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Represents the amount paid for offering expenses with the issuance of common stock.

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The common stock shares issued during the period.

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Represents the number of shares included in the public equity offering as a result of the exercise of the underwriters' over-allotment option.

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The cumulative number of shares that have been repurchased and are held in treasury.

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The cumulative equity impact of the cost of common stock repurchased. Recorded using the cost method.

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The cash inflow from the additional capital contribution to the entity.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

-Topic 230

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-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 18

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-Paragraph 19

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

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Oshkosh Corporation Shareholders' Equity (Details) (USD $) In Millions, except Share data	1 Months Ended	12 Months Ended
	Aug. 31, 2009	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009	Aug. 12, 2009	Jul. 31, 1995
Oshkosh Corporation Shareholders' Equity
Common stock issued under public equity offering (in shares)	14,950,000
Number of common shares included in public equity offering as a result of exercise of over-allotment option					1,950,000
Common stock issuance price (in dollars per share)					$ 25.00
Underwriting discounts and commissions	$ 15.1
Offering expenses	0.6
Net proceeds from public equity offering used to repay debt	358.1			358.1
Number of shares of common stock authorized for buyback (in shares)						6,000,000
Shares of common stock purchased (in shares)		2,769,210	2,769,210
Aggregate cost of common stock repurchased		$ 6.6	$ 6.6