Credit Facilities Credit Facilities (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Sep. 30, 2012
Line of Credit Facility [Line Items]
Line of Credit Facility, Amount Outstanding	$ 241.4	$ 218.2
Main line of credit facilities [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	385.0
HCO Syndicated line of credit facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	95.0
Line of Credit Facility, Amount Outstanding	78.0	48.0
INTL COM line of credit facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	140.0
Line of Credit Facility, Amount Outstanding	107.0	107.0
FCS Margin line of credit facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	75.0
Line of Credit Facility, Amount Outstanding	0	20.0
FMS Sub-note commodity line of credit facility [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	75.0
Line of Credit Facility, Amount Outstanding	$ 56.4	$ 43.2