Summary of Business Operations and Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 31, 2014 Segment	Jul. 31, 2013	Jul. 31, 2012
Significant Accounting Policies [Line Items]
Total unbilled receivables	$ 5.8	$ 4.9
Long-term portion of unbilled receivables	0	1.8
Total deferred revenue	11.8	10.6
Long-term portion of deferred revenue	1.1	1.4
Depreciation and amortization of property, plant, and equipment	14.3	13.0	13.4
Interest costs capitalized	0	0	0
Marketable securities	0	0
Amortization expense of capitalized software development costs	7.8	4.1	3.1
Foreign currency translation adjustments	(0.1)	4.6	(7.6)
Foreign exchange gains (losses)	(0.2)	(1.5)	0.7
Reportable segment	3
Computer Software, Intangible Asset
Significant Accounting Policies [Line Items]
Amortization expense of capitalized software development costs	$ 0	$ 0.2	$ 1.3
Minimum
Significant Accounting Policies [Line Items]
Ownership interests	10.00%
Standard product warranty term	12 months
Intangible assets, estimated useful lives	1 year
Minimum | Computer Software, Intangible Asset
Significant Accounting Policies [Line Items]
Intangible assets, estimated useful lives	3 years
Maximum
Significant Accounting Policies [Line Items]
Ownership interests	50.00%
Standard product warranty term	60 months
Intangible assets, estimated useful lives	14 years
Maximum | Computer Software, Intangible Asset
Significant Accounting Policies [Line Items]
Intangible assets, estimated useful lives	5 years