Retirement benefits (Tables)

12 Months Ended

Sep. 30, 2020

Defined Benefit Plan Disclosure [Line Items]

Schedule of Amount of Expense Associated with Defined Contribution Plans

The amount of expense associated with defined contribution plans was as follows:

	Year Ended September 30,
	2020		2019		2018
Company costs	$	33,769	$	35,510	$	34,084

Defined Benefit Pension Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Net Periodic Benefit Costs

Net periodic benefit costs consist of the following components reflected as expense in Woodward’s Consolidated Statement of Earnings:

	Year Ended September 30,
	United States									Other Countries									Total
	2020			2019			2018			2020			2019			2018			2020			2019			2018
Service cost	$	1,659		$	1,451		$	1,643		$	2,865		$	2,036		$	1,124		$	4,524		$	3,487		$	2,767
Interest cost		5,590			6,384			6,004			1,278			1,906			1,526			6,868			8,290			7,530
Expected return on plan assets		(12,346	)		(11,986	)		(11,614	)		(2,827	)		(2,638	)		(2,780	)		(15,173	)		(14,624	)		(14,394	)
Amortization of:
Net losses		1,430			617			598			1,046			283			291			2,476			900			889
Net prior service cost		936			709			709			23			—			—			959			709			709
Net periodic (benefit) cost	$	(2,731	)	$	(2,825	)	$	(2,660	)	$	2,385		$	1,587		$	161		$	(346	)	$	(1,238	)	$	(2,499	)

Schedule of Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan

The following tables provide a reconciliation of the changes in the projected benefit obligation and fair value of assets for the defined benefit pension plans:

	At or for the Year Ended September 30,
	United States						Other Countries						Total
	2020			2019			2020			2019			2020			2019
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	$	175,595		$	150,032		$	121,535		$	103,485		$	297,130		$	253,517
Plan amendment		—			—			—			601			—			601
Service cost		1,659			1,451			2,865			2,036			4,524			3,487
Interest cost		5,590			6,384			1,278			1,906			6,868			8,290
Net actuarial losses (gains)		7,811			23,841			(4,841	)		22,174			2,970			46,015
Contribution by participants		91			—			9			9			100			9
Benefits paid		(6,669	)		(6,113	)		(3,434	)		(3,181	)		(10,103	)		(9,294	)
Settlements		—			—			(476	)		—			(476	)		—
Foreign currency exchange rate changes		—			—			6,610			(5,495	)		6,610			(5,495	)
Projected benefit obligation at end of year	$	184,077		$	175,595		$	123,546		$	121,535		$	307,623		$	297,130
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	$	170,556		$	165,342		$	63,577		$	62,380		$	234,133		$	227,722
Actual return on plan assets		37,577			11,327			576			5,121			38,153			16,448
Contributions by the Company		—			—			2,272			1,697			2,272			1,697
Contributions by plan participants		91			—			9			9			100			9
Benefits paid		(6,669	)		(6,113	)		(3,434	)		(3,181	)		(10,103	)		(9,294	)
Settlements		—						(476	)					(476	)		—
Foreign currency exchange rate changes		—			—			2,630			(2,449	)		2,630			(2,449	)
Fair value of plan assets at end of year	$	201,555		$	170,556		$	65,154		$	63,577		$	266,709		$	234,133
Net over/(under) funded status at end of year	$	17,478		$	(5,039	)	$	(58,392	)	$	(57,958	)	$	(40,914	)	$	(62,997	)

Schedule of Accumulated Benefit Obligations In Excess of and Less Than Fair Value of Plan Assets

	Plans with accumulated benefit obligation in excess of plan assets						Plans with accumulated benefit obligation less than plan assets
	At September 30,						At September 30,
	2020			2019			2020			2019
Projected benefit obligation	$	(141,561	)	$	(286,495	)	$	(166,062	)	$	(10,635	)
Accumulated benefit obligation		(140,623	)		(284,368	)		(165,321	)		(9,605	)
Fair value of plan assets		79,963			222,661			186,746			11,472

Schedule of Amounts Recognized in Balance Sheet and Other Comprehensive Income (Loss)

The following tables provide the amounts recognized in the statement of financial position and accumulated other comprehensive losses for the defined benefit pension plans:

