Investments in real estate Schedule of investment in real estates (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Land/future value-added projects:
Investments in real estate, net	$ 10,046,521	$ 9,077,972
North America
Real Estate Properties [Line Items]
Land (related to rental properties)	1,206,152	1,131,416
Buildings and building improvements	8,466,889	7,810,269
Other improvements	714,834	584,565
Rental properties	10,387,875	9,526,250
Land Available for Development	289,314	253,551
Construction in progress ("CIP")/current value-added projects:
Real Estate Investment Property, at Cost	11,794,322	10,589,055
Land/future value-added projects:
Less: accumulated depreciation	(1,785,115)	(1,546,798)
Investments in real estate, net	10,009,207	9,042,257
Asia
Land/future value-added projects:
Investments in real estate, net	37,314	35,715
Near-term developments \| North America
Real Estate Properties [Line Items]
Development in Process	114,954	0
Intermediate developments \| North America
Real Estate Properties [Line Items]
Development in Process	333,870	0
Development projects, target delivery in 2017 \| Developments and redevelopments undergoing construction \| North America
Real Estate Properties [Line Items]
Development in Process	466,047	809,254
Development projects, target delivery in 2018 and 2019 \| Developments and redevelopments undergoing construction \| North America
Real Estate Properties [Line Items]
Development in Process	143,038	0
Redevelopment projects, target delivery in 2018 and 2019 \| Developments and redevelopments undergoing construction \| North America
Real Estate Properties [Line Items]
Redevelopment in process	$ 59,224	$ 0

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Carrying amount as of the balance sheet date of improvements not otherwise specified in the existing taxonomy.

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The current amount of expenditures for a real estate project that has not yet been completed.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.10)
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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-Name Accounting Standards Codification
-Glossary Phase
-URI http://asc.fasb.org/extlink&oid=49177889

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 4
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-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6812-107765

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Carrying amount of income producing properties held for rental.

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