Quarterly report pursuant to Section 13 or 15(d)

Acquisitions (Details)

v3.19.2
Acquisitions (Details)
$ in Thousands, ¥ in Billions
3 Months Ended
Apr. 19, 2017
USD ($)
Rate
Apr. 19, 2017
JPY (¥)
Rate
Jun. 30, 2019
USD ($)
manufacturing_site
Jun. 30, 2018
USD ($)
Dec. 31, 2017
USD ($)
Rate
Dec. 31, 2017
JPY (¥)
Rate
Sep. 30, 2017
Rate
Apr. 14, 2017
USD ($)
Apr. 14, 2017
JPY (¥)
Mar. 31, 2017
Rate
Business Acquisition [Line Items]                    
Foreign Currency Exchange Rate, Translation | Rate 10900.70% 10900.70%     11257.40% 11257.40% 11250.20%     11182.30%
Equity income (loss) from equity method investments | $     $ (250) $ (69)            
Business Acquisition Cost of Acquired Entity Working Capital Adjustment         $ 0 ¥ 0.3        
KEC [Member] | TOKIN [Member]                    
Business Acquisition [Line Items]                    
Equity Method Investment, Ownership Percentage 100.00% 100.00%                
Business Acquisition, Percentage of Voting Interests Acquired 66.00% 66.00%                
Payments to Acquire Businesses, Gross $ 148,600 ¥ 16.2                
TOKIN [Member]                    
Business Acquisition [Line Items]                    
Number of Manufacturing Sites | manufacturing_site     6              
Disposal Group, Including Discontinued Operation, Consideration         $ 10,100 ¥ 1.1   $ 431,000 ¥ 48.2  
Stock Purchase Agreement [Member] | NEC TOKIN Corporation [Member] | KEMET Electronics Corporation [Member]                    
Business Acquisition [Line Items]                    
Equity Method Investment, Ownership Percentage     34.00%              
Excess cash [Member] | KEC [Member] | TOKIN [Member]                    
Business Acquisition [Line Items]                    
Payments to Acquire Businesses, Gross 93,600 10.2                
Cash Distribution [Member] | KEC [Member] | TOKIN [Member]                    
Business Acquisition [Line Items]                    
Payments to Acquire Businesses, Gross $ 55,000 ¥ 6.0