Stockholders' Equity (Tables)

12 Months Ended

Sep. 30, 2023

Stockholders' Equity Note [Abstract]

Summary of accumulated other comprehensive income (loss)

The following is a summary of the components of accumulated other comprehensive income (loss), net of tax, at September 30, 2023, 2022 and 2021 (in thousands):

			Unrealized
			Gains (Losses)
			on Available-
	Currency		for-Sale		Gains (Losses)		Pension
	Translation		Securities		on Derivative asset		Liability
	Adjustments		Net of tax		Net of tax		Adjustments		Total
Balance at September 30, 2020	$	23,061		(1)		—		(1,141)		21,919
Other comprehensive income (loss) before reclassifications		(2,922)		—		—		333		(2,589)
Amounts reclassified from accumulated other comprehensive income (loss)		—		—		—		21		21
Balance at September 30, 2021		20,139		(1)		—		(787)		19,351
Other comprehensive income (loss) before reclassifications		(169,266)		(10,908)		93,020		412		(86,742)
Amounts reclassified from accumulated other comprehensive income (loss)		(16,567)		—		—		42		(16,525)
Balance at September 30, 2022		(165,694)		(10,909)		93,020		(333)		(83,916)
Other comprehensive income (loss) before reclassifications		77,246		5,774		(61,533)		(104)		21,383
Amounts reclassified from accumulated other comprehensive income (loss)		—		—		—		107		107
Balance at September 30, 2023	$	(88,448)	$	(5,135)	$	31,487	$	(330)	$	(62,426)