BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Deferred Rent Receivable and Charges (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Deferred Rent Receivable and Charges
Deferred rent receivable	$ 52,905	$ 64,010
Deferred leasing costs	52,860	76,063
Deferred leasing costs, accumulated amortization	23,294	25,914
Deferred offering costs	2,973	2,060
Other deferred costs	$ 1,550	$ 135