STOCKHOLDERS' EQUITY, Stock options by Exercise Price Range (Details)	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Stock Options by Exercise Price [Abstract]
Number of shares outstanding (in shares) | shares	175,500
Weighted average life	6 years 3 months 29 days
Weighted average exercise price (in dollars per share)	$ 37.73
Number of shares exercisable (in shares) | shares	86,500
Weighted average option price (in dollars per share)	$ 24.84
Weighted average life	3 years 2 months 19 days
$13.24-15.85 [Member]
Stock Options by Exercise Price [Abstract]
Options exercise price, lower limit (in dollars per share)	$ 13.24
Options exercise price, upper limit (in dollars per share)	$ 15.85
Number of shares outstanding (in shares) | shares	30,000
Weighted average life	3 years 10 months 6 days
Weighted average exercise price (in dollars per share)	$ 15.80
Number of shares exercisable (in shares) | shares	30,000
Weighted average option price (in dollars per share)	$ 15.80
Weighted average life	3 years 10 months 6 days
$17.00-29.21 [Member]
Stock Options by Exercise Price [Abstract]
Options exercise price, lower limit (in dollars per share)	$ 17.00
Options exercise price, upper limit (in dollars per share)	$ 29.21
Number of shares outstanding (in shares) | shares	34,000
Weighted average life	7 months 13 days
Weighted average exercise price (in dollars per share)	$ 24.34
Number of shares exercisable (in shares) | shares	34,000
Weighted average option price (in dollars per share)	$ 24.34
Weighted average life	7 months 13 days
$37.64-57.38 [Member]
Stock Options by Exercise Price [Abstract]
Options exercise price, lower limit (in dollars per share)	$ 37.64
Options exercise price, upper limit (in dollars per share)	$ 57.38
Number of shares outstanding (in shares) | shares	111,500
Weighted average life	8 years 8 months 23 days
Weighted average exercise price (in dollars per share)	$ 47.71
Number of shares exercisable (in shares) | shares	22,500
Weighted average option price (in dollars per share)	$ 37.64
Weighted average life	6 years 3 months 22 days