Special Charges (Narrative) (Details) $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2017 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)	Jun. 30, 2015 site
Restructuring Cost and Reserve [Line Items]
Special charges	$ 36.9		$ 3.1	$ 50.4	$ 8.9
Proceeds from Sale of Buildings			6.1
Gain (Loss) on Sale of Properties			5.2
Gain (Loss) on Disposition of Business		$ 1.0
Restructuring charges				11.5
Number of site closures | site						5
Integration and Business Realignment [Member]
Restructuring Cost and Reserve [Line Items]
Special charges	0.1		2.1	0.4	2.3
Integration and Business Realignment [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Special charges			1.4		1.4
Site Consolidation [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Special charges	0.5		1.7	0.7	1.7
Site Consolidation [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Special charges	3.8		$ 6.2	7.8	$ 9.8
Aggregate special charges recognized	42.8			42.8
Business Optimization [Member]
Restructuring Cost and Reserve [Line Items]
Special charges	9.6			18.8
Business Optimization [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Special charges	$ 4.8			$ 10.8