Financial Instruments and Fair Value Measurements (Financial Assets that are Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Sep. 30, 2022
Financial assets:
Total financial assets	$ 75,626	$ 98,573
Cross Currency Interest Rate Swaps [Member]
Financial assets:
Cross-currency interest rate swaps	7,546	38,168
Level 1 [Member]
Financial assets:
Total financial assets	68,080	60,405
Level 2 [Member]
Financial assets:
Total financial assets	7,546	38,168
Level 2 [Member] | Cross Currency Interest Rate Swaps [Member]
Financial assets:
Cross-currency interest rate swaps	7,546	38,168
Investments in Term Deposits with Foreign Banks [Member]
Financial assets:
Investments	41,909	37,605
Investments in Term Deposits with Foreign Banks [Member] | Level 1 [Member]
Financial assets:
Investments	41,909	37,605
Equity Securities [Member]
Financial assets:
Equity securities	26,171	22,800
Equity Securities [Member] | Level 1 [Member]
Financial assets:
Equity securities	$ 26,171	$ 22,800