Debt (Details) (USD $) In Millions, unless otherwise specified			3 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2012 Private Placement Notes [Member]	Sep. 30, 2012 Private Placement Notes [Member]	Dec. 31, 2012 Senior Notes Due May 2021 [Member]	Sep. 30, 2012 Senior Notes Due May 2021 [Member]	Dec. 31, 2012 Senior Notes Due May 2022 [Member]	Sep. 30, 2012 Senior Notes Due May 2022 [Member]	Jun. 30, 2012 Senior Notes Due May 2022 [Member]	Dec. 31, 2012 Term Loan Due 2012 [Member]	Sep. 30, 2012 Term Loan Due 2012 [Member]	Dec. 31, 2012 Debt With Variable Interest Rates [Member]
Short-term Debt [Abstract]
Notes payable	$ 289.2	$ 162.4
Short-term Debt, Weighted Average Interest Rate	2.00%	2.20%
Long-term Debt	2,263.7	2,370.1	1,165.0	1,165.0	600.0	600.0	498.7	498.6	500.0	0	106.5
Current maturities of long-term debt	125.0	231.5
Long-term debt	2,138.7	2,138.6
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum			4.30%
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Maximum			6.60%
Debt Instrument, Interest Rate, Stated Percentage					4.70%	4.70%	4.70%
Debt, Long-term and Short-term, Combined Amount	2,552.9											289.2
Total Committed Debt Facilities	2,937.9
Receivables Securitization Program, Maximum Borrowing Capacity	200
Receivables Securitization Program, Amount Outstanding	200.0
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	125.0
Long-term Debt, Maturities, Repayments of Principal in Year Two	220.0
Long-term Debt, Maturities, Repayments of Principal in Year Three	220.0
Long-term Debt, Maturities, Repayments of Principal in Year Four	290.0
Long-term Debt, Maturities, Repayments of Principal in Year Five	310.0
Long-term Debt, Maturities, Repayments of Principal after Year Five	$ 1,100.0