Accumulated Other Comprehensive Loss (Rollforward) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	$ (2,208.6)		$ (2,125.9)
Other comprehensive income (loss) before reclassifications	152.7		65.8
Amounts reclassified from AOCL	12.0		16.2
Net current period other comprehensive income (loss)	164.7	$ (190.9)	82.0	$ (424.7)
Amount attributable to noncontrolling interest	2.8	$ 0.6	2.8	$ (4.5)
Ending Balance	(2,046.7)		(2,046.7)
Net loss on derivatives qualifying as hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(46.2)		(42.9)
Other comprehensive income (loss) before reclassifications	12.8		28.8
Amounts reclassified from AOCL	(11.1)		(30.4)
Net current period other comprehensive income (loss)	1.7		(1.6)
Amount attributable to noncontrolling interest	(0.1)		(0.1)
Ending Balance	(44.4)		(44.4)
Foreign currency translation adjustments [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(1,057.0)		(956.5)
Other comprehensive income (loss) before reclassifications	139.9		37.0
Amounts reclassified from AOCL	0.4		2.8
Net current period other comprehensive income (loss)	140.3		39.8
Amount attributable to noncontrolling interest	2.9		2.9
Ending Balance	(919.6)		(919.6)
Pension and postretirement benefits [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(1,105.4)		(1,126.5)
Other comprehensive income (loss) before reclassifications	0.0		0.0
Amounts reclassified from AOCL	22.7		43.8
Net current period other comprehensive income (loss)	22.7		43.8
Amount attributable to noncontrolling interest	0.0		0.0
Ending Balance	$ (1,082.7)		$ (1,082.7)