Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	1 Months Ended	12 Months Ended
	Mar. 31, 2013	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011	Dec. 31, 2012
Goodwill and Intangible Assets Disclosure [Line Items]
Goodwill		$ 50,073	$ 1,849		$ 1,849
Increase in goodwill, due to acquisition of Ultrasonix	48,224
Indefinite lived intangible assets		9,507	9,507
Amortization expense related to acquired intangible assets		4,115	3,063	3,088
Percentage of excess fair value over carrying value		70.00%
Goodwill expected to be deductible for tax purposes		3,709	0
Minimum
Goodwill and Intangible Assets Disclosure [Line Items]
Intangible assets, estimated useful lives		1 year
Maximum
Goodwill and Intangible Assets Disclosure [Line Items]
Intangible assets, estimated useful lives		14 years
Trade Names
Goodwill and Intangible Assets Disclosure [Line Items]
Percentage of fair value over carrying value		40.00%
In Process Research And Development
Goodwill and Intangible Assets Disclosure [Line Items]
Percentage of fair value over carrying value		100.00%
Investment		$ 1,900