Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net Income (Loss) Attributable to Parent	$ 791.8	$ 431.3
Denominator:
Denominator for basic earnings per share — weighted average common shares	364.4	368.3
Effect of dilutive securities:
Employee stock awards (shares)	5.6	5.1
Denominator for diluted earnings per share — adjusted weighted average common shares	370.0	373.4
Basic net income per common share attributable to Parent (in dollars per share)	$ 2.17	$ 1.17
Diluted net income per common share attributable to Parent (in dollars per share)	$ 2.14	$ 1.16