EARNINGS (LOSS) PER SHARE (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net income (loss)	$ 6.2	$ (307.4)	$ (5.2)
Net income (loss) attributable to common stockholders	1.3	(312.4)	(10.1)
Numerator for basic EPS - income (loss) available to common stockholders - two class method	1.3	(312.4)	(10.1)
Numerator for diluted EPS - income (loss) available to common shareholders - two class method	$ 1.3	$ (312.4)	$ (10.1)
Denominator:
Denominator for basic - weighted-average shares	64,775,275	64,303,438	61,654,820
Denominator for diluted EPS - weighted-average shares	65,671,246	64,303,438	61,654,820
Basic earnings (loss) per share	$ 0.02	$ (4.86)	$ (0.16)
Diluted earnings (loss) per share	$ 0.02	$ (4.86)	$ (0.16)
Stock Option
Denominator:
Weighted-average shares outstanding - Equivalent	895,971
Series A
Numerator:
Less Series A preferred dividends	$ (4.9)	$ (5.0)	$ (4.9)
Denominator:
Preferred stock dividend rate (as a percent)	7.625%	7.625%	7.625%