Notes Payable to Former Stockholders - Additional Information (Detail) - USD ($) $ in Millions |
9 Months Ended | |
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Sep. 30, 2018 |
Sep. 30, 2017 |
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| Restricted Stock - Notes Payable [Member] | ||
| Debt Instrument [Line Items] | ||
| Unsecured notes interest rate | 5.00% | |
| Unsecured notes maturity date | Jun. 30, 2020 | |
| SARs - Notes Payable [Member] | ||
| Debt Instrument [Line Items] | ||
| Unsecured notes interest rate | 5.00% | |
| Unsecured notes maturity date | Jun. 30, 2020 | |
| Notes Payable to Former Stockholders [Member] | ||
| Debt Instrument [Line Items] | ||
| Principal and interest payments on notes payable to former stockholders | $ 1.5 | $ 1.5 |
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- Definition Date when the notes payable to former stockholders is scheduled to be fully repaid. No definition available.
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Amount of the required periodic payments including both interest and principal payments. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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