Derivative, Fixed Interest Rate, Payments

No definition available.

Name:	kem_DerivativeFixedInterestRatePayments
Namespace Prefix:	kem_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Derivative, Fixed Interest Rate, Receivable

+ References

No definition available.

+ Details

Name:	kem_DerivativeFixedInterestRateReceivable
Namespace Prefix:	kem_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The aggregate amount of recurring noncash expense charged against earnings in the period to allocate the cost of assets over their estimated remaining economic lives.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3602-108585

+ Details

Name:	us-gaap_AdjustmentForAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=112277219&loc=d3e80748-113994

+ Details

Name:	us-gaap_CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The percentage points added to the reference rate to compute the variable rate on the interest rate derivative.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeBasisSpreadOnVariableRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5579245-113959

+ Details

Name:	us-gaap_DerivativeNotionalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativesFairValueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash inflow from a financial contract that meets the hedge criteria as either cash flow hedge, fair value hedge or hedge of net investment in foreign operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 27
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3581-108585

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromHedgeFinancingActivities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CurrencySwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_CurrencyAxis=currency_MXN
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_FairValueHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_NetInvestmentHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=kem_CurrencySwapTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis=us-gaap_CashFlowHedgingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=kem_CurrencySwapOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=kem_JPYLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Derivatives - Narrative (Details) $ in Thousands, ¥ in Billions	9 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2019 JPY (¥)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 JPY (¥)	May 28, 2019 JPY (¥)	Mar. 31, 2019 USD ($)	Mar. 31, 2019 JPY (¥)	Nov. 07, 2018 JPY (¥)
Derivatives, Fair Value [Line Items]
Proceeds from Hedge, Financing Activities \| $	$ 6,476		$ 0
Currency Swap
Derivatives, Fair Value [Line Items]
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months \| $	(8,100)
Mexico, Pesos
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount \| $	94,700					$ 74,300
Fair Value Hedging \| Currency Swap
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	276,400			¥ 30.3		279,700	¥ 31.6
Net Investment Hedging \| Currency Swap Two
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount								¥ 33.0
Net Investment Hedging \| Currency Swap
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	$ 267,600			¥ 30.3		$ 279,700	¥ 31.6
Amortization		¥ 1.4
Derivative, fixed interest rate paid	2.61%			2.61%
Derivative, fixed interest rate received	6.25%			6.25%
Cash Flow Hedging [Member] \| Currency Swap One
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount					¥ 15.1
Derivative, fixed interest rate paid	4.88%			4.88%
Cash Flow Hedging [Member] \| Currency Swap Two
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount					¥ 16.5
Derivative, fixed interest rate paid	5.26%			5.26%
Cash Flow Hedging [Member] \| Currency Swap
Derivatives, Fair Value [Line Items]
Amortization		¥ 1.4
JPY LIBOR \| Cash Flow Hedging [Member] \| Currency Swap One
Derivatives, Fair Value [Line Items]
Derivative, basis spread on variable rate	2.00%			2.00%
JPY LIBOR \| Cash Flow Hedging [Member] \| Currency Swap Two
Derivatives, Fair Value [Line Items]
Derivative, basis spread on variable rate	2.25%			2.25%