Reportable Segment Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Apr. 30, 2013		Apr. 30, 2012		Apr. 30, 2013		Apr. 30, 2012		Jul. 31, 2012
Net revenue:
Revenues	$ 125,765		$ 121,270		$ 384,186		$ 365,560
Income (loss) from operations before income taxes:
Income (loss) from operations	6,712		9,873		27,950		23,248
Total other (expense) income, net	190	[1]	423	[1]	(1,118)	[1]	3,689	[1]
Income from continuing operations before income taxes	6,902		10,296		26,832		26,937
Identifiable assets:
Assets	566,609				566,609				557,996
Total	566,609				566,609				557,996
Share-based compensation:
Share based compensation	2,004		2,315		7,957		7,716
Depreciation and amortization:
Depreciation and amortization	4,493		4,446		12,537		13,729
Reportable segment assets
Identifiable assets:
Assets	474,585				474,585				362,669
Corporate assets
Identifiable assets:
Assets	92,024	[2]			92,024	[2]			195,327	[2]
Medical Imaging
Net revenue:
Revenues	71,634		72,760		228,310		220,697
Income (loss) from operations before income taxes:
Income (loss) from operations	6,506	[3]	4,847	[3]	22,440	[3]	12,859	[3]
Share-based compensation:
Share based compensation	1,180		1,441		4,861		4,852
Depreciation and amortization:
Depreciation and amortization	2,723		2,858		8,213		8,700
Medical Imaging | Reportable segment assets
Identifiable assets:
Assets	209,400	[4]			209,400	[4]			199,512	[4]
Ultrasound
Net revenue:
Revenues	33,990		33,889		106,134		109,568
Income (loss) from operations before income taxes:
Income (loss) from operations	(4,422)	[5]	2,350	[5]	(1,689)	[5]	6,713	[5]
Share-based compensation:
Share based compensation	442		490		1,620		1,606
Depreciation and amortization:
Depreciation and amortization	1,458		1,310		3,388		4,153
Ultrasound | Reportable segment assets
Identifiable assets:
Assets	225,986	[6]			225,986	[6]			136,388	[6]
Security Technology
Net revenue:
Revenues	20,141		14,621		49,742		35,295
Income (loss) from operations before income taxes:
Income (loss) from operations	4,628	[7]	2,676	[7]	7,199	[7]	3,676	[7]
Share-based compensation:
Share based compensation	382		384		1,476		1,258
Depreciation and amortization:
Depreciation and amortization	312		278		936		876
Security Technology | Reportable segment assets
Identifiable assets:
Assets	$ 39,199				$ 39,199				$ 26,769

[1] Includes a gain of $2,500 from the sale of our remaining interest in our China based affiliate received in the nine months ended April 30, 2012.

[2] Includes cash and cash equivalents of $43,455 and $153,122 at April 30, 2013 and July 31, 2012, respectively. The decrease in cash and cash equivalents is primarily due to our recent acquisition of Ultrasonix. See Note 3 for further information in regards to the acquisition of Ultrasonix.

[3] Includes $2,198 of contingent consulting fees related to the tax refund and related interest received in the nine months ended April 30, 2012.

[4] Includes goodwill of $1,849 relating to our 2008 acquisition of Copley Controls.

[5] Includes the operating results following our acquisition of Ultrasonix on March 2, 2013 as discussed in Note 3 and $496 of restructuring charges related to our Ultrasonix manufacturing consolidation as discussed in Note 8.

[6] Includes $48,380 of goodwill relating to our acquisition of Ultrasonix. See Note 3 for further information in regards to the acquisition of Ultrasonix.

[7] Includes $516 of contingent consulting fees related to the tax refund and related interest received in the nine months ended April 30, 2012.