STOCK-BASED COMPENSATION - Stock Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee awards
Vesting percentage on the day before each anniversary date follwoing date of grant	0.33%
Stock Options
Employee awards
Vesting percentage on the day before each anniversary date follwoing date of grant	0.33%
Award term	P7Y
Award vesting period	3 years
Grant-date valuations
Exercise price per share	$ 23.88
Grant-date fair value of stock option awards	$ 12.95
Options
Beginning balance (in shares)	1,287,000
Granted (in shares)	144,000		0	0
Exercised (in shares)	(1,000)
Expired or Canceled (in shares)	(3,000)
Ending balance (in shares)	1,427,000	1,287,000
Exercisable, end of year (in shares)	1,174,000
Weighted-Average Exercise Price
Beginning balance, weighted-average exercise price (in dollars per share)	$ 62.82
Granted weighted-average exercise price (in dollars per share)	23.88
Exercised weighted-average exercise price (in dollars per share)	20.17
Expired or Canceled weighted-average exercise price (in dollars per share)	22.28
Ending balance, weighted-average exercise price (in dollars per share)	59.00	$ 62.82
Exercisable, end of year, weighted-average exercise price (in dollars per share)	66.91
Weighted-Average Grant-Date Fair Value
Beginning balance, weighted-average grant date fair value (in dollars per share)	17.22
Weighted-average, grant date fair value of stock option awards granted (in dollars per share)	$ 12.95
Exercised, weighted average grant date fair value (in dollars per share)	10.02
Expired or Canceled weighted average, grant date fair value (in dollars per share)	11.69
Ending balance, weighted-average grant date fair value (in dollars per share)	$ 16.81	17.22
Exercisable, end of year, weighted-average grant date fair value (in dollars per share)	17.92
Stock Options | Black-Scholes valuation method
Grant-date valuations
Exercise price per share	$ 23.88	$ 20.17			$ 42.00	$ 81.10
Expected life (in years)	4 years 6 months	4 years 6 months			4 years 6 months	4 years 6 months
Expected volatility	78.26%	69.85%			44.70%	35.40%
Risk-free interest rate	2.47%	2.63%			1.56%	1.40%
Dividend yield	0.00%	0.00%			0.95%	0.50%
Grant-date fair value of stock option awards	$ 12.95	$ 10.02			$ 15.00	$ 19.80
Weighted-Average Exercise Price
Granted weighted-average exercise price (in dollars per share)	23.88	20.17			42.00	81.10
Weighted-Average Grant-Date Fair Value
Weighted-average, grant date fair value of stock option awards granted (in dollars per share)	$ 12.95	$ 10.02			$ 15.00	$ 19.80