Other Comprehensive Income (Loss) - Reclassifications out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Affected Line in the Consolidated Statement of Operations:
Net revenue	$ 392.0	$ 398.7	$ 404.6	$ 401.5	$ 468.7	$ 416.8	$ 396.8	$ 384.9	$ 1,596.8	$ 1,667.2	$ 1,553.4
Cost of goods sold									(1,026.4)	(1,078.0)	(1,034.7)
Operating expenses									(330.6)	(383.1)	(336.5)
Other (expense) income, net									(7.9)	8.7	(0.4)
Income before income taxes									162.3	159.9	93.7
Tax expense									(49.1)	(48.7)	(28.3)
Total reclassifications for the period, net of tax									6.9	0.5	5.2
Pension and Postretirement
Affected Line in the Consolidated Statement of Operations:
Total reclassifications for the period, net of tax									3.5	2.7	4.9
Net Unrealized Gain (Loss) on Derivative Instruments
Affected Line in the Consolidated Statement of Operations:
Total reclassifications for the period, net of tax									3.4	(2.2)	0.3
Reclassification out of Accumulated Other Comprehensive Income
Affected Line in the Consolidated Statement of Operations:
Net revenue									2.5	(1.6)	0.2
Cost of goods sold									4.1	2.5	5.3
Operating expenses									1.6	1.2	2.5
Other (expense) income, net									1.9	(1.1)	0.2
Income before income taxes									10.1	1.0	8.2
Tax expense									(3.2)	(0.5)	(3.0)
Total reclassifications for the period, net of tax									6.9	0.5	5.2
Reclassification out of Accumulated Other Comprehensive Income | Net Loss Recognized
Affected Line in the Consolidated Statement of Operations:
Net revenue									0.0	0.0	0.0
Cost of goods sold									3.5	2.5	4.8
Operating expenses									1.3	0.9	2.1
Other (expense) income, net									0.0	0.0	0.0
Income before income taxes									4.8	3.4	6.9
Reclassification out of Accumulated Other Comprehensive Income | Prior Service Costs Recognized
Affected Line in the Consolidated Statement of Operations:
Net revenue									0.0	0.0	0.0
Cost of goods sold									0.5	0.5	0.5
Operating expenses									0.3	0.3	0.4
Other (expense) income, net									0.0	0.0	0.0
Income before income taxes									0.8	0.8	0.9
Reclassification out of Accumulated Other Comprehensive Income | Net Unrealized Gain (Loss) on Derivative Instruments
Affected Line in the Consolidated Statement of Operations:
Net revenue									2.5	(1.6)	0.2
Cost of goods sold									0.1	(0.5)	0.0
Operating expenses									0.0	0.0	0.0
Other (expense) income, net									1.9	(1.1)	0.2
Income before income taxes									$ 4.5	$ (3.2)	$ 0.4