Reportable Segments Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2012		Oct. 31, 2011	Jul. 31, 2012
Net revenue:
Revenues	$ 119,867		$ 117,857
Income (loss) from operations
Income (loss) from operations	7,435		5,584
Total other income (expense), net	(906)		311
Income from continuing operations before income taxes	6,529		5,895
Identifiable assets:
Assets	542,830			557,996
Share-based compensation:
Share based compensation	2,644		2,251
Depreciation and amortization:
Depreciation and amortization	3,999		4,794
Medical Imaging
Net revenue:
Revenues	76,008		72,674
Income (loss) from operations
Income (loss) from operations	7,399		5,482
Share-based compensation:
Share based compensation	1,581		1,208
Depreciation and amortization:
Depreciation and amortization	2,872		2,996
Ultrasound
Net revenue:
Revenues	31,694		34,601
Income (loss) from operations
Income (loss) from operations	(794)		(341)
Share-based compensation:
Share based compensation	593		725
Depreciation and amortization:
Depreciation and amortization	856		1,475
Security Technology
Net revenue:
Revenues	12,165		10,582
Income (loss) from operations
Income (loss) from operations	830		443
Share-based compensation:
Share based compensation	470		318
Depreciation and amortization:
Depreciation and amortization	271		323
Reportable segment assets
Identifiable assets:
Assets	362,783			362,669
Reportable segment assets | Medical Imaging
Identifiable assets:
Assets	205,857			199,512
Reportable segment assets | Ultrasound
Identifiable assets:
Assets	134,204			136,388
Reportable segment assets | Security Technology
Identifiable assets:
Assets	22,722			26,769
Corporate assets
Identifiable assets:
Assets	$ 180,047	[1]		$ 195,327	[1]

[1] Includes cash and cash equivalents of $134,036 and $153,122 at October 31, 2012 and July 31, 2012, respectively.