XML 85 R73.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Fair Value Measurements - Schedule of Fair Value of Financial Assets and Liabilities (Detail) - USD ($) $ in Millions | Sep. 30, 2018 | Jun. 30, 2018
--- | --- | ---
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets and liability |  | $ 93.0 | $ 101.2
Money Market Funds [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets | [1] | 6.1 | 12.5
Corporate Bonds and Notes [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets |  | 60.7 | 53.3
Municipal Bonds [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets |  | 23.4 | 29.2
Federal Agency Issues [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets |  | 9.5 | 12.4
US Government Securities [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets |  | 8.2 | 8.3
Contingent Consideration [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial liability |  | (14.9) | (14.5)
Level 1 [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets and liability |  | 9.5 | 15.3
Level 1 [Member] | Money Market Funds [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets | [1] | 6.1 | 12.5
Level 1 [Member] | Corporate Bonds and Notes [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets |  | 3.4 | 2.8
Level 2 [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets and liability |  | 98.4 | 100.4
Level 2 [Member] | Corporate Bonds and Notes [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets |  | 57.3 | 50.5
Level 2 [Member] | Municipal Bonds [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets |  | 23.4 | 29.2
Level 2 [Member] | Federal Agency Issues [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets |  | 9.5 | 12.4
Level 2 [Member] | US Government Securities [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets |  | 8.2 | 8.3
Level 3 [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial assets and liability |  | (14.9) | (14.5)
Level 3 [Member] | Contingent Consideration [Member] |  |  |
Fair Value, Option, Qualitative Disclosures Related to Election [Line Items] |  |  |
Total fair value of financial liability |  | $ (14.9) | $ (14.5)
[1] | Money market funds are primarily comprised of exchange traded funds and accrued interest

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=99377789&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of asset after deduction of liability. + References No definition available. + Details
Name: | us-gaap_FairValueNetAssetLiability
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_FairValueOptionQualitativeDisclosuresRelatedToElectionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of financial and nonfinancial obligations. + 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=99377789&loc=d3e19207-110258 + Details
Name: | us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

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

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

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

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

X
- Details
Name: | us-gaap_ContingentConsiderationByTypeAxis=mygn_ContingentConsiderationMember
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: |