Postretirement Benefits - Funded Status (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Benefit obligation	$ 11,915	$ 11,144	$ 3,565
Fair value of plan assets	6,574	7,078	$ 2,225
Unfunded projected benefit obligation	$ (5,341)	$ (4,066)

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

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- Definition

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.

+ References

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+ Details

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- Definition

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.

+ References

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- References

No definition available.

+ Details

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