Business Restructuring and Cost Reduction Actions (Carrying Amount of Accrual) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015	Sep. 30, 2015	Sep. 30, 2014
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions	$ 8.6	$ 55.4	$ 8.6	$ 87.8
Cost Reduction Actions 2016 [Member]
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions	8.6
Cost Reduction Actions 2016 [Member] | Severance And Other Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions			8.6
Amount reflected in pension liability			(0.6)
Cash expenditures			(3.0)
Currency translation adjustment			0.3
Accrued Balance	5.3		5.3
Business Realignment and Reorganization 2015 [Member]
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions		$ 55.4		$ 87.8	$ 207.7
Amount reflected in pension liability					(14.0)
Noncash expenses					(47.4)
Cash expenditures			(27.8)		(114.7)
Currency translation adjustment			(0.3)		(0.4)
Accrued Balance	13.6		13.6		41.7	$ 10.5
Business Realignment and Reorganization 2015 [Member] | Severance And Other Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions					151.9
Amount reflected in pension liability					(14.0)
Noncash expenses					0.0
Cash expenditures			(24.0)		(113.5)
Currency translation adjustment			(0.3)		(0.4)
Accrued Balance	10.2		10.2		34.5	10.5
Business Realignment and Reorganization 2015 [Member] | Asset Actions [Member]
Restructuring Cost and Reserve [Line Items]
Business restructuring and cost reduction actions					55.8
Noncash expenses					(47.4)
Cash expenditures			(3.8)		(1.2)
Currency translation adjustment			0.0		0.0
Accrued Balance	$ 3.4		$ 3.4		$ 7.2	$ 0.0