Income per Share (Schedule of Antidilutive Securities Excluded from Computation of Earnings per Share) (Details) - shares	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	20,522,727	20,668,019
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)	9,229,911	8,295,287
Potentially dilutive Series C Cumulative Redeemable Perpetual Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	1,738,781	1,967,430
Potentially dilutive Series G Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	2,155,992	2,439,505
Potentially dilutive Series H Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	3,159,382	3,574,840
Potentially dilutive Series I Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	2,158,515	2,442,359
Potentially dilutive Series J Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	1,722,138	1,948,598
Potentially dilutive Series K Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (shares)	358,008	0