Fair Value Measurements (Tables)

6 Months Ended

Mar. 31, 2024

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

Financial assets (liabilities) measured at fair value on a recurring basis as of March 31, 2024 and September 30, 2023, are summarized in the following tables by the type of inputs applicable to the fair value measurements:

	March 31, 2024
			Total Fair Value		Quoted Prices (Level 1)		Significant Unobservable Inputs (Level 3)
Equity securities		$	13,048	$	13,048	$	—
Debt securities classified as trading securities			4,444		4,444		—
Executive savings plan assets			925		925		—
Executive savings plan liabilities			(793)		(793)		—
Total		$	17,624	$	17,624	$	—

	September 30, 2023
			Total Fair Value		Quoted Prices (Level 1)		Significant Unobservable Inputs (Level 3)
Executive savings plan assets		$	783	$	783	$	—
Executive savings plan liabilities			(657)		(657)		—
Contingent consideration liability			(4,465)		—		(4,465)
Total		$	(4,339)	$	126	$	(4,465)

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation

The table below presents the change in fair value of this obligation, which used significant unobservable inputs (Level 3). This obligation was settled during the six months ended March 31, 2024, and we did not have any other assets or liabilities measured using significant unobservable inputs at March 31, 2024.

	Contingent Consideration Agreements
Fair value at September 30, 2023	$	(4,465)
Net adjustments to fair value	(35)
Settlements	4,500
Fair value at March 31, 2024	$	—

Unrealized Gain (Loss) on Investments

Our unrealized net gains (losses), which are calculated as total net gains (losses) recognized during the period less net gains (losses) recognized on securities sold during the period, were as follows:

	Three Months Ended March 31,				Six Months Ended March 31,
	2024		2023		2024		2023
Unrealized loss on equity securities	$	(1,852)	$	—	$	(1,852)	$	—
Unrealized gain (loss) on debt securities	(57)		—		62		—
Total unrealized loss on trading securities	$	(1,909)	$	—	$	(1,790)	$	—