Significant Accounting Policies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Cash equivalents maturity period	3 months
Short-term investments maturity period	90 days
Period of royalties notification, minimum	30 days
Period of royalties notification, maximum	45 days
Cost capitalized	$ 0
Advertising expense	265,000	$ 344,000	$ 322,000
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred income tax assets, noncurrent	24,633,000	25,419,000
Deferred income tax assets, current	0	$ 9,377,000
New Accounting Principles, Early Adoption, Effect
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred income tax assets, noncurrent	2,900,000
Deferred income tax assets, current	$ (2,900,000)