Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Summary of Fair Value Assets Measured on Recurring Basis for Cash, Cash Equivalents and Marketable Securities (Details)

v3.20.4
Summary of Significant Accounting Policies - Summary of Fair Value Assets Measured on Recurring Basis for Cash, Cash Equivalents and Marketable Securities (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Cash and cash equivalents $ 211,962 $ 198,037
Fair Value Measurements Recurring    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Adjusted cost 231,219 209,086
Gross unrealized gains (losses)   8
Fair value 231,219 209,094
Cash and cash equivalents 211,962 198,037
Marketable securities 19,257 11,057
Fair Value Measurements Recurring | Cash    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Adjusted cost 52,812 51,560
Fair value 52,812 51,560
Cash and cash equivalents 52,812 51,560
Fair Value Measurements Recurring | Level 1 | Money Market Accounts    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Adjusted cost 159,150 146,477
Fair value 159,150 146,477
Cash and cash equivalents 159,150 146,477
Fair Value Measurements Recurring | Level 2 | Corporate Bonds    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Adjusted cost 11,549 2,011
Gross unrealized gains (losses) (1) 2
Fair value 11,548 2,013
Marketable securities 11,548 2,013
Fair Value Measurements Recurring | Level 2 | US Treasury Securities    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Adjusted cost 4,107 9,038
Gross unrealized gains (losses)   6
Fair value 4,107 9,044
Marketable securities 4,107 $ 9,044
Fair Value Measurements Recurring | Level 2 | Agency Mortgage-backed Securities    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]    
Adjusted cost 3,601  
Gross unrealized gains (losses) 1  
Fair value 3,602  
Marketable securities $ 3,602