Organization and Significant Accounting Policies - Revenue Recognition (Details)	12 Months Ended
Mar. 31, 2020
Accounting Policies [Abstract]
Product warranty period	1 year

Represents the period of warranty that the entity's goods and services meet certain specifications. The entity provides these warranties to its customers.

No definition available.

Name:	kem_ProductWarrantyPeriod
Namespace Prefix:	kem_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration