Discontinued Operations - Results of Discontinued Operations (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 25, 2016	Dec. 27, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on disposal of discontinued operations before income taxes			$ 80,800,000
Total gain (loss) of discontinued operations before income taxes	$ 0	$ (100,000)	75,500,000
Income tax expense	100,000	0	22,500,000
Income (loss) from discontinued operations	(100,000)	(100,000)	53,000,000
Herley | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	0	0	59,700,000
Cost of sales	0	0	40,600,000
Selling, general and administrative expenses	0	100,000	15,200,000
Interest expense, net	0	0	9,100,000
Other net income (expense) items that are not major	0	0	100,000
Loss from discontinued operations before income taxes	0	(100,000)	(5,300,000)
Gain on disposal of discontinued operations before income taxes	0	0	80,800,000
Total gain (loss) of discontinued operations before income taxes	0	(100,000)	75,500,000
Income tax expense	100,000	0	22,500,000
Income (loss) from discontinued operations	$ (100,000)	$ (100,000)	$ 53,000,000