Benefit Plans - Narrative (Details) $ in Thousands, £ in Millions			3 Months Ended					9 Months Ended
	Apr. 06, 2020 USD ($)	Apr. 06, 2020 GBP (£)	Dec. 31, 2021 USD ($)	Sep. 25, 2021 USD ($)	Sep. 26, 2020 USD ($)	Jun. 27, 2020 USD ($)	Jun. 27, 2020 GBP (£)	Sep. 25, 2021 USD ($)	Sep. 26, 2020 USD ($)	Apr. 07, 2020 USD ($)
Defined Benefit Plan Disclosure
Contributions expected				$ 2,200				$ 2,200
Expected direct payments				3,800				3,800
Defined benefit plan expense				1,084	$ 983			3,296	$ 2,617
Estimated decrease in pension cost										$ 55,000
Estimated percent reduction in pension costs										37.00%
Benefit obligation, unamortized actuarial loss	$ (13,400)	£ 13.4
Cash contribution						$ 10,400	£ 8.4
Defined benefit pension plan and other adjustments
Defined Benefit Plan Disclosure
Benefit obligation, unamortized actuarial loss | £		£ 10.9
Forecast | Minimum
Defined Benefit Plan Disclosure
Estimated settlement charge			$ 18,000
Forecast | Maximum
Defined Benefit Plan Disclosure
Estimated settlement charge			$ 22,000
Foreign Plan
Defined Benefit Plan Disclosure
Defined benefit plan expense				600	500			1,600	1,500
Other comprehensive income as component of net period benefit cost, before tax				$ 200	$ 200			$ 500	$ 500