Capital and Accumulated Other Comprehensive Income (Loss) (Partnership Units Narrative) (Details) $ in Millions	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Class of Stock [Line Items]
Common stock conversion ratio	1
Digital Realty Trust, L.P.
Class of Stock [Line Items]
Common stock conversion ratio	1
Redeemable noncontrolling interests - operating partnership	$ 997.6	$ 1,076.9
Redeemable noncontrolling interests - operating partnership	$ 997.6	$ 1,076.9