Schedule III: Real Estate and Accumulated Depreciation (Rollforward) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Carrying cost:
Balance at beginning of period	$ 24,712,478	$ 23,859,816	$ 22,500,638
Additions during period:
Acquisitions	318,895	702,501	1,380,044
Capital expenditures	446,490	453,829	271,288
Deductions during period:
Foreign currency translation	(105,192)	(93,490)	(6,252)
Other	(398,688)	(397,158)	(285,902)
Balance at end of period	24,973,983	24,712,478	23,859,816
Accumulated depreciation:
Balance at beginning of period	4,802,917	4,208,010	3,562,139
Additions during period:
Depreciation expense	791,882	760,314	732,309
Dispositions:
Sales and/or transfers to assets held for sale	(84,819)	(176,918)	(87,431)
Foreign currency translation	(17,670)	11,511	993
Balance at end of period	$ 5,492,310	$ 4,802,917	$ 4,208,010