Segment and Related Information (Tables)

6 Months Ended

Dec. 31, 2018

Segment Reporting [Abstract]

Schedule of Segment Performance Based on Income (Loss) before Interest Income and Other Income and Expense

Segment revenue and operating income (loss) were as follows during the periods presented:

	Diagnostics		Other			Total
Three months ended December 31, 2018
Revenues	$	203.0	$	13.8		$	216.8
Depreciation and amortization		16.7		1.3			18.0
Segment operating income (loss)		28.4		(22.3	)		6.1
Three months ended December 31, 2017
Revenues	$	173.1	$	14.8		$	187.9
Depreciation and amortization		11.7		1.4			13.1
Segment operating income		36.5		(30.2	)		6.3
Six months ended December 31, 2018
Revenues	$	392.0	$	27.1		$	419.1
Depreciation and amortization		33.7		2.6			36.3
Segment operating income		56.0		(48.7	)		7.3
Six months ended December 31, 2017
Revenues	$	340.5	$	26.2		$	366.7
Depreciation and amortization		23.5		2.8			26.3
Segment operating income (loss)		67.0		23.3			90.3

	Three months ended						Six months ended
	December 31,						December 31,
	2018			2017			2018			2017
Total operating income for reportable segments	$	6.1		$	6.3		$	7.3		$	90.3
Unallocated amounts:
Interest income		0.9			0.4			1.6			0.8
Interest expense		(3.4	)		(0.7	)		(5.6	)		(1.6	)
Other		0.0			(0.4	)		1.1			(0.7	)
Income from operations before income taxes		3.6			5.6			4.4			88.8
Income tax provision		1.0			(25.3	)		2.6			(20.8	)
Net income (loss)		2.6			30.9			1.8			109.6
Net loss attributable to non-controlling interest		—			—			(0.1	)		(0.1	)
Net income (loss) attributable to Myriad Genetics, Inc.    stockholders	$	2.6		$	30.9		$	1.9		$	109.7