Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash Flows From Operating Activities
Net income	$ 4,380	$ 3,376
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	92	101
Stock-based compensation	399	362
Accretion of premium on available-for-sale investments	(378)	(157)
Gain on disposal of fixed asset	(132)
Inventory valuation adjustment	50	43
Deferred income taxes	(265)	(357)
Noncash lease expense	178	177
Unrealized gain	(58)
Changes in operating assets and liabilities:
Accounts receivable	(5)	(46)
Inventory	(1,603)	(93)
Prepaid expenses and other current assets	130	(186)
Other assets	38	2
Accounts payable	(63)	(491)
Accrued liabilities	1,029	765
Customer deposits	(602)	185
Lease liabilities	(102)	4
Other liabilities	(89)	(170)
Net cash provided by operating activities	2,999	3,515
Cash Flows From Investing Activities
Purchase of property and equipment	(9)	(57)
Purchases of debt securities	(21,177)	(8,034)
Proceeds from maturities of debt securities	20,857	2,300
Net cash used in investing activities	(329)	(5,791)
Cash Flows From Financing Activities
Payment of dividends	(4,603)	(4,555)
Net proceeds from exercise of stock options	57	29
Payment for shares withheld for tax withholdings on vesting of restricted stock units	(39)	(35)
Net cash used in financing activities	(4,585)	(4,561)
Net decrease in cash and cash equivalents	(1,915)	(6,837)
Cash and cash equivalents at beginning of period	13,671	19,392
Cash and cash equivalents at end of period	11,756	12,555
Supplemental Disclosure of Cash Flow Information
Cash paid for income taxes	36	36
Supplemental Disclosure of Noncash Investing and Financing Information
Right-of-use assets obtained in exchange for lease liabilities	58
Property and equipment purchased but not yet paid		$ 19
Vender credit received upon disposal of fixed asset	$ 58