Condensed consolidating financial information Income Statement (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Revenues:
Rental	$ 137,718		$ 116,052		$ 403,280		$ 342,071
Tenant recoveries	45,572		38,691		128,198		110,125
Other Income	2,325		3,572		6,725		10,132
Total revenues	185,615		158,315		538,203		462,328
Expenses:
Rental operations	57,423		47,684		162,283		139,147
General and administrative	12,609		11,666		39,669		35,769
Interest	20,555		16,171		57,111		50,169
Depreciation and amortization	58,388		48,866		166,123		141,039
Gains (Losses) on Extinguishment of Debt	525		1,432		525		1,992
Total expenses	149,500		125,819		425,711		368,116
(Loss) income from continuing operations before equity in earnings of affiliates	36,115		32,496		112,492		94,212
Income (Loss) from Subsidiaries, before Tax	0		0		0		0
Income from continuing operations	36,115		32,496		112,492		94,212
(Loss) income from discontinued operations, net	(180)	[1]	(43)	[1]	(489)	[1]	1,043	[1]
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	8		0		805		772
Net income	35,943		32,453		112,808		96,027
Dividends on preferred stock	(6,471)		(6,472)		(19,414)		(19,414)
Net income attributable to noncontrolling interests	(1,340)		(960)		(3,842)		(2,922)
Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted	(506)		(442)		(1,285)		(1,187)
Net Income (Loss) Available to Common Stockholders, Basic	27,626		24,579		88,267		72,504
Alexandria Real Estate Equities, Inc. (Issuer)
Revenues:
Rental	0		0		0		0
Tenant recoveries	0		0		0		0
Other Income	2,797		2,802		8,632		8,071
Total revenues	2,797		2,802		8,632		8,071
Expenses:
Rental operations	0		0		0		0
General and administrative	11,369		10,140		33,735		32,573
Interest	15,307		10,238		41,339		32,048
Depreciation and amortization	1,408		1,473		4,335		4,394
Gains (Losses) on Extinguishment of Debt	525		1,432		525		1,992
Total expenses	28,609		23,283		79,934		71,007
(Loss) income from continuing operations before equity in earnings of affiliates	(25,812)		(20,481)		(71,302)		(62,936)
Income (Loss) from Subsidiaries, before Tax	60,415		51,975		180,275		155,694
Income from continuing operations	34,603		31,494		108,973		92,758
(Loss) income from discontinued operations, net	0		(1)		(7)		347
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	0				0		0
Net income	34,603		31,493		108,966		93,105
Dividends on preferred stock	(6,471)		(6,472)		(19,414)		(19,414)
Net income attributable to noncontrolling interests	0		0		0		0
Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted	(506)		(442)		(1,285)		(1,187)
Net Income (Loss) Available to Common Stockholders, Basic	27,626		24,579		88,267		72,504
Alexandria Real Estate Equities, L.P. (Guarantor Subsidiary)
Revenues:
Rental	0		0		0		0
Tenant recoveries	0		0		0		0
Other Income	(1,264)		(1)		(2,799)		(142)
Total revenues	(1,264)		(1)		(2,799)		(142)
Expenses:
Rental operations	0		0		0		0
General and administrative	0		0		0		0
Interest	0		0		0		0
Depreciation and amortization	0		0		0		0
Gains (Losses) on Extinguishment of Debt	0		0		0		0
Total expenses	0		0		0		0
(Loss) income from continuing operations before equity in earnings of affiliates	(1,264)		(1)		(2,799)		(142)
Income (Loss) from Subsidiaries, before Tax	58,381		48,477		172,989		144,660
Income from continuing operations	57,117		48,476		170,190		144,518
(Loss) income from discontinued operations, net	0		0		0		0
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	0				0		0
Net income	57,117		48,476		170,190		144,518
Dividends on preferred stock	0		0		0		0
Net income attributable to noncontrolling interests	0		0		0		0
Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted	0		0		0		0
Net Income (Loss) Available to Common Stockholders, Basic	57,117		48,476		170,190		144,518
Combined Non- Guarantor Subsidiaries
Revenues:
Rental	137,718		116,052		403,280		342,071
Tenant recoveries	45,572		38,691		128,198		110,125
Other Income	4,369		3,966		11,534		11,635
Total revenues	187,659		158,709		543,012		463,831
Expenses:
Rental operations	57,423		47,684		162,283		139,147
General and administrative	4,817		4,721		16,576		12,628
Interest	5,248		5,933		15,772		18,121
Depreciation and amortization	56,980		47,393		161,788		136,645
Gains (Losses) on Extinguishment of Debt	0		0		0		0
Total expenses	124,468		105,731		356,419		306,541
(Loss) income from continuing operations before equity in earnings of affiliates	63,191		52,978		186,593		157,290
Income (Loss) from Subsidiaries, before Tax	1,127		959		3,356		2,858
Income from continuing operations	64,318		53,937		189,949		160,148
(Loss) income from discontinued operations, net	(180)		(42)		(482)		696
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	8				805		772
Net income	64,146		53,895		190,272		161,616
Dividends on preferred stock	0		0		0		0
Net income attributable to noncontrolling interests	(1,340)		(960)		(3,842)		(2,922)
Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted	0		0		0		0
Net Income (Loss) Available to Common Stockholders, Basic	62,806		52,935		186,430		158,694
Eliminations
Revenues:
Rental	0		0		0		0
Tenant recoveries	0		0		0		0
Other Income	(3,577)		(3,195)		(10,642)		(9,432)
Total revenues	(3,577)		(3,195)		(10,642)		(9,432)
Expenses:
Rental operations	0		0		0		0
General and administrative	(3,577)		(3,195)		(10,642)		(9,432)
Interest	0		0		0		0
Depreciation and amortization	0		0		0		0
Gains (Losses) on Extinguishment of Debt	0		0		0		0
Total expenses	(3,577)		(3,195)		(10,642)		(9,432)
(Loss) income from continuing operations before equity in earnings of affiliates	0		0		0		0
Income (Loss) from Subsidiaries, before Tax	(119,923)		(101,411)		(356,620)		(303,212)
Income from continuing operations	(119,923)		(101,411)		(356,620)		(303,212)
(Loss) income from discontinued operations, net	0		0		0		0
Gain (Loss) on Sale of Properties, Net of Applicable Income Taxes	0				0		0
Net income	(119,923)		(101,411)		(356,620)		(303,212)
Dividends on preferred stock	0		0		0		0
Net income attributable to noncontrolling interests	0		0		0		0
Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted	0		0		0		0
Net Income (Loss) Available to Common Stockholders, Basic	$ (119,923)		$ (101,411)		$ (356,620)		$ (303,212)

[1] includes the results of operations of four properties that were classified as “held for sale” as of September 30, 2014, as well as the results of operations (prior to disposition) and gain on sale of real estate attributable to seven properties sold during the period from January 1, 2013, to September 30, 2014. In October 2014, we completed the sale of one property which was classified as “held for sale” as of September 30, 2014.