EQUITY - Additional Information (Details)						10 Months Ended	12 Months Ended
	Mar. 20, 2018 USD ($) $ / shares shares	Dec. 11, 2017 USD ($) $ / shares shares	Nov. 13, 2017 USD ($) shares	May 15, 2017 USD ($)	May 09, 2017 $ / shares shares	May 25, 2017 USD ($) shares	Dec. 31, 2018 USD ($) Vote $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2016 USD ($)	Sep. 30, 2017
Class of Stock [Line Items]
Common stock, shares authorized							500,000,000	500,000,000
Common stock, par value (in dollars per share) | $ / shares							$ 0.01	$ 0.01
Number of votes a share of outstanding common stock is entitled | Vote							1
Shares issued during stock offering (in shares)							0	10,350,000
Compensation entitled as percentage of gross proceeds of shares sold under sales agreements										2.00%
Shares reserved for issuance							14,591,213	15,275,114
Preferred stock, shares authorized							100,000,000	100,000,000
Preferred stock, par value (in dollars per share) | $ / shares							$ 0.01	$ 0.01
Premium on redemption of preferred stock | $							$ 3,277,000	$ 2,572,000	$ 2,125,000
Undesignated preferred stock
Class of Stock [Line Items]
Preferred stock, shares authorized							90,600,000
9.25% Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, redemption price (in dollars per share) | $ / shares							$ 25
7.875% Series B Preferred Stock
Class of Stock [Line Items]
Payments for repurchase of redeemable preferred shares | $		$ 75,200,000
Preferred stock, shares outstanding		3,000,000
Preferred stock, redemption price (in dollars per share) | $ / shares		$ 25
Premium on redemption of preferred stock | $		$ 2,600,000
7.125% Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock, dividend rate (as a percent)	7.125%							7.125%
Payments for repurchase of redeemable preferred shares | $	$ 85,300,000
Preferred stock, shares outstanding	3,400,000							3,400,000
Preferred stock, redemption price (in dollars per share) | $ / shares	$ 25
Premium on redemption of preferred stock | $	$ 3,300,000
6.45% Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized							3,000,000
Preferred stock, dividend rate (as a percent)							6.45%	6.45%
Preferred stock, shares outstanding							3,000,000	3,000,000
Preferred stock, redemption price (in dollars per share) | $ / shares							$ 25
Annual dividend rate per share (in dollars per share) | $ / shares							$ 1.6125
6.45% Series D Preferred Stock | Maximum
Class of Stock [Line Items]
Ratio for conversion							3.9216
6.25% Series E Preferred Stock
Class of Stock [Line Items]
Shares issued during stock offering (in shares)			6,400,000
Net proceeds from public shares offering | $			$ 154,700,000
Preferred stock, shares authorized							6,400,000
Preferred stock, dividend rate (as a percent)							6.25%	6.25%
Preferred shares offering underwriting discount and offering-related expenses | $			$ 5,300,000
Preferred stock, shares outstanding							6,400,000	6,400,000
Preferred stock, redemption price (in dollars per share) | $ / shares							$ 25,000
Annual dividend rate per share (in dollars per share) | $ / shares							$ 1.5625
6.25% Series E Preferred Stock | Maximum
Class of Stock [Line Items]
Ratio for conversion							3.1686
Underwriting Agreement
Class of Stock [Line Items]
Shares issued during stock offering (in shares)					9,000,000
Public offering price (in dollars per share) | $ / shares					$ 16.50
Underwriting discount (in dollars per share) | $ / shares					$ 0.66
Number of days option for underwriters to purchase common stock on same terms					30 days
Number of additional shares for underwriters to purchase					1,350,000
Net proceeds from public shares offering | $				$ 163,800,000
Underwriting discount and offering-related expenses | $				$ 7,000,000
Sales Agreements
Class of Stock [Line Items]
Common stock, shares authorized, amount | $						$ 200,000,000.0
ATM Program 2016
Class of Stock [Line Items]
Shares issued during stock offering (in shares)						6,151,514
Net proceeds from public shares offering | $						$ 89,100,000
Unaffiliated Third Parties [Member] | State income taxes, net of federal tax benefit
Class of Stock [Line Items]
Conversion ratio of limited partner common units into common stock							1
Number of common units of operating partnership owned by unaffiliated third parties (in shares)							259,265	323,391
Percentage of limited partnership interest in operating partnership (less than)							1.00%	1.00%