Discontinued Operations - Summary of Assets and Liabilities of Discontinued Operations (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 25, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Current liabilities of discontinued operations	$ 1.1	$ 1.6
Herley | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accrued compensation	0.0	0.6
Other current liabilities	1.1	1.0
Current liabilities of discontinued operations	1.1	1.6
Other long-term liabilities of discontinued operations	$ 3.8	$ 3.7