Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Assets [Abstract]
Investments in real estate, net	$ 6,375,182	$ 6,424,578
Cash and cash equivalents	87,001	140,971
Restricted cash	30,008	39,947
Tenant receivables	9,261	8,449
Deferred rent	170,100	170,396
Deferred leasing and financing costs, net	159,872	160,048
Investments	123,543	115,048
Other assets	135,952	90,679
Total assets	7,090,919	7,150,116
Liabilities and Equity [Abstract]
Secured notes payable	730,714	716,144
Unsecured senior notes payable	549,816	549,805
Unsecured senior line of credit	554,000	566,000
Unsecured senior bank term loans	1,350,000	1,350,000
Accounts payable, accrued expenses, and tenant security deposits	367,153	423,708
Dividends payable	43,955	41,401
Total liabilities	3,595,638	3,647,058
Commitments and contingencies
Redeemable noncontrolling interests	14,534	14,564
Alexandria Real Estate Equities, Inc.'s stockholders' equity:
Series D Convertible Preferred Stock	250,000	250,000
Series E Preferred Stock	130,000	130,000
Common stock	633	632
Additional paid-in capital	3,075,860	3,086,052
Accumulated other comprehensive loss	(22,890)	(24,833)
Alexandria Real Estate Equities, Inc.'s stockholders' equity	3,433,603	3,441,851
Noncontrolling interests	47,144	46,643
Total equity	3,480,747	3,488,494
Total liabilities, noncontrolling interests, and equity	$ 7,090,919	$ 7,150,116