CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2015		Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities:
Net income	$ 27,331		$ 14,185	$ 27,459
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	8,486		7,427	6,298
Investment premium amortization, net	635		530	827
Discontinued operations - gain on sale, net of taxes	(7,682)		0	0
Net loss on disposals of property and equipment	8		20	76
Foreign exchange (gain) loss	1,794		(477)	401
Share-based compensation expense	9,787		7,643	7,086
Excess tax benefits from share-based awards	(961)		(2,164)	(2,683)
Deferred income taxes	(3,954)		(785)	(1,307)
Equity in net (income) loss of unconsolidated affiliate	(37)		(33)	13
Changes in assets and liabilities:
Receivables, net	(1,306)		11,171	(9,418)
Inventories	(10,135)		(2,491)	(8,081)
Prepaid expenses and other current assets	787		2,962	4,269
Other assets	(55)		21	(9)
Accounts payable	116		(2,018)	1,746
Accrued payroll and related expenses	6,776		(1,626)	(67)
Accrued taxes	(1,294)		690	610
Other liabilities	5,514		(98)	935
Deferred revenue	(702)		131	1,504
Warranty reserve	1,288		484	(462)
Net cash provided by operating activities	36,396		35,572	29,197
Cash flows from investing activities:
Purchases of available-for-sale investments	0		(4,384)	0
Purchases of held-to-maturity investments	(36,804)		(27,798)	(18,337)
Proceeds from maturities and redemptions of available-for-sale investments	6,498		1,023	249
Proceeds from maturities and redemptions of held-to-maturity investments	26,969		23,311	22,067
Purchases of property and equipment	(6,077)		(5,554)	(5,640)
Proceeds from disposals of property and equipment	25		44	4
Acquisitions, net of cash acquired	(618)		0	0
Proceeds from sale of discontinued operations	20,100		0	0
Net cash provided by (used in) investing activities	10,093		(13,358)	(1,657)
Cash flows from financing activities:
Proceeds from the exercise of stock options	31		1,455	2,800
Tax withholdings related to net share settlements of restricted stock units	(3,026)		(4,683)	(1,625)
Excess tax benefits from share-based awards	961		2,164	2,683
Repurchases of common stock	0		(2,981)	0
Proceeds from the exercise of warrants	78		0	0
Dividends paid	(9,006)		0	(22,023)
Net cash used in financing activities	(10,962)		(4,045)	(18,165)
Effect of exchange rate changes on cash and cash equivalents	(2,101)		510	(308)
Net increase in cash and cash equivalents	33,426		18,679	9,067
Cash and cash equivalents at beginning of year	73,589		54,910	45,843
Cash and cash equivalents at end of year	107,015		73,589	54,910
Supplemental disclosure of cash flow information:
Cash paid for income taxes, net of refunds	15,888		4,943	12,330
Supplemental disclosure of non-cash flow information:
Change in unrealized gain (loss) on investments, net of tax	(3)		(47)	17
Transfers of equipment between inventory and property and equipment, net	2,295		2,285	904
Net change in capitalized share-based compensation	(29)		(14)	12
Common stock withheld for employee taxes in connection with share-based compensation	3,026		4,683	1,625
Repayment of notes payable by credits from municipal agency	101		101	101
Settlement of preexisting business relationship in connection with acquisition	931		0	0
Installment payment obligation related to acquisition	$ 2,336	[1]	$ 0	$ 0

[1] The installment payment obligation is denominated in GBP and the amount in the table above is based on the exchange rate at the acquisition date.