Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating activities
Net income (loss)	$ (3,342)	$ (6,214)	$ 608
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation	2,765	3,815	4,588
Amortization and impairment of intangible assets	331	435	590
Provision for bad debts	237	832	58
Stock-based compensation	800	891	606
Restructuring loss	0	355	319
(Gain) loss on disposal of assets	(103)	154	(26)
Amortization of premium on securities available-for-sale	286	285	454
Changes in operating assets and liabilities:
Accounts receivable	970	(806)	1,713
Inventories	(1,046)	1,280	(1,565)
Other assets	6	196	809
Accounts payable	(364)	74	(400)
Accrued compensation	691	(912)	(1,295)
Deferred revenue	(280)	(215)	(129)
Other accrued liabilities	208	59	(1,524)
Restricted cash	(194)	0	0
Net cash provided by operating activities	965	229	4,806
Investing activities
Purchases of property and equipment	(709)	(1,437)	(1,014)
Proceeds from sale of property and equipment	165	55	1,024
Purchases of securities available-for-sale	(13,086)	(5,477)	(20,360)
Sales and maturities of securities available-for-sale	16,145	13,569	16,586
Net cash provided by (used in) investing activities	2,515	6,710	(3,764)
Financing activities
Issuances of common stock	119	44	36
Repurchases of common stock	(19)	(48)	(991)
Repayment of obligations under capital leases	0	(36)	(52)
Net cash provided by (used in) financing activities	100	(40)	(1,007)
Net increase in cash and cash equivalents	3,580	6,899	35
Cash and cash equivalents at beginning of year	20,459	13,560	13,525
Cash and cash equivalents at end of year	24,039	20,459	13,560
Supplemental information:
Cash paid during the period for interest	0	6	9
Non-cash investing and financing activities:
Purchase of assets under capital leases	$ 0	$ 0	$ 113