Percentage points added to the reference rate to compute the variable rate on the debt instrument.

No definition available.

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

+ References

No definition available.

+ Details

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

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of the amount outstanding under the credit facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13476-108611

+ Details

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

- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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

- Definition

The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585

+ Details

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

- Definition

Debt And Line Of Credit Facility [Line Items]

+ References

No definition available.

+ Details

Name:	wwd_DebtAndLineOfCreditFacilityLineItems
Namespace Prefix:	wwd_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The current portion of the amount outstanding under the credit facility. Amount is expected to be repaid in one year or the normal operating cycle, if longer.

+ References

No definition available.

+ Details

Name:	wwd_LineOfCreditFacilityAmountOutstandingCurrent
Namespace Prefix:	wwd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility that the borrower has the option to increase to subject to lenders' participation.

+ References

No definition available.

+ Details

Name:	wwd_LineOfCreditFacilityOptionToIncreaseMaximumBorrowingCapacity
Namespace Prefix:	wwd_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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

- Details

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

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
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Credit Facilities and Short-term Borrowings (Narrative) (Details) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2018	Jun. 30, 2018	Sep. 30, 2017
Debt And Line Of Credit Facility [Line Items]
Debt financing costs		$ 1,325,000
Foreign Lines of Credit And Overdraft Facilities [Member]
Debt And Line Of Credit Facility [Line Items]
Outstanding borrowings		3,769,000	$ 0
Revolving Credit Agreement [Member]
Debt And Line Of Credit Facility [Line Items]
Maximum borrowing capacity		1,000,000,000
Option to increase maximum borrowings to this amount		$ 1,200,000,000
Line of Credit Facility, Expiration Date		Apr. 01, 2020
Variable Rate Basis	LIBOR
Credit facility effective interest rate on outstanding borrowing		2.87%	2.29%
Outstanding borrowings		$ 374,574,000	$ 32,600,000
Current portion of outstanding borrowings		$ 140,231,000	$ 32,600,000
Minimum [Member] \| Revolving Credit Agreement [Member]
Debt And Line Of Credit Facility [Line Items]
Basis Spread On Variable Rate		0.85%
Maximum [Member] \| Revolving Credit Agreement [Member]
Debt And Line Of Credit Facility [Line Items]
Basis Spread On Variable Rate		1.65%