Discontinued Operations (Details) - USD ($) $ in Millions		12 Months Ended
	Jun. 11, 2018	Dec. 30, 2018	Dec. 31, 2017	Dec. 25, 2016	Nov. 30, 2017
Senior notes | 6.5% Notes
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stated interest rate					6.50%
Public Safety & Security | Disposal Group, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Purchase price, in cash	$ 69.0
Working capital adjustments	8.0
Proceeds from divestiture	70.0
Working capital retained	7.0
Transaction costs	$ 2.7
Herley | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cost adjustments		$ 2.0
Transaction-related costs		2.7
Income tax expense (benefit) reclassification		2.1
Herley | Discontinued Operations, Disposed of by Sale | Selling, general and administrative expenses
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Depreciation and amortization expense		$ 0.1	$ 0.3	$ 0.3