CONSOLIDATED STATEMENTS OF EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	Cumulative-effect adjustment for the adoption of new accounting pronouncement	Total W.P. Carey Stockholders	Total W.P. Carey Stockholders Cumulative-effect adjustment for the adoption of new accounting pronouncement	$0.001 Par Value Common Stock	Additional Paid-in Capital	Distributions in Excess of Accumulated Earnings	Distributions in Excess of Accumulated Earnings Cumulative-effect adjustment for the adoption of new accounting pronouncement	Deferred Compensation Obligation	Accumulated Other Comprehensive Loss	Noncontrolling interests
Beginning equity balance at Dec. 31, 2018	$ 6,830,055		$ 6,824,278		$ 165	$ 8,187,335	$ (1,143,992)		$ 35,766	$ (254,996)	$ 5,777
Beginning equity balance, shares at Dec. 31, 2018					165,279,642
W.P. Carey Stockholders
Shares issued under ATM Program, net	523,377		523,377		$ 6	523,371
Shares issued under ATM Program, net, shares					6,672,412
Shares issued upon delivery of vested restricted share awards	(15,765)		(15,765)		$ 1	(15,766)
Shares issued upon delivery of vested restricted share awards, shares					322,831
Shares issued upon purchases under employee share purchase plan	113		113			113
Shares issued upon purchases under employee share purchase plan, value, shares					1,517
Amortization of stock-based compensation expense	13,848		13,848			13,848
Deferral of vested shares, net						(1,445)			1,445
Contributions from noncontrolling interests	849										849
Distributions to noncontrolling interests	(1,191)										(1,191)
Dividends declared	(533,637)		(533,637)			4,985	(538,674)		52
Net Income	176,752		175,871				175,871				881
Other comprehensive income (loss):
Foreign currency translation adjustments	(41,772)		(41,772)							(41,772)
Unrealized (loss) gain on derivative instruments	11,786		11,786							11,786
Unrealized gain on investments	7		7							7
Ending equity balance at Sep. 30, 2019	6,964,422		6,958,106		$ 172	8,712,441	(1,506,795)		37,263	(284,975)	6,316
Ending equity balance, shares at Sep. 30, 2019					172,276,402
Beginning equity balance at Dec. 31, 2018	6,830,055		6,824,278		$ 165	8,187,335	(1,143,992)		35,766	(254,996)	5,777
Beginning equity balance, shares at Dec. 31, 2018					165,279,642
Ending equity balance at Dec. 31, 2019	$ 6,948,173	$ (14,812)	6,941,929	$ (14,812)	$ 172	8,717,535	(1,557,374)	$ (14,812)	37,263	(255,667)	6,244
Ending equity balance, shares at Dec. 31, 2019	172,278,242				172,278,242
Other comprehensive income (loss):
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Beginning equity balance at Jun. 30, 2019	$ 6,990,794		6,984,405		$ 171	8,576,245	(1,368,457)		37,263	(260,817)	6,389
Beginning equity balance, shares at Jun. 30, 2019					170,756,507
W.P. Carey Stockholders
Shares issued under ATM Program, net	131,473		131,473		$ 1	131,472
Shares issued under ATM Program, net, shares					1,502,572
Shares issued upon delivery of vested restricted share awards	(23)		(23)		$ 0	(23)
Shares issued upon delivery of vested restricted share awards, shares					17,323
Amortization of stock-based compensation expense	4,747		4,747			4,747
Distributions to noncontrolling interests	(569)										(569)
Dividends declared	(179,677)		(179,677)				(179,677)
Net Income	41,835		41,339				41,339				496
Other comprehensive income (loss):
Foreign currency translation adjustments	(37,412)		(37,412)							(37,412)
Unrealized (loss) gain on derivative instruments	13,243		13,243							13,243
Unrealized gain on investments	11		11							11
Ending equity balance at Sep. 30, 2019	6,964,422		6,958,106		$ 172	8,712,441	(1,506,795)		37,263	(284,975)	6,316
Ending equity balance, shares at Sep. 30, 2019					172,276,402
Beginning equity balance at Dec. 31, 2019	$ 6,948,173	$ (14,812)	6,941,929	$ (14,812)	$ 172	8,717,535	(1,557,374)	$ (14,812)	37,263	(255,667)	6,244
Beginning equity balance, shares at Dec. 31, 2019	172,278,242				172,278,242
W.P. Carey Stockholders
Shares issued under forward sale agreements, net	$ 199,481		199,481		$ 3	199,478
Shares issued under forward sale agreements, net, shares					2,951,791
Shares issued upon delivery of vested restricted share awards	(5,272)		(5,272)		$ 0	(5,272)
Shares issued upon delivery of vested restricted share awards, shares					160,653
Shares issued upon purchases under employee share purchase plan	299		299			299
Shares issued upon purchases under employee share purchase plan, value, shares					5,472
Amortization of stock-based compensation expense	10,143		10,143			10,143
Deferral of vested shares, net						(3,854)			3,854
Distributions to noncontrolling interests	(5,280)										(5,280)
Dividends declared	(547,388)		(547,388)			1,191	(549,476)		897
Redemption of noncontrolling interest	(9,865)										(9,865)
Net Income	331,340		320,787				320,787				10,553
Other comprehensive income (loss):
Foreign currency translation adjustments	(4,183)		(4,183)							(4,183)
Unrealized (loss) gain on derivative instruments	(13,267)		(13,274)							(13,274)	7
Unrealized gain on investments	0
Ending equity balance at Sep. 30, 2020	$ 6,889,369		6,887,710		$ 175	8,919,520	(1,800,875)		42,014	(273,124)	1,659
Ending equity balance, shares at Sep. 30, 2020	175,396,158				175,396,158
Beginning equity balance at Jun. 30, 2020	$ 6,802,455		6,800,791		$ 174	8,815,108	(1,765,892)		42,014	(290,613)	1,664
Beginning equity balance, shares at Jun. 30, 2020					173,890,427
W.P. Carey Stockholders
Shares issued under forward sale agreements, net	99,849		99,849		$ 1	99,848
Shares issued under forward sale agreements, net, shares					1,488,291
Shares issued upon delivery of vested restricted share awards	0		0			0
Shares issued upon delivery of vested restricted share awards, shares					17,440
Amortization of stock-based compensation expense	4,564		4,564			4,564
Distributions to noncontrolling interests	(49)										(49)
Dividends declared	(184,380)		(184,380)				(184,380)
Net Income	149,434		149,397				149,397				37
Other comprehensive income (loss):
Foreign currency translation adjustments	34,170		34,170							34,170
Unrealized (loss) gain on derivative instruments	(16,674)		(16,681)							(16,681)	7
Unrealized gain on investments	0
Ending equity balance at Sep. 30, 2020	$ 6,889,369		$ 6,887,710		$ 175	$ 8,919,520	$ (1,800,875)		$ 42,014	$ (273,124)	$ 1,659
Ending equity balance, shares at Sep. 30, 2020	175,396,158				175,396,158