Investments in Unconsolidated Joint Ventures - Company Ownership (Details)	Dec. 31, 2018
443 Wabash MAB LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
AM Tysons LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
Biltmore Shopping Center Partners LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
CAM-CARSON LLC—Los Angeles Premium Outlets
Investments in unconsolidated joint ventures:
Ownership %	50.00%
Coolidge Holding LLC
Investments in unconsolidated joint ventures:
Ownership %	37.50%
Corte Madera Village, LLC
Investments in unconsolidated joint ventures:
Ownership %	50.10%
Country Club Plaza KC Partners LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
Fashion District Philadelphia—Various Entities
Investments in unconsolidated joint ventures:
Ownership %	50.00%
HPP-MAC WSP, LLC—One Westside
Investments in unconsolidated joint ventures:
Ownership %	25.00%
Jaren Associates 4
Investments in unconsolidated joint ventures:
Ownership %	12.50%
Kierland Commons Investment LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
Macerich HHF Broadway Plaza LLC—Broadway Plaza
Investments in unconsolidated joint ventures:
Ownership %	50.00%
Macerich HHF Centers LLC—Various Properties
Investments in unconsolidated joint ventures:
Ownership %	51.00%
MS Portfolio LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
New River Associates LLC—Arrowhead Towne Center
Investments in unconsolidated joint ventures:
Ownership %	60.00%
North Bridge Chicago LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
One Scottsdale Investors LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
Pacific Premier Retail LLC—Various Properties
Investments in unconsolidated joint ventures:
Ownership %	60.00%
Propcor II Associates, LLC—Boulevard Shops
Investments in unconsolidated joint ventures:
Ownership %	50.00%
Scottsdale Fashion Square Partnership
Investments in unconsolidated joint ventures:
Ownership %	50.00%
TM TRS Holding Company LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
Tysons Corner LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
Tysons Corner Hotel I LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
Tysons Corner Property Holdings II LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
Tysons Corner Property LLC
Investments in unconsolidated joint ventures:
Ownership %	50.00%
West Acres Development, LLP
Investments in unconsolidated joint ventures:
Ownership %	19.00%
Westcor/Surprise Auto Park LLC
Investments in unconsolidated joint ventures:
Ownership %	33.30%
WMAP, L.L.C.—Atlas Park, The Shops at
Investments in unconsolidated joint ventures:
Ownership %	50.00%