Restructuring Costs (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 26, 2020	Jun. 26, 2020	Dec. 27, 2019	Sep. 25, 2020	Mar. 27, 2020
Restructuring Cost And Reserve [Line Items]
Restructuring costs	$ 5,034		$ 3,300
Remaining restructuring commitments	3,231	$ 3,231	$ 1,584	$ 1,180	$ 526
COVID-19 [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring costs	$ 5,000	$ 5,000
COVID-19 [Member] | 2020 Restructuring Charge [Member]
Restructuring Cost And Reserve [Line Items]
Remaining restructuring commitments				900
COVID-19 [Member] | 2019 Restructuring Charge [Member]
Restructuring Cost And Reserve [Line Items]
Remaining restructuring commitments				$ 300