SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Supplement Disclosures Related to Consolidated Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accounting Policies [Abstract]
Total interest costs incurred			$ 26,730	$ 26,977
Interest capitalized			747	878
Interest expense	$ 12,652	$ 13,153	25,983	26,099
Cash paid for interest, net of amounts capitalized			21,984	24,076
Cash paid for income taxes			296	459
Accounts payable and accrued liabilities for construction in progress			2,113	(1,539)
Accrued leasing commissions			498	(7)
Reduction to capital for prepaid offering costs			$ 69	$ 154