XML 27 R46.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Investment in Joint Venture (Details) - USD ($)
$ in Millions
1 Months Ended 12 Months Ended
May 31, 2018
Dec. 31, 2019
Dec. 31, 2018
Apr. 30, 2018
Schedule of Equity Method Investments [Line Items]        
Variable interest entity, assets   $ 45.1 $ 48.3  
Noncontrolling interest in net loss joint venture   3.9    
Redeemable noncontrolling interest, fair value adjustment   11.7    
Guardant Health AMEA, Inc        
Schedule of Equity Method Investments [Line Items]        
Payments to acquire interest in joint venture $ 9.0      
Equity method investment, shares purchased 40,000      
Equity method investment, ownership percentage 50.00%     50.00%
Redeemable noncontrolling interest, fair value   $ 41.0    
Threshold period for unremedied material breach of the joint venture agreement by the other party   20 days    
Threshold percentage of fair value that is no less than internal rate of return   20.00%    
Percentage of the product   40.00%    
SoftBank | Guardant Health AMEA, Inc        
Schedule of Equity Method Investments [Line Items]        
Payments to acquire interest in joint venture $ 41.0      
Equity method investment, shares purchased 40,000      
Equity method investment, ownership percentage 50.00%      
Redeemable noncontrolling interest, redemption value $ 41.0      
Threshold percentage of fair value (greater than)   40.00%