Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax	$ (1,015.9)	$ (793.2)	$ (948.0)	$ (817.7)
Other comprehensive income (loss) before reclassifications, net of tax	(80.7)	10.2
Amounts reclassified from accumulated other comprehensive loss, net of tax	12.8	14.3
Other comprehensive income (loss), net of tax	(67.9)	24.5
Sales	1,574.4	1,591.7
Cost of Sales	(886.9)	(928.0)
Total before tax	287.5	272.8
Provision for tax	(73.3)	(74.7)
After tax	214.2	198.1
Pension and other postretirement benefit benefit plan adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax	(891.8)	(809.2)	(909.4)	(823.8)
Other comprehensive income (loss) before reclassifications, net of tax	0	0
Amounts reclassified from accumulated other comprehensive loss, net of tax	17.6	14.6
Other comprehensive income (loss), net of tax	17.6	14.6
Accumulated currency translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax	(145.4)	18.0	(52.5)	8.8
Other comprehensive income (loss) before reclassifications, net of tax	(92.9)	9.2
Amounts reclassified from accumulated other comprehensive loss, net of tax	0	0
Other comprehensive income (loss), net of tax	(92.9)	9.2
Net unrealized gains (losses) on cash flow hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax	21.3	(2.0)	13.9	(2.7)
Other comprehensive income (loss) before reclassifications, net of tax	12.2	1.0
Amounts reclassified from accumulated other comprehensive loss, net of tax	(4.8)	(0.3)
Other comprehensive income (loss), net of tax	7.4	0.7
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
After tax	12.8	14.3
Reclassification out of Accumulated Other Comprehensive Income [Member] | Pension and other postretirement benefit benefit plan adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of prior service credit	(4.4)	(3.2)
Amortization of net actuarial loss	31.2	25.6
Total before tax	26.8	22.4
Provision for tax	(9.2)	(7.8)
After tax	17.6	14.6
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net unrealized gains (losses) on cash flow hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Sales	1.2	0.2
Cost of Sales	(5.8)	(0.7)
Total before tax	(4.6)	(0.5)
Provision for tax	(0.2)	0.2
After tax	$ (4.8)	$ (0.3)