Schedule of Intangible Assets (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Cost	$ 80,060	$ 63,312
Accumulated Amortization	(34,833)	(27,227)
Net	45,227	36,085
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Cost	30,848	24,919
Accumulated Amortization	(21,343)	(17,943)
Net	9,505	6,976
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Cost	38,718	32,754
Accumulated Amortization	(11,038)	(8,492)
Net	27,680	24,262
Distributor Relationships
Finite-Lived Intangible Assets [Line Items]
Cost	1,895
Accumulated Amortization	(219)
Net	1,676
Core Technology
Finite-Lived Intangible Assets [Line Items]
Cost	7,446	4,760
Accumulated Amortization	(1,455)	(306)
Net	5,991	4,454
Net Beneficial Leases
Finite-Lived Intangible Assets [Line Items]
Cost	336	336
Accumulated Amortization	(336)	(334)
Net	0	2
Non-Compete Agreements
Finite-Lived Intangible Assets [Line Items]
Cost	334	343
Accumulated Amortization	(167)	(57)
Net	167	286
Other
Finite-Lived Intangible Assets [Line Items]
Cost	483	200
Accumulated Amortization	(275)	(95)
Net	$ 208	$ 105