STOCK-BASED COMPENSATION PLANS - Summary of SAR Activity (Details) - SARs	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Stock Grants and SARs
Outstanding at the beginning of the year (in shares) | shares	2,310,000
Granted (in shares) | shares	500,000
Exercised (in shares) | shares	(200,000)
Outstanding at the end of the year (in shares) | shares	2,610,000
Weighted-Average Price
Outstanding at the beginning of the year (in dollars per share) | $ / shares	$ 19.23
Granted (in dollars per share) | $ / shares	35.70
Exercised (in dollars per share) | $ / shares	15.78
Outstanding at the end of the year (in dollars per share) | $ / shares	$ 22.65