Stockholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands					3 Months Ended	6 Months Ended
	Jan. 25, 2023	Jan. 31, 2022	Jan. 26, 2022	Nov. 30, 2019	Mar. 31, 2023	Mar. 31, 2023	Mar. 31, 2024	Sep. 30, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares available for future grants	500,000
Stock compensation expense, before tax					$ 1,265
Total unrecognized compensation cost related to non-vested stock-based compensation arrangements					$ 26,750	$ 26,750
Forfeiture rate, Board of Directors					0.00%	0.00%
Forfeiture rate, non-Board of Directors					7.30%	7.30%
Unrecognized compensation cost is expected to be recognized over a weighted-average period						1 year 9 months 18 days
2017 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares available for future grants			800,000
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vested contractual term, in years						10 years
Vesting period, in years						4 years
Weighted-average exercise price					$ 100.49	$ 83.76
Stock Options [Member] | Share-based Compensation Award Tranche One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting rate						25.00%
2019 Authorization [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock repurchase program authorized amount				$ 500,000	$ 26,742	$ 26,742
Repurchase period in years				3 years
Stock repurchase program, number of shares authorized to be repurchased					233,000	233,000
2022 Authorization [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock repurchase program authorized amount		$ 800,000			$ 245,357	$ 245,357
Repurchase period in years		2 years
Stock repurchase program, number of shares authorized to be repurchased					2,047,000	2,047,000
2022 Authorization [Member] | Scenario Forecast [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock repurchase program authorized amount							$ 26,369
Stock repurchase program, number of shares authorized to be repurchased							274,000
2017 Authorization [Member] | 2017 Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future grants					2,709	2,709		2,938,000