EARNINGS PER SHARE - Summary of Components Used to Calculate Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net income	$ 8,753	$ 11,626	$ 49,069	$ 12,900	$ 5,757	$ 38,001	$ 37,677	$ 9,691	$ 82,348	$ 91,126	$ 99,521
Less: Preferred dividends									(14,838)	(16,671)	(17,408)
Premium on redemption of preferred stock									0	(3,277)	(2,572)
Allocation to participating securities									(309)	(271)	(307)
Attributable to non-controlling interest in Operating Partnership									(157)	(205)	(307)
Attributable to non-controlling interest in joint venture									419	0	0
Net income attributable to common stockholders, net of amount allocated to participating securities									$ 67,463	$ 70,702	$ 78,927
Denominator:
Weighted average common shares outstanding - basic (in shares)									103,887	103,623	99,406
Dilutive effect of equity-based compensation awards (in shares)									52	219	374
Weighted average common shares outstanding - diluted (in shares)									103,939	103,842	99,780
Basic and diluted (in dollars per share)	$ 0.05	$ 0.07	$ 0.43	$ 0.09					$ 0.65	$ 0.68	$ 0.79