Accumulated Other Comprehensive Loss (Details 1) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	$ 276.0	$ 252.3	$ 763.9	$ 706.2
Income tax provision	(59.1)	(61.3)	(142.8)	(161.7)
Net income	216.9	191.0	621.1	544.5
Reclassification out of Accumulated Other Comprehensive Loss [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	23.3	17.4	69.4	42.6
Pension and other postretirement benefit plan adjustments [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service credit	(2.4)	(3.5)	(7.3)	(10.6)
Amortization of net actuarial loss	38.8	31.8	116.1	95.3
Settlements	0.0	0.0	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	28.3	109.0	84.7
Income tax provision	(12.6)	(9.8)	(37.6)	(29.4)
Net income	23.8	18.5	71.4	55.3
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	(0.8)	(1.0)	(2.3)	(15.9)
Income tax provision	0.3	(0.1)	0.3	3.2
Net income	(0.5)	(1.1)	(2.0)	(12.7)
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	(0.7)	1.0	0.8	5.1
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	(0.2)	(2.0)	(3.8)	(21.0)
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	$ 0.1	$ 0.0	$ 0.7	$ 0.0