Quarterly report pursuant to Section 13 or 15(d)

Acquisitions - Schedule of Assets Acquired and Liabilities Assumed. High Power Acquisition (Details)

v3.10.0.1
Acquisitions - Schedule of Assets Acquired and Liabilities Assumed. High Power Acquisition (Details) - USD ($)
$ in Thousands
Jun. 30, 2018
Dec. 31, 2017
Apr. 21, 2017
Dec. 31, 2016
Business Acquisition [Line Items]        
Goodwill $ 101,511 $ 99,811   $ 88,727
Higher Power        
Business Acquisition [Line Items]        
Property, plant and equipment     $ 1,744  
Goodwill     643  
Total assets acquired     4,000  
Customer relationships | Higher Power        
Business Acquisition [Line Items]        
Identifiable intangible assets - customer relationships     $ 1,613