CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net income	$ 272	$ 880
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	145	132
Stock-based compensation	21	29
Deferred tax provision on other comprehensive income	(4)	(60)
Gain on sale of investments	(12)
Amortization of premium/(discount) on investments	(2)	2
Changes in assets and liabilities:
Accounts receivable	368	(11)
Inventories		1,600
Prepaid expenses and other current assets	(514)	(82)
Deferred tax assets	185	89
Accounts payable	(67)	(1,311)
Accrued expenses	13	(56)
Deferred revenue	(395)	(4)
Net cash provided by operating activities	10	1,208
Cash flows from investing activities:
Purchases of property and equipment	(14)	(11)
Sales of investments	529
Purchase of other assets	(320)
Net cash provided by (used in) investing activities	195	(11)
Cash flows from financing activities:
Proceeds from issuance of common stock		9
Excess tax benefits from stock-based compensation	582	594
Payments made for taxes of employees who surrendered shares related to unrestricted stock	(87)	(92)
Net cash provided by financing activities	495	511
Increase in cash and cash equivalents	700	1,708
Cash and cash equivalents, beginning of period	43,985	72,660
Cash and cash equivalents, end of period	44,685	74,368
Supplemental disclosure:
Cash paid for income taxes	$ 5	$ 2