ACQUISITIONS AND DISPOSITIONS - Carrying Value of Assets and Liabilities at Time of Sale and Held for Sale (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets
Total assets, net	$ 22,175	$ 0
Liabilities
Total liabilities	28,766	0
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Assets
Investments in real estate, net	0	631,740	$ 54,374
Deferred rent receivable and charges, net	0	34,071	0
Other intangible assets, net	0	11,283	528
Other assets	0	38	0
Total assets, net	0	677,132	54,902
Liabilities
Debt, net	0	115,037	0
Other liabilities	0	14,029	0
Intangible liabilities, net	0	1,800	0
Total liabilities	0	130,866	$ 0
Premium on assumed mortgage		665
Debt assumed by buyers		$ 50,260
Disposal Group, Held-for-sale, Not Discontinued Operations
Assets
Investments in real estate, net	17,123
Cash and cash equivalents	755
Accounts receivable, net	41
Deferred rent receivable and charges, net	4,009
Other intangible assets, net	220
Other assets	27
Total assets, net	22,175
Liabilities
Debt, net	28,018
Accounts payable and accrued expenses	370
Due to related parties	81
Other liabilities	297
Total liabilities	28,766
Investments in real estate	24,832
Investments in real estate, accumulated depreciation	7,709
Debt, gross	28,200
Deferred loan costs	243
Debt, accumulated amortization	61
Acquired in-place Leases | Disposal Group, Held-for-sale, Not Discontinued Operations
Assets
Other intangible assets, net	1,778
Liabilities
Other intangible assets, accumulated amortization	$ 1,558