Finite-Lived Intangible Assets (Detail) - USD ($) $ in Millions	6 Months Ended
	Jan. 31, 2017	Jul. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Cost	$ 77.8	$ 78.9
Accumulated Amortization	44.8	41.3
Net	$ 33.0	37.6
Developed technologies
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Amortization Period	10 years
Cost	$ 29.2	29.9
Accumulated Amortization	16.5	15.1
Net	$ 12.7	14.8
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Amortization Period	13 years
Cost	$ 46.8	47.1
Accumulated Amortization	27.2	25.2
Net	$ 19.6	21.9
Trade names
Finite-Lived Intangible Assets [Line Items]
Weighted-Average Amortization Period	3 years
Cost	$ 1.8	1.9
Accumulated Amortization	1.1	1.0
Net	$ 0.7	$ 0.9