Stockholders' Equity (Stock Options Vested, or Expected to Vest and Exercisable) (Details) - Stock Options [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options outstanding, Number of options	3,604	4,213	4,842
Options vested and exercisable, Number of options	2,703
Options vested and expected to vest, Number of options	3,575
Options outstanding, Weighted-Average Exercise Price	$ 85.77	$ 83.54	$ 80.48
Options vested and exercisable, Weighted-Average Exercise Price Per Share	81.8
Options vested and expected to vest, Weighted-Average Exercise Price Per Share	$ 85.61
Options outstanding, Weighted-Average Remaining Life in Years	5 years 6 months
Options vested and exercisable, Weighted-Average Remaining Life in Years	4 years 8 months 12 days
Options vested and expected to vest, Weighted-Average Remaining Life in Years	5 years 6 months
Options outstanding, Aggregate Intrinsic Value	$ 319,417
Options vested and exercisable, Aggregate Intrinsic Value	250,231
Options vested and expected to vest, Aggregate Intrinsic Value	$ 317,387