Discontinued Operations - Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 27, 2020	Dec. 29, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Current assets of discontinued operations	$ 0.0	$ 3.3
Current liabilities of discontinued operations	3.0	3.3
Long-term liabilities of discontinued operations	2.6	2.8
Public Safety & Security | Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accounts receivable, net	0.0	3.3
Current assets of discontinued operations	0.0	3.3
Accounts payable	0.2	0.2
Accrued expenses	0.1	0.3
Other current liabilities	2.7	2.8
Current liabilities of discontinued operations	3.0	3.3
Long-term liabilities of discontinued operations	$ 2.6	$ 2.8