Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	AOCI Attributable to Parent	Retained Earnings
Beginning Balances at Dec. 31, 2020	$ 37,373	$ 2	$ 22,523	$ 41	$ 14,807
Beginning Balances, Shares at Dec. 31, 2020		17,690,062
Other comprehensive loss – unrealized loss on available-for-sale debt securities	(20)			(20)
Issuance of common stock upon exercise of stock options and vesting of early exercised options	77		77
Issuance of common stock upon exercise of stock options and vesting of early exercised options, Shares		47,766
Issuance of common stock upon vesting of restricted stock units, Shares		24,125
Shares repurchased for tax withholdings on vesting of restricted stock units	(29)		(29)
Shares repurchased for tax withholdings on vesting of restricted stock units, Shares		(3,920)
Stock-based compensation	371		371
Net income	3,853				3,853
Ending Balances at Mar. 31, 2021	41,625	$ 2	22,942	21	18,660
Ending Balances, Shares at Mar. 31, 2021		17,758,033
Beginning Balances at Dec. 31, 2021	51,817	$ 2	24,251	(26)	27,590
Beginning Balances, Shares at Dec. 31, 2021		17,928,748
Other comprehensive loss – unrealized loss on available-for-sale debt securities	(50)			(50)
Issuance of common stock upon exercise of stock options and vesting of early exercised options	142		142
Issuance of common stock upon exercise of stock options and vesting of early exercised options, Shares		79,517
Issuance of common stock upon vesting of restricted stock units, Shares		32,225
Shares repurchased for tax withholdings on vesting of restricted stock units	(82)		(82)
Shares repurchased for tax withholdings on vesting of restricted stock units, Shares		(5,906)
Stock-based compensation	515		515
Net income	4,377				4,377
Ending Balances at Mar. 31, 2022	$ 56,719	$ 2	$ 24,826	$ (76)	$ 31,967
Ending Balances, Shares at Mar. 31, 2022		18,034,584