CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Statement of Stockholders' Equity [Abstract]
Dividend declared per share (in dollars per share)	$ 0.30	$ 0.30
Changes in unrealized gains (losses) on marketable securities, tax	$ 0	$ 0
Actuarial gain or loss arising in the year, tax	$ 4

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

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Amount, after reclassification adjustment, of tax (expense) benefit for (increase) decrease in accumulated other comprehensive income of defined benefit plan.

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Amount, before adjustment, of tax expense (benefit) for unrealized holding gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Excludes 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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