Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 246,000	$ 116,000	$ 63,000
Deferred tax assets operating loss carryforwards federal	82,108,000	58,846,000
State net operating loss carryforwards	$ 78,205,000	47,386,000
Federal net operating loss carryforwards start to expire	Dec. 31, 2025
State net operating loss carryforwards start to expire	Dec. 31, 2019
Net operating loss carryforwards and other deferred tax assets	$ 0	0
Valuation allowance	37,448,000	24,013,000
Net change in valuation allowance	13,435,000	9,662,000
Increase in equity due to untimely realization of deferred tax assets	455,000	455,000
Net operating loss, expected to expire	$ 430,000
Percentage of eligible tax positions for recognition	50.00%
Unrecognized Tax Benefits	$ 0	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	0	0
Liability for Uncertain Tax Positions, Noncurrent	$ 0	$ 0