Cover Page - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2019	Jan. 15, 2020	Jun. 30, 2019
Cover page.
Entity Central Index Key	0001035443
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Voluntary Filers	No
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Document Type	10-K
Document Period End Date	Dec. 31, 2019
Entity File Number	1-12993
Entity Registrant Name	ALEXANDRIA REAL ESTATE EQUITIES, INC.
Entity Incorporation, State or Country Code	MD
Entity Tax Identification Number	95-4502084
Entity Address, Address Line One	26 North Euclid Avenue
Entity Address, City or Town	Pasadena
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	91101
City Area Code	626
Local Phone Number	578-0777
Title of 12(b) Security	Common Stock, $0.01 par value per share
Trading Symbol	ARE
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 15.8
Entity Common Stock, Shares Outstanding		122,699,875
Document Annual Report	true
Document Transition Report	false