Capital and Accumulated Other Comprehensive Income (Loss) (Forward Equity Sale) (Details) - USD ($) $ in Millions	Sep. 24, 2020	Sep. 27, 2018	Sep. 30, 2020	Dec. 31, 2019
Digital Realty Trust, L.P.
Class of Stock [Line Items]
Partnership units issued			8,166,661	8,843,155
Forward Sale Agreement
Class of Stock [Line Items]
Common stock issued in public offering (shares)	9,775,000
Partnership units issued	9,775,000
Forward Sale Agreement | Digital Realty Trust, L.P.
Class of Stock [Line Items]
Common stock issued in public offering (shares)	9,775,000	9,775,000
Net proceeds on public offering	$ 1,000
Over-Allotment Option
Class of Stock [Line Items]
Net proceeds on public offering	$ 1,000
Over-Allotment Option | Digital Realty Trust, L.P.
Class of Stock [Line Items]
Common stock issued in public offering (shares)		1,275,000