STOCK-BASED COMPENSATION - ACTIVITY OF NON-VESTED STOCK, OTHER THAN OPTIONS (Details) - LTIP	6 Months Ended
	Jun. 30, 2019 $ / shares shares
Restricted shares
Restricted Stock
Non-vested at beginning of year (in shares) | shares	480,835
Granted (in shares) | shares	251,000
Vested (in shares) | shares	(128,642)
Forfeited (in shares) | shares	(5,090)
Non-vested at end of year (in shares) | shares	598,103
Weighted-Average Grant-Date Fair Value
Non-vested at beginning of year (in dollars per share) | $ / shares	$ 30.83
Granted (in dollars per share) | $ / shares	22.76
Vested (in dollars per share) | $ / shares	23.50
Forfeited (in dollars per share) | $ / shares	33.22
Non-vested at end of year (in dollars per share) | $ / shares	$ 26.99
Performance Shares
Restricted Stock
Non-vested at beginning of year (in shares) | shares	53,689
Granted (in shares) | shares	102,379
Vested (in shares) | shares	(2,598)
Forfeited (in shares) | shares	0
Non-vested at end of year (in shares) | shares	153,470
Weighted-Average Grant-Date Fair Value
Non-vested at beginning of year (in dollars per share) | $ / shares	$ 29.92
Granted (in dollars per share) | $ / shares	22.15
Vested (in dollars per share) | $ / shares	23.55
Forfeited (in dollars per share) | $ / shares	0
Non-vested at end of year (in dollars per share) | $ / shares	$ 24.74