Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets
Investments in real estate	$ 14,844,038	$ 11,913,693
Investment in unconsolidated real estate joint ventures	346,890	237,507
Cash and cash equivalents	189,681	234,181
Restricted cash	53,008	37,949
Tenant receivables	10,691	9,798
Deferred rent	641,844	530,237
Deferred leasing costs	270,043	239,070
Investments	1,140,594	892,264
Investments in and advances to affiliates	0	0
Other assets	893,714	370,257
Total assets	18,390,503	14,464,956
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	349,352	630,547
Unsecured senior notes payable	6,044,127	4,292,293
Unsecured senior line of credit	384,000	208,000
Unsecured senior bank term loans	0	347,415
Accounts payable, accrued expenses, and other liabilities	1,320,268	981,707
Dividends payable	126,278	110,280
Total liabilities	8,224,025	6,570,242
Redeemable noncontrolling interests	12,300	10,786
Alexandria Real Estate Equities, Inc.'s stockholders' equity	8,865,826	7,341,965
Noncontrolling interests	1,288,352	541,963
Total equity	10,154,178	7,883,928	$ 6,471,660	$ 5,370,971
Total liabilities, noncontrolling interests, and equity	18,390,503	14,464,956
Eliminations
Assets
Investments in real estate	0	0
Investment in unconsolidated real estate joint ventures	0	0
Cash and cash equivalents	0	0
Restricted cash	0	0
Tenant receivables	0	0
Deferred rent	0	0
Deferred leasing costs	0	0
Investments	0	0
Investments in and advances to affiliates	(29,733,414)	(23,408,191)
Other assets	0	0
Total assets	(29,733,414)	(23,408,191)
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	0	0
Unsecured senior notes payable	0	0
Unsecured senior line of credit	0	0
Unsecured senior bank term loans		0
Accounts payable, accrued expenses, and other liabilities	0	0
Dividends payable	0	0
Total liabilities	0	0
Redeemable noncontrolling interests	0	0
Alexandria Real Estate Equities, Inc.'s stockholders' equity	(29,733,414)	(23,408,191)
Noncontrolling interests	0	0
Total equity	(29,733,414)	(23,408,191)
Total liabilities, noncontrolling interests, and equity	(29,733,414)	(23,408,191)
Alexandria Real Estate Equities, Inc. (Issuer)
Assets
Investments in real estate	0	0
Investment in unconsolidated real estate joint ventures	0	0
Cash and cash equivalents	4,202	119,112
Restricted cash	230	193
Tenant receivables	0	0
Deferred rent	0	0
Deferred leasing costs	0	0
Investments	0	0
Investments in and advances to affiliates	15,498,357	12,235,577
Other assets	70,022	56,353
Total assets	15,572,811	12,411,235
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	0	0
Unsecured senior notes payable	6,044,127	4,292,293
Unsecured senior line of credit	384,000	208,000
Unsecured senior bank term loans		347,415
Accounts payable, accrued expenses, and other liabilities	152,580	111,282
Dividends payable	126,278	110,280
Total liabilities	6,706,985	5,069,270
Redeemable noncontrolling interests	0	0
Alexandria Real Estate Equities, Inc.'s stockholders' equity	8,865,826	7,341,965
Noncontrolling interests	0	0
Total equity	8,865,826	7,341,965
Total liabilities, noncontrolling interests, and equity	15,572,811	12,411,235
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Assets
Investments in real estate	0	0
Investment in unconsolidated real estate joint ventures	0	0
Cash and cash equivalents	0	0
Restricted cash	0	0
Tenant receivables	0	0
Deferred rent	0	0
Deferred leasing costs	0	0
Investments	1,014	1,262
Investments in and advances to affiliates	13,950,850	10,949,631
Other assets	0	0
Total assets	13,951,864	10,950,893
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	0	0
Unsecured senior notes payable	0	0
Unsecured senior line of credit	0	0
Unsecured senior bank term loans		0
Accounts payable, accrued expenses, and other liabilities	0	0
Dividends payable	0	0
Total liabilities	0	0
Redeemable noncontrolling interests	0	0
Alexandria Real Estate Equities, Inc.'s stockholders' equity	13,951,864	10,950,893
Noncontrolling interests	0	0
Total equity	13,951,864	10,950,893
Total liabilities, noncontrolling interests, and equity	13,951,864	10,950,893
Combined Non- Guarantor Subsidiaries
Assets
Investments in real estate	14,844,038	11,913,693
Investment in unconsolidated real estate joint ventures	346,890	237,507
Cash and cash equivalents	185,479	115,069
Restricted cash	52,778	37,756
Tenant receivables	10,691	9,798
Deferred rent	641,844	530,237
Deferred leasing costs	270,043	239,070
Investments	1,139,580	891,002
Investments in and advances to affiliates	284,207	222,983
Other assets	823,692	313,904
Total assets	18,599,242	14,511,019
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	349,352	630,547
Unsecured senior notes payable	0	0
Unsecured senior line of credit	0	0
Unsecured senior bank term loans		0
Accounts payable, accrued expenses, and other liabilities	1,167,688	870,425
Dividends payable	0	0
Total liabilities	1,517,040	1,500,972
Redeemable noncontrolling interests	12,300	10,786
Alexandria Real Estate Equities, Inc.'s stockholders' equity	15,781,550	12,457,298
Noncontrolling interests	1,288,352	541,963
Total equity	17,069,902	12,999,261
Total liabilities, noncontrolling interests, and equity	$ 18,599,242	$ 14,511,019