FIXED ASSETS Components of Fixed Assets (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014		Mar. 31, 2013
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 89,634		$ 75,468
Less - accumulated depreciation	(66,536)		(55,790)
Property, plant and equipment, net, total	23,098		19,678
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Fixed assets, gross	3,693		3,337
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Estimated Useful Life	3 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Estimated Useful Life	7 years
Computer equipment and internal use software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Estimated Useful Life	3 years
Fixed assets, gross	62,045		52,170
Computer equipment and internal use software | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Estimated Useful Life	3 years
Computer equipment and internal use software | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Estimated Useful Life	5 years
Demonstration and spare part units
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Estimated Useful Life	2 years
Fixed assets, gross	10,755		8,041
Leasehold improvements
Property, Plant and Equipment [Line Items]
Fixed assets, gross	$ 13,141	[1]	$ 11,920	[1]
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Estimated Useful Life	0 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Estimated Useful Life	12 years

[1] Leasehold improvements are depreciated over the shorter of the lease term or anticipated useful life of the improvement.