Shareholders' Equity - Summary of Shares of Common Stock Reserved for Future Issuance under Plans (Detail) - shares	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Common Stock Number Of Shares Par Value And Other Disclosures [Abstract]
Stock options outstanding	1,778,697	1,553,360	1,515,621
Restricted stock units outstanding	104,463	80,179
Stock options available for future grant	1,020,477	654,083
Common stock reserved for future issuance	2,903,637	2,287,622