INTANGIBLES (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 1,052,321	$ 363,971
Remaining weighted average amortization period (in years)	18 years 9 months 18 days	20 years 10 months 24 days
Accumulated amortization	$ (615,599)	$ (514,133)
Net intangible assets	1,817,362	838,542
Intangible liabilities:
Below market lease intangibles	256,081	229,495
Other lease intangibles	34,160	32,103
Accumulated amortization	(108,151)	(97,371)
Purchase option intangibles	3,568	13,549
Net intangible liabilities	$ 185,658	$ 177,776
Below market leases, remaining weighted average amortization period (in years)	14 years 2 months 12 days	14 years 1 month 6 days
Other lease intangibles, remaining weighted average amortization period (in years)	27 years 9 months 18 days	26 years 1 month 6 days
Net intangible liabilities, remaining weighted average amortization period (in years)	15 years 3 months 18 days	15 years 1 month 6 days
Above market lease intangibles
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 154,944	$ 150,474
Remaining weighted average amortization period (in years)	7 years 1 month 6 days	6 years 9 months 18 days
In-place and other lease intangibles
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 1,189,764	$ 801,776
Remaining weighted average amortization period (in years)	20 years 4 months 24 days	24 years 4 months 24 days
Other intangibles
Finite-Lived Intangible Assets [Line Items]
Other intangibles	$ 35,932	$ 36,454
Remaining weighted average amortization period (in years)	8 years 3 months 18 days	7 years 10 months 24 days