	Year Ended September 30,
	United States						Other Countries						Total
	2020			2019			2020			2019			2020			2019
Amounts recognized in statement of financial position consist of:
Other non-current assets	$	19,064		$	—		$	1,476		$	838		$	20,540		$	838
Accrued liabilities		—			—			(1,059	)		(1,539	)		(1,059	)		(1,539	)
Other non-current liabilities		(1,586	)		(5,039	)		(58,809	)		(57,256	)		(60,395	)		(62,295	)
Net over/(under) funded status at end of year	$	17,478		$	(5,039	)	$	(58,392	)	$	(57,957	)	$	(40,914	)	$	(62,996	)
Amounts recognized in accumulated other comprehensive income consist of:
Unrecognized net prior service cost	$	4,814		$	5,750		$	583		$	579		$	5,397		$	6,329
Unrecognized net losses		9,317			28,167			30,794			32,641			40,111			60,808
Total amounts recognized		14,131			33,917			31,377			33,220			45,508			67,137
Deferred taxes		(6,721	)		(11,577	)		(9,457	)		(10,029	)		(16,178	)		(21,606	)
Amounts recognized in accumulated other comprehensive income	$	7,410		$	22,340		$	21,920		$	23,191		$	29,330		$	45,531

Schedule of Changes in Plan Assets and Benefit Obligations Recorded in Other Comprehensive Income (Loss)

The following table reconciles the changes in accumulated other comprehensive losses for the defined benefit pension plans:

	Year Ended September 30,
	United States						Other Countries						Total
	2020			2019			2020			2019			2020			2019
Accumulated other comprehensive losses at beginning of year	$	33,917		$	10,744		$	33,220		$	14,529		$	67,137		$	25,273
Net (gain) loss		(17,420	)		24,499			(2,446	)		19,691			(19,866	)		44,190
Prior service cost due to plan amendment		—			—			—			601			—			601
Amortization of:
Net losses		(1,430	)		(617	)		(1,046	)		(283	)		(2,476	)		(900	)
Prior service cost		(936	)		(709	)		(23	)		—			(959	)		(709	)
Foreign currency exchange rate changes		—			—			1,672			(1,318	)		1,672			(1,318	)
Accumulated other comprehensive losses at end of year	$	14,131		$	33,917		$	31,377		$	33,220		$	45,508		$	67,137

Schedule of Expected Benefit Payments

Pension benefit payments are made from the assets of the pension plans.  The German pension plans are unfunded; therefore, benefit payments are made from Company contributions into these plans as required to meet the payment obligations.  Using foreign exchange rates as of September 30, 2020 and expected future service assumptions, it is anticipated that the future benefit payments will be as follows:

Year Ending September 30,	United States		Other Countries		Total
2021	$	7,650	$	3,493	$	11,143
2022		8,280		3,347		11,627
2023		8,809		3,952		12,761
2024		9,283		3,841		13,124
2025		9,647		3,792		13,439
2026 – 2030		51,942		20,898		72,840

Schedule of Allocation of Plan Assets, Actual and Target Allocations

The asset allocations are monitored and rebalanced regularly by investment managers assigned to the individual pension plans.  The actual allocations of pension plan assets and target allocation ranges by asset class, are as follows:

	At September 30,
	2020									2019
	Percentage of Plan Assets			Target Allocation Ranges						Percentage of Plan Assets			Target Allocation Ranges
United States:
Asset Class
Equity Securities		64.4	%		41.7	%	—	81.7	%		60.6	%		41.4	%	—	81.4	%
Debt Securities		35.0	%		28.3	%	—	48.3	%		37.9	%		28.6	%	—	48.6	%
Other		0.6	%	0.0%							1.5	%	0.0%
		100.0	%								100.0	%
United Kingdom:
Asset Class
Equity Securities		39.6	%		50.0	%	—	90.0	%		41.6	%		30.0	%	—	60.0	%
Debt Securities		60.1	%		45.0	%	—	70.0	%		57.8	%		45.0	%	—	70.0	%
Other		0.3	%	0.0%							0.6	%	0.0%
		100.0	%								100.0	%
Japan:
Asset Class
Equity Securities		39.7	%		36.0	%	—	44.0	%		41.4	%		36.0	%	—	44.0	%
Debt Securities		59.4	%		55.0	%	—	63.0	%		57.7	%		55.0	%	—	63.0	%
Other		0.9	%		0.0	%	—	2.0	%		0.9	%		0.0	%	—	2.0	%
		100.0	%								100.0	%

Schedule of Allocation of Plan Assets, Fair Value Hierarchy

The following table presents Woodward’s pension plan assets using the fair value hierarchy established by U.S. GAAP as of September 30, 2020 and September 30, 2019.

