Share-based Arrangements - Compensation Arrangements by Share-based Payment Award (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 02, 2020	Sep. 27, 2019	Oct. 02, 2020	Sep. 27, 2019
Share-based Compensation Arrangement by Share-based Payment Award
Stock compensation expense	$ 700		$ 4,254	$ 3,969
Selling, General and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Stock compensation expense		$ 400		4,000
Discontinued Operations [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Stock compensation expense		$ 2,600		$ 2,900
Restructuring Charges [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Stock compensation expense	$ 400		$ 400