XML 42 R32.htm IDEA: XBRL DOCUMENT v3.20.2
Financial Instruments - Cash Equivalents, Restricted Cash and Investments, Classified as Available-for-Sale Securities (Details) - USD ($)
$ in Thousands
Sep. 30, 2020
Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost $ 990,548 $ 535,042
Unrealized Gains 1,444 1,595
Unrealized Losses (48) (8)
Cash equivalents 101,065 122,900
Debt Securities, Available-for-sale, Current 682,886 355,407 [1]
Debt Securities, Available-for-sale, Noncurrent 207,993 58,322 [1]
Total cash equivalents and investments 991,944 536,629
Money market funds    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 101,013 122,900
Unrealized Gains 0 0
Unrealized Losses 0 0
Fair Value 101,013 122,900
Commercial paper    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 73,938 204,144
Unrealized Gains 30 871
Unrealized Losses 0 (4)
Fair Value 73,968 205,011
Corporate bonds    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 284,902 181,340
Unrealized Gains 784 557
Unrealized Losses (29) (3)
Fair Value 285,657 181,894
U.S. treasury securities    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 468,178 25,658
Unrealized Gains 561 167
Unrealized Losses (14) (1)
Fair Value 468,725 25,824
U.S. agency securities    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost 62,517  
Unrealized Gains 69  
Unrealized Losses (5)  
Fair Value $ 62,581  
Certificates of deposit    
Debt Securities, Available-for-sale [Line Items]    
Amortized Cost   1,000
Unrealized Gains   0
Unrealized Losses   0
Fair Value   $ 1,000
[1] The balance sheet as of December 31, 2019 is derived from the audited financial statements as of that date.