Leases, Commitments and Contingencies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015 USD ($) LegalMatter	Dec. 31, 2014 USD ($)	Jul. 18, 2007 ft²
Future Minimum Lease Payments Under Noncancellable Operating Leases [Line Items]
Lease expiration year	2016
Number of square feet | ft²			72,000
Deferred rent	$ 37,000	$ 97,000
Building rent expense	591,000	593,000
Payments related to indemnifications	0	0
Liabilities related to indemnifications obligation	$ 0	$ 0
Claims or pending litigation | LegalMatter	0
Mendel [Member]
Future Minimum Lease Payments Under Noncancellable Operating Leases [Line Items]
Number of square feet | ft²			48,000