SEGMENT INFORMATION (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Revenues:
Total revenues	$ 751,254	$ 684,109	$ 1,492,724	$ 1,367,018
Net real estate property:
Total net real estate property	17,886,270		17,886,270		18,075,586
United States
Revenues:
Total revenues	724,725	660,657	1,444,833	1,320,186
Net real estate property:
Total net real estate property	17,336,386		17,336,386		17,705,962
Canada
Revenues:
Total revenues	21,821	23,452	43,038	46,832
Net real estate property:
Total net real estate property	362,736		362,736		369,624
UNITED KINGDOM
Revenues:
Total revenues	4,708		4,853
Net real estate property:
Total net real estate property	$ 187,148		$ 187,148