Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ (438,000)	$ 29,000	$ (916,000)	$ 29,000
Effective tax rate			(0.59%)	(1.00%)
Federal and state Net Operating Losses	145,000,000		$ 145,000,000
Year of expiration of net operating loss carryforward expiration year			2027
Accruals related to uncertainties tax positions	$ 0	$ 0	$ 0	$ 0
Tax year remain subject to examination			2014 2015 2016 2017

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The amount of estimated penalties and interest accrued as of the balance sheet date arising from income tax examinations.

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Tax year being audited in the income tax examination, in CCYY format.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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