EMPLOYEE BENEFITS - Stock Options Exercise Price Range (Details)	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Options Outstanding
Number of Shares (in shares) | shares	909,351
Weighted- Average Exercise Price (in dollars per share)	$ 29.59
Weighted- Average Remaining Contractual Life in Years	7 years 3 months 10 days
Options Exercisable
Number of Shares (in shares) | shares	406,361
Weighted- Average Exercise Price (in dollars per share)	$ 24.97
$14.67 - $20.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices - Lower Range Limit (in dollars per share)	14.67
Range of Exercise Prices - Upper Range Limit (in dollars per share)	$ 20.00
Options Outstanding
Number of Shares (in shares) | shares	110,291
Weighted- Average Exercise Price (in dollars per share)	$ 15.89
Weighted- Average Remaining Contractual Life in Years	3 years 12 days
Options Exercisable
Number of Shares (in shares) | shares	110,291
Weighted- Average Exercise Price (in dollars per share)	$ 15.89
$20.01 - $25.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices - Lower Range Limit (in dollars per share)	20.01
Range of Exercise Prices - Upper Range Limit (in dollars per share)	$ 25.00
Options Outstanding
Number of Shares (in shares) | shares	106,826
Weighted- Average Exercise Price (in dollars per share)	$ 22.92
Weighted- Average Remaining Contractual Life in Years	5 years 5 months 6 days
Options Exercisable
Number of Shares (in shares) | shares	82,747
Weighted- Average Exercise Price (in dollars per share)	$ 23.01
$25.01 - $30.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices - Lower Range Limit (in dollars per share)	25.01
Range of Exercise Prices - Upper Range Limit (in dollars per share)	$ 30.00
Options Outstanding
Number of Shares (in shares) | shares	202,009
Weighted- Average Exercise Price (in dollars per share)	$ 26.68
Weighted- Average Remaining Contractual Life in Years	6 years 5 months 20 days
Options Exercisable
Number of Shares (in shares) | shares	136,613
Weighted- Average Exercise Price (in dollars per share)	$ 26.58
$30.01 - $35.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices - Lower Range Limit (in dollars per share)	30.01
Range of Exercise Prices - Upper Range Limit (in dollars per share)	$ 35.00
Options Outstanding
Number of Shares (in shares) | shares	346,965
Weighted- Average Exercise Price (in dollars per share)	$ 34.52
Weighted- Average Remaining Contractual Life in Years	9 years 4 months 28 days
Options Exercisable
Number of Shares (in shares) | shares	0
Weighted- Average Exercise Price (in dollars per share)	$ 0.00
$35.01 - $37.28
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices - Lower Range Limit (in dollars per share)	35.01
Range of Exercise Prices - Upper Range Limit (in dollars per share)	$ 37.28
Options Outstanding
Number of Shares (in shares) | shares	143,260
Weighted- Average Exercise Price (in dollars per share)	$ 37.28
Weighted- Average Remaining Contractual Life in Years	7 years 10 months 25 days
Options Exercisable
Number of Shares (in shares) | shares	76,710
Weighted- Average Exercise Price (in dollars per share)	$ 37.28