Acquisitions and Divestitures - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2012
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Loss (gain) on sales of businesses	$ (3,138)
Proceeds from sale of operations	10,178
Brandy Medical [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Loss (gain) on sales of businesses	3,675
Proceeds from sale of operations	3,378
Non-cash consideration	360
Cash	3,018
Varitronics [Member]
Business Acquisition Actual Revenue And Pre Tax Income Loss [Line Items]
Loss (gain) on sales of businesses	237
Proceeds from sale of operations	8,410
Proceeds from cash distribution	7,160
Proceeds in the form of a promissory note	$ 1,250