Summary of Significant Accounting Policies - Shares Used in Computing Basic and Diluted Earnings Per Share (Details) - shares	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Denominator (thousands of shares):
Weighted-average common shares outstanding - basic (in shares)	209,857,000	210,163,000	209,902,000	209,919,000
Incremental shares issuable for stock options, common stock awards and Equity Units (in shares)	6,263,000	5,765,000	0	6,017,000
Weighted-average common shares outstanding - diluted (in shares)	216,120,000	215,928,000	209,902,000	215,936,000
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)			6,348,000
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	5,980	6,535,000		6,535,000