Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 26, 2021	Dec. 27, 2020
Deferred tax assets:
Accounts receivable	$ 30.8	$ 32.7
Inventories	14.1	14.0
Loss and credit carryforwards	175.7	221.6
Operating leases	17.8	23.1
Operating expenses	23.5	32.9
Pension	16.3	16.6
Other compensation	37.3	33.7
Postretirement benefits	8.5	7.9
Interest rate hedge	4.7	5.0
Tax sharing agreement	1.5	2.2
Deferred revenue	4.0	8.3
Other	13.5	12.0
Gross deferred tax assets	347.7	410.0
Deferred tax liabilities:
Depreciation and amortization of long-lived assets	144.5	181.2
Equity method investment	6.7	21.3
Operating leases	15.1	20.1
Foreign exchange	13.7	7.3
Prepaid expenses	3.5	3.6
Other	8.8	19.5
Gross deferred tax liabilities	192.3	253.0
Valuation allowance	(171.2)	(174.2)
Net deferred income taxes	$ (15.8)	$ (17.2)