Consolidated Statements of Total Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income	Non-controlling Interests
Beginning Balances at Sep. 30, 2013	$ 4,061.4	$ 3.3	$ 2,042.0	$ 2,145.6	$ (134.3)	$ 1.9	$ 2.9
Increase (Decrease) in Stockholders' Equity
Net income	533.5			533.5
Issuances under employee benefit plans	1.4		1.4
Exercise of stock options	43.8		43.8
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	(3.4)	0.0	(3.4)
Stock issued under Performance Unit Plan	5.5		5.5
Conversion of Stock, Amount Issued	498.6	0.4	498.2
Stock based compensation expense	26.2		26.2
Cash dividends declared	(48.6)			(48.6)
Other comprehensive income (loss)	0.3					0.3
Noncontrolling interests	1.0						1.0
Ending Balances at Sep. 30, 2014	5,119.7	3.7	2,613.7	2,630.5	(134.3)	2.2	3.9
Increase (Decrease) in Stockholders' Equity
Net income	750.7			750.7
Issuances under employee benefit plans	1.7		1.7
Exercise of stock options	60.1	0.1	60.0
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	7.9	0.0	7.9	0.0	0.0	0.0	0.0
Stock issued under Performance Unit Plan	8.3		8.3
Stock based compensation expense	42.2		42.2
Cash dividends declared	(91.6)			(91.6)
Other comprehensive income (loss)	(0.8)					(0.8)
Noncontrolling interests	(2.8)						(2.8)
Ending Balances at Sep. 30, 2015	5,895.4	3.8	2,733.8	3,289.6	(134.3)	1.4	1.1
Increase (Decrease) in Stockholders' Equity
Net income	886.3			886.3
Issuances under employee benefit plans	2.2		2.2
Exercise of stock options	70.1	0.0	70.1
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation	2.7	0.0	2.7	0.0	0.0	0.0	0.0
Stock issued under Performance Unit Plan	8.0		8.0
Stock based compensation expense	49.0		49.0
Cash dividends declared	(118.7)			(118.7)
Other comprehensive income (loss)	(1.4)					(1.4)
Noncontrolling interests	(0.6)						(0.6)
Ending Balances at Sep. 30, 2016	$ 6,793.0	$ 3.8	$ 2,865.8	$ 4,057.2	$ (134.3)	$ 0.0	$ 0.5