	At September 30, 2020
	Level 1				Level 2				Level 3
	United States		Other Countries		United States		Other Countries		United States		Other Countries		Total
Asset Category:
Cash and cash equivalents	$	1,115	$	270	$	—	$	—	$	—	$	—	$	1,385
Mutual funds:
U.S. corporate bond fund		70,492		—		—		—		—		—		70,492
U.S. equity large cap fund		65,025		—		—		—		—		—		65,025
International equity large cap growth fund		64,923		—		—		—		—		—		64,923
Pooled funds:
Japanese equity securities		—		—		—		2,470		—		—		2,470
International equity securities		—		—		—		2,135		—		—		2,135
Japanese fixed income securities		—		—		—		5,151		—		—		5,151
International fixed income securities		—		—		—		1,734		—		—		1,734
Global target return equity/bond fund		—		—		—		13,002		—		—		13,002
Index linked U.K. equity fund		—		—		—		2,878		—		—		2,878
Index linked international equity fund		—		—		—		5,351		—		—		5,351
Index linked U.K. corporate bonds fund		—		—		—		18,055		—		—		18,055
Index linked U.K. government securities fund		—		—		—		5,767		—		—		5,767
Index linked U.K. long-term government securities fund		—		—		—		8,341		—		—		8,341
Total assets	$	201,555	$	270	$	—	$	64,884	$	—	$	—	$	266,709

	At September 30, 2019
	Level 1				Level 2				Level 3
	United States		Other Countries		United States		Other Countries		United States		Other Countries		Total
Asset Category:
Cash and cash equivalents	$	2,568	$	418	$	—	$	—	$	—	$	—	$	2,986
Mutual funds:
U.S. corporate bond fund		64,514		—		—		—		—		—		64,514
U.S. equity large cap fund		56,829		—		—		—		—		—		56,829
International equity large cap growth fund		46,645		—		—		—		—		—		46,645
Pooled funds:
Japanese equity securities		—		—		—		2,518		—		—		2,518
International equity securities		—		—		—		2,226		—		—		2,226
Japanese fixed income securities		—		—		—		4,915		—		—		4,915
International fixed income securities		—		—		—		1,710		—		—		1,710
Global target return equity/bond fund		—		—		—		12,488		—		—		12,488
Index linked U.K. equity fund		—		—		—		3,738		—		—		3,738
Index linked international equity fund		—		—		—		5,438		—		—		5,438
Index linked U.K. corporate bonds fund		—		—		—		16,737		—		—		16,737
Index linked U.K. government securities fund		—		—		—		5,491		—		—		5,491
Index linked U.K. long-term government securities fund		—		—		—		7,898		—		—		7,898
Total assets	$	170,556	$	418	$	—	$	63,159	$	—	$	—	$	234,133

Other Postretirement Benefit Plans [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Actuarial Assumptions Used

The actuarial assumptions used in measuring the net periodic benefit cost and plan obligations of postretirement benefits were as follows:

	2020			2019			2018
Weighted-average discount rate used to determine benefit obligation at September 30		2.45	%		3.05	%		4.30	%
Weighted-average discount rate used to determine net periodic benefit cost for years ended September 30		3.05			4.30			3.80

Schedule of Net Periodic Benefit Costs

Net periodic benefit costs consist of the following components reflected as expense in Woodward’s Consolidated Statements of Earnings:

	Year Ended September 30,
	2020		2019			2018
Service cost	$	2	$	5		$	7
Interest cost		782		1,154			1,165
Amortization of:
Net losses		47		55			94
Net prior service cost (benefit)		3		(5	)		(158	)
Curtailment gain		—		—			(330	)
Net periodic cost	$	834	$	1,209		$	778

Schedule of Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan

The following table provides a reconciliation of the changes in the accumulated postretirement benefit obligation and fair value of assets for the postretirement benefits for the fiscal years ended September 30:

	Year Ended September 30,
	2020			2019
Changes in accumulated postretirement benefit obligation:
Accumulated postretirement benefit obligation at beginning of year	$	26,671		$	27,985
Service cost		2			5
Interest cost		782			1,154
Premiums paid by plan participants		1,088			1,192
Net actuarial gains		(313	)		(373	)
Benefits paid		(2,785	)		(3,292	)
Accumulated postretirement benefit obligation at end of year	$	25,445		$	26,671
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	$	—		$	—
Contributions by the company		1,697			2,100
Premiums paid by plan participants		1,088			1,192
Benefits paid		(2,785	)		(3,292	)
Fair value of plan assets at end of year	$	—		$	—
Funded status at end of year	$	(25,445	)	$	(26,671	)

Schedule of Amounts Recognized in Balance Sheet and Other Comprehensive Income (Loss)

The following tables provide the amounts recognized in the statement of financial position and accumulated other comprehensive losses for the postretirement plans:

