Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Sep. 30, 2013	Sep. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax	$ (760.6)	$ (1,187.7)	$ (760.6)	$ (1,187.7)	$ (817.7)	$ (1,225.3)
Other comprehensive income (loss) before reclassifications, net of tax			11.2	(25.7)
Amounts reclassified from accumulated other comprehensive loss, net of tax			45.9	63.3
Other comprehensive income (loss), net of tax	15.0	9.4	57.1	37.6
Sales	1,481.2	1,466.2	4,332.6	4,163.9
Cost of Sales	(849.8)	(859.6)	(2,485.3)	(2,428.6)
Total before tax	274.0	257.4	795.2	701.7
Provision for tax	(74.3)	(53.7)	(217.1)	(160.7)
After tax	199.7	203.7	578.1	541.0
Pension and other postretirement benefit benefit plan adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax	(780.1)	(1,160.6)	(780.1)	(1,160.6)	(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			43.7	65.4
Other comprehensive income (loss), net of tax			43.7	65.4
Accumulated currency translation adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax	24.3	(31.1)	24.3	(31.1)	8.8	0.5
Other comprehensive income (loss) before reclassifications, net of tax			15.5	(31.6)
Amounts reclassified from accumulated other comprehensive loss, net of tax			0	0
Other comprehensive income (loss), net of tax			15.5	(31.6)
Net unrealized gains (losses) on cash flow hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income (loss), net of tax	(4.8)	4.0	(4.8)	4.0	(2.7)	0.2
Other comprehensive income (loss) before reclassifications, net of tax			(4.3)	5.9
Amounts reclassified from accumulated other comprehensive loss, net of tax			2.2	(2.1)
Other comprehensive income (loss), net of tax			(2.1)	3.8
Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
After tax	17.1	20.1	45.9	63.3
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	(3.3)	(3.3)	(9.9)	(10.0)
Amortization of net actuarial loss	25.8	37.2	77.2	111.8
Total before tax	22.5	33.9	67.3	101.8
Provision for tax	(7.9)	(12.2)	(23.6)	(36.4)
After tax	14.6	21.7	43.7	65.4
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	0.6	(1.0)	1.6	(1.5)
Cost of Sales	2.0	(1.6)	(0.4)	(1.8)
Total before tax	2.6	(2.6)	1.2	(3.3)
Provision for tax	(0.1)	1.0	1.0	1.2
After tax	$ 2.5	$ (1.6)	$ 2.2	$ (2.1)