| Document and Entity Information | Feb. 03, 2020 |
| Cover page. | |
| Document Type | 8-K |
| Document Period End Date | Feb. 3, 2020 |
| Entity Registrant Name | KEMET CORP |
| Entity Central Index Key | 0000887730 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-15491 |
| Entity Tax Identification Number | 57-0923789 |
| Entity Address, Address Line One | KEMET Tower, One East Broward Blvd. |
| Entity Address, City or Town | Fort Lauderdale |
| Entity Address, State or Province | FL |
| Entity Address, Postal Zip Code | 33301 |
| City Area Code | 954 |
| Local Phone Number | 766-2800 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.01 |
| Trading Symbol | KEM |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
