Selected Balance Sheet Data - Additional Information (Detail) - USD ($) |
3 Months Ended | 6 Months Ended | |||||||
|---|---|---|---|---|---|---|---|---|---|
Jan. 01, 2016 |
Jan. 01, 2015 |
Jan. 01, 2014 |
Jun. 30, 2016 |
Jun. 30, 2015 |
Jun. 30, 2016 |
Jun. 30, 2015 |
Dec. 31, 2015 |
Mar. 31, 2013 |
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| Schedule Of Accrued Expenses [Line Items] | |||||||||
| SARs frozen liability amount | $ 21,856,000 | $ 21,856,000 | $ 21,399,000 | ||||||
| Interest expense | 384,000 | $ 386,000 | $ 775,000 | $ 969,000 | |||||
| Maximum payment deferral period for certain commissions payable | 3 years | ||||||||
| Fair value of deferred compensation plan assets | 110.00% | ||||||||
| SARs [Member] | |||||||||
| Schedule Of Accrued Expenses [Line Items] | |||||||||
| SARs frozen liability amount | $ 20,000,000 | ||||||||
| SARs liability frozen value date | Mar. 31, 2013 | ||||||||
| SARs liability interest accrual commencement date | Jan. 01, 2014 | ||||||||
| Interest expense | $ 228,000 | $ 214,000 | $ 457,000 | $ 428,000 | |||||
| Treasury note term | 10 years | ||||||||
| Base spread on SARs liability variable rate | 2.00% | ||||||||
| SARs liability interest accrual rates | 4.273% | 4.173% | |||||||
| X | ||||||||||
- Definition Maximum payment deferral period for certain commissions payable. No definition available.
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| X | ||||||||||
- Definition The amount the Company may, in its sole and absolute discretion, elect to withdraw at any time all or a portion of the amount by which the fair market value of the Deferred Compensation Plan's assets exceeds the stated percentage of the aggregate amount credited to the Deferred Compensation Plan's participants' accounts. No definition available.
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| X | ||||||||||
- Definition Schedule Of Accrued Expenses [Line Items] No definition available.
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| X | ||||||||||
- Definition Aggregate carrying value (includes principal and accrued interest) as of the balance sheet date of deferred compensation associated with Stock Appreciation Rights payable to each participant in installments upon retirement or departure under terms of the agreement. No definition available.
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| X | ||||||||||
- Definition SARS liability frozen value date. No definition available.
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| X | ||||||||||
- Definition SARS liability interest accrual commencement date No definition available.
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| X | ||||||||||
- Definition Interest accrual rate for the outstanding balance on the SARs liability. No definition available.
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| X | ||||||||||
- Definition Treasury note term rate used to determine SARs liability interest accrual rate. No definition available.
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| X | ||||||||||
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. No definition available.
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| X | ||||||||||
- Definition Amount of the cost of borrowed funds accounted for as interest expense. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Details
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