Intangible assets and goodwill (Tables)

6 Months Ended

Jan. 31, 2017

Goodwill and Intangible Assets Disclosure [Abstract]

Finite-Lived Intangible Assets

Finite-lived intangible assets are summarized as follows:

			As of January 31, 2017						As of July 31, 2016
(in millions)	Weighted Average Amortization Period		Cost		Accumulated Amortization/ Write-Offs		Net		Cost		Accumulated Amortization		Net
Developed technologies		10 years	$	29.2	$	16.5	$	12.7	$	29.9	$	15.1	$	14.8
Customer relationships		13 years		46.8		27.2		19.6		47.1		25.2		21.9
Trade names		3 years		1.8		1.1		0.7		1.9		1.0		0.9
Total finite-lived intangible assets			$	77.8	$	44.8	$	33.0	$	78.9	$	41.3	$	37.6

Estimated Future Amortization Expense Related to Intangible Assets

The estimated future amortization expense related to intangible assets for the five succeeding fiscal years is expected to be as follows:

(in millions)	Estimated Future Amortization Expense
Remaining 2017	$	3.9
2018		6.8
2019		5.6
2020		5.2
2021		4.8
Thereafter		6.7
	$	33.0

Changes in the Carrying Amount of Goodwill by Reportable Segments

Changes in the carrying amount of goodwill by reportable segments for the six months ended January 31, 2017 are as follows:

(in millions)	Medical Imaging		Ultrasound			Security and Detection		Total Goodwill
Balance as of July 31, 2016 Goodwill	$	1.9	$	71.5		$	0.5	$	73.9
Impairment losses		—		(9.8	)		—		(9.8	)
Balance as of January 31, 2017 Goodwill		1.9		71.5			0.5		73.9
Accumulated impairment losses		—		(9.8	)		—		(9.8	)
	$	1.9	$	61.7		$	0.5	$	64.1