Condensed consolidating financial information Comprehensive Income (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net income	$ 140,249	$ 105,528	$ 135,393
Unrealized (losses) gains on marketable securities:
Unrealized holding (losses) gains arising during the period	1,300	990	238
Reclassification adjustment for losses (gains) included in net income	(1,183)	(3,351)	(2,561)
Unrealized gains (losses) on marketable securities, net	117	(2,361)	(2,323)
Unrealized gains on interest rate swaps:
Unrealized interest rate swap gains arising during the period	1,918	(9,990)	(9,630)
Reclassification adjustment for amortization of interest expense included in net income	15,422	22,309	21,457
Unrealized gains on interest rate swap agreements, net	17,340	12,319	11,827
Foreign currency translation losses	(28,912)	(318)	(25,605)
Total other comprehensive (loss) income	(11,455)	9,640	(16,101)
Comprehensive income	128,794	115,168	119,292
Less: comprehensive income attributable to noncontrolling interests	(3,948)	(3,364)	(4,050)
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	124,846	111,804	115,242
Alexandria Real Estate Equities, Inc. (Issuer)
Net income	136,217	102,126	131,418
Unrealized (losses) gains on marketable securities:
Unrealized holding (losses) gains arising during the period	0	0	0
Reclassification adjustment for losses (gains) included in net income	0	0	0
Unrealized gains (losses) on marketable securities, net	0	0	0
Unrealized gains on interest rate swaps:
Unrealized interest rate swap gains arising during the period	1,918	(9,990)	(9,630)
Reclassification adjustment for amortization of interest expense included in net income	15,422	22,309	21,457
Unrealized gains on interest rate swap agreements, net	17,340	12,319	11,827
Foreign currency translation losses	0	0	0
Total other comprehensive (loss) income	17,340	12,319	11,827
Comprehensive income	153,557	114,445	143,245
Less: comprehensive income attributable to noncontrolling interests	0	0	0
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	153,557	114,445	143,245
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Net income	205,919	184,428	191,674
Unrealized (losses) gains on marketable securities:
Unrealized holding (losses) gains arising during the period	(438)	(319)	148
Reclassification adjustment for losses (gains) included in net income	148	155	28
Unrealized gains (losses) on marketable securities, net	(290)	(164)	176
Unrealized gains on interest rate swaps:
Unrealized interest rate swap gains arising during the period	0	0	0
Reclassification adjustment for amortization of interest expense included in net income	0	0	0
Unrealized gains on interest rate swap agreements, net	0	0	0
Foreign currency translation losses	0	0	0
Total other comprehensive (loss) income	(290)	(164)	176
Comprehensive income	205,629	184,264	191,850
Less: comprehensive income attributable to noncontrolling interests	0	0	0
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	205,629	184,264	191,850
Combined Non- Guarantor Subsidiaries
Net income	228,331	200,317	211,066
Unrealized (losses) gains on marketable securities:
Unrealized holding (losses) gains arising during the period	1,738	1,309	90
Reclassification adjustment for losses (gains) included in net income	(1,331)	(3,506)	(2,589)
Unrealized gains (losses) on marketable securities, net	407	(2,197)	(2,499)
Unrealized gains on interest rate swaps:
Unrealized interest rate swap gains arising during the period	0	0	0
Reclassification adjustment for amortization of interest expense included in net income	0	0	0
Unrealized gains on interest rate swap agreements, net	0	0	0
Foreign currency translation losses	(28,912)	(318)	(25,605)
Total other comprehensive (loss) income	(28,505)	(2,515)	(28,104)
Comprehensive income	199,826	197,802	182,962
Less: comprehensive income attributable to noncontrolling interests	(3,948)	(3,364)	(4,050)
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	195,878	194,438	178,912
Eliminations
Net income	(430,218)	(381,343)	(398,765)
Unrealized (losses) gains on marketable securities:
Unrealized holding (losses) gains arising during the period	0	0	0
Reclassification adjustment for losses (gains) included in net income	0	0	0
Unrealized gains (losses) on marketable securities, net	0	0	0
Unrealized gains on interest rate swaps:
Unrealized interest rate swap gains arising during the period	0	0	0
Reclassification adjustment for amortization of interest expense included in net income	0	0	0
Unrealized gains on interest rate swap agreements, net	0	0	0
Foreign currency translation losses	0	0	0
Total other comprehensive (loss) income	0	0	0
Comprehensive income	(430,218)	(381,343)	(398,765)
Less: comprehensive income attributable to noncontrolling interests	0	0	0
Comprehensive income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	$ (430,218)	$ (381,343)	$ (398,765)