CAPITAL STOCK (Tables)

3 Months Ended

Mar. 31, 2020

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of weighted average valuation assumptions

The fair value of each option grant was estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted average assumptions for options granted in the three months ended March 31,2020 and 2019.

	Three Months Ended March 31,
	2020	2019
Risk-free interest rate	0.72%	2.45%
Expected lives	4.5 years	4.7 years
Expected volatility	39%	39%
Expected dividend yield	0%	0%

Schedule of stock options plans

The following table summarizes restricted stock transactions for the three months ended March 31, 2020:

	RSAs		Weighted-Average Grant Date Fair Value Per Award
Non-vested as of December 31, 2019	335,667		$	74.29
Granted	250		86.57
Vested	(16,894	)	48.77
Forfeited	(46,000	)	64.59
Non-vested as of March 31, 2020	273,023		$	77.44

A summary of our stock option plans is as follows:

	Three Months Ended March 31,				Year Ended December 31,
	2020				2019
	Options		Weighted Average Exercise Price		Options		Weighted Average Exercise Price
Outstanding at beginning of period	536,315		$	54.855	620,553		$	40.741
Granted at market	250		$	95.660	88,200		$	84.234
Forfeited	(35,641	)	$	70.546	(1,353	)	$	98.660
Expired	(1,051	)	$	98.660	(716	)	$	98.660
Exercised	(10,483	)	$	8.779	(170,369	)	$	18.125
Outstanding at end of period	489,390		$	54.626	536,315		$	54.855
Exercisable at end of period	339,845		$	41.893	315,964		$	37.644

Schedule of shares authorized under stock options plans by exercise price

The following table summarizes information about stock options outstanding and exercisable at March 31, 2020:

	Options Outstanding				Options Exercisable
Exercise Prices	Number of Options Outstanding at March 31, 2020	Weighted Average Remaining Contractual Life in Years	Weighted Average Exercise Price		Number of Options Exercisable at March 31, 2020	Weighted Average Exercise Price
4.96-7.36	78,733	2.72	$	7.022	78,733	$	7.022
7.37-62.50	123,943	3.72	$	26.115	123,838	$	26.088
62.51-69.77	101,668	6.90	$	69.770	71,669	$	69.770
69.78-72.85	84,391	6.67	$	72.237	41,779	$	72.850
72.86-108.25	100,655	8.77	$	96.909	23,826	$	101.137
4.96-108.25	489,390	5.77	$	54.626	339,845	$	41.893

Schedule of pricing models

The weighted average assumptions used for the periods presented were as follows:

	Three Months Ended March 31,
	2020	2019
Risk-free interest rate	1.34%	2.35%
Expected lives	1.1 years	1.1 years
Expected volatility	44%	40%
Expected dividend yield	0%	0%