EQUITY - Narrative (Details)						6 Months Ended		10 Months Ended	12 Months Ended
	May 15, 2017 USD ($)	May 09, 2017 $ / shares shares	Oct. 28, 2016 USD ($) $ / shares shares	Jun. 30, 2016 USD ($)	Jun. 28, 2016 USD ($) shares	Jun. 30, 2017 USD ($) $ / shares shares	Jun. 30, 2016 USD ($) shares	May 25, 2017 USD ($) $ / shares shares	Dec. 31, 2016 $ / shares shares	Jul. 31, 2016
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
Shares issued during stock offering (in shares)						10,350,000	0
Net proceeds from public shares offering | $						$ 163,670,000	$ 72,337,000
Compensation entitled as percentage of gross proceeds of shares sold under sales agreements						2.00%
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						90,600,000
7.875% Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized						3,000,000
Preferred stock, dividend rate						7.875%			7.875%
Preferred stock, shares outstanding						3,000,000			3,000,000
Preferred stock, liquidation preference (in dollars per share) | $ / shares						$ 25
Annual dividend rate per share (in dollars per share) | $ / shares						$ 1.96875
7.875% Series B Preferred Stock | Maximum
Class of Stock [Line Items]
Ratio for conversion						5.6497
7.125% Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized						3,400,000
Preferred stock, dividend rate						7.125%			7.125%
Preferred stock, shares outstanding						3,400,000			3,400,000
Preferred stock, liquidation preference (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
6.450% Series D Preferred Stock
Class of Stock [Line Items]
Shares issued during stock offering (in shares)					3,000,000
Net proceeds from public shares offering | $					$ 72,300,000
Preferred stock, shares authorized						3,000,000
Preferred stock, dividend rate						6.45%			6.45%
Preferred shares offering underwriting discount and offering-related expenses | $					$ 2,700,000
Preferred stock, shares outstanding						3,000,000			3,000,000
Preferred stock, liquidation preference (in dollars per share) | $ / shares						$ 25
Annual dividend rate per share (in dollars per share) | $ / shares						$ 1.6125
6.450% Series D Preferred Stock | Maximum
Class of Stock [Line Items]
Ratio for conversion						3.9216
9.25% Series A Preferred Stock
Class of Stock [Line Items]
Payments for repurchase of redeemable preferred shares | $			$ 50,700,000
Preferred stock, shares outstanding			2,000,000
Preferred stock, redemption price (in dollars per share) | $ / shares			$ 25
Preferred stock, liquidation preference (in dollars per share) | $ / shares						$ 25
Operating partnership | Non-controlling Interests in Operating Partnership
Class of Stock [Line Items]
Number of common units of operating partnership owned by unaffiliated third parties (in shares)						366,056			396,713
Percentage of limited partnership interest in operating partnership (less than)						1.00%			1.00%
Leasehold Venture
Class of Stock [Line Items]
Payments to acquire interest in joint venture | $				$ 400,000
Ownership interest in joint venture (as a percent)										100.00%
Underwriting Agreement
Class of Stock [Line Items]
Common stock, par value (in dollars per share) | $ / shares		$ 0.01
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, par value (in dollars per share) | $ / shares								$ 0.01
Common stock, shares authorized, amount | $								$ 200,000,000
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