Organization (Details)	Dec. 31, 2017 state country property	May 11, 2015	Mar. 31, 2015	Dec. 31, 2014
U.S. and Puerto Rico
Real Estate Properties
Number of properties	207
Number of U.S. states containing property locations | state	37
U.S. and Puerto Rico | Malls
Real Estate Properties
Number of properties	107
U.S. and Puerto Rico | Premium Outlets
Real Estate Properties
Number of properties	68
U.S. and Puerto Rico | The Mills
Real Estate Properties
Number of properties	14
U.S. and Puerto Rico | Community/Lifestyle Centers
Real Estate Properties
Number of properties	4
U.S. and Puerto Rico | Other shopping centers or outlet centers
Real Estate Properties
Number of properties	14
Japan | Premium Outlets
Real Estate Properties
Number of properties	9
South Korea | Premium Outlets
Real Estate Properties
Number of properties	4
Canada | Premium Outlets
Real Estate Properties
Number of properties	2
Canada | Designer Outlets
Real Estate Properties
Number of properties	1
Malaysia | Premium Outlets
Real Estate Properties
Number of properties	2
Mexico | Premium Outlets
Real Estate Properties
Number of properties	1
Europe | Klepierre
Real Estate Properties
Ownership percentage	21.00%	20.30%	18.30%	28.90%
Number of countries | country	16
Europe | Designer Outlets
Real Estate Properties
Number of properties	8
Europe | Designer Outlets | Consolidated properties
Real Estate Properties
Number of properties	6
Italy | Designer Outlets
Real Estate Properties
Number of properties	2
Netherlands | Designer Outlets
Real Estate Properties
Number of properties	2
Austria | Designer Outlets
Real Estate Properties
Number of properties	1
France | Designer Outlets
Real Estate Properties
Number of properties	1
Germany | Designer Outlets
Real Estate Properties
Number of properties	1
United Kingdom | Designer Outlets
Real Estate Properties
Number of properties	1