Retirement Benefits (Schedule of Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan) (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Japan
Changes in fair value of plan assets:
Fair value of plan assets at end of year	$ 11,472
United Kingdom
Changes in fair value of plan assets:
Fair value of plan assets at end of year	52,105
Defined Benefit Pension Plan [Member]
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	253,517	$ 227,499
Plan amendments	601
Obligation assumed in L'Orange aquisition		39,257
Service cost	3,487	2,767	$ 2,808
Interest cost	8,290	7,530	6,965
Net actuarial losses (gains)	46,015	(13,511)
Contribution by participants	9	43
Benefits paid	(9,294)	(8,539)
Foreign currency exchange rate changes	(5,495)	(1,529)
Projected benefit obligation at end of year	297,130	253,517	227,499
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	227,722	224,712
Actual return on plan assets	16,448	12,034
Contributions by the Company	1,697	994
Contributions by plan participants	9	43
Benefits paid (plan assets)	(9,294)	(8,539)
Foreign currency exchange rate changes	(2,449)	(1,522)
Fair value of plan assets at end of year	234,133	227,722	224,712
Net (under)/over funded status at end of year	(62,997)	(25,795)
Defined Benefit Pension Plan [Member] \| United States [Member]
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	150,032	161,130
Plan amendments
Obligation assumed in L'Orange aquisition
Service cost	1,451	1,643	1,675
Interest cost	6,384	6,004	5,757
Net actuarial losses (gains)	23,841	(13,128)
Contribution by participants		34
Benefits paid	(6,113)	(5,651)
Foreign currency exchange rate changes
Projected benefit obligation at end of year	175,595	150,032	161,130
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	165,342	160,332
Actual return on plan assets	11,327	10,627
Contributions by the Company
Contributions by plan participants		34
Benefits paid (plan assets)	(6,113)	(5,651)
Foreign currency exchange rate changes
Fair value of plan assets at end of year	170,556	165,342	160,332
Net (under)/over funded status at end of year	(5,039)	15,310
Defined Benefit Pension Plan [Member] \| Other Countries [Member]
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	103,485	66,369
Plan amendments	601
Obligation assumed in L'Orange aquisition		39,257
Service cost	2,036	1,124	1,133
Interest cost	1,906	1,526	1,208
Net actuarial losses (gains)	22,174	(383)
Contribution by participants	9	9
Benefits paid	(3,181)	(2,888)
Foreign currency exchange rate changes	(5,495)	(1,529)
Projected benefit obligation at end of year	121,535	103,485	66,369
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	62,380	64,380
Actual return on plan assets	5,121	1,407
Contributions by the Company	1,697	994
Contributions by plan participants	9	9
Benefits paid (plan assets)	(3,181)	(2,888)
Foreign currency exchange rate changes	(2,449)	(1,522)
Fair value of plan assets at end of year	63,577	62,380	64,380
Net (under)/over funded status at end of year	(57,958)	(41,105)
Defined Benefit Pension Plan [Member] \| Japan
Changes in projected benefit obligation:
Projected benefit obligation at end of year	11,110
Defined Benefit Pension Plan [Member] \| United Kingdom
Changes in projected benefit obligation:
Plan amendments	601
Projected benefit obligation at end of year	58,494
Defined Benefit Pension Plan [Member] \| Germany [Member]
Changes in projected benefit obligation:
Projected benefit obligation at end of year	51,931
Other Postretirement Benefit Plans [Member]
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	27,985	32,252
Service cost	5	7	14
Interest cost	1,154	1,165	1,244
Net actuarial losses (gains)	(373)	(2,716)
Contribution by participants	1,192	1,311
Benefits paid	(3,292)	(3,707)
Curtailment (gain) loss		(330)
Foreign currency exchange rate changes		3
Projected benefit obligation at end of year	26,671	27,985	32,252
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year
Contributions by the Company	2,100	2,396
Contributions by plan participants	1,192	1,311
Benefits paid (plan assets)	(3,292)	(3,707)
Fair value of plan assets at end of year
Net (under)/over funded status at end of year	$ (26,671)	$ (27,985)

Amount of increase (decrease) in plan assets of defined benefit plan from actual return (loss) determined by change in fair value of plan assets adjusted for contributions, benefit payments, and other expenses.

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Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan.

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Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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Amount of payment to participant of defined benefit plan which decreases benefit obligation. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of contribution received by defined benefit plan from employer which increases plan assets.

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Amount of (increase) decrease in benefit obligation of defined benefit plan from event reducing expected years of future service of present employees or eliminating accrual of benefits for some or all future services of present employees.

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Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee.

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Amount of funded (unfunded) status of defined benefit plan, measured as difference between fair value of plan assets and benefit obligation. Includes, but is not limited to, overfunded (underfunded) status.

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Amount of cost recognized for passage of time related to defined benefit plan.

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