Joint Venture (Narrative) (Details) - Woodward and General Electric Joint Venture [Member] - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Schedule Of Equity Method Investments [Line Items]
Agreement to Form Joint Venture, Execution Date			Jan. 04, 2016
Ownership interest, joint venture			50.00%
Cash received annually from formation of joint venture	$ 4,894	$ 4,894	$ 4,894
Other Liabilities [Member]
Schedule Of Equity Method Investments [Line Items]
Contract liabilities			70,618	$ 69,079
Reduction in contract liabilities and costs to fulfill contract			6,609	2,790
Other Assets [Member]
Schedule Of Equity Method Investments [Line Items]
Costs to fulfill a contract			70,618	69,079
Reduction in contract assets and costs to fulfill contract			6,261	2,774
Sales [Member]
Schedule Of Equity Method Investments [Line Items]
Amortization of deferred income recognized as an increase to sales			5,493	7,652	$ 5,854
Reduction to sales related to royalties owed to joint venture			$ 23,904	$ 34,236	$ 26,023