Quarterly report pursuant to Section 13 or 15(d)

Equity Method Investments Narrative (Details)

v3.10.0.1
Equity Method Investments Narrative (Details) - USD ($)
$ in Thousands
Sep. 30, 2018
Mar. 31, 2018
Schedule of Equity Method Investments [Line Items]    
Equity Method Investments $ 12,215 $ 12,016
Novasentis [Member]    
Schedule of Equity Method Investments [Line Items]    
Equity Method Investment, Ownership Percentage 15.00%  
Equity Method Investments $ 2,351 2,870
Nippon Yttrium Co., Ltd (NYC) [Member]    
Schedule of Equity Method Investments [Line Items]    
Equity Method Investment, Ownership Percentage 30.00%  
Equity Method Investments $ 7,883 8,148
NT Sales Co., Ltd (NTS) [Member]    
Schedule of Equity Method Investments [Line Items]    
Equity Method Investment, Ownership Percentage 33.00%  
Equity Method Investments $ 1,052 998
KEMET Jianghai [Member]    
Schedule of Equity Method Investments [Line Items]    
Equity Method Investment, Ownership Percentage 50.00%  
Equity Method Investments $ 929 $ 0
NT Sales Co., Ltd (NTS) [Member] | TOKIN [Member] | Discontinued Operations, Disposed of by Sale [Member]    
Schedule of Equity Method Investments [Line Items]    
Equity Method Investment, Ownership Percentage 67.00%