STOCK-BASED COMPENSATION - Stock Options Rollforward (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares
Number of Shares
Outstanding at beginning of period (in shares) | shares	396
Granted (in shares) | shares	0
Exercised (in shares) | shares	0
Cancelled/expired/forfeited (in shares) | shares	(56)
Outstanding at end of period (in shares) | shares	340
Exercisable, Number of shares (in shares) | shares	340
Weighted-Average Exercise Price
Outstanding at beginning of period (in dollars per share) | $ / shares	$ 106.56
Granted (in dollars per share) | $ / shares	0
Exercised (in dollars per share) | $ / shares	0
Cancelled/expired/forfeited (in dollars per share) | $ / shares	96.90
Outstanding at end of period (in dollars per share) | $ / shares	107.84
Exercisable, Weighted-average exercise price (in dollars per share) | $ / shares	$ 107.84
Weighted-average remaining contractual term, Outstanding	4 years 7 months 9 days
Weighted-average remaining contractual term, Exercisable	4 years 7 months 9 days
Aggregate intrinsic value, Outstanding | $	$ 0
Aggregate intrinsic value, Exercisable | $	$ 0