Long-term debts, net - Scheduled Future Maturities of Total Debts (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total maturities		$ 65,000
Less: unamortized debt issuance costs		3,737
Long-term debt, net		$ 62,963
Refinanced Term Loan Due 2023
Debt Instrument [Line Items]
2019	$ 3,500
2020	3,500
2021	3,500
2022	3,500
2023	46,320
Total maturities	60,320
Less: unamortized debt issuance costs	4,848
Long-term debt, net	$ 55,472

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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