INTANGIBLES (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Intangible assets:
Intangible assets	$ 1,279,490	$ 1,502,955
Goodwill	1,050,876	1,050,548
Accumulated amortization	(910,861)	(921,107)
Net intangible assets	$ 1,455,298	$ 1,668,155
Finite-lived intangible assets, remaining amortization period	11 years 2 months 12 days	22 years 10 months 24 days
Intangible liabilities:
Below market lease intangibles	$ 356,757	$ 356,771
Other lease intangibles	13,498	31,418
Accumulated amortization	(196,405)	(191,909)
Purchase option intangibles	3,568	3,568
Net intangible liabilities	$ 177,418	$ 199,848
Below market leases, remaining weighted average amortization period (in years)	14 years 7 months 6 days	14 years 4 months 24 days
Other lease intangibles, remaining weighted average amortization period (in years)		46 years 6 months
Net intangible liabilities, remaining weighted average amortization period (in years)	14 years 7 months 6 days	17 years 2 months 12 days
Above Market Lease Intangibles
Intangible assets:
Intangible assets	$ 181,259	$ 181,393
Finite-lived intangible assets, remaining amortization period	6 years 7 months 6 days	6 years 8 months 12 days
In-place and Other Lease Intangibles
Intangible assets:
Intangible assets	$ 1,098,231	$ 1,321,562
Finite-lived intangible assets, remaining amortization period	11 years 10 months 24 days	24 years 8 months 12 days
Other Intangibles
Intangible assets:
Other intangibles	$ 35,793	$ 35,759
Finite-lived intangible assets, remaining amortization period	11 years 7 months 6 days	11 years 9 months 18 days