Schedule III: Real Estate and Accumulated Depreciation (Rollforward) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Carrying cost:
Balance at beginning of period	$ 22,458,032	$ 19,241,735	$ 20,393,411
Additions during period:
Acquisitions	1,380,044	4,063,355	1,769,790
Capital expenditures	270,664	229,560	189,711
Deductions during period:
Foreign currency translation	(6,252)	(209,460)	(87,776)
Other	(285,902)	(867,158)	(3,023,401)
Balance at end of period	23,816,586	22,458,032	19,241,735
Accumulated depreciation:
Balance at beginning of period	3,544,625	2,925,508	2,881,950
Additions during period:
Depreciation expense	732,309	778,419	725,485
Dispositions:
Sales and/or transfers to assets held for sale	(87,431)	(144,545)	(675,846)
Foreign currency translation	993	(14,757)	(6,081)
Balance at end of period	$ 4,190,496	$ 3,544,625	$ 2,925,508