Subsequent events (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 25, 2021 USD ($) ft² property	Sep. 30, 2021 USD ($) ft² property	Jun. 30, 2021 USD ($) ft² property	Sep. 30, 2021 USD ($) ft² property	Sep. 30, 2020 USD ($)	Mar. 31, 2021 ft² property
Subsequent Event [Line Items]
Number of real estate properties acquired | property		27	24	27		25
Payments to acquire real estate | $				$ 3,758,704	$ 1,989,648
Operating with future development/redevelopment
Subsequent Event [Line Items]
Area of real estate property | ft²		1,251,105	1,140,916	1,251,105		431,066
San Francisco Bay Area
Subsequent Event [Line Items]
Number of real estate properties acquired | property		1	7	1
Payments to acquire real estate | $		$ 105,250	$ 217,000
San Francisco Bay Area | Operating with future development/redevelopment
Subsequent Event [Line Items]
Area of real estate property | ft²		223,232	187,043	223,232
Subsequent Event | San Francisco Bay Area
Subsequent Event [Line Items]
Number of real estate properties acquired | property	2
Payments to acquire real estate | $	$ 203,800
Subsequent Event | San Francisco Bay Area | Operating with future development/redevelopment
Subsequent Event [Line Items]
Area of real estate property | ft²	185,228