	Year Ended September 30,
	2020			2019
Amounts recognized in statement of financial position consist of:
Accrued liabilities	$	(1,992	)	$	(2,048	)
Other non-current liabilities		(23,453	)		(24,623	)
Funded status at end of year	$	(25,445	)	$	(26,671	)
Amounts recognized in accumulated other comprehensive income consist of:
Unrecognized net prior service cost (benefit)	$	1		$	4
Unrecognized net gains		(363	)		(3	)
Total amounts recognized		(362	)		1
Deferred taxes		(324	)		(414	)
Amounts recognized in accumulated other comprehensive income	$	(686	)	$	(413	)

Schedule of Changes in Plan Assets and Benefit Obligations Recorded in Other Comprehensive Income (Loss)

The following table reconciles the changes in accumulated other comprehensive losses for the other postretirement benefit plans:

	Year Ended September 30,
	2020			2019
Accumulated other comprehensive losses at beginning of year	$	1		$	424
Net gain		(313	)		(373	)
Curtailment arising during the period		—			—
Amortization of:
Net losses		(47	)		(55	)
Prior service (cost) benefit		(3	)		5
Accumulated other comprehensive losses at end of year	$	(362	)	$	1

Schedule of Health Care Cost Trend Rates

Assumed healthcare cost trend rates at September 30, were as follows:

	2020			2019
Health care cost trend rate assumed for next year		6.00	%		6.25	%
Rate to which the cost trend rate is assumed to decline
(the ultimate trend rate)		5.00	%		5.00	%
Year that the rate reaches the ultimate trend rate	2025			2025

Schedule of Future Postretirement Company Contributions

Using foreign currency exchange rates as of September 30, 2020 and expected future service, it is anticipated that the future Company contributions to pay benefits, excluding participate contributions, will be as follows:

Year Ending September 30,
2021	$	3,113
2022		3,078
2023		3,017
2024		2,949
2025		2,867
2026 – 2030		12,690

Multiemployer Defined Benefit Plan

Defined Benefit Plan Disclosure [Line Items]

Schedule of Amounts of Contributions Associated with Multiemployer Defined Benefit Plans

The amounts of contributions associated with the multiemployer defined benefit plans were as follows:

	Year Ended September 30,
	2020		2019		2018
Company contributions	$	417	$	252	$	334

United States [Member] | Defined Benefit Pension Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Actuarial Assumptions Used

The actuarial assumptions used in measuring the net periodic benefit cost and plan obligations of retirement pension benefits were as follows:

	2020		2019		2018
United States:
Weighted-average assumptions to determine benefit obligation at September 30:
Discount rate	2.75%		3.25%		4.35%
Weighted-average assumptions to determine periodic benefit costs for years ended September 30:
Discount rate		3.25		4.35		3.80
Long-term rate of return on plan assets		7.39		7.39		7.39

United Kingdom | Defined Benefit Pension Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Actuarial Assumptions Used

	2020		2019		2018
United Kingdom:
Weighted-average assumptions to determine benefit obligation at September 30:
Discount rate	1.62%		1.74%		2.68%
Rate of compensation increase		3.30		3.50		3.60
Weighted-average assumptions to determine periodic benefit costs for years ended September 30:
Discount rate - service cost		1.79		2.70		2.58
Discount rate - interest cost		1.59		2.51		2.36
Rate of compensation increase		3.50		3.60		3.60
Long-term rate of return on plan assets		4.75		4.75		4.75

Japan | Defined Benefit Pension Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Actuarial Assumptions Used

	2020		2019		2018
Japan:
Weighted-average assumptions to determine benefit obligation at September 30:
Discount rate	1.10%		0.53%		0.62%
Rate of compensation increase		2.00		2.00		2.00
Weighted-average assumptions to determine periodic benefit costs for years ended September 30:
Discount rate - service cost		0.72		0.80		0.72
Discount rate - interest cost		0.31		0.42		0.38
Rate of compensation increase		2.00		2.00		2.00
Long-term rate of return on plan assets		2.50		2.50		2.50

Germany [Member] | Defined Benefit Pension Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Actuarial Assumptions Used

	2020		2019		2018
Germany:
Weighted-average assumptions to determine benefit obligation at September 30:
Discount rate	0.97%		0.81%		1.87%
Rate of compensation increase		2.50		2.50		2.50
Weighted-average assumptions to determine periodic benefit costs for years ended September 30:
Discount rate - service cost		1.01		2.06		2.05
Discount rate - interest cost		0.56		1.53		1.49
Rate of compensation increase		2.50		2.50		2.50