Discontinued Operations - Results of Discontinued Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 30, 2018	Dec. 31, 2017	Dec. 25, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on disposal of discontinued operations before income taxes	$ 0.0
Total gain (loss) of discontinued operations before income taxes	(9.4)	$ 6.3	$ (0.6)
Income tax expense (benefit)	(1.8)	2.1	2.3
Income (loss) from discontinued operations	(7.6)	4.2	(2.9)
Herley | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	44.2	149.9	127.1
Cost of sales	34.2	110.1	93.9
Selling, general and administrative expenses	16.7	33.6	33.8
Other net income (expense) items that are not major	2.7	(0.1)	0.0
Income (loss) from discontinued operations before income taxes	(9.4)	6.3	(0.6)
Gain on disposal of discontinued operations before income taxes	0.0	0.0	0.0
Total gain (loss) of discontinued operations before income taxes	(9.4)	6.3	(0.6)
Income tax expense (benefit)	(1.8)	2.1	2.3
Income (loss) from discontinued operations	$ (7.6)	$ 4.2	$ (2.9)