contract assets	$ 246,000
TFE | Customer Advances
Revenue From Contract With Customers [Line Items]
Contract with customer liability revenue recognized	14,300,000
Contract liabilities	4,007,000	14,314,000
TFE | Deferred Revenue
Revenue From Contract With Customers [Line Items]
Contract with customer liability revenue recognized	527,000
Contract liabilities	320,000	633,000
Photonics
Revenue From Contract With Customers [Line Items]
Change in contract assets	1,659,000
Revenue remaining performance obligation	71,000,000
Photonics | Accounts Receivable, Unbilled
Revenue From Contract With Customers [Line Items]
Change in contract assets	1,717,000
Photonics | Deferred Revenue
Revenue From Contract With Customers [Line Items]
Contract with customer liability revenue recognized	$ 1,100,000
Contract liabilities		$ 1,101,000