Other Liabilities - Additional Information (Detail) - USD ($)	1 Months Ended		12 Months Ended
	Sep. 30, 2016	Oct. 31, 2013	Dec. 31, 2016	Dec. 31, 2015	Oct. 23, 2013
Office Furniture, Equipment and Systems [Member]
Other Liabilities [Line Items]
Net book value of capital leases			$ 62,000	$ 11,000
Office Furniture, Equipment and Systems [Member] | Minimum [Member]
Other Liabilities [Line Items]
Interest rate on capital leases			6.94%
Office Furniture, Equipment and Systems [Member] | Maximum [Member]
Other Liabilities [Line Items]
Interest rate on capital leases			8.56%
Silicon Valley Bank [Member]
Other Liabilities [Line Items]
Loan repaid date			2014-03
Term loan facility with Silicon Valley Bank					$ 4,000,000
Term loan, amount borrowed		$ 2,500,000
Common stock issued for exercise of warrants on a net settlement basis	3,001
Warrants to Purchase Common Stock [Member] | Silicon Valley Bank [Member]
Other Liabilities [Line Items]
Warrants to purchase shares of stock, shares					11,363
Warrants to purchase per share					$ 10.56