CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Total	Redeemable Limited Partner Common Units	Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Dividends in Excess of Earnings	Accumulated Other Comprehensive Income (Loss), net	Total Stockholders’ Equity	Noncontrolling Interests in Operating Partnership	Noncontrolling Interests in Consolidated Joint Ventures	Total Noncontrolling Interests	Series E Preferred Stock	Series E Preferred Stock Preferred Stock	Series E Preferred Stock Accumulated Dividends in Excess of Earnings	Series E Preferred Stock Total Stockholders’ Equity	Series J Preferred Stock	Series J Preferred Stock Preferred Stock	Series J Preferred Stock Total Stockholders’ Equity	Series F Preferred Stock	Series F Preferred Stock Preferred Stock	Series F Preferred Stock Accumulated Dividends in Excess of Earnings	Series F Preferred Stock Total Stockholders’ Equity	DFT Merger	DFT Merger Redeemable Limited Partner Common Units	DFT Merger Common Stock	DFT Merger Additional Paid-in Capital	DFT Merger Total Stockholders’ Equity	DFT Merger Noncontrolling Interests in Operating Partnership	DFT Merger Total Noncontrolling Interests	DFT Merger Series C Preferred Stock	DFT Merger Series C Preferred Stock Preferred Stock	DFT Merger Series C Preferred Stock Total Stockholders’ Equity	Ascenty Acquisition	Ascenty Acquisition Noncontrolling Interests in Operating Partnership	Ascenty Acquisition Noncontrolling Interests in Consolidated Joint Ventures	Ascenty Acquisition Total Noncontrolling Interests
Balance at beginning of period at Dec. 31, 2015	$ 4,536,502	$ 0	$ 1,290,135	$ 1,456	$ 4,655,220	$ (1,350,089)	$ (96,590)	$ 4,500,132	$ 29,612	$ 6,758	$ 36,370
Balance at beginning of period (in shares) at Dec. 31, 2015				146,384,247
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of common units to common stock	0			$ 5	5,237			5,242	(5,242)		(5,242)
Conversion of common units to common stock (in shares)				430,493
Issuance of unvested restricted stock, net of forfeitures (in shares)				120,082
Issuance of common stock in exchange for cash, net of offering costs	1,085,444			$ 120	1,085,324			1,085,444
Issuance of series J preferred units, net of offering costs (in shares)				12,000,000
Exercise of stock options	1,380				1,380			1,380
Exercise of stock options (in shares)				33,948
Redemption of preferred units												$ (287,500)	$ (277,172)	$ (10,328)	$ (287,500)
Preferred stock offering costs	(2)		(2)					(2)
Amortization of unearned compensation on share-based awards	24,113				24,113			24,113
Reclassification of vested share-based awards	0				(10,125)			(10,125)	10,125		10,125
Dividends declared on preferred stock	(83,771)					(83,771)		(83,771)
Dividends and distributions on common stock and common and incentive units	(538,888)					(529,419)		(529,419)	(9,469)		(9,469)
Distributions to noncontrolling interests in consolidated joint ventures, net of contributions	(527)									(527)	(527)
Net income	431,852					426,187		426,187	5,298	367	5,665
Other comprehensive income— foreign currency translation adjustments	(86,621)						(85,300)	(85,300)	(1,321)		(1,321)
Other comprehensive income— fair value of interest rate swaps	41,998						41,395	41,395	603		603
Other comprehensive income— reclassification of accumulated other comprehensive income to interest expense	4,968						4,890	4,890	78		78
Balance at end of period at Dec. 31, 2016	5,132,297	0	1,012,961	$ 1,582	5,764,497	(1,547,420)	(135,605)	5,096,015	29,684	6,598	36,282
Balance at end of period (in shares) at Dec. 31, 2016				159,019,118
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of common units to common stock	0			$ 6	10,003			10,009	(10,009)		(10,009)
Conversion of common units to common stock (in shares)				562,582
Issuance of unvested restricted stock, net of forfeitures (in shares)				249,050
Units issued in connection with business combinations																							$ 5,924,124	$ 66,259	$ 432	$ 5,247,126	$ 5,247,558	$ 676,566	$ 676,566
Units issued in connection with business combinations (in shares)																									43,175,629
