Statement 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	$ 7,648	$ 30,306	$ 36,647
Adjustments to reconcile net income to net cash provided by operating activities, net of assets acquired and liabilities assumed:
Depreciation and amortization	12,492	13,467	18,059
Provision for receivable allowances	10,064	8,524	8,534
Write-down of goodwill and other intangibles	0	6,448	702
Write-down of marketable equity securities	1,342	0	0
Net change in inventory provision	1,295	1,322	(4,395)
Stock-based compensation	3,451	3,779	3,398
Deferred income taxes	2,495	1,696	(5,398)
Tax impacts due to employee equity incentive plans	38	(663)	(305)
Loss on disposal of plant and equipment	0	71	217
Gain on investments	(362)	(217)	(358)
Other non-cash items, net	220	(1,212)	3,442
Changes in operating assets and liabilities, net of business acquired:
Accounts receivable	(487)	(2,795)	(15,279)
Inventories	(839)	(13,420)	(3,403)
Prepaid expenses and other current assets	(3,878)	2,842	488
Other assets	832	540	(889)
Accounts payable	(1,304)	(2,006)	(1,407)
Accrued expenses and other liabilities	(744)	(3,634)	(5,608)
Pension liabilities	(626)	(602)	(578)
Net cash provided by operating activities	31,637	44,446	33,867
Cash flows from investing activities:
Change in restricted cash	195	84	220
Purchases of investments	(4,538)	(1,048)	(561)
Purchases of plant and equipment	(7,192)	(11,842)	(8,855)
Proceeds from sale of investments	453	431	255
Net cash used in investing activities	(11,082)	(12,375)	(8,941)
Cash flows from financing activities:
Principal payments on capital lease obligations	(2,774)	(3,222)	(3,120)
Repayments of loans and notes payable	(1,667)	(1,374)	(8,447)
Proceeds from loans	0	423	0
Tax impacts due to employee equity incentive plans	(38)	663	305
Purchases of treasury stock	(6,505)	(7,576)	(4,005)
Payment of cash dividends to stockholders	(1,854)	0	0
Proceeds from employee equity plans	1,982	3,379	3,866
Net cash used in financing activities	(10,856)	(7,707)	(11,401)
Effect of exchange rate fluctuations on cash and cash equivalents	(1,187)	(1,166)	1,357
Net increase in cash and cash equivalents	8,512	23,198	14,882
Cash and cash equivalents at beginning of the year	98,604	75,406	60,524
Cash and cash equivalents at end of the year	107,116	98,604	75,406
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	897	1,129	1,045
Cash paid during the period for income taxes	126	11,329	14,238
Supplemental disclosure of noncash investing and financing activities:
Fixed assets acquired under capital leases and loans	$ 0	$ 5,764	$ 4,780