Goodwill and Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended
	Mar. 31, 2014 Segment	Mar. 31, 2013	Mar. 31, 2012
Acquired Finite-Lived Intangible Assets [Line Items]
Number of reportable units	2
Goodwill	$ 203,446,000	$ 202,453,000	$ 170,384,000
Intangible assets, net	58,513,000	63,827,000
Payments to acquire intangible assets	1,086,000	277,000	200,000
Weighted average useful life of identifiable intangible assets acquired	10 years 1 month 6 days
Amortization expenses	3,432,000	2,877,000	2,131,000
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Payments to acquire intangible assets	500,000
Weighted average useful life of identifiable intangible assets acquired	6 years 3 months 18 days
Expected payments to acquire intangible assets	300,000
Expected weighted average useful life of identifiable intangible assets acquired	3 years
Indefinite-lived trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite lived intangible	18,600,000	18,600,000
Acquired software and core technology
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life of identifiable intangible assets acquired	6 years 8 months 12 days
Acquired software and core technology | Included as cost of product revenue
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expenses	3,300,000	4,500,000	4,700,000
Other acquired intangible assets | Included as operating expense
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expenses	3,600,000	3,100,000	2,200,000
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life of identifiable intangible assets acquired	13 years 3 months 18 days
Unified Service Delivery
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	201,000,000	199,500,000
Test Automation
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 2,400,000	$ 3,000,000