INCENTIVE PLANS - Stock Options Outstanding (Details)	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number outstanding (in shares) | shares	762,225
Options outstanding, Weighted-average contractual life remaining	11 months
Options outstanding, Weighted-average exercise price (in dollars per share)	$ 101.84
Options exercisable, Number exercisable (in shares) | shares	762,225
Options exercisable, Weighted-average exercise price (in dollars per share)	$ 101.84
$39.00—$99.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, low end of the range (in dollars per share)	39.00
Exercise price, high end of the range (in dollars per share)	$ 99.99
Number outstanding (in shares) | shares	312,309
Options outstanding, Weighted-average contractual life remaining	2 years 1 month
Options outstanding, Weighted-average exercise price (in dollars per share)	$ 43.56
Options exercisable, Number exercisable (in shares) | shares	312,309
Options exercisable, Weighted-average exercise price (in dollars per share)	$ 43.56
$100.00—$199.99
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price, low end of the range (in dollars per share)	100.00
Exercise price, high end of the range (in dollars per share)	$ 199.99
Number outstanding (in shares) | shares	449,916
Options outstanding, Weighted-average contractual life remaining	14 days
Options outstanding, Weighted-average exercise price (in dollars per share)	$ 142.30
Options exercisable, Number exercisable (in shares) | shares	449,916
Options exercisable, Weighted-average exercise price (in dollars per share)	$ 142.30