XML 101 R85.htm IDEA: XBRL DOCUMENT
v3.20.4

Cash, Cash Equivalents, and Marketable Debt Securities - Schedule of Marketable Debt Securities in Continuous Loss Position (Details) $ in Millions | Dec. 31, 2020 USD ($) security | Dec. 31, 2019 USD ($) security
--- | --- | ---
Schedule Of Available For Sale Securities [Line Items] |  |
Fair Value of Marketable Debt Securities | $ | $ 48.1 | $ 78.1
Number of Marketable Debt Securities in a Loss Position | security | 62 | 71
Certificates of Deposit |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Fair Value of Marketable Debt Securities | $ | $ 1.3 |
Number of Marketable Debt Securities in a Loss Position | security | 2 |
Commercial Paper |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Fair Value of Marketable Debt Securities | $ | $ 2.2 | $ 0.8
Number of Marketable Debt Securities in a Loss Position | security | 1 | 1
U.S. Treasury Securities |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Fair Value of Marketable Debt Securities | $ | $ 1.7 | $ 14.0
Number of Marketable Debt Securities in a Loss Position | security | 3 | 9
Corporate Debt Securities |  |
Schedule Of Available For Sale Securities [Line Items] |  |
Fair Value of Marketable Debt Securities | $ | $ 42.9 | $ 63.3
Number of Marketable Debt Securities in a Loss Position | security | 56 | 61

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position without allowance for credit loss. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=121582814&loc=SL82922888-210455 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=121590138&loc=SL82922954-210456 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 50 -Paragraph 4 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=121582814&loc=SL82922888-210455 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CertificatesOfDepositMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_CommercialPaperMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |