Income per Share (Schedule of Antidilutive Securities Excluded from Computation of Earnings per Share) (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	20,270,271	9,792,977	20,468,837	11,103,025
Weighted average of Operating Partnership common units not owned by Digital Realty Trust, Inc.
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	8,332,194	2,244,710	8,313,432	2,211,476
Series C Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	1,898,314	0	1,932,872	0
Potentially dilutive Series F Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	0	70,119	0	926,601
Series G Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	2,353,805	2,157,221	2,396,655	2,297,648
Series H Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	3,449,255	3,161,182	3,512,048	3,366,963
Series I Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	2,356,559	2,159,745	2,399,459	2,300,337
Potentially dilutive Series J Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	1,880,144	0	1,914,371	0