XML 94 R63.htm IDEA: XBRL DOCUMENT
v3.19.3

Fair Value Measurements - Summary of Placement in the Fair Value Hierarchy of Financial Assets that are Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018
--- | --- | ---
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | $ 64,233 | $ 122,181
Quoted Prices in Active Markets (Level 1) |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 1,687 | 1,626
Significant Other Observable Inputs (Level 2) |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 45,836 | 120,364
Significant Unobservable Inputs (Level 3) |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 16,710 | 191
U.S. government debt securities |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 44,945 | 119,340
U.S. government debt securities | Quoted Prices in Active Markets (Level 1) |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 0 | 0
U.S. government debt securities | Significant Other Observable Inputs (Level 2) |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 44,945 | 119,340
U.S. government debt securities | Significant Unobservable Inputs (Level 3) |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 0 | 0
Equity securities |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 18,305 | 2,182
Equity securities | Quoted Prices in Active Markets (Level 1) |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 1,687 | 1,626
Equity securities | Significant Other Observable Inputs (Level 2) |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 298 | 556
Equity securities | Significant Unobservable Inputs (Level 3) |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 16,320 | 0
Other |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 983 | 659
Other | Quoted Prices in Active Markets (Level 1) |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 0 | 0
Other | Significant Other Observable Inputs (Level 2) |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | 593 | 468
Other | Significant Unobservable Inputs (Level 3) |  |
Assets |  |
Fair value of financial assets measured at fair value on a recurring basis | $ 390 | $ 191

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -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_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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: |

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

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

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