EQUITY - Additional Information (Details)					10 Months Ended	12 Months Ended
	Dec. 11, 2017 USD ($) $ / shares shares	Nov. 13, 2017 USD ($) shares	May 15, 2017 USD ($)	May 09, 2017 $ / shares shares	May 25, 2017 USD ($) shares	Dec. 31, 2017 USD ($) Vote $ / shares shares	Dec. 31, 2016 $ / shares shares	Feb. 05, 2018 $ / shares shares	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)						10,350,000	6,151,514
Compensation entitled as percentage of gross proceeds of shares sold under sales agreements									2.00%
Shares reserved for issuance						15,275,114	6,332,307
Preferred stock, shares authorized						100,000,000	100,000,000
Preferred stock, par value (in dollars per share) | $ / shares						$ 0.01	$ 0.01
Undesignated preferred stock
Class of Stock [Line Items]
Preferred stock, shares authorized						87,200,000
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]
Preferred stock, dividend rate (as a percent)							7.875%
Payments for repurchase of redeemable preferred shares | $	$ 75,200,000
Preferred stock, shares outstanding	3,000,000						3,000,000
Preferred stock, redemption price (in dollars per share) | $ / shares	$ 25					$ 25
7.125% Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized						3,400,000
Preferred stock, dividend rate (as a percent)						7.125%	7.125%
Preferred stock, shares outstanding						3,400,000	3,400,000
Preferred stock, redemption price (in dollars per share) | $ / shares						$ 25
Annual dividend rate per share (in dollars per share) | $ / shares						$ 1.78125
7.125% Series C Preferred Stock | Maximum
Class of Stock [Line Items]
Ratio for conversion						5.1440
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%
Preferred shares offering underwriting discount and offering-related expenses | $		$ 5,300,000
Preferred stock, shares outstanding						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
ATM Program 2017
Class of Stock [Line Items]
Stock issuance costs | $						$ 200,000
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)						323,391	396,713
Percentage of limited partnership interest in operating partnership (less than)						1.00%	1.00%
Subsequent events | 7.125% Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares outstanding								3,400,000
Preferred stock, redemption price (in dollars per share) | $ / shares								$ 25.00