Capital Stock - Reserved Shares of Common Stock (Detail) - shares	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Equity [Abstract]
Issuance in connection with outstanding stock options	1,570,765	1,949,089	2,244,363	1,675,506
Issuance in connection with restricted stock units outstanding	1,994,790	1,898,025	2,279,081
Reserved for future stock option and restricted stock unit grants	2,464,181	1,726,346
Reserved for future issuance under the employee stock purchase plan	1,161,396	1,049,524
Total	7,191,132	6,622,984