Stock Transactions - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended			1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Aug. 31, 2013	Feb. 28, 2013
Class of Stock [Line Items]
Total share-based compensation expense	$ 11,666	$ 6,220	$ 8,686
Cost of Revenue [Member]
Class of Stock [Line Items]
Total share-based compensation expense	591	159	212
Research and Development [Member]
Class of Stock [Line Items]
Total share-based compensation expense	2,055	1,425	1,620
Sales and Marketing [Member]
Class of Stock [Line Items]
Total share-based compensation expense	5,108	1,373	2,060
General and Administrative [Member]
Class of Stock [Line Items]
Total share-based compensation expense	3,912	3,263	4,794
Investors [Member]
Class of Stock [Line Items]
Total share-based compensation expense		2,400	7,300
Investors [Member] | Cost of Revenue [Member]
Class of Stock [Line Items]
Total share-based compensation expense			200
Investors [Member] | Research and Development [Member]
Class of Stock [Line Items]
Total share-based compensation expense		800	1,400
Investors [Member] | Sales and Marketing [Member]
Class of Stock [Line Items]
Total share-based compensation expense		200	1,800
Investors [Member] | General and Administrative [Member]
Class of Stock [Line Items]
Total share-based compensation expense		$ 1,400	$ 3,900
Common Stock [Member] | Investors [Member]
Class of Stock [Line Items]
Number of outstanding stock under tender offer				347,000	347,000	862,000
Stock purchase price under tender offer				$ 17.4089	$ 17.4089	$ 17.4089