Condensed consolidating financial information Balance Sheet (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Assets
Investments in real estate, net	$ 7,939,179	$ 7,629,922
Investments in and advances to affiliates	133,580	127,212
Cash and cash equivalents	157,928	125,098	$ 76,383	$ 86,011
Restricted cash	16,406	28,872
Tenant receivables	9,635	10,485
Deferred rent	318,286	280,570
Deferred leasing costs	191,765	192,081
Investments	320,989	353,465
Investments in and advances to affiliates	0	0
Other assets	206,133	133,312
Total assets	9,293,901	8,881,017
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	789,450	809,818
Unsecured senior notes payable	2,377,482	2,030,631
Unsecured senior line of credit	416,000	151,000
Unsecured senior bank term loans	746,162	944,243
Accounts payable, accrued expenses, and tenant security deposits	605,181	589,356
Dividends payable	66,705	62,005
Total liabilities	5,000,980	4,587,053
Redeemable noncontrolling interests	9,012	14,218
Alexandria Real Estate Equities, Inc.’s stockholders’ equity	3,910,078	3,975,087
Noncontrolling interests	373,831	304,659
Total equity	4,283,909	4,279,746
Total liabilities, noncontrolling interests, and equity	9,293,901	8,881,017
Eliminations
Assets
Investments in real estate, net	0	0
Investments in and advances to affiliates	0	0
Cash and cash equivalents	0	0	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	(14,510,119)	(13,816,222)
Other assets	0	0
Total assets	(14,510,119)	(13,816,222)
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	0
Accounts payable, accrued expenses, and tenant security deposits	0	0
Dividends payable	0	0
Total liabilities	0	0
Redeemable noncontrolling interests	0	0
Alexandria Real Estate Equities, Inc.’s stockholders’ equity	(14,510,119)	(13,816,222)
Noncontrolling interests	0	0
Total equity	(14,510,119)	(13,816,222)
Total liabilities, noncontrolling interests, and equity	(14,510,119)	(13,816,222)
Alexandria Real Estate Equities, Inc. (Issuer)
Assets
Investments in real estate, net	0	0
Investments in and advances to affiliates	0	0
Cash and cash equivalents	18,530	31,982	42,738	52,491
Restricted cash	107	91
Tenant receivables	0	0
Deferred rent	0	0
Deferred leasing costs	0	0
Investments	0	0
Investments in and advances to affiliates	7,521,833	7,194,092
Other assets	42,811	36,808
Total assets	7,583,281	7,262,973
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	0	0
Unsecured senior notes payable	2,377,482	2,030,631
Unsecured senior line of credit	416,000	151,000
Unsecured senior bank term loans	746,162	944,243
Accounts payable, accrued expenses, and tenant security deposits	67,049	100,294
Dividends payable	66,510	61,718
Total liabilities	3,673,203	3,287,886
Redeemable noncontrolling interests	0	0
Alexandria Real Estate Equities, Inc.’s stockholders’ equity	3,910,078	3,975,087
Noncontrolling interests	0	0
Total equity	3,910,078	3,975,087
Total liabilities, noncontrolling interests, and equity	7,583,281	7,262,973
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Assets
Investments in real estate, net	0	0
Investments in and advances to affiliates	0	0
Cash and cash equivalents	0	0	8	63
Restricted cash	0	0
Tenant receivables	0	0
Deferred rent	0	0
Deferred leasing costs	0	0
Investments	4,487	4,702
Investments in and advances to affiliates	6,848,858	6,490,009
Other assets	0	0
Total assets	6,853,345	6,494,711
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	0
Accounts payable, accrued expenses, and tenant security deposits	0	0
Dividends payable	0	0
Total liabilities	0	0
Redeemable noncontrolling interests	0	0
Alexandria Real Estate Equities, Inc.’s stockholders’ equity	6,853,345	6,494,711
Noncontrolling interests	0	0
Total equity	6,853,345	6,494,711
Total liabilities, noncontrolling interests, and equity	6,853,345	6,494,711
Combined Non- Guarantor Subsidiaries
Assets
Investments in real estate, net	7,939,179	7,629,922
Investments in and advances to affiliates	133,580	127,212
Cash and cash equivalents	139,398	93,116	$ 33,637	$ 33,457
Restricted cash	16,299	28,781
Tenant receivables	9,635	10,485
Deferred rent	318,286	280,570
Deferred leasing costs	191,765	192,081
Investments	316,502	348,763
Investments in and advances to affiliates	139,428	132,121
Other assets	163,322	96,504
Total assets	9,367,394	8,939,555
Liabilities, Noncontrolling Interests, and Equity
Secured notes payable	789,450	809,818
Unsecured senior notes payable	0	0
Unsecured senior line of credit	0	0
Unsecured senior bank term loans	0	0
Accounts payable, accrued expenses, and tenant security deposits	538,132	489,062
Dividends payable	195	287
Total liabilities	1,327,777	1,299,167
Redeemable noncontrolling interests	9,012	14,218
Alexandria Real Estate Equities, Inc.’s stockholders’ equity	7,656,774	7,321,511
Noncontrolling interests	373,831	304,659
Total equity	8,030,605	7,626,170
Total liabilities, noncontrolling interests, and equity	$ 9,367,394	$ 8,939,555