SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Supplement Disclosures Related to Consolidated Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accounting Policies [Abstract]
Total interest costs incurred			$ 41,009	$ 40,368
Interest capitalized			1,153	1,220
Interest expense	$ 13,873	$ 13,049	39,856	39,148
Cash paid for interest, net of amounts capitalized			33,720	36,070
Cash paid for income taxes			296	459
Accounts payable and accrued liabilities for construction in progress			(3,019)	(471)
Accrued leasing commissions			1,410	275
Reduction to capital for prepaid offering costs			$ 129	$ 0