SHAREHOLDERS' EQUITY AND NONCONTROLLING INTERESTS (Details)	1 Months Ended		3 Months Ended	9 Months Ended
	Aug. 31, 2016 USD ($) shares	Apr. 29, 2016 USD ($) shares	Sep. 30, 2016 USD ($) $ / shares shares	Sep. 30, 2016 USD ($) $ / shares shares	Sep. 30, 2015 USD ($) shares	Jun. 30, 2016 USD ($)	Dec. 31, 2015 shares
Noncontrolling Interest [Line Items]
Proceeds from issuance of common stock | $				$ 357,262,000	$ 26,933,000
Operating Partnership, as General Partner or Managing Member
Noncontrolling Interest [Line Items]
Limited partners' capital account, units issued (in shares) | shares			442,478	442,478
Limited partners' common OP units (in shares) | shares			3,308,875	3,308,875			2,931,198
Common stock
Noncontrolling Interest [Line Items]
Common stock issued during the period (in shares) | shares	4,830,000
Gross proceeds from issuance of common stock | $	$ 175,200,000
Proceeds from issuance of common stock | $	$ 172,100,000
Series A Preferred Stock | Operating Partnership, as General Partner or Managing Member
Noncontrolling Interest [Line Items]
Limited partners' common OP units (in shares) | shares			188	188	188		188
Series C Preferred Stock | Operating Partnership, as General Partner or Managing Member
Noncontrolling Interest [Line Items]
Limited partners' capital account, units issued (in shares) | shares			141,593	141,593
Limited partners' value per unit (in dollars per share) | $ / shares			$ 100.00	$ 100.00
Limited partners' quarterly distribution (in dollars per share) | $ / shares			$ 0.9375
Limited partners' common OP units (in shares) | shares			141,593	141,593	141,593
At The Market Equity Program | Common stock
Noncontrolling Interest [Line Items]
Common stock issued during the period (in shares) | shares				4,600,000.0
Gross proceeds from issuance of common stock | $				$ 158,800,000
Proceeds from issuance of common stock | $				$ 156,800,000
Additional maximum gross proceeds amount | $			$ 250,000,000
Sale of stock, remaining value under program | $			$ 218,000,000
LTIP Units
Noncontrolling Interest [Line Items]
Share-based compensation, outstanding (in shares) | shares			1,163,841	1,163,841			929,169
At The Market Equity Program
Noncontrolling Interest [Line Items]
Common stock, shares authorized not issued, value | $						$ 200,000,000.0
Forward Sale and Underwritten Public Offering | Common stock
Noncontrolling Interest [Line Items]
Common stock issued during the period (in shares) | shares		3,600,000	867,612
Proceeds from issuance of common stock | $		$ 124,500,000	$ 30,000,000
Minimum | Series C Preferred Stock | Operating Partnership, as General Partner or Managing Member
Noncontrolling Interest [Line Items]
Share price (in dollars per share) | $ / shares			$ 28.80	$ 28.80
Share price, conversion ratio				3.4722
Maximum | Series C Preferred Stock | Operating Partnership, as General Partner or Managing Member
Noncontrolling Interest [Line Items]
Share price (in dollars per share) | $ / shares			$ 35.20	$ 35.20
Share price, conversion ratio				2.8409