XML 66 R54.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions | Sep. 30, 2018 | Jun. 30, 2018
--- | --- | ---
Goodwill And Intangible Assets [Line Items] |  |
Goodwill | $ 413.3 | $ 318.6
Diagnostics [Member] |  |
Goodwill And Intangible Assets [Line Items] |  |
Goodwill | 347.5 |
Other [Member] |  |
Goodwill And Intangible Assets [Line Items] |  |
Goodwill | $ 65.8 |

X
- Definition Goodwill and intangible assets. + References No definition available. + Details
Name: | mygn_GoodwillAndIntangibleAssetsLineItems
Namespace Prefix: | mygn_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=mygn_DiagnosticsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=us-gaap_AllOtherSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |