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Short-term and long-term debt - Additional Information (Details) |  |  |  | 1 Months Ended | 3 Months Ended | 6 Months Ended | 9 Months Ended | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Oct. 01, 2019 | Nov. 30, 2018 USD ($) | Oct. 10, 2017 USD ($) | Nov. 30, 2018 USD ($) | Mar. 31, 2020 | Sep. 30, 2019 USD ($) | Jun. 30, 2019 USD ($) | Mar. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Sep. 30, 2018 USD ($) | Jun. 30, 2019 | Jun. 30, 2018 | Sep. 30, 2019 USD ($) | Dec. 31, 2019 | Sep. 30, 2019 USD ($) | Dec. 31, 2018 USD ($) | Nov. 30, 2019 USD ($) | Jul. 31, 2019 USD ($) | Aug. 14, 2018 | Jul. 01, 2018
Debt Instrument, Leverage Ratio, Actual |  |  |  |  |  |  |  |  |  |  |  |  | $ 13.79 |  | $ 0.40 |  |  |  |  |
Debt Instrument, Leverage Ratio, Required |  |  |  |  |  |  |  |  |  |  |  |  | 6.40 |  |  |  |  |  |  |
Line of Credit Facility, Remaining Borrowing Capacity |  |  |  |  |  | $ 23,200,000 |  |  |  |  |  |  | $ 23,200,000 |  | 23,200,000 |  |  | $ 23,200,000 |  |
Line of Credit Facility, Maximum Borrowing Capacity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 28,000,000 |  |
Capital leased assets gross |  |  |  |  |  | $ 0.03 |  |  |  |  |  |  | $ 0.03 |  | $ 0.03 |  |  |  |  |
Earnings Before Interest , Tax ,Depreciation And Amortization |  |  |  |  |  |  | $ 14,195,000 | $ 9,270,000 | $ 9,428,000 | $ 9,240,000 |  |  |  |  |  |  |  |  |  |
Ratios Of Indebtedness To Net Capital Requirement |  |  |  |  |  |  |  |  |  |  |  |  | 4.75 |  |  |  |  |  |  |
Ratios Of Indebtedness To Net Capital |  |  |  |  | 4:75 |  |  | 12.95: |  | 12.45 | 8.25 | 10.15 | 6.40 | 5:70 |  | 12.75 |  |  |  |
Deferred Tax Liabilities, Deferred Expense, Debt Issuance Costs |  | $ 250,000 |  | $ 250,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Fee Amount |  | 250,000 |  | 250,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
FCCR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Fixed Charges Coverage Ratio |  |  |  |  |  | 1.00 |  |  |  |  |  |  |  |  |  |  |  |  |  |
TLR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ratios Of Indebtedness To Net Capital |  |  |  |  |  |  |  |  |  |  |  |  | 13.79 |  |  | 11.82 |  |  |  |
Amended And Restated Revolving Credit And Security Agreement | London Interbank Offered Rate Daily Libor [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  |  |  |  |  |  |  |  |  |  | 1.00% |  |  |  |  |  |  |
Amended And Restated Revolving Credit And Security Agreement | Federal Funds Purchased [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  |  |  |  |  |  |  |  |  |  | 0.50% |  |  |  |  |  |  |
Term Loan Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Leverage Ratio, Required |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.75 |  |  |  |
Percent per annum |  |  |  |  |  | 1.00% |  |  |  |  |  |  | 1.00% |  | 1.00% |  |  |  |  |
Prepayment premium percentage year two |  |  |  |  |  |  |  |  | 3.00% |  |  |  |  |  |  | 3.00% |  |  |  |
Prepayment premium percentage year three |  |  |  |  |  |  |  |  | 1.00% |  |  |  |  |  |  | 1.00% |  |  |  |
Prepayment premium percentage year four and thereafter |  |  |  |  |  |  |  |  | 0.00% |  |  |  |  |  |  | 0.00% |  |  |  |
Second Amendment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Basis points increase in interest rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.00%
Exit fee percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.00% |
One time waiver fee percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.00% |
Second Amendment | Repayment Of Loans In Full Occurring Between January 1 2020 And Prior To March 31 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reduction in exit fee percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.50% |
Third Amendment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of Credit Facility, Remaining Borrowing Capacity |  | 28,000,000 |  | 28,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Exit fee percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.00% |  |  |
Line of Credit Facility, Periodic Payment, Principal |  | $ 525,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Third Amendment | Additional Principal Repayment On Or Before November 14 2019 Minimum Undrawn Availability Greater Than $35000000 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage Excess Cash Flow |  | 100.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Third Amendment | Additional Principal Repayment On Or Before November 14 2019 Minimum Undrawn Availability Greater Than 15000000 Less Than 35000000 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage Excess Cash Flow |  | 50.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Third Amendment | Additional Principal Repayment On Or Before November 14 2019 Minimum Undrawn Availability Less Than 15000000 [Member |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage Excess Cash Flow |  | 0.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Third Amendment | Voluntary Prepayments Of Loans Made Prior to January 1 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reduction in exit fee percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0.10% |  |  |
Voluntary prepayment sharehold amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,000,000 |  |  |
Third Amendment | Repayment Of Loans In Full Occurring Between January 1 2020 And Prior To March 31 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reduction in exit fee percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 50.00% |  |  |
Minimum | Amended And Restated Revolving Credit And Security Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Additional interest percentage |  |  |  |  |  | 0.50% |  |  |  |  |  |  | 0.50% |  | 0.50% |  |  |  |  |
Minimum | Amended And Restated Revolving Credit And Security Agreement | Euro Dollar |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  |  |  |  |  |  |  |  |  |  | 1.50% |  |  |  |  |  |  |
Minimum | Second Revolver Amendment | Euro Dollar |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate | 2.50% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum | Third Amendment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Exit fee percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.00% |  |  |
Minimum | Third Amendment | Additional Principal Repayment On Or Before November 14 2019 Minimum Undrawn Availability Greater Than $35000000 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum aggregate undrawn loan availability |  | $ 35,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum | Third Amendment | Additional Principal Repayment On Or Before November 14 2019 Minimum Undrawn Availability Greater Than 15000000 Less Than 35000000 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum aggregate undrawn loan availability |  | 15,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum | Amended And Restated Revolving Credit And Security Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Additional interest percentage |  |  |  |  |  | 1.00% |  |  |  |  |  |  | 1.00% |  | 1.00% |  |  |  |  |
Maximum | Amended And Restated Revolving Credit And Security Agreement | Euro Dollar |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  |  |  |  |  |  |  |  |  |  |  | 2.00% |  |  |  |  |  |  |
Maximum | Second Revolver Amendment | Euro Dollar |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate | 3.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum | Term Loan Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage Excess Cash Flow |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 50.00% |  |  |  |
