INTANGIBLES (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Intangible assets:
Goodwill	$ 1,044,983	$ 1,047,497
Accumulated amortization	(695,365)	(655,176)
Net intangible assets	$ 1,728,668	$ 1,772,535
Remaining Weighted Average Amortization Period in Years	19 years 9 months 18 days	19 years 2 months 12 days
Intangible liabilities:
Below market lease intangibles	$ 256,121	$ 256,034
Other lease intangibles	35,925	35,925
Accumulated amortization	(119,216)	(113,647)
Purchase option intangibles	3,568	3,568
Net intangible liabilities	$ 176,398	$ 181,880
Below market leases, remaining weighted average amortization period (in years)	14 years 2 months 12 days	14 years 2 months 12 days
Other lease intangibles, remaining weighted average amortization period (in years)	30 years 7 months 6 days	30 years 1 month 6 days
Net intangible liabilities, remaining weighted average amortization period (in years)	15 years 7 months 6 days	15 years 7 months 6 days
Other intangibles
Intangible assets:
Other intangibles	$ 35,863	$ 35,792
Remaining Weighted Average Amortization Period in Years	9 years	8 years 7 months 6 days
Above market lease intangibles
Intangible assets:
Intangible assets	$ 155,008	$ 155,161
Remaining Weighted Average Amortization Period in Years	6 years 9 months 18 days	7 years
In-place and other lease intangibles
Intangible assets:
Intangible assets	$ 1,188,179	$ 1,189,261
Remaining Weighted Average Amortization Period in Years	21 years 7 months 6 days	20 years 10 months 24 days