EQUITY STRUCTURE AND ACCOUNTS - Additional Information (Details)	6 Months Ended
	Jun. 30, 2018 USD ($) Vote Class_of_Stock $ / shares shares	Jun. 30, 2017 shares	Oct. 30, 2014 USD ($)
Class of Stock [Line Items]
Number of classes of common stock | Class_of_Stock	2
2014 Share Repurchase Authorization Program
Class of Stock [Line Items]
Remaining amount available for repurchase | $	$ 41,800,000
Percentage of aggregate common stock outstanding under Repurchase Program	2.70%
Share price (in dollars per share) | $ / shares	$ 15.62
Series REIT LP Units
Class of Stock [Line Items]
Exchange of noncontrolling interest for common stock, units exchanged (in shares)	4,349,832	13,737,365
Series TRS LP Units
Class of Stock [Line Items]
Exchange of noncontrolling interest for common stock, units exchanged (in shares)	4,349,832	13,737,365
Class A Common Stock
Class of Stock [Line Items]
Number of votes per share | Vote	1
Exchange of noncontrolling interest for common stock (in shares)	4,349,832	13,737,365
Class A Common Stock | 2014 Share Repurchase Authorization Program
Class of Stock [Line Items]
Authorized amount of stock repurchase (up to) | $			$ 50,000,000
Purchase of treasury stock (in shares)	0	0
Class B Common Stock
Class of Stock [Line Items]
Number of votes per share | Vote	1
Exchange of noncontrolling interest for common stock (in shares)	4,349,832	13,737,365