Summary Of Significant Accounting Policies (Schedule Of Derivatives Not Designated As Hedging Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018	Sep. 30, 2018
Summary Of Significant Accounting Policies [Line Items]
Net realized and unrealized (gains) losses	$ 1,327	$ 2,449	$ 1,823	$ 353
In Gain Position [Member]
Summary Of Significant Accounting Policies [Line Items]
Derivative Assets					$ (583)
In loss position [Member]
Summary Of Significant Accounting Policies [Line Items]
Derivative Assets	33		33		82
Cash Held By Broker [Member]
Summary Of Significant Accounting Policies [Line Items]
Derivative Assets	(324)		(324)		(545)
Future And Option Contracts [Member]
Summary Of Significant Accounting Policies [Line Items]
Derivative Assets	(770)		(770)		(1,046)
Derivative Liability	523		523		1,567
Fair Value, Inputs, Level 1 [Member]
Summary Of Significant Accounting Policies [Line Items]
Derivative Assets	(479)		(479)		(583)
Derivative Liability	33		33		82
corn [Member] | Future And Option Contracts [Member]
Summary Of Significant Accounting Policies [Line Items]
Net realized and unrealized (gains) losses	(1,030)	(406)	(1,049)	(672)
corn [Member] | Forward Contracts [Member]
Summary Of Significant Accounting Policies [Line Items]
Net realized and unrealized (gains) losses	$ (297)	$ (2,043)	$ (774)	$ 319
Derivative Liability					$ 1,567