Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2013	Sep. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax	$ (793.2)	$ (1,180.1)	$ (817.7)	$ (1,225.3)
Other comprehensive income (loss) before reclassifications, net of tax	10.2	23.8
Amounts reclassified from accumulated other comprehensive loss, net of tax	14.3	21.4
Other comprehensive income (loss), net of tax	24.5	45.2
Sales	1,422.3	1,334.2
Cost of Sales	(810.4)	(774.8)
Total before tax	272.8	217.2
Tax (expense) benefit	(74.7)	(55.8)
Net of tax	198.1	161.4
Pension and other postretirement benefit benefit plan adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax	(809.2)	(1,204.1)	(823.8)	(1,226.0)
Other comprehensive income (loss) before reclassifications, net of tax	0	0
Amounts reclassified from accumulated other comprehensive loss, net of tax	14.6	21.9
Other comprehensive income (loss), net of tax	14.6	21.9
Accumulated currency translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax	18.0	24.8	8.8	0.5
Other comprehensive income (loss) before reclassifications, net of tax	9.2	24.3
Amounts reclassified from accumulated other comprehensive loss, net of tax	0	0
Other comprehensive income (loss), net of tax	9.2	24.3
Net unrealized gains (losses) on cash flow hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax	(2.0)	(0.8)	(2.7)	0.2
Other comprehensive income (loss) before reclassifications, net of tax	1.0	(0.5)
Amounts reclassified from accumulated other comprehensive loss, net of tax	(0.3)	(0.5)
Other comprehensive income (loss), net of tax	0.7	(1.0)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net of tax	14.3	21.4
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	(3.2)	(3.3)
Amortization of net actuarial loss	25.6	37.4
Total before tax	22.4	34.1
Tax (expense) benefit	(7.8)	(12.2)
Net of tax	14.6	21.9
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	0.2	0.4
Cost of Sales	(0.7)	(1.2)
Total before tax	(0.5)	(0.8)
Tax (expense) benefit	0.2	0.3
Net of tax	$ (0.3)	$ (0.5)