Line of Credit Facility, Borrowing Capacity, Increase (Decrease)

No definition available.

Name:	kmt_LineOfCreditFacilityBorrowingCapacityIncreaseDecrease
Namespace Prefix:	kmt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value amount of debt instrument that was repurchased.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentRepurchaseAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

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

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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+ Details

Name:	us-gaap_LongTermDebtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash inflow from a borrowing with the highest claim on the assets of the entity in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle, if longer).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
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-SubTopic 10
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+ Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=kmt_FivePointEightPercentSeniorUnsecuredNotesDueInTwoThousandAndThirtySixMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=kmt_FourPointSixTwoFivePercentSeniorUnsecuredNotesDueInTwoThousandAndTwentyEightMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=kmt_TwentyEighteenCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=kmt_TwoPointEightPercentSeniorUnsecuredNotesDueInTwoThousandAndThirtyOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Long -Term Debt - Narrative (Details) - USD ($) $ in Millions	1 Months Ended
	May 31, 2026	Feb. 28, 2021	Sep. 30, 2026	Jun. 30, 2026	May 31, 2025
Line of Credit Facility [Line Items]
Long-term debt, fair value			$ 551.0	$ 666.7
Senior Notes \| 5.800% Senior Unsecured Notes due fiscal 2036
Line of Credit Facility [Line Items]
Proceeds from issuance of senior long-term debt	$ 300.0
Interest rate, stated percentage					5.80%
Senior Notes \| 4.625% Senior Unsecured Notes due fiscal 2028
Line of Credit Facility [Line Items]
Interest rate, stated percentage					4.625%
Debt instrument, repurchase amount					$ 209.4
Debt instrument, face amount					300.0
Senior Notes \| Twenty Eighteen Credit Agreement
Line of Credit Facility [Line Items]
Increase in borrowing capacity					200.0
Senior Notes \| 2.800% Senior Unsecured Notes due fiscal 2031
Line of Credit Facility [Line Items]
Proceeds from issuance of senior long-term debt		$ 300.0
Interest rate, stated percentage		2.80%
Line of Credit \| Twenty Eighteen Credit Agreement \| Secured Debt
Line of Credit Facility [Line Items]
Long-term debt, gross					$ 500.0