Statement of Changes in Equity (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2012	Sep. 30, 2011
Stockholders' Equity Attributable to Parent	$ 2,335.0	$ 1,994.2	$ 2,233.1
Net losses on derivative instruments, net of tax	(9.3)	(41.3)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	(21.8)	(12.5)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	16.1	(22.2)
Net Income Attributable to Parent	102.6	87.0
Stockholders' Equity Attributable to Noncontrolling Interest	1,110.5	205.5	1,085.7
Net Income Attributable to Noncontrolling Interest	68.1	23.1
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	3,445.5	2,199.7	3,318.8
Common Stock Including Additional Paid in Capital [Member]
Stockholders' Equity Attributable to Parent	1,170.0	939.1	1,157.7	937.4
Common Stock issued in connection with employee and director plans, net of tax withheld	9.6	1.5
Stock Issued During Period, Value, Dividend Reinvestment Plan	0.5	0.5
Excess tax benefits realized on equity-based compensation	1.3	0.2
Stock-based compensation expense	0.9	(0.5)
Retained Earnings [Member]
Stockholders' Equity Attributable to Parent	1,238.1	1,143.6	1,166.1	1,085.8
Net Income Attributable to Parent	102.6	87.0
Dividends, Common Stock, Cash	(30.6)	(29.2)
Accumulated Other Comprehensive Income (Loss) [Member]
Stockholders' Equity Attributable to Parent	(43.7)	(61.8)	(62.0)	(17.7)
Net losses on derivative instruments, net of tax	(7.4)	(33.5)
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Net of Tax	9.3	11.5
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	16.1	(22.2)
Treasury Stock [Member]
Stockholders' Equity Attributable to Parent	(29.4)	(26.7)	(28.7)	(27.8)
Stock Issued During Period, Value, Other	7.2	0.8
Stock Repurchased During Period, Value	(8.1)	0
Stock Issued During Period, Value, Dividend Reinvestment Plan	0.2	0.3
Parent [Member]
Stockholders' Equity Attributable to Parent	2,335.0	1,994.2
Noncontrolling Interest [Member]
Stockholders' Equity Attributable to Noncontrolling Interest	1,110.5	205.5	1,085.7	213.4
Net Income Attributable to Noncontrolling Interest	68.1	23.1
Net Gain Loss on Derivative Instruments	(1.9)	(7.8)
Reclassifications of Net Losses (gains) on Derivative Instruments	12.5	1.0
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(55.2)	(24.0)
Stockholders' Equity, Other	1.3	(0.2)
Accumulated Defined Benefit Plans Adjustment [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ 0.3	$ 0.1