INTANGIBLES (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017
Intangible assets:
Goodwill	$ 1,034,274	$ 1,034,644
Accumulated amortization	(886,238)	(864,576)
Net intangible assets	$ 1,694,553	$ 1,754,032
Remaining weighted average amortization period in years	22 years 6 months	22 years 1 month 6 days
Intangible liabilities:
Below market lease intangibles	$ 358,914	$ 359,118
Other lease intangibles	32,324	40,141
Accumulated amortization	(184,803)	(160,985)
Purchase option intangibles	3,568	3,568
Net intangible liabilities	$ 210,003	$ 241,842
Below market leases, remaining weighted average amortization period (in years)	14 years 7 months 6 days	13 years 8 months 12 days
Other lease intangibles, remaining weighted average amortization period (in years)	43 years 1 month 6 days	40 years 9 months 18 days
Net intangible liabilities, remaining weighted average amortization period (in years)	16 years 7 months 6 days	15 years 7 months 6 days
Above Market Lease Intangibles
Intangible assets:
Intangible assets	$ 184,111	$ 185,012
Remaining weighted average amortization period in years	6 years 10 months 24 days	7 years
In-place and Other Lease Intangibles
Intangible assets:
Intangible assets	$ 1,326,587	$ 1,363,062
Remaining weighted average amortization period in years	24 years 4 months 24 days	24 years
Other Intangibles
Intangible assets:
Intangible assets	$ 35,819	$ 35,890
Remaining weighted average amortization period in years	12 years 3 months 18 days	14 years 1 month 6 days