EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Numerator:
Net income	$ 37,677	$ 34,083	$ 47,368	$ 67,289
Less: Preferred dividends	(3,709)	(4,200)	(9,252)	(8,400)
Premium on redemption of preferred stock	0	0	(3,277)	0
Allocation to participating securities	(120)	(126)	(137)	(240)
Attributable to non-controlling interest	(101)	(114)	(104)	(234)
Net income attributable to common stockholders	$ 33,747	$ 29,643	$ 34,598	$ 58,415
Denominator:
Weighted average common shares outstanding - basic (in shares)	103,643,000	98,184,000	103,572,000	95,488,000
Dilutive effect of equity-based compensation awards (in shares)	240,000	522,000	320,000	495,000
Weighted average common shares outstanding - diluted (in shares)	103,883,000	98,706,000	103,892,000	95,983,000
Basic (in dollars per share)	$ 0.33	$ 0.30	$ 0.33	$ 0.61
Diluted (in dollars per share)	$ 0.32	$ 0.30	$ 0.33	$ 0.61
Restricted Stock Awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of diluted earnings per share (in shares)	453,664	619,429	453,664	619,429