INTANGIBLES (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Remaining weighted average amortization period	16 years 10 months 24 days	19 years 10 months 24 days
Intangible assets:
Goodwill and other intangibles	$ 1,146,286	$ 489,384
Accumulated amortization	(575,397)	(549,026)
Net intangible assets	1,871,543	980,009
Intangible liabilities:
Below market lease intangibles	456,165	425,092
Other lease intangibles	36,067	32,103
Accumulated amortization	(163,652)	(158,480)
Indefinite-Lived Intangible Liabilities, Purchase Options	22,644	22,900
Net intangible liabilities	351,224	321,615
Below market leases, remaining weighted average amortization period	14 years 8 months 12 days	14 years 8 months 12 days
Other lease intangibles, remaining weighted average amortization period	30 years 3 months 18 days	26 years 1 month 6 days
Finite-lived intangible liabilities, remaining weighted average amortization period	15 years 6 months	15 years 2 months 12 days
Above market lease intangibles
Finite-Lived Intangible Assets [Line Items]
Intangible assets	230,710	210,573
Remaining weighted average amortization period	8 years 9 months 18 days	8 years 2 months 12 days
In-place and other lease intangibles
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 1,069,944	$ 829,078
Remaining weighted average amortization period	19 years	23 years 10 months 24 days
Other intangibles
Finite-Lived Intangible Assets [Line Items]
Remaining weighted average amortization period	7 years 10 months 24 days	7 years 10 months 24 days