Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 25, 2022	Dec. 26, 2021
Deferred tax assets:
Accounts receivable	$ 28.8	$ 30.8
Inventories	22.6	14.1
Loss and credit carryforwards	175.3	179.1
Operating leases	11.2	17.8
Operating expenses	29.9	29.9
Pension	9.1	16.3
Other compensation	50.7	37.3
Postretirement benefits	5.7	8.5
Interest rate hedge	4.5	4.7
Tax sharing agreement	0.3	1.5
Deferred revenue	4.4	4.0
Capitalized research and experimentation	81.2	26.1
Other	11.7	13.5
Gross deferred tax assets	435.4	383.6
Deferred tax liabilities:
Depreciation and amortization of long-lived assets	61.8	170.5
Equity method investment	14.9	13.1
Operating leases	9.3	15.1
Foreign exchange	0.0	13.7
Prepaid expenses	4.4	3.5
Other	15.4	12.3
Gross deferred tax liabilities	105.8	228.2
Valuation allowance	(189.8)	(171.2)
Net deferred income taxes	$ 139.8
Net deferred income taxes		$ (15.8)