Stockholders' Equity (Schedule of Assumptions Used in Estimate of Fair Value of Stock Option Awards) (Details) - Stock Options [Member] - $ / shares	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date market value of Woodward stock	$ 72.01	$ 69.45	$ 78.91	$ 69.45
Weighted-average exercise price per share	$ 72.01	$ 62.64	$ 78.91	$ 62.64
Estimated dividend yield	0.80%	0.70%		0.70%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term		6 years	6 years 4 months 24 days	6 years
Estimated volatility		31.50%	29.10%	31.50%
Estimated dividend yield			0.60%
Risk-free interest rate	2.70%	2.20%	2.10%	2.20%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term	6 years 4 months 24 days	8 years 8 months 12 days	8 years 8 months 12 days	8 years 8 months 12 days
Estimated volatility	29.10%	33.70%	32.70%	33.70%
Estimated dividend yield			0.80%
Risk-free interest rate	2.80%	2.50%	2.80%	2.50%