Income Taxes - Deferred Taxes (Details) - USD ($) $ in Millions	Dec. 25, 2022	Dec. 26, 2021
Deferred tax assets:
Stock-based compensation	$ 9.4	$ 9.7
Payroll related accruals	6.7	9.2
Lease accruals	25.7	21.8
Net operating loss carryforwards	55.1	58.1
Tax credit carryforwards	11.3	13.1
Deferred expenses	14.1	10.8
Other	19.4	16.5
Gross deferred tax assets	141.7	139.2
Valuation allowance	(14.6)	(9.0)
Total deferred tax assets, net of valuation allowance	127.1	130.2
Deferred tax liabilities:
Unearned revenue	(3.3)	(4.3)
Operating lease right-of-use assets	(23.2)	(19.6)
Other intangibles	(23.1)	(28.0)
Property and equipment, principally due to differences in depreciation	(5.6)	(7.1)
Other	(1.6)	(1.6)
Total deferred tax liabilities	(56.8)	(60.6)
Net deferred tax asset	$ 70.3	$ 69.6