Accumulated Other Comprehensive Loss (Details 1) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	$ 257.6	$ 236.9
Income tax provision	(42.9)	(51.4)
Net income	214.7	185.5
Reclassification out of Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	23.6	13.5
Pension and other postretirement benefit plan adjustments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service credit	(2.3)	(3.5)
Amortization of net actuarial loss	38.5	31.7
Settlements	0.2	0.0
Pension and other postretirement benefit plan adjustments [Member] | Reclassification out of Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	36.4	28.2
Income tax provision	(12.6)	(9.8)
Net income	23.8	18.4
Net unrealized gains (losses) on cash flow hedges [Member] | Reclassification out of Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	(0.2)	(6.3)
Income tax provision	0.0	1.4
Net income	(0.2)	(4.9)
Net unrealized gains (losses) on cash flow hedges [Member] | Foreign Exchange Forward [Member] | Sales [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from accumulated other comprehensive loss	0.5	2.5
Net unrealized gains (losses) on cash flow hedges [Member] | Foreign Exchange Forward [Member] | Cost of sales [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from accumulated other comprehensive loss	(1.0)	(8.8)
Net unrealized gains (losses) on cash flow hedges [Member] | Foreign Exchange Forward [Member] | Selling, General and Administrative Expenses [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amounts reclassified from accumulated other comprehensive loss	$ 0.3	$ 0.0