Summary of Significant Accounting Policies - Shares Used in Computing Basic and Diluted Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Denominator (thousands of shares):
Weighted-average common shares outstanding - basic (in shares)	209,706	210,190	209,811	209,992
Incremental shares issuable for stock options, common stock awards and Equity Units (in shares)	0	0	0	5,973
Weighted-average common shares outstanding - diluted (in shares)	209,706	210,190	209,811	215,965
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	5,972	5,668	6,222
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)				5,718