CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Statement of Stockholders' Equity [Abstract]
Dividend declared per share (in dollars per share)	$ 0.10	$ 0.40	$ 0.40
Unrealized gain on derivative asset	$ 31,769
Unrealized loss on marketable securities, tax	(3,729)	$ 0	$ 0
Actuarial gains (losses)	$ (121)	$ (77)	$ 27

Aggregate dividends declared during the period for each share of common stock outstanding.

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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), before 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.

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Amount, after adjustment, of tax expense (benefit) for unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) and tax expense (benefit) for unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale.

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