Income per Unit (Summary of Basic and Diluted Earnings per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Class of Stock [Line Items]
Net income available to common unitholders	$ 95,869	$ 86,298
Weighted average units outstanding-basic (units)	207,809,383	205,714,173
Potentially dilutive common units:
Unvested incentive units (units)	323,064	302,016
Forward equity offering (units)	221,448	0
Market performance-based awards (units)	172,354	491,287
Weighted average shares/units outstanding-diluted (shares/units)	208,526,249	206,507,476
Income per share:
Basic (in dollars per unit)	$ 0.46	$ 0.42
Diluted (in dollars per unit)	$ 0.46	$ 0.42
Digital Realty Trust, L.P.
Class of Stock [Line Items]
Net income available to common unitholders	$ 100,169	$ 89,778
Weighted average units outstanding-basic (units)	217,039,295	214,009,460
Potentially dilutive common units:
Unvested incentive units (units)	323,064	302,016
Forward equity offering (units)	221,448	0
Market performance-based awards (units)	172,354	491,287
Weighted average shares/units outstanding-diluted (shares/units)	217,756,161	214,802,763
Income per share:
Basic (in dollars per unit)	$ 0.46	$ 0.42
Diluted (in dollars per unit)	$ 0.46	$ 0.42