Income taxes (Tables)

9 Months Ended

Apr. 30, 2018

Income Tax Disclosure [Abstract]

Provision for Income Taxes and Effective Tax Rate

The following table presents the provision for income taxes and our effective tax rate for the three and nine months ended April 30, 2018 and 2017:

	Three Months Ended						Nine Months Ended
	April 30,						April 30,
(in millions except percentages)	2018			2017			2018			2017
Provision (benefit) for income taxes	$	0.5		$	(4.9	)	$	13.1		$	(1.9	)
Effective tax rate		7	%		8	%		40	%		4	%