Discontinued Operations - Results of Discontinued Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 27, 2015	Dec. 28, 2014	Dec. 29, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on disposal of discontinued operations before income taxes	$ 80.8
Total gain (loss) of discontinued operations before income taxes	75.5	$ (1.1)	$ (8.8)
Income tax expense (benefit)	22.5	1.2	(1.1)
Income (loss) from discontinued operations	53.0	(2.3)	(7.7)
Herley
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	59.7	108.9	114.5
Cost of sales	40.6	70.1	78.2
Selling, general and administrative expenses	15.2	24.1	26.7
Interest expense, net	9.1	15.1	17.5
Other net expense items that are not major	0.1	0.7	0.9
Loss from discontinued operations before income taxes	(5.3)	(1.1)	(8.8)
Gain on disposal of discontinued operations before income taxes	80.8	0.0	0.0
Total gain (loss) of discontinued operations before income taxes	75.5	(1.1)	(8.8)
Income tax expense (benefit)	22.5	1.2	(1.1)
Income (loss) from discontinued operations	$ 53.0	$ (2.3)	$ (7.7)