v3.7.0.1

SEGMENT INFORMATION - Revenue and Net Real Estate Property (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Revenues:
Total revenues	$ 895,490	$ 848,404	$ 1,778,933	$ 1,700,693
Net real estate property:
Total net real estate property	20,539,766		20,539,766		$ 20,394,754
United States
Revenues:
Total revenues	844,623	797,394	1,677,443	1,601,595
Net real estate property:
Total net real estate property	19,190,206		19,190,206		19,105,939
Canada
Revenues:
Total revenues	44,412	44,045	89,008	85,174
Net real estate property:
Total net real estate property	1,056,233		1,056,233		1,037,105
United Kingdom
Revenues:
Total revenues	6,455	$ 6,965	12,482	$ 13,924
Net real estate property:
Total net real estate property	$ 293,327		$ 293,327		$ 251,710

X

- References

No definition available.

+ Details

Name:	us-gaap_GeographicAreasLongLivedAssetsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_GeographicAreasRevenuesFromExternalCustomersAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of real estate investment property, net of accumulated depreciation, which may include the following: (1) land available-for-sale; (2) land available-for-development; (3) investments in building and building improvements; (4) tenant allowances; (5) developments in-process; (6) rental properties; and (7) other real estate investments.

+ 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 210.7-03.1(d))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_RealEstateInvestmentPropertyNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

Name:	us-gaap_Revenues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Details

Name:	us-gaap_StatementGeographicalAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementGeographicalAxis=country_CA
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_StatementGeographicalAxis=country_GB
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: