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Investment in Joint Venture (Details) - USD ($)
$ in Thousands
1 Months Ended 3 Months Ended
May 31, 2018
Mar. 31, 2019
Mar. 31, 2018
Dec. 31, 2018
Apr. 30, 2018
Schedule of Equity Method Investments [Line Items]          
Variable interest entity, assets   $ 47,000   $ 48,300  
Redeemable noncontrolling interest   46,500   $ 41,800  
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest   $ 4,700 $ 0    
Guardant Health AMEA, Inc          
Schedule of Equity Method Investments [Line Items]          
Payments to acquire interest in joint venture $ 9,000        
Equity method investment, shares purchased 40,000        
Equity method investment, ownership percentage 50.00%       50.00%
SoftBank | Guardant Health AMEA, Inc          
Schedule of Equity Method Investments [Line Items]          
Equity method investment, shares purchased 40,000        
Equity method investment, ownership percentage 50.00%        
Redeemable noncontrolling interest, redemption value $ 41,000