Equity Method Investments - Reconciliation (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Mar. 31, 2018
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 12,925	$ 12,016
Nippon Yttrium Co., Ltd (NYC)
Schedule of Equity Method Investments [Line Items]
Equity method investments	8,215	8,148
NT Sales Co., Ltd (NTS)
Schedule of Equity Method Investments [Line Items]
Equity method investments	1,218	998
Novasentis
Schedule of Equity Method Investments [Line Items]
Equity method investments	977	2,870
KEMET Jianghai [Member]
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 2,515	$ 0