Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Feb. 21, 2020	Jun. 30, 2019
Cover page.
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	1-12504
Entity Registrant Name	MACERICH CO
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	95-4448705
Entity Address, Address Line One	401 Wilshire Boulevard,
Entity Address, Address Line Two	Suite 700,
Entity Address, City or Town	Santa Monica,
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	90401
City Area Code	(310)
Local Phone Number	394-6000
Title of 12(b) Security	Common Stock, $0.01 Par Value
Trading Symbol	MAC
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 4.7
Entity Common Stock, Shares Outstanding		141,296,774
Documents Incorporated by Reference	Portions of the proxy statement for the annual stockholders meeting to be held in 2020 are incorporated by reference into Part III of this Form 10-K.
Entity Central Index Key	0000912242
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false