Accumulated Other Comprehensives Income (Loss) - Reclassifications Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Loss on Cash Flow Hedges, net of tax(A)	$ (2.9)	$ (1.1)
Reclassification from Accumulated Other Comprehensive Loss	3.5
Loss on Cash Flow Hedges, net of tax
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Loss	3.4
Pension and Postretirement Benefits, net of tax
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Loss	0.1
Reclassification out of Accumulated Other Comprehensive Income | Loss on Cash Flow Hedges, net of tax | Forward exchange contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Loss on Cash Flow Hedges, net of tax(A)	$ (3.4)