Financial Instruments and Fair Value Measurements (Financial Assets and Liabilities that are Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022
Financial assets:
Total financial assets	$ 58,862	$ 98,573
Investments in Banks and Financial Institutions [Member]
Financial assets:
Investments in term deposits with foreign banks	28,560	37,605
Equity Securities [Member]
Financial assets:
Equity securities	24,913	22,800
Cross Currency Interest Rate Swaps [Member]
Financial assets:
Cross currency interest rate swaps	5,389	38,168
Level 1 [Member]
Financial assets:
Total financial assets	53,473	60,405
Level 1 [Member] | Investments in Banks and Financial Institutions [Member]
Financial assets:
Investments in term deposits with foreign banks	28,560	37,605
Level 1 [Member] | Equity Securities [Member]
Financial assets:
Equity securities	24,913	22,800
Level 2 [Member]
Financial assets:
Total financial assets	5,389	38,168
Level 2 [Member] | Cross Currency Interest Rate Swaps [Member]
Financial assets:
Cross currency interest rate swaps	$ 5,389	$ 38,168