CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Cash flows from operating activities:
Net income	$ 12,278	$ 5,365
Adjustments to reconcile net income to net cash provided by operating activites:
Depreciation	1,816	1,101
Amortization	1,071	431
Stock-based compensation	1,827	1,013
Deferred income tax provision (benefit)	7,359	(336)
Other	409	130
Changes in assets and liabilities:
Accounts receivable, net	(1,700)	(642)
Inventory	(25)	1,596
Other current and noncurrent assets	(48)	405
Deferred cost of goods sold	(18)	(6)
Accounts payable	(38)	(2,059)
Accrued compensation	663	319
Accrued warranty	35	34
Accrued taxes and fees	495	(396)
Deferred revenue	61	(75)
Other current and noncurrent liabilities	1,806	(472)
Net cash provided by operating activities	25,991	6,408
Cash flows from investing activities:
Purchases of property and equipment	(5,245)	(1,743)
Acquisition of businesses, net of cash acquired	0	(713)
Net cash used in investing activities	(5,245)	(2,456)
Cash flows from financing activities:
Capital lease payments	(73)	(273)
Repurchase of common stock	(285)	(1,038)
Proceeds from issuance of common stock, net of issuance costs	0	(60)
Proceeds from issuance of common stock under employee stock plans	1,743	949
Net cash provided by (used in) financing activities	1,385	(422)
Net increase in cash and cash equivalents	22,131	3,530
Cash and cash equivalents at the beginning of the period	22,426	16,474
Cash and cash equivalents at the end of the period	44,557	20,004
Supplemental cash flow information
Issuance of common stock in connection with acquisitions of businesses	0	31,358
Fair value of options assumed in connection with acquisitions of businesses	0	274
Acquisition of net assets in connection with acquisitions of businesses	0	372
Transfer of net assets in purchase of strategic investment	$ 0	$ 297