CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Statement of Stockholders' Equity [Abstract]
Dividend declared per share (in dollars per share)	$ 0.40	$ 0.40	$ 0.40
Changes in unrealized gains (losses) on marketable securities, tax	$ (1)	$ 0	$ 0
Actuarial gain or loss arising in the year, tax	$ 13	$ (49)	$ (74)

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

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Amount of tax expense (benefit) before reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities.

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