Acquisition - SPG Purchase Price Allocation (Details) - USD ($) $ in Thousands	Jun. 25, 2018	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition
Goodwill		$ 550,202		$ 359,688	$ 345,269
SPG acquisition member
Business Acquisition
Trade accounts and notes receivable, net		19,173	$ 15,805
Inventories, net	$ 42,758	42,758	46,073
Other current assets		1,322	424
Property, plant and equipment, net	6,653	6,653	7,345
Identifiable intangible assets	150,430	150,430	178,220
Deferred tax asset		831	0
Other noncurrent assets		12	398
Current liabilities		(26,473)	(26,196)
Deferred tax liabilities		(35,533)	(42,110)
Other noncurrent liabilities		(1,412)	(1,006)
Net Assets Acquired		157,761	178,953
Goodwill	$ 183,729	183,729	162,251
Total Purchase Price		$ 341,490	$ 341,204
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years
Developed Technology | SPG acquisition member
Business Acquisition
Identifiable intangible assets	$ 20,070
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	8 years
Trademarks and Trade names | SPG acquisition member
Business Acquisition
Identifiable intangible assets	$ 6,670
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	12 years
Customer Relationships | SPG acquisition member
Business Acquisition
Identifiable intangible assets	$ 107,790
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	12 years
Other | SPG acquisition member
Business Acquisition
Identifiable intangible assets	$ 15,900
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	11 months