Consolidated Statements Of Cash Flows (USD $) In Thousands	3 Months Ended
Aug. 31, 2011	Aug. 31, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 6,004	$ 5,824
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	1,379	1,259
Share based compensation	600	675
Excess income tax benefit from the exercise of stock options	(556)	(155)
Changes in operating assets and liabilities, net of business acquisitions:
Accounts receivable	(4,039)	683
Inventories	(2,208)	1,438
Prepaid expenses and other current assets	(176)	(375)
Accounts payable and accruals	457	2,197
Other	(114)	0
NET CASH PROVIDED BY OPERATING ACTIVITIES	1,347	11,546
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment and other assets	(6,827)	(1,574)
Proceeds from the sale of marketable securities	16,070	0
Purchases of marketable securities	(25,157)	(10,945)
Payments for business acquisitions	(810)	0
NET CASH USED IN INVESTING ACTIVITIES	(16,724)	(12,519)
CASH FLOWS FROM FINANCING ACTIVITIES:
Increases in other long-term liabilities	(86)	140
Net proceeds from issuance of common stock	1,098	628
Excess income tax benefit from the exercise of stock options	556	155
NET CASH PROVIDED BY FINANCING ACTIVITIES	1,568	923
EFFECT OF EXCHANGE RATE ON CASH	(3)	0
INCREASE IN CASH	(13,812)	(50)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	35,844	22,806
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 22,032	$ 22,756

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).