Business combination contingent consideration number of performance based milestones.

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- Definition

Goodwill adjustment to deferred tax assets liabilities.

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Value of input used to measure alternative investment.

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Amount of direct costs of the business combination including legal, accounting, and other costs incurred to consummate the business acquisition.

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Date when the business acquisition agreement was executed, in CCYY-MM-DD format.

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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.

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No definition available.

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Total revenue reported by the acquired entity for its previous full fiscal year before the business acquisition.

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- Definition

For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid.

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Amount of liability recognized arising from contingent consideration in a business combination.

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Indicates valuation technique for measuring business combination contingent consideration liability.

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Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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- Definition

Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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Amount recognized for assets, including goodwill, in excess of (less than) the aggregate liabilities assumed.

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Amount of escrow deposit disbursements related to property acquisition in noncash investing or financing transactions.

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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.

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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.

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Amount of increase (decrease) of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting 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.

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Amount of transfers into (out 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.

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Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

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The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.

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Business Acquisitions - Additional Information (Detail) $ in Millions	1 Months Ended	10 Months Ended	12 Months Ended
	Aug. 31, 2016 USD ($) Milestone	Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Aug. 31, 2017 USD ($)
Business Acquisition [Line Items]
Cash payment on acquisition				$ 216.1	$ 37.0
Goodwill		$ 318.6	$ 318.6	316.1	$ 195.3
Change in non-controlling interest			1.9	$ 3.6
Assurex [Member]
Business Acquisition [Line Items]
Date of acquisition agreement	Aug. 31, 2016
Total consideration transferred	$ 351.6	351.6	351.6
Business acquisition, net cash acquired	5.5
Cash payment on acquisition	$ 216.1		216.1
Number of potential performance-based milestones \| Milestone	2
Additional payments upon completion of performance based milestones	$ 185.0
Contingent consideration	$ 130.0	130.0	130.0
Business Combination, Contingent Consideration, Liability, Valuation Technique [Extensible List]	mygn:MonteCarloMethodMember
Amount of cash consideration deposited in escrow account	$ 19.1
Goodwill		121.1	121.1			$ 119.2
Fair value increase to equipment		(0.1)	(0.1)
Change in non-controlling interest		0.2	0.2
Net increase to goodwill due to change in non-controlling interest			0.1
Increase in deferred tax liability due to differences in GAAP and tax purchase accounting		1.8	1.8
Acquired intangible assets		295.6	295.6
Acquisition costs		$ 5.0	5.0
Revenue contributed by acquired entity			124.9
Operating expenses related to acquired entity			$ 120.6
Assurex [Member] \| Measurement Input, Discount Rate [Member]
Business Acquisition [Line Items]
Estimated net cash flows, discount rate		16	16
Assurex [Member] \| Developed Technology [Member]
Business Acquisition [Line Items]
Acquired intangible assets		$ 256.5	$ 256.5
Intangible assets estimated useful lives			17 years
Assurex [Member] \| Database [Member]
Business Acquisition [Line Items]
Acquired intangible assets		$ 39.1	$ 39.1
Intangible assets estimated useful lives			5 years