Earnings per share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share Reconciliation
Net income	$ 124,433	$ 95,799	$ 554,486	$ 370,038
Net income attributable to noncontrolling interests	(21,286)	(14,743)	(58,134)	(40,563)
Net income attributable to unvested restricted stock awards	(1,883)	(1,730)	(5,750)	(5,304)
Numerator for basic and diluted EPS – net income attributable to Alexandria Real Estate Equities, Inc.’s common stockholders	$ 101,264	$ 79,326	$ 490,602	$ 324,171
Denominator for basic EPS – weighted-average shares of common stock outstanding	150,854	124,901	144,716	123,561
Dilutive effect of forward equity sales agreements	707	927	437	466
Denominator for diluted EPS – weighted-average shares of common stock outstanding	151,561	125,828	145,153	124,027
Earnings per share attributable to Alexandria Real Estate Equities, Inc.'s common stockholders - basic and diluted:
Earnings (loss) per share – basic (USD per share)	$ 0.67	$ 0.64	$ 3.39	$ 2.62
Earnings (loss) per share - diluted (USD per share)	$ 0.67	$ 0.63	$ 3.38	$ 2.61