XML 51 R29.htm IDEA: XBRL DOCUMENT
v3.20.4

Fair Value Measurements (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2020
Fair Value Measurements |
Schedule of assets measured at fair value on a recurring basis | Assets measured at fair value on a recurring basis as of December 31, 2020 were as follows (in thousands): ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ |  | ​ | ​ |  | Quoted Prices |  | Significant |  | ​ | ​
​ | ​ | ​ | ​ | ​ | in Active | ​ | Other | ​ | Significant
​ | ​ | ​ | ​ | ​ | Markets for | ​ | Observable | ​ | Unobservable
​ | ​ | December 31, | ​ | Identical Assets | ​ | Inputs | ​ | Inputs
Financial Assets | ​ | 2020 | ​ | (Level 1) | ​ | (Level 2) | ​ | (Level 3)
Cash equivalents: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Money market funds | ​ | $ | 139,682 | ​ | $ | 139,682 | ​ | $ | — | ​ | $ | —
Marketable securities: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
U.S. Treasuries | ​ | ​ | 180,373 | ​ | ​ | 180,373 | ​ | ​ | — | ​ | ​ | —
Government agency securities | ​ | ​ | 107,645 | ​ | ​ | — | ​ | ​ | 107,645 | ​ | ​ | —
Commercial paper | ​ | ​ | 41,904 | ​ | ​ | — | ​ | ​ | 41,904 | ​ | ​ | —
Corporate bonds | ​ | ​ | 42,170 | ​ | ​ | — | ​ | ​ | 42,170 | ​ | ​ | —
Restricted cash and other non-current assets: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Money market funds | ​ | ​ | 3,877 | ​ | ​ | 3,877 | ​ | ​ | — | ​ | ​ | —
Total financial assets | ​ | $ | 515,651 | ​ | $ | 323,932 | ​ | $ | 191,719 | ​ | $ | —
​ Assets measured at fair value on a recurring basis as of December 31, 2019 were as follows (in thousands): ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ |  | ​ | ​ |  | Quoted Prices |  | Significant |  | ​ | ​
​ | ​ | ​ | ​ | ​ | in Active | ​ | Other | ​ | Significant
​ | ​ | ​ | ​ | ​ | Markets for | ​ | Observable | ​ | Unobservable
​ | ​ | December 31, | ​ | Identical Assets | ​ | Inputs | ​ | Inputs
Financial Assets | ​ | 2019 | ​ | (Level 1) | ​ | (Level 2) | ​ | (Level 3)
Cash equivalents: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Money market funds | ​ | $ | 230,201 | ​ | $ | 230,201 | ​ | $ | — | ​ | $ | —
U.S. Treasuries | ​ | ​ | 7,982 | ​ | ​ | 7,982 | ​ | ​ | — | ​ | ​ | —
Marketable securities: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
U.S. Treasuries | ​ | ​ | 63,386 | ​ | ​ | 63,386 | ​ | ​ | — | ​ | ​ | —
Government agency securities | ​ | ​ | 155,571 | ​ | ​ | 155,571 | ​ | ​ | — | ​ | ​ | —
Restricted cash and other non-current assets: | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Corporate equity securities | ​ | ​ | 3,667 | ​ | ​ | — | ​ | ​ | 3,667 | ​ | ​ | —
Money market funds | ​ | ​ | 1,619 | ​ | ​ | 1,619 | ​ | ​ | — | ​ | ​ | —
Total financial assets | ​ | $ | 462,426 | ​ | $ | 458,759 | ​ | $ | 3,667 | ​ | $ | —

X
- References No definition available. + Details
Name: | us-gaap_FairValueDisclosuresAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of assets and liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
Name: | us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration