Revenue Recognition - Additional Information (Details 1) $ in Millions	Sep. 30, 2020 USD ($)
Disaggregation Of Revenue [Abstract]
Revenue, Remaining Performance Obligation, Amount	$ 3,900.0
Transaction price allocated to performance obligations to be satisfied during fiscal 2021	3,100.0
Transaction price allocated to performance obligations to be satisfied during fiscal 2022	649.1
Transaction price allocated to performance obligations to be satisfied beyond fiscal 2022	$ 159.6

Amount of transaction price allocated to performance obligations expected to be satisfied during subsequent fiscal year.

No definition available.

+ Details

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- Definition

Transaction price allocated to performance obligations expected to be satisfied beyond subsequent fiscal year.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Transaction price allocated to performance obligations to be satisfied during current fiscal year.

+ References

No definition available.

+ Details

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Namespace Prefix:	osk_
Data Type:	xbrli:monetaryItemType
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- References

No definition available.

+ Details

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- Definition

Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130556-203045

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