EQUITY (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended	9 Months Ended		12 Months Ended
	Feb. 18, 2019	Apr. 30, 2018	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Stock-based compensation plans
Dividends declared per common share (in dollars per share)	$ 0.38738		$ 0.39	$ 0.39	$ 1.16	$ 0.38738
Additional shares of common stock authorized		2,000,000
Shares of common stock authorized for issuance				4,650,000
Unrecognized share-based compensation
Unrecognized compensation cost				$ 12.6
Weighted-average period of recognition				1 year 8 months 12 days
Maximum
Stock-based compensation plans
Shares that may be granted in the form of stock options or stock appreciation rights to any eligible employee or director in any calendar year				300,000
Restricted stock
Shares
Non-vested shares outstanding at the beginning of the period				338,771
Shares granted				551,214
Shares forfeited, cancelled or retired				(25,363)
Non-vested shares outstanding at the end of the period				864,622		338,771
Weighted Average Grant Date Fair Value
Non-vested shares outstanding at the beginning of the period (in dollars per share)				$ 14.31
Shares granted (in dollars per share)				9.87
Shares forfeited, cancelled or retired (in dollars per share)				10.76
Non-vested shares outstanding at the end of the period (in dollars per share)				$ 11.58		$ 14.31
Performance shares
Shares
Non-vested shares outstanding at the beginning of the period				35,626
Shares granted				371,672
Shares forfeited, cancelled or retired				(8,755)
Non-vested shares outstanding at the end of the period				398,543		35,626
Weighted Average Grant Date Fair Value
Non-vested shares outstanding at the beginning of the period (in dollars per share)				$ 21.97
Shares granted (in dollars per share)				9.86
Shares forfeited, cancelled or retired (in dollars per share)				12.95
Non-vested shares outstanding at the end of the period (in dollars per share)				$ 13.29		$ 21.97