Cover Page
| Cover Page | Jul. 29, 2019 |
| Document Information [Line Items] | |
| Entity Central Index Key | 0001035443 |
| Amendment Flag | false |
| Document Type | 8-K |
| Document Period End Date | Jul. 29, 2019 |
| Entity Registrant Name | ALEXANDRIA REAL ESTATE EQUITIES INC |
| Entity Incorporation, State or Country Code | MD |
| Entity File Number | 1-12993 |
| Entity Tax Identification Number | 95-4502084 |
| Entity Address, Address Line One | 385 East Colorado Boulevard, Suite 299 |
| 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Common Stock, $.01 par value per share | |
| Document Information [Line Items] | |
| Title of 12(b) Security | Common Stock, $.01 par value per share |
| Trading Symbol | ARE |
| Security Exchange Name | NYSE |
| 7.00% Series D Cumulative Convertible Preferred Stock | |
| Document Information [Line Items] | |
| Title of 12(b) Security | 7.00% Series D Cumulative Convertible Preferred Stock |
| Trading Symbol | ARE/PD |
| Security Exchange Name | NYSE |