Commodity and Other Repurchase Agreements and Collateralized Transactions Schedule of Gross Collateralized Financings by Maturity (Tables)

6 Months Ended

Mar. 31, 2019

Assets Sold under Agreements to Repurchase [Line Items]

Schedule of Repurchase Agreement Counterparties with Whom Repurchase Agreements Exceed 10 Percent of Stockholders' Equity [Table Text Block]

	March 31, 2019
	Overnight and Open		Less than 30 Days		30-90 Days		Over 90 Days		Total
Securities sold under agreements to repurchase	$	1,179.3	$	847.4	$	338.0	$	20.0	$	2,384.7
Securities loaned	1,376.5		—		—		—		1,376.5
Gross amount of secured financing	$	2,555.8	$	847.4	$	338.0	$	20.0	$	3,761.2

	September 30, 2018
	Overnight and Open		Less than 30 Days		30-90 Days		Over 90 Days		Total
Securities sold under agreements to repurchase	$	934.9	$	661.3	$	340.5	$	—	$	1,936.7
Securities loaned	277.9		—		—		—		277.9
Gross amount of secured financing	$	1,212.8	$	661.3	$	340.5	$	—	$	2,214.6