Note 10 - Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	2023			2022			2021
Dividend yield		1.02	%		1.06	%		0.91	%
Volatility		43.0	%		44.6	%		46.0	%
Risk-free interest rate		4.3	%		3.9	%		1.1	%
Weighted average expected option term (in years)		4.5			4.5			4.6
Weighted average fair value per share of options granted	$	20.75		$	18.10		$	17.64

Share-Based Payment Arrangement, Option, Activity [Table Text Block]

				Weighted		Weighted Average		Aggregate
	Number			Average		Remaining		Intrinsic
	of Shares			Exercise Price		Contractual Term		Value
						(in years)		(in thousands)
Balance outstanding at December 31, 2020		931,840		$	28.22		4.49	$	11,442
Granted		151,161		$	48.60
Exercised		(217,121	)	$	20.95			$	6,975
Canceled / Expired		(19,126	)	$	23.18
Balance outstanding at December 31, 2021		846,754		$	33.83		4.50	$	13,888
Granted		159,275		$	47.21
Exercised		(133,963	)	$	25.80			$	3,021
Canceled / Expired		(12,091	)	$	35.53
Balance outstanding at December 31, 2022		859,975		$	37.53		4.35	$	7,878
Granted		148,115		$	54.71
Exercised		(207,643	)	$	29.72			$	5,914
Canceled / Expired		(19,323	)	$	41.55
Balance outstanding at December 31, 2023		781,124		$	42.78		4.42	$	10,924
Exercisable at:
December 31, 2021		301,692		$	27.40		3.30	$	6,886
December 31, 2022		369,593		$	32.16		3.17	$	5,223
December 31, 2023		356,519		$	36.83		3.21	$	7,107
Expected to vest at:
December 31, 2021		545,062		$	37.38		5.16
December 31, 2022		490,382		$	41.59		5.23
December 31, 2023		424,605		$	47.78		5.43

Share-Based Payment Arrangement, Restricted Stock Unit, Activity [Table Text Block]

				Weighted
				Average
	Number			Grant Date
	of Shares			Fair Value
Balance outstanding at December 31, 2020		147,015		$	30.24
Granted		48,298		$	48.65
Vested		(51,414	)	$	26.32
Canceled		(10,068	)	$	30.70
Balance outstanding at December 31, 2021		133,831		$	38.26
Granted		51,031		$	47.11
Vested		(45,489	)	$	35.75
Canceled		(6,229	)	$	40.79
Balance outstanding at December 31, 2022		133,144		$	42.38
Granted		48,225		$	54.68
Vested		(49,400	)	$	39.31
Canceled		(5,975	)	$	42.89
Balance outstanding at December 31, 2023		125,994		$	48.20

Accelerated Share Repurchases [Table Text Block]

	2023		2022		2021
Shares of common stock repurchased for net settlement of equity awards		15,917		13,690		16,333
Average per share repurchase price	$	53.59	$	46.90	$	49.10
Aggregate purchase price (in thousands)	$	853	$	642	$	802

Share-Based Payment Arrangement, Performance Shares, Activity [Table Text Block]

				Weighted
				Average
	Number			Grant Date
	of Shares			Fair Value
Balance outstanding at December 31, 2020		-		$	-
Granted		31,181		$	48.60
Vested		-		$	-
Canceled		-		$	-
Balance outstanding at December 31, 2021		31,181		$	48.60
Granted		28,830		$	47.13
Vested		-		$	-
Canceled		(31,538	)	$	48.53
Balance outstanding at December 31, 2022		28,473		$	47.19
Granted		26,883		$	54.65
Vested		-		$	-
Canceled		(1,192	)	$	47.19
Balance outstanding at December 31, 2023		54,164		$	50.85

Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	2023		2022		2021
			(in thousands)
Stock option awards	$	2,705	$	2,487	$	2,199
Restricted stock units		1,951		1,654		1,247
Performance-based restricted stock units		663		32		33
Total stock-based compensation	$	5,319	$	4,173	$	3,479

	2023		2022		2021
			(in thousands)
Cost of sales	$	686	$	494	$	407
Sales and marketing		966		771		527
General and administrative		3,143		2,500		2,185
Research and development		524		408		360
Total stock-based compensation	$	5,319	$	4,173	$	3,479

Schedule of Dividends Payable [Table Text Block]

Record Date	Payment Date	Per Share Amount		Dividend Payment
				(in thousands)
Fiscal Year 2023
March 9, 2023	March 23, 2023	$	0.140	$	3,099
May 17, 2023	June 1, 2023	$	0.140	$	3,116
August 17, 2023	August 31, 2023	$	0.140	$	3,117
November 16, 2023	November 30, 2023	$	0.140	$	3,117
Fiscal Year 2022
March 8, 2022	March 24, 2022	$	0.125	$	2,743
May 17, 2022	June 2, 2022	$	0.125	$	2,745
August 25, 2022	September 8, 2022	$	0.125	$	2,750
November 17, 2022	December 1, 2022	$	0.125	$	2,750