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Amount represents the information of principal repayments.

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Fixed charge coverage ratio reported during the year.

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No definition available.

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Represents the minimum amount to be derived from availability.

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No definition available.

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No definition available.

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The minimum aggregate undrawn term loan availability used to determine percentage of excess cash flow to be used to paydown the loan.

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No definition available.

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Amount of forgiveness under payment protection program.

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Represents the period for FCCR covenant.

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No definition available.

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Represents agent shall receive the right to dominion over certain of the Borrowers' bank accounts in the event of an Event of Default or if undrawn availability.

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No definition available.

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Represents the information pertaining to total leverage ratio.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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No definition available.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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The effective interest rate at the end of the reporting period.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Period between issuance and maturity of long-term debt, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

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Short-term and long-term debt - Additional Information (Details) - USD ($)			1 Months Ended										3 Months Ended	9 Months Ended	12 Months Ended
	Apr. 23, 2020	Dec. 19, 2019	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Sep. 30, 2021	Sep. 30, 2021	Dec. 31, 2020	Oct. 10, 2017
Forgiveness of loan														$ (2,475,000)
Paycheck Protection Program [Member] \| CARES Act Loan [Member]
Debt Instrument, Interest Rate, Stated Percentage	1.00%
Unsecured loan	$ 2,475,000
Term of unforgiven loan	2 years
Deferral term of unforgiven loan	9 months
Forgiveness of loan													$ 2,475,000
TLR [Member]
Total Leverage Ratio														2.35%	5.84%
Term Loan Facility [Member]
Percent per annum				10.25%									10.25%	10.25%
First Amendment
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,500,000
Fourth Amendment
Principal repayment		$ 14,000,000
Total Leverage Ratio			5.36%	6.08%	7.03%	7.75%	8.89%	8.89%	10.87%	16.57%	14.54%	15.67%
Minimum Aggregate Undrawn Availability Excess Cash Flow Calculation		$ 5,000,000
Last twelve months adjusted earnings before interest, tax, depreciation and amortization			$ 16,267,000	$ 15,431,000	$ 14,566,000	$ 14,295,000	$ 12,300,000	$ 12,021,000.000	$ 11,745,000	$ 7,359,000	$ 7,954,000	$ 7,887,000
Threshold period after trigger event the entity shall commence transaction														6 months
Threshold period after trigger event the entity shall consummate transaction		18 months
Fourth Amendment \| Effective March 31, 2020 [Member]
Principal repayment		$ 562,000
Fourth Amendment \| Effective December 31, 2020 [Member]
Principal repayment		$ 1,312,000
Fourth Amendment \| Through March 31, 2020 [Member]
Amendment fee (as a percent)		0.50%
Fourth Amendment \| From April 1, 2020 through March 31, 2021 [Member]
Amendment fee (as a percent)		2.50%
Fourth Amendment \| From April 1, 2021 and thereafter [Member]
Amendment fee (as a percent)		5.00%
Fifth Amendment To Term Loan Credit And Security Agreement [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,500,000
Maximum \| Term Loan Facility [Member]
Debt Instrument, Interest Rate, Stated Percentage				3.00%									3.00%	3.00%
Vehicle and Equipment Loans
Line of Credit Facility, Expiration Period														60 months
Vehicle and Equipment Loans \| Minimum
Credit facility effective rate of interest				0.00%									0.00%	0.00%
Vehicle and Equipment Loans \| Maximum
Credit facility effective rate of interest				8.30%									8.30%	8.30%
Term Loan
Debt Instrument, Face Amount																$ 105,000,000
Term Loan \| Fourth Amendment
Amendment fee (as a percent)		0.50%
Deferred Financing Costs		$ 500,000
Domestic Rate Loans [Member] \| Amended And Restated Revolving Credit And Security Agreement \| London Interbank Offered Rate Daily Libor [Member]
Debt Instrument, Basis Spread on Variable Rate		1.00%
Domestic Rate Loans [Member] \| Amended And Restated Revolving Credit And Security Agreement \| Federal Funds Purchased [Member]
Debt Instrument, Basis Spread on Variable Rate		0.50%
Domestic Rate Loans [Member] \| Minimum \| Amended And Restated Revolving Credit And Security Agreement
Additional interest percentage		1.25%
Domestic Rate Loans [Member] \| Maximum \| Amended And Restated Revolving Credit And Security Agreement
Additional interest percentage		1.75%
Eurodollar Rate Loans [Member] \| Minimum \| Amended And Restated Revolving Credit And Security Agreement \| Euro Dollar
Debt Instrument, Basis Spread on Variable Rate		2.25%
Eurodollar Rate Loans [Member] \| Maximum \| Amended And Restated Revolving Credit And Security Agreement \| Euro Dollar
Debt Instrument, Basis Spread on Variable Rate		2.75%
Wells Fargo \| Amended And Restated Revolving Credit And Security Agreement
Line of Credit Facility, Maximum Borrowing Capacity		$ 60,000,000
Wells Fargo \| Swing Line Loan [Member]
Line of Credit Facility, Maximum Borrowing Capacity		5,000,000
Wells Fargo \| Letter of Credit [Member]
Line of Credit Facility, Maximum Borrowing Capacity		2,000,000
Wells Fargo \| Revolving Credit Facility
Minimum amount to be derived from availability		3,000,000
Minimum aggregate undrawn loan availability		$ 7,500,000
Wells Fargo \| Revolving Credit Facility \| FCCR [Member]
Fixed Charges Coverage Ratio		1.00
Period for FCCR covenant		2 months
Revolver Guaranty and Security Agreement \| Wells Fargo
Right to dominion over certain borrower's bank accounts														$ 9,000,000