Note 9 - Stockholders' Equity (Tables)

6 Months Ended

Mar. 31, 2025

Notes Tables

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

				Unrealized
				Gains (Losses)
				on Available-						Pension
	Currency			for-Sale			​Gains (Losses)			Liability
	Translation			Securities			on Derivative			Adjustments
	Adjustments			Net of tax			Net of tax			Net of tax			Total
Balance at September 30, 2023	$	(88,448	)	$	(5,135	)	$	31,487		$	(330	)	$	(62,426	)
Other comprehensive income (loss) before reclassifications		25,725			3,276			(8,288	)		(61	)		20,652
Amounts reclassified from accumulated other comprehensive loss		—			—			—			46			46
Balance at March 31, 2024	$	(62,723	)	$	(1,859	)	$	23,199		$	(345	)	$	(41,728	)

				Unrealized
				Gains (Losses)
				on Available-						Pension
	Currency			for-Sale			​Gains (Losses)			Liability
	Translation			Securities			on Derivative			Adjustments
	Adjustments			Net of tax			Net of tax			Net of tax			Total
Balance at September 30, 2024	$	(34,170	)	$	(263	)	$	21,468		$	(499	)	$	(13,464	)
Other comprehensive income (loss) before reclassifications		(23,860	)		363			(5,088	)		(136	)		(28,721	)
Amounts reclassified from accumulated other comprehensive loss		—			—			—			36			36
Balance at March 31, 2025	$	(58,030	)	$	100		$	16,380		$	(599	)	$	(42,149	)