Stockholders' Equity (Stock Options Vested, or Expected to Vest and Exercisable) (Details) - Stock Options [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
	Mar. 31, 2025	Dec. 31, 2024	Sep. 30, 2024
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding, Number of options	2,956	3,220	3,578
Options vested and exercisable, Number of options	2,455
Options vested and expected to vest, Number of options	2,938
Options outstanding, Weighted-Average Exercise Price	$ 89.2	$ 86.54	$ 86.03
Options vested and exercisable, Weighted-Average Exercise Price Per Share	85.34
Options vested and expected to vest, Weighted-Average Exercise Price Per Share	$ 88.96
Options outstanding, Weighted-Average Remaining Life in Years	5 years 1 month 6 days
Options vested and exercisable, Weighted-Average Remaining Life in Years	4 years 7 months 6 days
Options vested and expected to vest, Weighted-Average Remaining Life in Years	5 years 1 month 6 days
Options outstanding, Aggregate Intrinsic Value	$ 276,144
Options vested and exercisable, Aggregate Intrinsic Value	238,491
Options vested and expected to vest, Aggregate Intrinsic Value	$ 275,121