Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Accounting Policies [Abstract]
Deferred financing cost amortization	$ 318	$ 288	$ 294
Debt Issuance Costs, Noncurrent, Net	782	912
Accounts Receivable, Allowance for Credit Loss	(1,184)	(868)	$ (650)
Deferred tax assets	$ 40,874	$ 46,580
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	24.53%	35.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		$ 31,333
Loss Contingency, Undiscounted Amount of Insurance-related Assessment Liability	$ 4,975	$ 5,286
Accrual for Loss Contingencies, Undiscounted, First Year	1,422
Accrual for Loss Contingencies, Undiscounted, Second Year	1,065
Accrual for Loss Contingencies, Undiscounted, Third Year	727
Accrual for Loss Contingencies, Undiscounted, Fourth Year	504
Accrual for Loss Contingencies, Undiscounted, Fifth Year	290
Accrual for Insurance Loss Contingencies, Undiscounted, after Fifth Year	$ 967
Loss Contingency Accrual, Insurance-related Assessment, Discount Rate	1.60%	2.90%
Accrued Insurance, Current	$ 6,683	$ 6,202
Letters of Credit Outstanding, Amount	$ 6,468
Noncontrolling Interest, Ownership Percentage by Parent	80.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	20.00%
Redeemable Noncontrolling Interest, Equity, Redemption Value	$ 3,294
Noncontrolling Interest, Change in Redemption Value		$ 44	$ (44)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 35,000

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Carrying value as of the balance sheet date of obligations incurred through that date and payable to insurance entities to mitigate potential loss from various risks or to satisfy a promise to provide certain coverage's to employees. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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