Annual report pursuant to Section 13 and 15(d)

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

v3.20.4
Marketable Securities and Fair Value Measurements - Summary of Company's Available-for-Sale Securities (Detail) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis $ 92,443 $ 125,487
Fair Value 68,667 39,633
Fair Value 0 1,510
Cash Equivalents - Money Market Funds, Commercial Paper and Corporate Bonds    
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis 23,793 84,361
Unrealized Gain 0 1
Unrealized Loss 0 0
Fair Value 23,793 84,362
Marketable Securities, Current - Commercial Paper, Treasury Bills and Corporate Bonds    
Schedule Of Available For Sale Securities [Line Items]    
Cost Basis 68,650 39,616
Unrealized Gain 19 17
Unrealized Loss (2) 0
Fair Value 68,667 39,633
Marketable Securities, Non-current - Treasury Bills    
Schedule Of Available For Sale Securities [Line Items]    
Unrealized Gain 0 0
Unrealized Loss 0 0
Cost Basis 0 1,510
Fair Value $ 0 $ 1,510