Summary of Fair Values of Assets Acquired and Liabilities Assumed Purchase Price Allocation (Details) $ in Thousands, £ in Millions	May 01, 2018 USD ($)	Sep. 28, 2018 USD ($)	May 01, 2018 GBP (£)	Dec. 31, 2017 USD ($)
Business Acquisition [Line Items]
Goodwill		$ 219,772		$ 210,988
Zettlex Holdings Limited
Business Acquisition [Line Items]
Cash	$ 3,776
Accounts receivable	2,237
Inventories	928
Property, plant and equipment	2,590
Intangible assets	14,585
Goodwill	11,649
Other assets	145
Total assets acquired	35,910
Accounts payable	509
Accrued expenses and other liabilities	894
Deferred tax liabilities	2,481
Total liabilities assumed	3,884
Total assets acquired, net of liabilities assumed	32,026	$ 32,000	£ 23.3
Less: cash acquired	3,776
Total purchase price, net of cash acquired	$ 28,250