Income per Unit (Summary of Basic and Diluted Earnings per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Class of Stock [Line Items]
Net income (loss) available to common unitholders	$ 67,268	$ (4,140)	$ 218,700	$ 119,842
Weighted average units outstanding-basic (in units)	206,118,472	170,194,254	205,931,031	163,481,306
Potentially dilutive common units:
Unvested incentive units (units)	169,100	0	160,117	150,369
Forward equity offering (units)	37,884	0	1,847	166,493
Market performance-based awards (units)	440,800	0	462,632	572,928
Weighted average shares/units outstanding-diluted (shares/units)	206,766,256	170,194,254	206,555,627	164,371,096
Income (loss) per share:
Basic (in dollars per unit)	$ 0.33	$ (0.02)	$ 1.06	$ 0.73
Diluted (in dollars per unit)	$ 0.33	$ (0.02)	$ 1.06	$ 0.73
Digital Realty Trust, L.P.
Class of Stock [Line Items]
Net income (loss) available to common unitholders	$ 69,968	$ (4,219)	$ 227,580	$ 121,474
Weighted average units outstanding-basic (in units)	214,289,384	173,460,704	214,199,414	166,048,072
Potentially dilutive common units:
Unvested incentive units (units)	169,100	0	160,117	166,493
Forward equity offering (units)	37,884	0	1,847	150,369
Market performance-based awards (units)	440,800	0	462,632	572,928
Weighted average shares/units outstanding-diluted (shares/units)	214,937,168	173,460,704	214,824,010	166,937,862
Income (loss) per share:
Basic (in dollars per unit)	$ 0.33	$ (0.02)	$ 1.06	$ 0.73
Diluted (in dollars per unit)	$ 0.33	$ (0.02)	$ 1.06	$ 0.73