XML 41 R25.htm IDEA: XBRL DOCUMENT v3.8.0.1
Organization and Operations - Additional Information (Detail) - USD ($)
$ in Thousands
 9 Months Ended
Sep. 30, 2017
Dec. 31, 2016
Mar. 24, 2015
Organization and operations [Line Items]      
Company formation date Oct. 28, 2013    
Company formation country name Basel, Switzerland    
Accumulated deficit $ (125,580) $ (57,083)  
Cash $ 253,519 $ 315,520  
CRISPR Therapeutics Limited [Member] | United Kingdom [Member]      
Organization and operations [Line Items]      
Subsidiary formation date Feb. 07, 2014    
CRISPR Therapeutics, Inc. [Member] | United States [Member]      
Organization and operations [Line Items]      
Subsidiary formation date Feb. 16, 2015    
TRACR Hematology Limited [Member]      
Organization and operations [Line Items]      
Formation date, VIE Jan. 23, 2014    
Relationship nature and extent of involvement in VIE On January 23, 2014, the founders of the Company formed TRACR Hematology Limited (“TRACR”), wholly-owned subsidiary of the Company, in the United Kingdom, to further the development of the CRISPR/Cas9 technology into medicines for the treatment of blood-borne illnesses. As the Company was funding and managing TRACR’s operations in 2014, it has been consolidated by the Company from the date that the Company established a variable interest in TRACR in April 2014. In March 2015, the Company acquired 82.1% of the outstanding equity of TRACR in a share exchange transaction. Concurrent with its initial public offering (“IPO”) in October 2016, the Company acquired the outstanding non-controlling interest in TRACR.    
Purpose of VIE To further the development of the CRISPR/Cas9 technology into medicines for the treatment of blood-borne illnesses.    
Percentage of outstanding equity acquired     82.10%