Income Taxes - Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Assets
Deferred compensation	$ 8,358	$ 8,005
Loss carryforwards	1,240	1,208
Accruals deductible for tax purposes when paid	452	409
Depreciation	56	57
Allowance for doubtful accounts	300	324
State taxes	767us-gaap_DeferredTaxAssetsStateTaxes	836us-gaap_DeferredTaxAssetsStateTaxes
Gross deferred tax assets	11,173us-gaap_DeferredTaxAssetsGross	10,839us-gaap_DeferredTaxAssetsGross
Deferred tax asset valuation allowance	(3,135)	(2,170)	(2,269)	(1,404)
Gross deferred tax assets less valuation allowance	8,038us-gaap_DeferredTaxAssetsNet	8,669us-gaap_DeferredTaxAssetsNet	8,485us-gaap_DeferredTaxAssetsNet
Liabilities
Depreciation	(470)	(965)
Other	(125)us-gaap_DeferredTaxLiabilitiesOther	(197)us-gaap_DeferredTaxLiabilitiesOther
Gross deferred tax liabilities	(595)us-gaap_DeferredIncomeTaxLiabilities	(1,162)us-gaap_DeferredIncomeTaxLiabilities
Net deferred tax assets	7,443us-gaap_DeferredTaxAssetsLiabilitiesNet	7,507us-gaap_DeferredTaxAssetsLiabilitiesNet
Net current assets	1,079us-gaap_DeferredTaxAssetsNetCurrent	1,113us-gaap_DeferredTaxAssetsNetCurrent
Net non-current assets	6,364us-gaap_DeferredTaxAssetsNetNoncurrent	6,487us-gaap_DeferredTaxAssetsNetNoncurrent
Net non-current liabilities	$ 0	$ 93

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards expected to be realized or consumed within one year or operating cycle, if longer.

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Amount after allocation of valuation allowances of noncurrent deferred tax asset attributable to deductible temporary differences and carryforwards. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible operating loss carryforwards.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from property, plant, and equipment.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from state taxes.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from share-based compensation.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from reserves and accruals.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from the allowance for doubtful accounts.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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Amount of deferred tax liability attributable to taxable temporary differences not separately disclosed.

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