Equity and Accumulated Other Comprehensive Loss, Net (Noncontrolling Interests in Operating Partnership) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Number of units (units)	208,583,244	206,425,656
Percentage of total	95.80%	95.10%
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	$ 1,121.8	$ 1,076.9
Ascenty Acquisition
Class of Stock [Line Items]
Issuance of units in connection with Ascenty Acquisition (units)	2,338,874	2,338,874
Percentage of total	1.10%	1.10%
Common units held by third parties
Class of Stock [Line Items]
Common units held by third parties (units)	4,762,394	6,297,272
Percentage of total	2.20%	2.90%
Incentive units held by employees and directors (see Note 14)
Class of Stock [Line Items]
Incentive units held by employees and directors (units)	2,042,713	1,944,738
Percentage of total	0.90%	0.90%
Noncontrolling Interests in Operating Partnership
Class of Stock [Line Items]
Number of units (units)	217,727,225	217,006,540
Percentage of total	100.00%	100.00%