SEGMENT INFORMATION - Revenue and Net Real Estate Property (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Revenues:
Total revenues	$ 1,022,938	$ 919,194	$ 2,040,492	$ 1,829,485
Net Real Estate Property:
Total net real estate property	21,725,783		21,725,783		$ 21,816,838
United States
Revenues:
Total revenues	903,057	803,242	1,800,990	1,601,010
Net Real Estate Property:
Total net real estate property	18,581,304		18,581,304		18,562,738
Canada
Revenues:
Total revenues	112,809	108,342	224,953	213,375
Net Real Estate Property:
Total net real estate property	2,927,708		2,927,708		3,007,008
United Kingdom
Revenues:
Total revenues	7,072	$ 7,610	14,549	$ 15,100
Net Real Estate Property:
Total net real estate property	$ 216,771		$ 216,771		$ 247,092