CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2021	Sep. 30, 2020
Foreign currency translation adjustments, taxes	$ 0	$ 0
Amortization of accumulated other comprehensive loss into net periodic benefit cost, taxes	0	0
Net actuarial gain (loss) arising during the period, taxes	0	0
Curtailment gain and gain on termination of post-retirement medical plan, taxes	0	0
Pension Plan And Supplemental Employee Retirement Plan
Curtailment gain and gain on termination of post-retirement medical plan, taxes	0	0
Post-retirement Medical
Curtailment gain and gain on termination of post-retirement medical plan, taxes	$ 0	$ 0

Amount of tax expense (benefit) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

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Amount of tax expense (benefit) for increase (decrease) to other comprehensive income from settlement and curtailment gain (loss) of defined benefit plan.

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Amount of tax expense (benefit), after reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

+ References

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Amount of tax (expense) benefit for reclassification adjustment from accumulated other comprehensive (income) loss of defined benefit plan.

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