Stock-Based Compensation (Options and Common Shares Reserved for Grant) (Details) - Stock Options $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Jun. 30, 2023 USD ($) $ / shares shares
Options Outstanding [Roll Forward]
Options Outstanding, Beginning Balance (in shares) | shares	1,790
Options Outstanding, Granted (in shares) | shares	66
Options Outstanding, Exercised (in shares) | shares	(182)
Options Outstanding, Forfeited / Canceled (in shares) | shares	(34)
Options Outstanding, Ending Balance (in shares) | shares	1,640
Options Outstanding, Exercisable (in shares) | shares	1,046
Weighted Average Exercise Price [Roll Forward]
Weighted Average Exercise Price, Beginning Balance	$ 17.29
Weighted Average Exercise Price, Granted	40.63
Weighted Average Exercise Price, Exercised	22.77
Weighted Average Exercise Price, Forfeited / Canceled	20.76
Weighted Average Exercise Price, Ending Balance	18.43
Weighted Average Exercise Price, Exercisable	$ 15.99
Weighted Average Remaining Contractual Term [Abstract]
Weighted Average Remaining Contractual Term, Outstanding	4 years 1 month 6 days
Weighted Average Remaining Contractual Term, Exercisable	3 years 6 months
Aggregate Intrinsic Value, Outstanding | $	$ 34,471	[1]
Aggregate Intrinsic Value, Exercisable | $	$ 24,481	[1]
Closing Stock Price	$ 39.39

[1] The aggregate intrinsic value represents the total pre-tax intrinsic value, based on our closing stock price of $39.39 as of June 30, 2023, which would have been received by the option holders had all option holders exercised their options as of that date. 14. STOCK-BASED COMPENSATION (CONTINUED)The intrinsic value of an option is the amount by which the fair value of the underlying stock exceeds its exercise price.