Subsequent Event - Additional Information (Detail) - USD ($)		1 Months Ended	3 Months Ended				6 Months Ended		9 Months Ended		12 Months Ended
	Oct. 10, 2017	Nov. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2019	Jun. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument, Payment Terms		the Third Amendment requires a further repayment of principal on or before November 14, 2019 in an amount equal to (x) 100% of Excess Cash Flow (as defined in the Term Loan Facility) for the four fiscal quarter period ending September 30, 2019 if after giving effect to the payment thereof, the Borrowers have minimum aggregate Undrawn Availability (as defined in the Term Loan Facility) of at least $35,000,000, (y) 50% of Excess Cash Flow for the four fiscal quarter period ending September 30, 2019 if after giving effect to the payment thereof, the Borrowers have minimum aggregate Undrawn Availability of at least $15,000,000 but less than $35,000,000, and (z) 0% of Excess Cash Flow for the four fiscal quarter period ending September 30, 2019 if after giving effect to the payment thereof, the Borrowers have minimum aggregate Undrawn Availability less than $15,000,000, with any such payment subject to reduction by the amount of any voluntary prepayments made following the date of the Third Amendment.
Line of Credit Facility, Remaining Borrowing Capacity										$ 43,500,000
Earnings Before Interest , Tax ,Depreciation And Amortization					$ 26,100,000	$ 21,900,000
Third Amendment [Member]
Ratios Of Indebtedness To Net Capital								10.15:1.00		12.45:1.00
Third Amendment [Member] | Scenario, Forecast [Member]
Ratios Of Indebtedness To Net Capital			4:75:1.00	12.95:1.00			8.25:1.00		6.40:1.00		5:70:1.00	12.75:1.00
Term Loan [Member]
Debt Instrument, Payment Terms	Principal payments on the Term Loans are required on a quarterly basis, commencing with the quarter ended March 31, 2018, in the amount of 1% per annum of the original principal of the outstanding Term Loans. Commencing with the fiscal year ending December 31, 2018, the Term Loan Facility also requires annual principal payments of up to 50% of Excess Cash Flow (as defined in the Term Loan Facility) if the Company’s Total Leverage Ratio (as defined in the Term Loan Facility) for the applicable year is greater than 2.75 to 1.00. The Term Loan Facility also requires mandatory prepayments of the Term Loans in the event of certain asset dispositions, debt issuances, and casualty and condemnation events. The Term Loans may be prepaid at the option of the Borrowers at par in an amount up to $30 million. Additional prepayments are permitted after the first anniversary of the closing date and were originally subject to a prepayment premium of 3% in year two, 1% in year three and zero in year four and thereafter.
Line of Credit Facility, Interest Rate Description										Interest charges with respect to loans are computed on the actual principal amount of loans outstanding during the month at a rate per annum equal to (A) with respect to domestic rate loans, the sum of (i) a rate per annum equal to the higher of (1) the base commercial lending rate of PNC, (2) the federal funds open rate plus 0.5% and (3) the daily LIBOR plus 1.0%, plus (ii) between 0.50% and 1.00% depending on average quarterly undrawn availability and (B) with respect to Eurodollar rate loans, the sum of the Eurodollar rate plus between 1.50% and 2.00% depending on average quarterly undrawn availability.
Term Loan [Member] | Third Amendment [Member] | Scenario, Forecast [Member]
Line of Credit Facility, Periodic Payment, Principal		$ 525,000
Line of Credit Facility, Remaining Borrowing Capacity		$ 28,000,000
Line of Credit Facility, Commitment Fee Description		The Third Amendment also amended the exit fee payable to the term loan lenders to five percent (5.00%) of the outstanding principal balance of the term loans on November 30, 2018 (the “Exit Fee”), which Exit Fee shall be payable in full in cash upon the earlier to occur of (x) repayment in full of the term loans, or (y) any acceleration of the term loans. The Exit Fee will be reduced by one-tenth of one percent (0.10%) for every $1,000,000 in voluntary prepayments made prior to January 1, 2020; provided, that, in no event shall the Exit Fee be reduced below three percent (3.00%) as a result of any such prepayments, (ii) payment of the Exit Fee shall be waived in the event that repayment in full of the term loans occurs prior to January 1, 2020, and (iii) the Exit Fee shall be reduced by an amount equal to fifty percent (50%) of the amount that would otherwise be payable in the event that repayment in full occurs on or after January 1, 2020 but prior to March 31, 2020.
PNC Facility [Member]
Earnings Before Interest , Tax ,Depreciation And Amortization										$ 9,240,000
PNC Facility [Member] | Scenario, Forecast [Member]
Earnings Before Interest , Tax ,Depreciation And Amortization				$ 9,270,000			$ 14,195,000					$ 9,428,000
Fixed Charge Coverage Ratio Requirement									1.00:1.00
Line of Credit Facility, Interest Rate Description		The Second Revolver Amendment also increases the applicable interest rate margin to 3% for Eurodollar Rate Loans (as defined in the PNC Facility) and 2% for Domestic Rate Loans (as defined in the PNC Facility) through September 30, 2019, with applicable margins thereafter of between 2.5% and 3% for Eurodollar Rate Loans and 1.5% and 2% for Domestic Rate Loans based on the applicable fixed charge coverage ratio.
Debt Instrument, Fee Amount		$ 250,000