Commitments and Contingencies - Other Contractual Obligations (Details) - USD ($)	Dec. 30, 2017	Dec. 31, 2016	Jun. 24, 2016	Dec. 26, 2015	Dec. 27, 2014
Purchase obligations
Total	$ 40,578,000
Senior secured term loan facility-principal payments
2018	37,500,000
2019	48,750,000
2020	1,250,000
Total	106,250,000	$ 139,375,000
Senior secured term loan facility-interest payments
2017	3,085,000
2018	2,336,000
2019	840,000
2020	4,000
Total	6,265,000
Debt Instrument [Line Items]
Unrecognized tax benefits	$ 18,296,000	$ 17,978,000		$ 17,033,000	$ 16,333,000
Cascade Microtech | Senior Secured Term Loan
Debt Instrument [Line Items]
Senior secured loan to finance merger			$ 150,000,000