XML 89 R68.htm IDEA: XBRL DOCUMENT
v3.20.4

Fair Value of Financial Instruments (Details) - USD ($) | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | $ 441,186,000 | $ 363,542,000
Equity method investment, ownership percentage | 25.00% | 25.00%
Equity method investment | $ 2,800,000 | $ 3,600,000
Money market funds |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 32,815,000 | 10,065,000
U.S. Government bonds and notes |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 169,880,000 | 39,086,000
Corporate notes, bonds and commercial paper |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 238,491,000 | 314,391,000
Recurring basis |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 441,186,000 | 363,542,000
Recurring basis | Money market funds |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 32,815,000 | 10,065,000
Recurring basis | U.S. Government bonds and notes |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 169,880,000 | 39,086,000
Recurring basis | Corporate notes, bonds and commercial paper |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 238,491,000 | 314,391,000
Recurring basis | Quoted market prices in active markets (Level 1) |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 32,815,000 | 10,065,000
Recurring basis | Quoted market prices in active markets (Level 1) | Money market funds |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 32,815,000 | 10,065,000
Recurring basis | Quoted market prices in active markets (Level 1) | U.S. Government bonds and notes |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 0 | 0
Recurring basis | Quoted market prices in active markets (Level 1) | Corporate notes, bonds and commercial paper |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 0 | 0
Recurring basis | Significant other observable inputs (Level 2) |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 408,371,000 | 353,477,000
Recurring basis | Significant other observable inputs (Level 2) | Money market funds |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 0 | 0
Recurring basis | Significant other observable inputs (Level 2) | U.S. Government bonds and notes |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 169,880,000 | 39,086,000
Recurring basis | Significant other observable inputs (Level 2) | Corporate notes, bonds and commercial paper |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 238,491,000 | 314,391,000
Recurring basis | Significant unobservable inputs (Level 3) |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 0 | 0
Recurring basis | Significant unobservable inputs (Level 3) | Money market funds |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 0 | 0
Recurring basis | Significant unobservable inputs (Level 3) | U.S. Government bonds and notes |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 0 | 0
Recurring basis | Significant unobservable inputs (Level 3) | Corporate notes, bonds and commercial paper |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | $ 0 | $ 0

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 25 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8813-108599 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_EquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasuryAndGovernmentShorttermDebtSecuritiesMember
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: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |