Revenue - Additional Information (Detail)
3 Months Ended 9 Months Ended 1 Months Ended 3 Months Ended 9 Months Ended 1 Months Ended 3 Months Ended 9 Months Ended 1 Months Ended 3 Months Ended 9 Months Ended 3 Months Ended 9 Months Ended 3 Months Ended 9 Months Ended
Sep. 30, 2013
USD ($)
Sep. 30, 2014
USD ($)
Sep. 30, 2014
RUB
Sep. 30, 2013
USD ($)
Sep. 30, 2013
RUB
Dec. 31, 2013
Amgen, Inc. [Member]
Jan. 31, 2013
Amgen, Inc. [Member]
USD ($)
Sep. 30, 2014
Amgen, Inc. [Member]
USD ($)
Jun. 30, 2014
Amgen, Inc. [Member]
USD ($)
Sep. 30, 2013
Amgen, Inc. [Member]
USD ($)
Sep. 30, 2014
Amgen, Inc. [Member]
USD ($)
Sep. 30, 2013
Amgen, Inc. [Member]
USD ($)
Mar. 31, 2013
Pfizer Inc. [Member]
USD ($)
Option
Sep. 30, 2014
Pfizer Inc. [Member]
USD ($)
Sep. 30, 2013
Pfizer Inc. [Member]
USD ($)
Sep. 30, 2014
Pfizer Inc. [Member]
USD ($)
Sep. 30, 2013
Pfizer Inc. [Member]
USD ($)
Apr. 30, 2013
AstraZeneca AB [Member]
USD ($)
Sep. 30, 2014
AstraZeneca AB [Member]
USD ($)
Sep. 30, 2013
AstraZeneca AB [Member]
USD ($)
Sep. 30, 2014
AstraZeneca AB [Member]
USD ($)
Sep. 30, 2013
AstraZeneca AB [Member]
USD ($)
Sep. 30, 2014
Ministry of Industry and Trade of Russian Federation [Member]
Russia [Member]
USD ($)
Sep. 30, 2013
Ministry of Industry and Trade of Russian Federation [Member]
Russia [Member]
USD ($)
Sep. 30, 2014
Ministry of Industry and Trade of Russian Federation [Member]
Russia [Member]
USD ($)
Sep. 30, 2013
Ministry of Industry and Trade of Russian Federation [Member]
Russia [Member]
USD ($)
Sep. 30, 2014
F. Hoffmann-La Roche Ltd [Member]
USD ($)
Sep. 30, 2014
F. Hoffmann-La Roche Ltd [Member]
USD ($)
Revenues [Line Items]                                                        
Total revenue   $ 600,000 22,300,000 $ 600,000 19,900,000                                              
Contract amount recognized 151,000 418,000   516,000                                     0 200,000 400,000 500,000    
Company recognized amount related to the research, option and license agreement               0   1,600,000 800,000 3,900,000   300,000 1,400,000 400,000 2,100,000   2,800,000 1,300,000 5,500,000 1,900,000         300,000 300,000
Company received upfront payment             5,000,000   800,000       4,000,000         4,000,000                    
Total contingent payments                         89,500,000         193,000,000                    
Company granted option                         2                              
Agreement expiration period                         2015-09                              
Additional contingent payments                         $ 110,000,000                              
Option exercise period           9 months                                            
Reduction in net loss per share, basic and diluted                 $ 0.05