The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

+ Details

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- Definition

The number of countries in which the entity operates as of balance sheet date.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
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Period Type:	instant

- Definition

The number of real estate properties owned as of the balance sheet date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of states the entity operates in as of the balance sheet date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Organization (Details)	Jun. 30, 2015 state country property	May. 11, 2015	May. 10, 2015	Mar. 31, 2015	Dec. 31, 2014
Klepierre
Owned, developed and managed retail properties
Joint venture ownership percentage		20.30%	18.30%	18.30%	28.90%
Premium Outlets \| European Joint Venture
Owned, developed and managed retail properties
Number of properties	5
U.S. and Puerto Rico
Owned, developed and managed retail properties
Number of properties	207
Number of U.S. states containing property locations \| state	37
U.S. and Puerto Rico \| Malls
Owned, developed and managed retail properties
Number of properties	110
U.S. and Puerto Rico \| Premium Outlets
Owned, developed and managed retail properties
Number of properties	68
U.S. and Puerto Rico \| The Mills
Owned, developed and managed retail properties
Number of properties	14
U.S. and Puerto Rico \| Lifestyle/Community Centers
Owned, developed and managed retail properties
Number of properties	3
U.S. and Puerto Rico \| Other
Owned, developed and managed retail properties
Number of properties	12
Japan \| Premium Outlets
Owned, developed and managed retail properties
Number of properties	9
South Korea \| Premium Outlets
Owned, developed and managed retail properties
Number of properties	3
Canada \| Premium Outlets
Owned, developed and managed retail properties
Number of properties	2
Mexico \| Premium Outlets
Owned, developed and managed retail properties
Number of properties	1
Malaysia \| Premium Outlets
Owned, developed and managed retail properties
Number of properties	1
Europe \| Klepierre
Owned, developed and managed retail properties
Joint venture ownership percentage	20.30%	20.30%		18.30%	28.90%
Number of countries \| country	16
Italy \| Premium Outlets
Owned, developed and managed retail properties
Number of properties	2
Austria \| Premium Outlets
Owned, developed and managed retail properties
Number of properties	1
Netherlands \| Premium Outlets
Owned, developed and managed retail properties
Number of properties	1
United Kingdom \| Premium Outlets
Owned, developed and managed retail properties
Number of properties	1