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, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Denominator (thousands of shares):
Weighted-average common shares outstanding - basic (in shares)	210,190	209,099	209,992	208,934
Incremental shares issuable for stock options, common stock awards and Equity Units (in shares)	0	1,752	5,973	1,260
Weighted-average common shares outstanding - diluted (in shares)	210,190	210,851	215,965	210,194
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	5,668
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	2,502	5,718	2,502