XML 54 R43.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands | Sep. 30, 2017 | Dec. 31, 2016
--- | --- | ---
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | $ 142,258 | $ 121,151
Money market funds |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 12,882 | 10,681
US Treasury and Government Short-term Debt Securities [Member] |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 30,489 | 48,292
Corporate notes, bonds and commercial paper |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 98,887 | 62,178
Recurring basis |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 142,258 | 121,151
Recurring basis | Money market funds |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 12,882 | 10,681
Recurring basis | US Treasury and Government Short-term Debt Securities [Member] |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 30,489 | 48,292
Recurring basis | Corporate notes, bonds and commercial paper |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 98,887 | 62,178
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 | 14,169 | 10,984
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 | 12,882 | 10,681
Recurring basis | Quoted Market Prices in Active Markets (Level 1) | US Treasury and Government Short-term Debt Securities [Member] |  |
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 | 1,287 | 303
Recurring basis | Significant Other Observable Inputs (Level 2) |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 128,089 | 110,167
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) | US Treasury and Government Short-term Debt Securities [Member] |  |
Financial assets subject to fair value measurements and the necessary disclosures |  |
Total available-for-sale securities | 30,489 | 48,292
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 | 97,600 | 61,875
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) | US Treasury and Government Short-term Debt Securities [Member] |  |
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 Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=75030427&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26610-111562 + Details
Name: | us-gaap_AvailableForSaleSecurities
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_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_MoneyMarketFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USTreasuryAndGovernmentShorttermDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=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: |