Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Tax Contingency [Line Items]
Deferred tax assets, valuation allowance	$ 28,448,000	$ 13,645,000
Deferred tax assets, valuation allowance, change in amount	14,800,000	8,900,000
Unrecognized deferred tax assets related to stock compensation	100,000
Deferred tax assets, federal operating loss carry forwards	57,000,000
Deferred tax assets, state operating loss carry forwards	$ 54,500,000
Operating loss carry forwards, expiry year start	2021
Operating loss carry forwards, expiry year end	2035
Deferred tax credit carry forwards	$ 1,900,000
Deferred tax credit carry forwards, year begin to expiration	2031
Unrecognized tax benefits, accrued interest and penalties	$ 0	$ 0
Earliest Tax Year [Member]
Income Tax Contingency [Line Items]
Open tax year	2012
Latest Tax Year [Member]
Income Tax Contingency [Line Items]
Open tax year	2014