Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Income Taxes
Statutory tax rate	35.00%	35.00%	35.00%
Deferred Tax Assets, Operating Loss Carryforwards, Foreign	$ 4,707	$ 5,255
Undistributed foreign earnings for which Woodward has not provided for taxes	405,286
Unrecognized Tax Benefits	20,132	23,526	$ 21,469	$ 22,687
Estimated decrease in liability for unrecognized tax benefits	7,726
Unrecognized tax benefits that, if recognized, would affect the effective tax rate	9,677	11,426
Accrued interest and penalties	$ 1,123	$ 1,273