Capital Stock (Changes in Common Shares) (Details) - shares	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Changes in Common Shares [Roll Forward]
Balance, beginning of year (shares)	221,838,696	221,396,755	221,017,459
Issuance of treasury shares for stock option and award plans (shares)	361,149	441,941	379,296
Balance, end of year (shares)	222,199,845	221,838,696	221,396,755