Share-Based Compensation - Summary of Performance Share and Restricted Stock Unit Activity (Details) - $ / shares shares in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Performance shares
Shares (in thousands)
Outstanding at beginning of period (in shares)	119
Granted (in shares)	37
Adjustment for performance results achieved (in shares)	21
Vested and issued (in shares)	(68)	(31)	(28)
Forfeited (in shares)	(12)
Outstanding at end of period (in shares)	97	119
Wtd. Avg. Grant Date Share Fair Value
Outstanding at beginning of period (in dollars per share)	$ 232.94
Granted (in dollars per share)	481.28	$ 298.10	$ 265.04
Adjustment for performance results achieved (in dollars per share)	155.04
Vested and issued (in dollars per share)	155.04
Forfeited (in dollars per share)	316.27
Outstanding at end of period (in dollars per share)	$ 354.29	$ 232.94
Vesting period	3 years
Restricted stock and restricted stock units
Shares (in thousands)
Outstanding at beginning of period (in shares)	351
Granted (in shares)	252
Vested and issued (in shares)	(116)
Forfeited (in shares)	(39)
Outstanding at end of period (in shares)	448	351
Wtd. Avg. Grant Date Share Fair Value
Outstanding at beginning of period (in dollars per share)	$ 239.89
Granted (in dollars per share)	298.44	$ 265.32	$ 200.36
Vested and issued (in dollars per share)	231.97
Forfeited (in dollars per share)	275.08
Outstanding at end of period (in dollars per share)	$ 271.71	$ 239.89