Issuance of common stock in exchange for cash, net of offering costs	$ 211,897			$ 24	211,873			211,897								$ 193,540	$ 193,540	$ 193,540												$ 219,250	$ 219,250	$ 219,250
Issuance of series J preferred units, net of offering costs (in shares)	6,111,770			2,375,000
Exercise of stock options	$ 729				729			729
Exercise of stock options (in shares)				17,668
Shares issued under employee stock purchase plan	$ 5,143
Shares issued under employee stock purchase plan (in shares)	71,253
Redemption of preferred units																			$ (182,500)	$ (176,191)	$ (6,309)	$ (182,500)
Amortization of unearned compensation on share-based awards	$ 27,981				27,981			27,981
Reclassification of vested share-based awards	0				(10,057)			(10,057)	10,057		10,057
Adjustment to redeemable noncontrolling interests—operating partnership	(12,357)				(4,166)			(4,166)	(8,191)		(8,191)													$ 12,357
Dividends declared on preferred stock	(68,802)					(68,802)		(68,802)
Dividends and distributions on common stock and common and incentive units	(701,974)					(681,280)		(681,280)	(20,694)		(20,694)
Distributions to noncontrolling interests in consolidated joint ventures, net of contributions	(8,593)									(8,593)	(8,593)
Net income	256,267					248,259		248,259	3,770	4,238	8,008
Other comprehensive income— foreign currency translation adjustments	28,709						28,272	28,272	437		437
Other comprehensive income— fair value of interest rate swaps	(3,434)						(3,513)	(3,513)	79		79
Other comprehensive income— reclassification of accumulated other comprehensive income to interest expense	2,459						2,414	2,414	45		45
Balance at end of period at Dec. 31, 2017	11,049,450	53,902	1,249,560	$ 2,044	11,261,461	(2,055,552)	(108,432)	10,349,081	698,126	2,243	700,369
Balance at end of period (in shares) at Dec. 31, 2017				205,470,300
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of common units to common stock	0			$ 7	61,997			62,004	(62,004)		(62,004)
Conversion of common units to common stock (in shares)				711,892
Issuance of unvested restricted stock, net of forfeitures (in shares)				220,765
Units issued in connection with business combinations																																	$ 278,837	$ 253,837	$ 25,000	$ 278,837
Issuance of common stock in exchange for cash, net of offering costs	$ 1,194				1,194			1,194
Issuance of series J preferred units, net of offering costs (in shares)	2,338,874
Shares issued under employee stock purchase plan	$ 5,874			$ 1	5,873			5,874
Shares issued under employee stock purchase plan (in shares)				69,532
Shares repurchased and retired to satisfy tax withholding upon vesting	$ (5,055)			$ (1)	(5,054)			(5,055)
Shares repurchased and retired to satisfy tax withholding upon vesting (in shares)	(46,833)			(46,833)
Amortization of unearned compensation on share-based awards	$ 32,456				32,456			32,456
Reclassification of vested share-based awards	0				(3,772)			(3,772)	3,772		3,772
Adjustment to redeemable noncontrolling interests—operating partnership	37,274	(37,274)			1,596			1,596	35,678		35,678
Dividends declared on preferred stock	(81,316)					(81,316)		(81,316)
Dividends and distributions on common stock and common and incentive units	(865,675)	(1,271)				(833,364)		(833,364)	(32,311)		(32,311)
Contributions from noncontrolling interests in consolidated joint ventures, net of distributions	66,124									66,124	66,124
Net income	341,115
Net income	340,640	475				331,246		331,246	9,705	(311)	9,394
Other comprehensive income— foreign currency translation adjustments	(11,736)						(11,279)	(11,279)	(457)		(457)
Other comprehensive income— fair value of interest rate swaps	8,197						7,890	7,890	307		307
Other comprehensive income— reclassification of accumulated other comprehensive income to interest expense	(3,969)						(3,826)	(3,826)	(143)		(143)
Balance at end of period at Dec. 31, 2018	10,858,210	$ 15,832	$ 1,249,560	$ 2,051	$ 11,355,751	(2,633,071)	$ (115,647)	9,858,644	$ 906,510	$ 93,056	$ 999,566
Balance at end of period (in shares) at Dec. 31, 2018				206,425,656
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect adjustment from adoption of new accounting standard	$ 5,915					$ 5,915		$ 5,915