CONSOLIDATED STATEMENTS OF CAPITAL - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance (in units)		205,470,300			205,470,300
Conversion of limited partner common units to general partner common units					$ 62,004	$ 10,009	$ 5,242
Issuance of series J preferred units, net of offering costs (in units)					2,338,874	6,111,770
Units issued in connection with employee stock purchase plan					$ 5,874	$ 5,143
Shares repurchased and retired to satisfy tax withholding upon vesting					$ (5,055)
Units repurchased and retired to satisfy tax withholding upon vesting (in units)					(46,833)
Units issued in connection with employee stock purchase plan (in units)						71,253
Amortization of unearned compensation on share-based awards					$ 32,456	$ 27,981	24,113
Cumulative effect adjustment from adoption of new accounting standard	$ 5,915				5,915
Net income	$ 52,597	$ 110,095	$ 79,658	$ 84,563	341,115	256,267	431,852
Other comprehensive income— foreign currency translation adjustments					(11,736)	28,709	(86,621)
Other comprehensive income— fair value of interest rate swaps					8,197	(3,434)	41,998
Other comprehensive income— reclassification of accumulated other comprehensive income to interest expense					$ (3,969)	$ 2,459	4,968
Balance (in units)	206,425,656		205,470,300		206,425,656	205,470,300
DFT Merger
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common units in connection with business combinations						$ 5,924,124
Ascenty Acquisition
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common units in connection with business combinations					$ 278,837
Digital Realty Trust, L.P.
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period		11,049,450		5,132,297	11,049,450	5,132,297	4,535,137
Common unit offering costs					1,194	211,897	1,085,444
Issuance of common units in connection with the exercise of stock options						729	1,380
Preferred unit offering costs							2
Units issued in connection with employee stock purchase plan					5,874	5,143	3,349
Shares repurchased and retired to satisfy tax withholding upon vesting					(5,055)
Issuance of series J preferred units, net of offering costs						193,540
Redemption of preferred units						(182,500)	(287,500)
Amortization of unearned compensation on share-based awards					32,456	27,981	24,113
Adjustment to redeemable common units					37,274	12,357
Distributions					(946,991)	(770,776)	(621,294)
Contributions from noncontrolling interests in consolidated joint ventures, net of distributions					66,124	(8,593)	(527)
Net income	$ 52,597	110,095	$ 79,658	84,563	341,115	256,267	431,852
Net income					340,640
Other comprehensive income— foreign currency translation adjustments					(11,736)	28,709	(86,621)
Other comprehensive income— fair value of interest rate swaps					8,197	(3,434)	41,998
Other comprehensive income— reclassification of accumulated other comprehensive income to interest expense					(3,969)	2,459	4,968
Balance at end of period	10,858,210		11,049,450		10,858,210	11,049,450	5,132,297
Digital Realty Trust, L.P. | DFT Merger
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common units in connection with business combinations						5,924,124
Digital Realty Trust, L.P. | Ascenty Acquisition
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common units in connection with business combinations					278,837
Redeemable Limited Partner Common Units | Digital Realty Trust, L.P.
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period		53,902		0	53,902	0	0
Adjustment to redeemable common units					(37,274)	(12,357)
Distributions					(1,271)
Net income					475
Balance at end of period	15,832		53,902		15,832	$ 53,902	0
Redeemable Limited Partner Common Units | Digital Realty Trust, L.P. | DFT Merger
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common units in connection with business combinations (in units)						66,259,000
Accumulated Other Comprehensive Income (Loss) | Digital Realty Trust, L.P.
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period		(112,885)		(140,619)	(112,885)	$ (140,619)	(100,964)
Other comprehensive income— foreign currency translation adjustments					(11,736)	28,709	(86,621)
Other comprehensive income— fair value of interest rate swaps					8,197	(3,434)	41,998
Other comprehensive income— reclassification of accumulated other comprehensive income to interest expense					(3,969)	2,459	4,968
Balance at end of period	(120,393)		(112,885)		(120,393)	(112,885)	(140,619)
Noncontrolling Interests in Consolidated Joint Ventures | Digital Realty Trust, L.P.
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period		2,243		6,598	2,243	6,598	6,758
Contributions from noncontrolling interests in consolidated joint ventures, net of distributions					66,124	(8,593)	(527)
Net income						4,238	367
Net income					(311)
Balance at end of period	93,056		2,243		93,056	2,243	6,598
Noncontrolling Interests in Consolidated Joint Ventures | Digital Realty Trust, L.P. | Ascenty Acquisition
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common units in connection with business combinations					25,000
General Partner | Preferred Units | Digital Realty Trust, L.P.
