Investments in Unconsolidated Entities and International Investments - Asian Joint Ventures (Details) - Premium Outlets - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Japan \| Mitsubishi Estate Co., Ltd.
Investment in Unconsolidated Entities
Ownership percentage	40.00%	40.00%
Our net Investment in unconsolidated entities, at equity	$ 211.1	$ 216.8
South Korea \| Shinsegae International Co
Investment in Unconsolidated Entities
Ownership percentage	50.00%	50.00%
Our net Investment in unconsolidated entities, at equity	$ 187.3	$ 184.7

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
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-URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 25
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e8813-108599

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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