Stockholders' Equity (Tables)

6 Months Ended

Mar. 31, 2025

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Summary of Activity in Common Stock and Treasury Stock Shares

Activity in common stock and treasury stock shares were as follows:

	Common Stock		Treasury Stock			Treasury stock held for deferred compensation
Balances as of January 1, 2024		72,960		(12,823	)		(54	)
Sales of treasury stock		—		479			—
Common shares issued for benefit plans		—		159			—
Purchases of stock by deferred compensation		—		—			—
Distribution of stock from deferred compensation		—		—			1
Balances as of March 31, 2024		72,960		(12,185	)		(53	)
Balances as of January 1, 2025		72,960		(13,607	)		(31	)
Sales of treasury stock		—		344			—
Purchase of treasury stock		—		(243	)		—
Common shares issued for benefit plans		—		126			—
Purchases of stock by deferred compensation		—		—			—
Distribution of stock from deferred compensation		—		—			1
Balances as of March 31, 2025		72,960		(13,380	)		(30	)

	Common Stock		Treasury Stock			Treasury stock held for deferred compensation
Balances as of September 30, 2023		72,960		(13,070	)		(55	)
Sales of treasury stock		—		726			—
Common shares issued for benefit plans		—		159			—
Purchases of stock by deferred compensation		—		—			(1	)
Distribution of stock from deferred compensation		—		—			3
Balances as of March 31, 2024		72,960		(12,185	)		(53	)
Balances as of September 30, 2024		72,960		(13,787	)		(45	)
Sales of treasury stock		—		725			—
Purchase of treasury stock		—		(449	)		—
Common shares issued for benefit plans		—		131			—
Purchases of stock by deferred compensation		—		—			(1	)
Distribution of stock from deferred compensation		—		—			16
Balances as of March 31, 2025		72,960		(13,380	)		(30	)

Summary of Activity for RSUs

A summary of the activity for RSUs:

	Three Months Ended March 31, 2025					Six Months Ended March 31, 2025
	Number of units			Weighted-Average Grant Date Fair Value		Number of units			Weighted-Average Grant Date Fair Value
Beginning balance		303		$	122.07		318		$	118.19
Granted		101			193.09		113			191.08
Released		(51	)		137.63		(77	)		125.32
Forfeited		(3	)		144.37		(4	)		126.88
Ending balance		350		$	140.11		350		$	140.11

Stock Options [Member]

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Summary of Activity for Stock Option Awards

The following is a summary of the activity for stock option awards:

	Three Months Ended March 31, 2025					Six Months Ended March 31, 2025
	Number of options			Weighted-Average Exercise Price per Share		Number of options			Weighted-Average Exercise Price per Share
Beginning balance		3,220		$	86.54		3,578		$	86.03
Granted		38			193.09		41			191.45
Exercised		(298	)		73.59		(659	)		78.24
Forfeited		(4	)		108.31		(4	)		108.31
Ending balance		2,956		$	89.20		2,956		$	89.20

Changes in Non-vested Stock Options

Changes in non-vested stock options were as follows:

	Three Months Ended March 31, 2025					Six Months Ended March 31, 2025
	Number of options			Weighted-Average Grant Date Fair Value per Share		Number of options			Weighted-Average Grant Date Fair Value Per Share
Beginning balance		495		$	40.62		898		$	37.30
Granted		38			84.13		41			83.65
Vested		(28	)		50.20		(434	)		34.62
Forfeited		(4	)		44.31		(4	)		44.31
Ending balance		501		$	43.35		501		$	43.35

Stock Options Vested, or Expected to Vest and Exercisable

Information about stock options that have vested, or are expected to vest, and are exercisable at March 31, 2025 was as follows:

	Number of options		Weighted-Average Exercise Price		Weighted-Average Remaining Life in Years		Aggregate Intrinsic Value
Options outstanding		2,956	$	89.20		5.1	$	276,144
Options vested and exercisable		2,455		85.34		4.6		238,491
Options vested and expected to vest		2,938		88.96		5.1		275,121

Performance Restricted Stock Units [Member]

Share Based Compensation Arrangement By Share Based Payment Award [Line Items]

Schedule of Assumptions to Value PSUs Granted

The fair value of the PSUs at the grant date was determined based upon a Monte Carlo valuation method. The assumptions used in the Monte Carlo method to value the PSUs granted, which includes the grant date fair value outcome from the Monte Carlo method, were as follows:

	March 31, 2025			March 31, 2024
Expected volatility		30.9	%		30.2	%
Risk free interest rate		4.1	%		4.5	%
Expected life	3 years			3 years
Grant date fair value	$	196.63		$	146.47

Summary of Activity for PSUs

A summary of the activity for PSUs:

	Three Months Ended March 31, 2025					Six Months Ended March 31, 2025
	Number of units			Weighted-Average Grant Date Fair Value		Number of units			Weighted-Average Grant Date Fair Value
Beginning balance		106		$	167.31		62		$	146.47
Granted		—			—		44			196.63
Forfeited		(1	)		173.87		(1	)		171.60
Ending balance		105		$	167.25		105		$	167.25