Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Net Cash Provided By Used In Operating Activities [Abstract]
Net income (loss)	$ 16,688	$ 9,455
Income from discontinued operations	0	(409)
Depreciation and amortization	6,221	5,711
Deferred income taxes and related valuation allowance	155	261
Gain on sale of real estate/investments	(253)	(223)
Gain on disposal of assets	0	0
Stock-based compensation	1,649	1,447
Amortization of deferred financing costs	130	192
Non-cash restructuring charges	0	0
Increase Decrease In Operating Capital [Abstract]
Trade accounts receivable	(4,618)	3,421
Inventories	(7,231)	(6,037)
Prepaid expenses	(3,477)	1,288
Other assets	445	143
Trade accounts payable	6,002	(481)
Accrued and non-current liabilities	(5,369)	(4,470)
Net Cash Provided By Used In Operating Activities	7,574	4,418
Net Cash Provided By Used In Investing Activities [Abstract]
Proceeds from sale of marketable securities	3,101	3,978
Purchases of marketable securities	(1,936)	(3,538)
Capital expenditures	(4,080)	(7,225)
Proceeds from sale of businesses or assets	1,482	0
Net cash used for investing activities from continuing operations	(1,433)	(6,785)
Net cash provided by investing activities from discontinued operations	0	409
Net cash used for investing activities	(1,433)	(6,376)
Net Cash Provided By Used In Financing Activities [Abstract]
Proceeds from exercise of stock options	219	1,733
Net payments under lines-of-credit	(51)	(202)
Repayments of debt	393	459
Change in ESOP guarantee	(213)	(217)
Net cash provided by (used) for financing activities	(12)	1,289
Effect Of Exchange Rate On Cash And Cash Equivalents	(675)	(724)
Cash And Cash Equivalents Period Increase Decrease	5,454	(1,393)
Cash And Cash Equivalents At Carrying Value - Beginning of Period	89,473	80,139
Cash And Cash Equivalents At Carrying Value - End of Period	94,927	78,746
Supplemental Cash Flow Information [Abstract]
Interest Paid	6,898	6,785
Income Taxes Paid	$ 3,591	$ 3,946