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period		$ 1,249,560		$ 1,012,961	$ 1,249,560	$ 1,012,961	$ 1,290,135
Balance (in units)		50,650,000		41,900,000	50,650,000	41,900,000	53,400,000
Issuance of common units in connection with business combinations						$ 219,250
Issuance of common units in connection with business combinations (in units)						8,050,000
Issuance of series J preferred units, net of offering costs (in units)						8,000,000
Preferred unit offering costs							$ 2
Issuance of series J preferred units, net of offering costs						$ 193,540
Redemption of preferred units						$ (176,191)	$ (277,172)
Redemption of preferred units (in units)						(7,300,000)	(11,500,000)
Distributions					$ (81,316)	$ (68,802)	$ (83,771)
Net income						68,802	83,771
Net income					81,316
Balance at end of period	$ 1,249,560		$ 1,249,560		$ 1,249,560	$ 1,249,560	$ 1,012,961
Balance (in units)	50,650,000		50,650,000		50,650,000	50,650,000	41,900,000
General Partner | Common Units | Digital Realty Trust, L.P.
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period		$ 9,207,953		$ 4,218,659	$ 9,207,953	$ 4,218,659	$ 3,305,222
Balance (in units)		205,470,300		159,019,118	205,470,300	159,019,118	146,384,247
Conversion of limited partner common units to general partner common units					$ 62,004	$ 10,009	$ 5,242
Conversion of limited partner common units to general partner common units (in units)					711,892	562,582	430,493
Issuance of restricted common units, net of forfeitures (in units)					220,765	249,050	120,082
Common unit offering costs					$ 1,194	$ 211,897	$ 1,085,444
Issuance of common units, net of offering costs (in units)						2,375,000	12,000,000
Issuance of common units in connection with the exercise of stock options						$ 729	$ 1,380
Issuance of common units in connection with the exercise of stock options (in units)						17,668	33,948
Units issued in connection with employee stock purchase plan					$ 5,874	$ 5,143	$ 3,349
Units issued in connection with employee stock purchase plan (in units)					69,532	71,253	50,348
Redemption of preferred units						$ (6,309)	$ (10,328)
Amortization of unearned compensation on share-based awards					$ 32,456	27,981	24,113
Reclassification of vested share-based awards					(3,772)	(10,057)	(10,125)
Adjustment to redeemable common units					1,596	4,166
Distributions					(833,364)	(681,280)	(528,054)
Cumulative effect adjustment from adoption of new accounting standard	$ 5,915				5,915
Net income						179,457	342,416
Net income					249,930
Balance at end of period	$ 8,724,731		$ 9,207,953		$ 8,724,731	$ 9,207,953	$ 4,218,659
Balance (in units)	206,425,656		205,470,300		206,425,656	205,470,300	159,019,118
General Partner | Common Units | Digital Realty Trust, L.P. | DFT Merger
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common units in connection with business combinations						$ 5,247,558
Issuance of common units in connection with business combinations (in units)						43,175,629
Limited Partners | Common Units | Digital Realty Trust, L.P.
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period		$ 702,579		$ 34,698	$ 702,579	$ 34,698	$ 33,986
Balance (in units)		8,489,095		2,475,663	8,489,095	2,475,663	2,833,326
Conversion of limited partner common units to general partner common units					$ (62,004)	$ (10,009)	$ (5,242)
Conversion of limited partner common units to general partner common units (in units)					711,892	562,582	430,493
Issuance of common units, net of forfeitures (in units)					464,807	464,244	72,830
Reclassification of vested share-based awards					$ 3,772	$ 10,057	$ 10,125
Adjustment to redeemable common units					35,678	8,191
Distributions					(32,311)	(20,694)	(9,469)
Net income						3,770	5,298
Net income					9,705
Balance at end of period	$ 911,256		$ 702,579		$ 911,256	$ 702,579	$ 34,698
Balance (in units)	10,580,884		8,489,095		10,580,884	8,489,095	2,475,663
Limited Partners | Common Units | Digital Realty Trust, L.P. | DFT Merger
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common units in connection with business combinations						$ 676,566
Issuance of common units in connection with business combinations (in units)						6,111,770
Limited Partners | Common Units | Digital Realty Trust, L.P. | Ascenty Acquisition
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common units in connection with business combinations					$ 253,837
Issuance of common units in connection with business combinations (in units)					2,338,874