Equity and Accumulated Other Comprehensive Income (Loss), Net - Noncontrolling Interests in Operating Partnership (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Class of Stock
Number of units (units)	280,289,726	208,900,758
Percentage of total	97.20%	95.90%
Common stock conversion ratio	1
Digital Realty Trust, L.P.
Class of Stock
Common stock conversion ratio	1
Redeemable noncontrolling interests - operating partnership	$ 1,078.9	$ 997.6
Common units held by third parties
Class of Stock
Common units held by third parties (units)	6,212,369	6,820,201
Percentage of total	2.20%	3.20%
Incentive units held by employees and directors (see Note 14)
Class of Stock
Incentive units held by employees and directors (units)	1,833,898	2,022,954
Percentage of total	0.60%	0.90%
Noncontrolling Interests in Operating Partnership
Class of Stock
Number of units (units)	288,335,993	217,743,913
Percentage of total	100.00%	100.00%