Earnings per share (Details) - USD ($) $ / shares in Units, shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Class of Stock [Line Items]
Dilutive Securities, Effect on Basic Earnings Per Share			$ 0
Income from continuing operations	$ (108,116,000)	$ 38,430,000	(98,150,000)	$ 63,481,000
Net income attributable to noncontrolling interests	(3,500,000)	(263,000)	(7,530,000)	(755,000)
Income (Loss) from Continuing Operations Attributable to Parent	(111,616,000)	38,167,000	(105,680,000)	62,726,000
Net (loss) income attributable to Alexandria Real Estate Equities, Inc.’s stockholders	(111,616,000)	38,167,000	(105,680,000)	62,683,000
Dividends on preferred stock	(5,474,000)	(6,246,000)	(11,381,000)	(12,493,000)
Preferred stock redemption charge	(9,473,000)	0	(12,519,000)	0
Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted	(1,085,000)	(630,000)	(1,886,000)	(1,113,000)
Income from continuing operations attributable to Alexandria Real Estate Equities, Inc.'s common stockholders - basic and diluted	(127,648,000)	31,291,000	(131,466,000)	49,120,000
(Loss) income from discontinued operations, net	0	0	0	(43,000)
Net income attributable to Alexandria’s common stockholders	$ (127,648,000)	$ 31,291,000	$ (131,466,000)	$ 49,077,000
Weighted-average shares of common stock outstanding – basic and diluted	74,319	71,412	73,452	71,389
Earnings per share attributable to Alexandria Real Estate Equities, Inc.'s common stockholders - basic and diluted:
Continuing operations (usd per share)	$ (1.72)	$ 0.44	$ (1.79)	$ 0.69
Discontinued operations (usd per share)	0.00	0.00	0.00	0.00
Earnings per share – basic and diluted (usd per share)	$ (1.72)	$ 0.44	$ (1.79)	$ 0.69
Series D Convertible Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage			7.00%