Income Taxes - Income Tax Provision Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 26, 2021	Sep. 27, 2020	Sep. 26, 2021	Sep. 27, 2020
Income Tax Disclosure [Abstract]
Income tax expense at federal statutory rate	$ 1.0	$ 1.6	$ 0.3	$ 0.8
State and foreign taxes, net of federal tax benefit and valuation allowance	2.1	1.9	0.6	1.2
Release of valuation allowance due to acquisitions	0.0	(0.1)	0.0	(1.0)
Nondeductible expenses and other	3.2	2.5	1.0	1.2
Impact of deferred tax liabilities for indefinite-lived assets	0.0	1.1	0.0	0.5
Increase in reserves for uncertain tax positions	0.4	2.2	0.5	1.2
Stock compensation - excess tax benefits	(0.1)	0.0	(2.7)	0.0
Federal impact of research & development tax credits	0.9	0.0	0.3	0.0
Decrease in federal valuation allowance	0.0	(4.2)	0.0	(2.1)
Provision (benefit) for income taxes from continuing operations	$ 5.7	$ 5.0	$ (0.6)	$ 1.8