Revenue Recognition - Schedule of Changes in Service-type Warranties (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Disaggregation of Revenue [Abstract]
Balance at beginning of period	$ 110.4	$ 96.0
Deferred revenue for new service warranties	12.4	10.3
Amortization of service warranty revenue	(9.4)	(9.8)
Foreign currency translation	(0.2)	0.5
Balance at end of period	$ 113.2	$ 97.0

Product warranty amortization.

No definition available.

Name:	osk_ProductWarrantyAmortization
Namespace Prefix:	osk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Amount as of the balance sheet date of the aggregate extended product warranty liability. Does not include the ending balance for the standard product warranty liability.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-8

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (c)(5)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-8

+ Details

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

- Definition

Amount of foreign currency translation gain (loss) which decreases (increases) the extended product warranty accrual. Excludes standard product warranties.

+ References

+ Details

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

- Definition

Amount of increase in the extended product warranty accrual from warranties issued. Excludes standard product warranties.

+ References

+ Details

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