Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Statement of Comprehensive Income
Net income (loss)	$ 404,047	$ 402,793	$ 194,204
Unrealized (losses) gains on available-for-sale equity securities:
Unrealized holding gains (losses) arising during the period	0	0	(24,360)
Reclassification adjustment for losses (gains) included in net income	0	0	6,118
Unrealized gains (losses) on available-for-sale equity securities, net	0	0	30,478
Unrealized gains (losses) on interest rate hedge agreements:
Unrealized interest rate hedge (losses) gains arising during the period	(1,763)	1,622	2,837
Reclassification adjustment for amortization (income) expense to interest expense included in net income	(1,777)	(4,941)	1,915
Reclassification of losses related to terminated interest rate hedge instruments to interest expense included in net (loss) income	1,702	0	0
Unrealized gains (losses) on interest rate swap agreements, net	(1,838)	(3,319)	4,752
Unrealized gains (losses) on foreign currency translations:
Unrealized foreign currency translation gains (losses) arising during the period	2,524	(7,369)	7,774
Reclassification adjustment for cumulative foreign currency translation losses included in net income (loss) upon sale or liquidation	0	0	1,599
Unrealized gains (losses) on foreign currency translation, net	2,524	(7,369)	9,373
Total other comprehensive income (loss)	686	(10,688)	44,603
Comprehensive income (loss)	404,733	392,105	238,807
Less: comprehensive income attributable to noncontrolling interests	(40,882)	(23,481)	(25,045)
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.'s stockholders	363,851	368,624	213,762
Eliminations
Condensed Statement of Comprehensive Income
Net income (loss)	(1,158,401)	(1,056,573)	(672,537)
Unrealized (losses) gains on available-for-sale equity securities:
Unrealized holding gains (losses) arising during the period			0
Reclassification adjustment for losses (gains) included in net income			0
Unrealized gains (losses) on available-for-sale equity securities, net			0
Unrealized gains (losses) on interest rate hedge agreements:
Unrealized interest rate hedge (losses) gains arising during the period	0	0	0
Reclassification adjustment for amortization (income) expense to interest expense included in net income	0	0	0
Reclassification of losses related to terminated interest rate hedge instruments to interest expense included in net (loss) income	0
Unrealized gains (losses) on interest rate swap agreements, net	0	0	0
Unrealized gains (losses) on foreign currency translations:
Unrealized foreign currency translation gains (losses) arising during the period	0	0	0
Reclassification adjustment for cumulative foreign currency translation losses included in net income (loss) upon sale or liquidation			0
Unrealized gains (losses) on foreign currency translation, net	0	0	0
Total other comprehensive income (loss)	0	0	0
Comprehensive income (loss)	(1,158,401)	(1,056,573)	(672,537)
Less: comprehensive income attributable to noncontrolling interests	0	0	0
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.'s stockholders	(1,158,401)	(1,056,573)	(672,537)
Alexandria Real Estate Equities, Inc. (Issuer)
Condensed Statement of Comprehensive Income
Net income (loss)	363,165	379,312	169,093
Unrealized (losses) gains on available-for-sale equity securities:
Unrealized holding gains (losses) arising during the period			0
Reclassification adjustment for losses (gains) included in net income			0
Unrealized gains (losses) on available-for-sale equity securities, net			0
Unrealized gains (losses) on interest rate hedge agreements:
Unrealized interest rate hedge (losses) gains arising during the period	(1,763)	1,622	3,025
Reclassification adjustment for amortization (income) expense to interest expense included in net income	(1,777)	(4,941)	1,914
Reclassification of losses related to terminated interest rate hedge instruments to interest expense included in net (loss) income	1,702
Unrealized gains (losses) on interest rate swap agreements, net	(1,838)	(3,319)	4,939
Unrealized gains (losses) on foreign currency translations:
Unrealized foreign currency translation gains (losses) arising during the period	0	0	0
Reclassification adjustment for cumulative foreign currency translation losses included in net income (loss) upon sale or liquidation			0
Unrealized gains (losses) on foreign currency translation, net	0	0	0
Total other comprehensive income (loss)	(1,838)	(3,319)	4,939
Comprehensive income (loss)	361,327	375,993	174,032
Less: comprehensive income attributable to noncontrolling interests	0	0	0
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.'s stockholders	361,327	375,993	174,032
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Condensed Statement of Comprehensive Income
Net income (loss)	490,427	456,102	325,655
Unrealized (losses) gains on available-for-sale equity securities:
Unrealized holding gains (losses) arising during the period			5
Reclassification adjustment for losses (gains) included in net income			2
Unrealized gains (losses) on available-for-sale equity securities, net			(3)
Unrealized gains (losses) on interest rate hedge agreements:
Unrealized interest rate hedge (losses) gains arising during the period	0	0	0
Reclassification adjustment for amortization (income) expense to interest expense included in net income	0	0	0
Reclassification of losses related to terminated interest rate hedge instruments to interest expense included in net (loss) income	0
Unrealized gains (losses) on interest rate swap agreements, net	0	0	0
Unrealized gains (losses) on foreign currency translations:
Unrealized foreign currency translation gains (losses) arising during the period	0	0	0
Reclassification adjustment for cumulative foreign currency translation losses included in net income (loss) upon sale or liquidation			0
Unrealized gains (losses) on foreign currency translation, net	0	0	0
Total other comprehensive income (loss)	0	0	(3)
Comprehensive income (loss)	490,427	456,102	325,652
Less: comprehensive income attributable to noncontrolling interests	0	0	0
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.'s stockholders	490,427	456,102	325,652
Combined Non- Guarantor Subsidiaries
Condensed Statement of Comprehensive Income
Net income (loss)	708,856	623,952	371,993
Unrealized (losses) gains on available-for-sale equity securities:
Unrealized holding gains (losses) arising during the period			(24,365)
Reclassification adjustment for losses (gains) included in net income			6,116
Unrealized gains (losses) on available-for-sale equity securities, net			30,481
Unrealized gains (losses) on interest rate hedge agreements:
Unrealized interest rate hedge (losses) gains arising during the period	0	0	(188)
Reclassification adjustment for amortization (income) expense to interest expense included in net income	0	0	1
Reclassification of losses related to terminated interest rate hedge instruments to interest expense included in net (loss) income	0
Unrealized gains (losses) on interest rate swap agreements, net	0	0	(187)
Unrealized gains (losses) on foreign currency translations:
Unrealized foreign currency translation gains (losses) arising during the period	2,524	(7,369)	7,774
Reclassification adjustment for cumulative foreign currency translation losses included in net income (loss) upon sale or liquidation			1,599
Unrealized gains (losses) on foreign currency translation, net	2,524	(7,369)	9,373
Total other comprehensive income (loss)	2,524	(7,369)	39,667
Comprehensive income (loss)	711,380	616,583	411,660
Less: comprehensive income attributable to noncontrolling interests	(40,882)	(23,481)	(25,045)
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.'s stockholders	$ 670,498	$ 593,102	$ 386,615