Note 15 - Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

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

	Year Ended December 31,
	2021		2020		2019
	(Dollars in thousands)
Cost of revenues	$	4,656	$	4,435	$	3,633
Selling and marketing expenses		766		1,081		916
General and administrative expenses		3,746		4,314		4,810
Total stock-based compensation expense		9,168		9,830		9,359
Tax effect on stock-based compensation expense		872		858		736
Net effect of stock-based compensation expense	$	8,296	$	8,972	$	8,623

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

	Year Ended December 31,
	2021			2020			2019
For stock based awards issued by the Company:
Risk-free interest rates		0.7	%		0.4	%		1.8	%
Expected lives (in weighted average years)		3.8			5.8			3.5
Dividend yield		0.6	%		0.6	%		0.7	%
Expected volatility (weighted average)		36.7	%		28.8	%		25.1	%

	Year Ended December 31,
	2021			2020			2019
Weighted average forfeiture rate		6.1	%		8.2	%		8.6	%

Risk-free interest rates	0.14%	-	0.16%
Expected life (in years)		1
Dividend yield		0.65%
Expected volatility (weighted average)		43.26%

Risk-free interest rates	0.13%	-	0.51%
Expected life (in years)	2	-	6
Dividend yield		0.61%
Expected volatility (weighted average)	37.68%	-	30.15%

Risk-free interest rates	0.12%	-	0.44%
Expected life (in years)	1	-	6
Dividend yield		0.61%
Expected volatility (weighted average)	45.2%	-	29.4%

Risk-free interest rates		0.44%
Expected life (in years)	2	-	6
Dividend yield		0.63%
Expected volatility (weighted average)		28.14%

Risk-free interest rates	0.44%	-	0.28%
Expected life (in years)	2	-	6
Dividend yield		0.64%
Expected volatility (weighted average)	28.5%	-	5.2%

Risk-free interest rates	0.41%	-	0.17%
Expected life (in years)	2	-	6
Dividend yield		0.64%
Expected volatility (weighted average)	28.5%	-	35.7%

Schedule of Share-based Payment Award, Equity Awards Other than Options, Valuation Assumptions [Table Text Block]

Risk-free interest rate		1.79%
Expected life (in years)	1	-	6
Dividend yield		0.57%
Expected volatility		24.80%

Share-based Payment Arrangement, Option and Stock Appreciation Rights, Activity [Table Text Block]

	Year Ended December 31,
	2021					2020					2019
	Awards (In thousands)			Weighted Average Exercise Price		Awards (In thousands)			Weighted Average Exercise Price		Awards (In thousands)			Weighted Average Exercise Price
Outstanding at beginning of year		2,240		$	57.68		1,792		$	50.39		2,527		$	46.77
Granted:
SARs (1)		15			77.22		957			68.82		38			69.13
RSUs (2)		12			—		35			—		9			—
PSUs (3)		0			—		25			—		—			—
Exercised		(159	)		40.47		(469	)		45.71		(711	)		37.83
Forfeited		(83	)		64.34		(100	)		55.05		(71	)		50.59
Expired		—			—		—			—		—			—
Outstanding at end of year		2,025			58.70		2,240			57.68		1,792			50.39
Options and SARs exercisable at end of year		881			53.20		704			51.64		479			48.35
Weighted-average fair value of awards granted during the year				$	46.23				$	20.84				$	29.24

Share-based Payment Arrangement, Option, Exercise Price Range [Table Text Block]

		Awards Outstanding						Awards Exercisable
Exercise Price		Number of Stock-based Awards Outstanding		Weighted Average Remaining Contractual Life in Years		Aggregate Intrinsic Value		Number of Stock-based Awards Exercisable		Weighted Average Remaining Contractual Life in Years		Aggregate Intrinsic Value
$	—		66		1.3	$	5,208		—		—	$	—
	42.87		187		0.5		6,796		187		0.5		6,796
	47.46		15		1.9		478		15		1.9		478
	51.71		8		3.0		221		4		3.0		110
	53.16		31		2.9		819		26		2.9		689
	53.44		386		2.5		9,985		227		2.5		5,859
	55.16		296		1.9		7,137		296		1.9		7,137
	57.97		15		2.6		320		15		2.6		320
	58.79		1		0.5		19		1		0.5		19
	63.35		88		1.9		1,401		88		1.9		1,401
	63.40		45		4.5		721		—		4.5		—
	67.54		12		4.9		139		12		4.9		139
	68.34		47		4.4		513		—		4.4		—
	69.14		799		4.4		8,123		1		4.4		12
	70.10		1		0.5		5				0.5		—
	71.71		4		3.6		30		2		3.6		15
	76.43		8		3.9		24		8		3.9		24
	76.54		9		5.9		23		—		5.9
	78.53		6		5.3		5		—		5.3
	90.28		1		5.0		—		—		5		—
			2,025		3.0	$	41,967		882		1.8	$	22,999

		Awards Outstanding						Awards Exercisable
Exercise Price		Number of Stock-based Awards Outstanding		Weighted Average Remaining Contractual Life in Years		Aggregate Intrinsic Value		Number of Stock-based Awards Exercisable		Weighted Average Remaining Contractual Life in Years		Aggregate Intrinsic Value
$	—		85		2.1	$	7,677		—		—	$	—
	42.87		235		1.5		11,129		235		1.5		11,129
	47.46		15		2.9		642		15		2.9		642
	51.71		8		4.0		309		0		4.0		0
	53.16		31		3.9		1,164		21		3.9		792
	53.44		486		3.5		17,893		129		3.5		4,719
	55.16		296		2.9		10,384		213		2.9		7,484
	57.97		15		3.6		485		15		3.6		485
	58.79		1		1.5		33		—		1.5		—
	63.35		94		2.9		2,525		68		2.9		1,843
	63.40		45		5.5		1,219		—		5.5		—
	67.54		12		5.9		269		—		5.9		—
	68.34		47		5.4		1,027		—		5.4		—
	69.14		842		5.4		17,820		—		5.4		—
	71.71		4		4.6		74		—		4.6		—
	72.14		15		4.7		272		—		4.7		—
	76.43		8		4.9		117		8		4.9		117
	90.28		1		2.8		—		—		2.8		—
			2,240		3.9	$	73,039		704		2.6	$	27,211