Contract Assets and Contract Liabilities - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Increase (decrease) in contract assets			$ 2,000
Customer advances and billings in excess of costs			19,282	$ 26,297
Recognition of contract liabilities	$ 1,100	$ 4,500	$ 33,400	$ 16,600