Goodwill and intangible assets.

No definition available.

Name:	mygn_GoodwillAndIntangibleAssetsLineItems
Namespace Prefix:	mygn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 928
-SubTopic 340
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6473545&loc=d3e61844-108004

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

+ Details

Name:	us-gaap_FiniteLivedIntangibleAssetsGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of increase in assets, excluding financial assets, lacking physical substance with a definite life, from an acquisition.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

+ Details

Name:	us-gaap_FinitelivedIntangibleAssetsAcquired1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13854-109267

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=99380562&loc=d3e13777-109266

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 55
-Paragraph 24
-URI https://asc.fasb.org/extlink&oid=122137925&loc=d3e14258-109268

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (e)
-URI https://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of an intangible asset (excluding goodwill) to fair value.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275

+ Details

Name:	us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_CustomerRelationshipsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=mygn_GatewayGenomicsLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_TrademarksMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_DevelopedTechnologyRightsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReportingUnitAxis=mygn_MyriadAutoimmuneReportingUnitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ReportingUnitAxis=mygn_ClinicReportingUnitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Goodwill and Intangible Assets - Narrative (Details) - USD ($)		3 Months Ended	6 Months Ended	12 Months Ended
	Nov. 01, 2022	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Jun. 30, 2020
Goodwill And Intangible Assets [Line Items]
Goodwill impairment charge			$ 0	$ 0	$ 0
Estimated remaining useful life				14 years 4 months 24 days	14 years 7 months 6 days
Impairment of long-lived assets			$ 0	$ 0	$ 0	$ 17,700,000
Customer relationships
Goodwill And Intangible Assets [Line Items]
Gross carrying amount, amortizable				$ 1,600,000
Estimated remaining useful life				10 years
Customer relationships \| Gateway Genomics, LLC
Goodwill And Intangible Assets [Line Items]
Identifiable intangible assets	$ 1,600,000
Trademarks
Goodwill And Intangible Assets [Line Items]
Gross carrying amount, amortizable				$ 6,100,000
Estimated remaining useful life				10 years
Trademarks \| Gateway Genomics, LLC
Goodwill And Intangible Assets [Line Items]
Identifiable intangible assets	6,100,000
Developed technologies
Goodwill And Intangible Assets [Line Items]
Gross carrying amount, amortizable				$ 625,000,000.0	$ 616,600,000
Estimated remaining useful life				14 years 4 months 24 days	14 years 7 months 6 days
Developed technologies \| Gateway Genomics, LLC
Goodwill And Intangible Assets [Line Items]
Identifiable intangible assets	$ 10,100,000
Developed technologies \| Minimum
Goodwill And Intangible Assets [Line Items]
Estimated remaining useful life				8 years
Developed technologies \| Maximum
Goodwill And Intangible Assets [Line Items]
Estimated remaining useful life				13 years
Myriad Autoimmune reporting unit
Goodwill And Intangible Assets [Line Items]
Goodwill impairment charge		$ 80,700,000
Clinic reporting unit
Goodwill And Intangible Assets [Line Items]
Goodwill impairment charge						$ 1,300,000