Business Restructuring and Cost Reduction Actions (Narrative) (Details) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Mar. 31, 2016 USD ($) Employees $ / shares	Mar. 31, 2015 USD ($) $ / shares	Mar. 31, 2016 USD ($)	Mar. 31, 2015 USD ($) $ / shares	Sep. 30, 2015 USD ($)
Restructuring and Related Cost [Line Items]
Business restructuring and cost reduction actions	$ 8.6	$ 55.4	$ 8.6	$ 87.8
Cost Reduction Actions 2016 [Member]
Restructuring and Related Cost [Line Items]
Business restructuring and cost reduction actions	8.6
Business restructuring and cost reduction actions, after-tax	$ 7.1
Business restructuring and cost reduction actions, per share | $ / shares	$ 0.03
Number of positions to be eliminated | Employees	170
Cost Reduction Actions 2016 [Member] | Severance And Other Benefits [Member]
Restructuring and Related Cost [Line Items]
Business restructuring and cost reduction actions			$ 8.6
Business Realignment and Reorganization 2015 [Member]
Restructuring and Related Cost [Line Items]
Business restructuring and cost reduction actions		55.4		87.8	$ 207.7
Business restructuring and cost reduction actions, after-tax		$ 38.2		$ 59.9
Business restructuring and cost reduction actions, per share | $ / shares		$ 0.18		$ 0.27
Business Realignment and Reorganization 2015 [Member] | Asset Actions [Member]
Restructuring and Related Cost [Line Items]
Business restructuring and cost reduction actions					55.8
Business Realignment and Reorganization 2015 [Member] | Severance And Other Benefits [Member]
Restructuring and Related Cost [Line Items]
Business restructuring and cost reduction actions					$ 151.9