REDEEMABLE PREFERRED STOCK - Narrative (Details) - USD ($)				3 Months Ended				6 Months Ended
	Aug. 08, 2019	Nov. 21, 2017	Jul. 01, 2016	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Preferred stock redemption, trading days prior to redemption								20 days
Costs specifically identifiable to the offering								$ 7,153,000
Non issuance specific costs								5,087,000
Deferred rent receivable and charges reclassified to temporary equity								$ 49,019,000
Preferred stock, dividends, declared (in usd per share)				$ 0.34375	$ 0.34375	$ 0.34375	$ 0.34375
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock redemption, trading days prior to redemption								20 days
Proceeds from issuance of preferred stock								$ 90,006,000
Costs specifically identifiable to the offering								7,042,000
Reclassification of Series A Preferred Stock from temporary equity to permanent equity								$ 476,000
Number of shares redeemed								12,772
Cumulative dividend rate								5.50%
Dividend per share per year (in usd per share)								$ 0.34375
Preferred stock, shares issued (in shares)				1,460,245				1,460,245	1,566,386
Preferred stock, liquidation preference per share (in usd per share)				$ 25.00				$ 25.00	$ 25.00
Series A Preferred Unit
Class of Stock [Line Items]
Units issued (in shares)				3,614,493				3,614,493
Proceeds from issuance of preferred stock and warrants								$ 90,362,000
Warrant
Class of Stock [Line Items]
Net proceeds from issuance of warrants								356,000
Costs specifically identifiable to the offering								111,000
Reclassification of Series A Preferred Stock from temporary equity to permanent equity								$ 1,000
Series L Preferred Stock
Class of Stock [Line Items]
Proceeds from issuance of preferred stock and warrants		$ 229,251,000
Costs specifically identifiable to the offering		15,928,000
Non issuance specific costs		$ 2,532,000
Number of shares redeemed				0
Cumulative dividend rate		5.50%
Dividend per share per year (in usd per share)		$ 1.56035
Preferred stock, shares issued (in shares)		8,080,740		8,080,740				8,080,740	8,080,740
Preferred stock, liquidation preference per share (in usd per share)				$ 28.37				$ 28.37	$ 28.37
Preferred stock discount		$ 2,946,000
Failure to declare or pay distributions, temporary increase per year		1.00%
Failure to declare or pay distributions, temporary increase per year, maximum increase		8.50%
Minimum fixed charge coverage ratio								125.00%
Registration Statement
Class of Stock [Line Items]
Maximum amount of offering				$ 900,000,000				$ 900,000,000
Warrant right to purchase a share of common stock (in shares)				0.25				0.25
Maximum number of units in offering (in shares)				36,000,000				36,000,000
Registration Statement | Series A Preferred Stock
Class of Stock [Line Items]
Redeemable preferred stock, par value (in usd per share)				$ 0.001				$ 0.001
Preferred stock, stated value (in usd per share)				$ 25				$ 25
Registration Statement | Series L Preferred Stock
Class of Stock [Line Items]
Preferred stock, liquidation preference per share (in usd per share)		$ 28.37
Preferred Stock, Redemption Period, Year Two | Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, redemption fee			13.00%
Preferred Stock, Redemption Period, After Year Two, Before Year Five | Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, redemption fee			10.00%
Preferred Stock, Redemption Period, After Year Five | Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, redemption fee			0.00%
Subsequent Event | Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividends, declared (in usd per share)	$ 0.34375