Income per Share (Schedule of Antidilutive Securities Excluded From Computation Of Earnings Per Share) (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	20,028,886	13,559,863	16,421,253
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 (in shares)	8,227,463	3,996,550	2,406,018
Potentially dilutive Series C Cumulative Redeemable Perpetual Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	1,876,584	540,773	0
Potentially dilutive Series E Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	0	0	2,880,254
Potentially dilutive Series F Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	0	463,301	1,939,905
Potentially dilutive Series G Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	2,326,861	2,261,153	2,652,503
Potentially dilutive Series H Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	3,409,772	3,313,484	3,886,966
Potentially dilutive Series I Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	2,329,584	2,263,799	2,655,607
Potentially dilutive Series J Cumulative Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities (in shares)	1,858,622	720,803	0