Summary of Charges Related to Accrued Restructuring Activities (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Apr. 30, 2017		Apr. 30, 2017
Restructuring Cost and Reserve [Line Items]
Balance at beginning period		$ 1.4		$ 5.2
Restructuring charge		2.1		2.5
Adjustments				(0.1)
Cash payments		(1.1)		(5.2)
Balance at end period		2.4		2.4
Employee Severance and Benefits
Restructuring Cost and Reserve [Line Items]
Balance at beginning period		1.4	[1]	5.2	[2]
Restructuring charge		2.1	[1]	2.5	[2]
Adjustments	[2]			(0.1)
Cash payments		(1.1)	[1]	(5.2)	[2]
Balance at end period	[1],[2]	$ 2.4		$ 2.4

[1] Restructuring charges in fiscal year 2017 includes $2.1 million with respect to the Fiscal Year 2017 Restructuring Plan. All other activity pertains to the Fiscal Year 2016 Restructuring Plan.

[2] Restructuring charges in fiscal year 2017 includes $2.4 million with respect to the Fiscal Year 2017 Restructuring Plan. All other activity pertains to the Fiscal Year 2016 Restructuring Plan.