SEGMENT INFORMATION (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Revenues:
Total revenues	$ 779,035	$ 711,249	$ 2,271,759	$ 2,078,267
Net real estate property:
Total net real estate property	18,925,811		18,925,811		18,075,586
United States
Revenues:
Total revenues	739,320	687,925	2,184,152	2,008,111
Net real estate property:
Total net real estate property	17,420,653		17,420,653		17,705,962
Canada
Revenues:
Total revenues	35,129	23,324	78,168	70,156
Net real estate property:
Total net real estate property	1,328,742		1,328,742		369,624
UNITED KINGDOM
Revenues:
Total revenues	4,586		9,439
Net real estate property:
Total net real estate property	$ 176,416		$ 176,416