Income Tax Expense Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Expected U.S. federal income taxes at statutory rate (percent)	21.00%	24.60%	34.30%
Partnership income not taxed at Partnership level (percent)	(260.90%)	(6.40%)	(125.30%)
Valuation allowance (percent)	65.00%	(20.90%)	84.70%
State and local income taxes, net of federal benefit (percent)	26.90%	(6.40%)	16.40%
Nondeductible expenses (percent)	101.80%	(8.60%)	6.20%
Federal tax rate change (percent)	0.00%	10.20%	0.00%
Other (percent)	0.30%	0.10%	0.10%
Income tax expense (percent)	(45.90%)	(7.30%)	16.40%
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Expected U.S. federal income taxes at statutory rate	$ 81	$ (1,139)	$ 370
Partnership income not taxed at Partnership level	1,007	(294)	1,352
Valuation allowance	(251)	(965)	(914)
State and local income taxes, net of federal benefit	104	295	177
Nondeductible expenses	393	398	67
Federal tax rate change	0	(471)	0
Other	1	(5)	1
Income tax (benefit) expense	$ (177)	$ 337	$ 177

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible expenses.

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