CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net income	$ 13,939	$ 69,228	$ 6,494
Adjustments to reconcile net income to net cash provided by operating activites:
Depreciation	2,523	1,535	1,235
Amortization	1,428	788	94
Stock-based compensation expense	2,634	1,506	458
Tax benefit from stock-based compensation	(49)	0	0
Change in fair value of warrant liability	0	0	(167)
Deferred income tax provision (benefit)	9,308	(62,422)	0
Other	616	561	84
Changes in assets and liabilities:
Accounts receivable	(2,171)	(1,059)	(358)
Inventory	27	1,535	29
Other current and noncurrent assets	(30)	489	75
Deferred cost of goods sold	(60)	1	(16)
Accounts payable	410	(1,214)	916
Accrued compensation	524	128	278
Accrued warranty	65	25	31
Accrued taxes and fees	440	(356)	24
Deferred revenue	345	(197)	(475)
Other current and noncurrent liabilities	1,839	(1,337)	(113)
Net cash provided by operating activities	31,788	9,211	8,589
Cash flows from investing activities:
Acquisitions of property and equipment	(5,678)	(2,300)	(2,057)
Cost of capitalized software	(190)	0	0
Restricted cash decrease	0	28	0
Purchase of investments	0	0	(2,000)
Purchase of strategic investment	0	0	(315)
Acquisition of businesses, net of cash acquired	0	(713)	(998)
Proceeds from the sale of property and equipment	0	0	6
Net cash used in investing activities	(5,868)	(2,985)	(5,364)
Cash flows from financing activities:
Capital lease payments	(86)	(275)	(38)
Repurchase of common stock	(419)	(2,550)	(7,662)
Buyback of employee stock options and stock purchase rights	0	(384)	(539)
Proceeds from exercise of warrants	0	0	880
Tax benefit from stock-based compensation	49	0	0
Proceeds from issuance of common stock, net of issuance costs	(43)	(60)	278
Proceeds from issuance of common stock under employee stock plans	2,458	2,995	2,274
Net cash provided by (used in) financing activities	1,959	(274)	(4,807)
Net increase in cash and cash equivalents	27,879	5,952	(1,582)
Cash and cash equivalents at the beginning of the period	22,426	16,474	18,056
Cash and cash equivalents at the end of the period	50,305	22,426	16,474
Supplemental and non-cash disclosures:
Issuance of common stock in connection with acquisitions of businesses	0	31,358	600
Fair value of options assumed in connection with acquisitions of businesses	0	274	0
Acquisition of property and equipment, net in connection with acquisitions of businesses	0	364	80
Acquisition of capital lease in connection with acquisitions of businesses	0	317	0
Transfer of net assets in purchase of strategic investment	0	0	41
Assets acquired under capital lease	0	45	0
Interest paid	8	5	10
Income taxes paid	$ 415	$ 94	$ 6