Note 16 - Stock Based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Notes Tables

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

	201 9			201 8			2017
Dividend yield (1)	0.0%			0.0%			0.0%
Expected volatility	28.81% (2)			28.22% (2)			44.00%	to	50.09% (3)
Risk-free interest rate (4)	1.42%	to	2.78%	2.35%	to	2.96%	1.89%	to	2.30%
Expected life (in years) (5)	6.25			6.25			5.5	to	7.0
Assumed forfeiture rate (6)	4.0%			4.0%			6.0%

Share-based Payment Arrangement, Activity [Table Text Block]

	201 9		201 8		201 7
Stock based compensation expense recognized	$	2,632,000	$	2,116,000	$	1,842,000
Number of unvested stock options		2,367,515		1,962,163		1,659,102
Fair value of unvested stock options	$	6,108,271	$	5,550,820	$	4,587,565
Amount remaining to be recognized as expense	$	3,574,740	$	3,406,394	$	2,508,314

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

	For the Years Ended December 31,
	201 9					201 8					201 7
	Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price		Shares			Weighted Average Exercise Price
Outstanding, beginning of year		3,861,650		$	5.96		3,005,825		$	4.98		2,332,900		$	3.70
Granted		1,356,500			6.35		1,106,800			8.34		916,000			8.03
Exercised		(53,550	)		4.88		(174,850	)		3.83		(197,975	)		3.26
Forfeited		(185,125	)		6.76		(76,125	)		6.80		(45,100	)		7.95
Outstanding, end of year		4,979,475		$	6.05		3,861,650		$	5.96		3,005,825		$	4.98
Options exercisable at year-end		2,611,960		$	5.28		1,899,487		$	4.53		1,346,723		$	3.55
Weighted average fair value of options granted during the year				$	2.15				$	2.85				$	3.75

Schedule of Share-based Compensation, Options, Exercises [Table Text Block]

	For the Years Ended December 31,
	201 9		201 8		201 7
Number of options exercised		53,550		174,850		197,975
Cash received	$	261,143	$	670,413	$	646,263
Intrinsic value	$	72,187	$	814,855	$	991,957
Tax benefit	$	5,159	$	12,288	$	81,589

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

	Options Outstanding						Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted- Average Remaining Contractual Life		Weighted- Average Exercise Price		Shares		Weighted- Average Exercise Price
$1.55 to $3.53		516,200		2.5	$	2.51		516,200	$	2.51
$3.55 to $3.95		650,475		4.5		3.62		648,475		3.62
$3.99 to $7.85		1,928,125		5.7		5.69		423,874		4.17
$8.00 to $9.45		1,884,675		8.2		8.22		1,023,411		8.19
		4,979,475			$	6.05		2,611,960	$	5.28

Schedule of Nonvested Share Activity [Table Text Block]

	Number of Shares			Weighted- Average Grant Date Fair Value
Nonvested, beginning of year		1,962,163		$	2.83
Granted		1,356,500			2.15
Vested		(842,898	)		2.83
Forfeited		(108,250	)		2.83
Nonvested, end of year		2,367,515		$	2.58