Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Feb. 28, 2019		Feb. 28, 2018
Cash flows from operating activities:
Net (loss) income	$ (5,345)		$ 337
Adjustments to reconcile net (loss) income to net cash used in operating activities:
Stock-based compensation expense	705		822
Recovery of doubtful accounts	(3)		(3)
Depreciation and amortization	333		300
Accretion of investment discount	0		(24)
Changes in operating assets and liabilities:
Accounts receivable	871		(527)
Inventories	(121)		(2,392)
Prepaid expenses and other assets	(47)		(603)
Accounts payable	(1,132)		(268)
Accrued expenses	431		31
Customer deposits and deferred revenue	(582)		(764)
Deferred rent	88		0
Income taxes payable	9		(5)
Net cash used in operating activities	(4,793)		(3,096)
Cash flows from investing activities:
Purchases of investments	0		(5,965)
Purchases of property and equipment	(124)		(458)
Net cash used in investing activities	(124)		(6,423)
Cash flows from financing activities:
Proceeds from issuance of common stock under employee plans, net of taxes paid related to share settlement of equity awards	435		727
Net cash provided by financing activities	435		727
Effect of exchange rates on cash and cash equivalents	(66)		66
Net decrease in cash and cash equivalents	(4,548)		(8,726)
Cash and cash equivalents, beginning of period	16,848	[1]	17,803
Cash and cash equivalents, end of period	12,300		9,077
Supplemental disclosure of non-cash flow information:
Transfer of property and equipment to inventories	$ 20		$ 372

[1] The condensed consolidated balance sheet at May 31, 2018 has been derived from the audited consolidated financial statements at that date.