Annual report pursuant to Section 13 and 15(d)

Marketable Securities and Fair Value Measurements - Summary of Company's Available-for-Sale Securities (Detail)

v3.20.1
Marketable Securities and Fair Value Measurements - Summary of Company's Available-for-Sale Securities (Detail) - USD ($)
$ in Thousands
Dec. 31, 2019
Dec. 31, 2018
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis $ 125,487  
Fair Value 39,633 $ 10,234
Fair Value 1,510 0
Cash Equivalents - Money Market Funds, Commercial Paper and Corporate Bonds    
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis 84,361  
Unrealized Gain 1  
Unrealized Loss 0  
Fair Value 84,362  
Marketable Securities, Current - Commercial Paper, Treasury Bills and Corporate Bonds    
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis 39,616  
Unrealized Gain 17  
Unrealized Loss 0  
Fair Value 39,633  
Marketable Securities, Non-current - Treasury Bills    
Schedule Of Available For Sale Securities [Line Items]    
Unrealized Gain 0  
Unrealized Loss 0  
Cost Basis 1,510  
Fair Value $ 1,510  
Cash Equivalents - Money Market Funds    
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis   85,434
Unrealized Gain   0
Unrealized Loss   0
Fair Value   85,434
Marketable Securities, Current - Commercial Paper    
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis   10,234
Unrealized Gain   0
Unrealized Loss   0
Fair Value   $ 10,234