Principal prepayment |  |  |  |  |  |  |  |  | $ 30,000,000 |  |  |  |  |  |  | $ 30,000,000 |  |  |  |
Maximum | Third Amendment | Additional Principal Repayment On Or Before November 14 2019 Minimum Undrawn Availability Greater Than 15000000 Less Than 35000000 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum aggregate undrawn loan availability |  | 35,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Maximum | Third Amendment | Additional Principal Repayment On Or Before November 14 2019 Minimum Undrawn Availability Less Than 15000000 [Member |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum aggregate undrawn loan availability |  | $ 15,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
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 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity |  |  | $ 25,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Face Amount |  |  | $ 105,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term Loan | Second Amendment [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Financing Costs |  |  |  | $ 1,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Term Loan | Euro Dollar |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  |  | 7.25% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Interest Rate, Stated Percentage |  |  | 3.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
PNC Bank [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Letters of Credit Outstanding, Amount |  |  |  |  |  | $ 130,000 |  |  |  |  |  |  | $ 130,000 |  | $ 130,000 |  |  |  |  |
Debt Instrument, Face Amount |  |  |  |  |  | $ 15,200,000 |  |  |  |  |  |  | $ 15,200,000 |  | $ 15,200,000 |  |  |  |  |
PNC Bank [Member] | Amended And Restated Revolving Credit And Security Agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity |  |  | $ 150,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
PNC Bank [Member] | Swing Line Loan [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity |  |  | 15,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
PNC Bank [Member] | Letter of Credit [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Line of Credit Facility, Maximum Borrowing Capacity |  |  | $ 5,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Domestic Rate Loans [Member] | Second Revolver Amendment | Base Rate [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 2.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Eurodollar Rate Loans [Member] | Second Revolver Amendment | Euro Dollar |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate |  | 3.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Eurodollar Rate Loans [Member] | Minimum | Second Revolver Amendment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate | 1.50% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Eurodollar Rate Loans [Member] | Maximum | Second Revolver Amendment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument, Basis Spread on Variable Rate | 2.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition The percent per annum of the original principal amount required as a principal payment on the loan. + References No definition available. + Details
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- Definition The number of basis points increase in loan interest rate. + References No definition available. + Details
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- Definition Percentage points added to the calculated interest rate dependent on average quarterly undrawn availability. + References No definition available. + Details
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- Definition The percentage applied to the outstanding balance to arrive at the fee required to be paid to exit the loan. + References No definition available. + Details
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- Definition Represents the information pertaining to leverage ratio of the company, as calculated. + References No definition available. + Details
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- Definition Represents the information pertaining to leverage ratio, required. + References No definition available. + Details
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- Definition Prepayment premium percentage in year four and thereafter. + References No definition available. + Details
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- Definition Prepayment premium percentage in year three. + References No definition available. + Details
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- Definition Prepayment premium percentage in year two. + References No definition available. + Details
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- Definition Represents the information pertaining to deferred financing costs. + References No definition available. + Details
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- Definition The amount of ebitda reported during the year. + References No definition available. + Details
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- Definition Fixed charge coverage ratio reported during the year. + References No definition available. + Details
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- Definition The minimum aggregate undrawn term loan availability used to determine percentage of excess cash flow to be used to paydown the loan. + References No definition available. + Details
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- Definition The required one time waiver fee as a percent of the outstanding loan balance. + References No definition available. + Details
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- Definition The amount, at the Borrower's option, of a loan principal prepayment. + References No definition available. + Details
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- Definition The percentage of excess cash flow used to calculate the required additional annual principal payment. + References No definition available. + Details
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- Definition Indebtedness divided by net capitals. + References No definition available. + Details
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- Definition Indebtedness divided by net capital required to maintain. + References No definition available. + Details
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- Definition The reduction in the exit fee percentage in the event the loan is repaid in full or in part according to conditions. + References No definition available. + Details
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- Definition The amount of voluntary prepayments of debt to which the exit fee reduction percentage is applied to arrive at the amount of the exit fee. + References No definition available. + Details
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- Definition Amount before accumulated depreciation of leased physical assets used in the normal conduct of business to produce goods and services. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=84164758&loc=d3e45014-112735 + Details
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- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
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- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 + Details
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