EMPLOYEE BENEFIT PLANS (Information Regarding Stock Options) (Details)	12 Months Ended
	Dec. 31, 2018 $ / shares shares
$54.51 - $78.33
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise price, minimum, (in dollars per share)	$ 54.51
Range of exercise price, maximum, (in dollars per share)	$ 78.33
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Number of shares (in shares) | shares	300
Weighted-average remaining contractual life (in years)	1 year 11 months 1 day
Weighted- average exercise price (in dollars per share)	$ 54.51
Options Exercisable [Abstract]
Number of shares (in shares) | shares	300
Weighted-average exercise price (in dollars per share)	$ 54.51
$78.34 - $142.45
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise price, minimum, (in dollars per share)	78.34
Range of exercise price, maximum, (in dollars per share)	$ 142.45
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Number of shares (in shares) | shares	58,844
Weighted-average remaining contractual life (in years)	4 years 2 months 8 days
Weighted- average exercise price (in dollars per share)	$ 102.16
Options Exercisable [Abstract]
Number of shares (in shares) | shares	58,844
Weighted-average exercise price (in dollars per share)	$ 102.16
$142.46 - $188.22
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise price, minimum, (in dollars per share)	142.46
Range of exercise price, maximum, (in dollars per share)	$ 188.22
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Number of shares (in shares) | shares	57,768
Weighted-average remaining contractual life (in years)	7 years 2 months 8 days
Weighted- average exercise price (in dollars per share)	$ 182.75
Options Exercisable [Abstract]
Number of shares (in shares) | shares	33,033
Weighted-average exercise price (in dollars per share)	$ 182.75
$188.23 - $197.37
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise price, minimum, (in dollars per share)	188.23
Range of exercise price, maximum, (in dollars per share)	$ 197.37
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Number of shares (in shares) | shares	34,264
Weighted-average remaining contractual life (in years)	6 years 2 months 1 day
Weighted- average exercise price (in dollars per share)	$ 193.69
Options Exercisable [Abstract]
Number of shares (in shares) | shares	34,264
Weighted-average exercise price (in dollars per share)	$ 193.69
$197.38 - $202.98
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise price, minimum, (in dollars per share)	197.38
Range of exercise price, maximum, (in dollars per share)	$ 202.98
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Number of shares (in shares) | shares	34,600
Weighted-average remaining contractual life (in years)	5 years 1 month 28 days
Weighted- average exercise price (in dollars per share)	$ 201.04
Options Exercisable [Abstract]
Number of shares (in shares) | shares	34,600
Weighted-average exercise price (in dollars per share)	$ 201.04
$202.99 - $273.52
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise price, minimum, (in dollars per share)	202.99
Range of exercise price, maximum, (in dollars per share)	$ 273.52
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Number of shares (in shares) | shares	82,500
Weighted-average remaining contractual life (in years)	8 years 1 month 28 days
Weighted- average exercise price (in dollars per share)	$ 204.91
Options Exercisable [Abstract]
Number of shares (in shares) | shares	24,364
Weighted-average exercise price (in dollars per share)	$ 204.91
$273.53 - $342.13
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise price, minimum, (in dollars per share)	273.53
Range of exercise price, maximum, (in dollars per share)	$ 342.13
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Number of shares (in shares) | shares	76,000
Weighted-average remaining contractual life (in years)	9 years 1 month 28 days
Weighted- average exercise price (in dollars per share)	$ 342.13
Options Exercisable [Abstract]
Number of shares (in shares) | shares	0
Weighted-average exercise price (in dollars per share)	$ 0.00
$54.51 - $342.13
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of exercise price, minimum, (in dollars per share)	54.51
Range of exercise price, maximum, (in dollars per share)	$ 342.13
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, End of Period [Abstract]
Number of shares (in shares) | shares	344,276
Weighted-average remaining contractual life (in years)	7 years 11 days
Weighted- average exercise price (in dollars per share)	$ 212.28
Options Exercisable [Abstract]
Number of shares (in shares) | shares	185,405
Weighted-average exercise price (in dollars per share)	$ 165.31