Consolidated Statement of Equity (Unaudited) - USD ($) $ in Thousands	Total	Total W.P. Carey Stockholders	$0.001 Par Value Common Stock	Additional Paid-in Capital	Distributions in Excess of Accumulated Earnings	Deferred Compensation Obligation	Accumulated Other Comprehensive Loss	Noncontrolling interests
Balance - beginning of period at Dec. 31, 2016	$ 3,425,140	$ 3,301,667	$ 106	$ 4,399,961	$ (894,137)	$ 50,222	$ (254,485)	$ 123,473
Beginning equity balance, shares at Dec. 31, 2016			106,294,162
W.P. Carey Stockholders
Contributions from noncontrolling interest	80,513							80,513
Shares issued upon delivery of vested restricted shares awards, value	(9,434)	(9,434)	$ 1	(9,435)
Shares issued upon delivery of vested restricted shares awards, shares			187,922
Shares issued upon exercise of stock options and purchases under employee share purchase plan, value	(1,384)	(1,384)	$ 0	(1,384)
Shares issued upon exercise of stock options and purchases under employee share purchase plan, shares			28,968
Delivery of deferred vested shares, net	0	0		3,179		(3,179)
Amortization of stock-based compensation expense	6,910	6,910		6,910
Distributions to noncontrolling interests	(6,261)							(6,261)
Distributions declared	(107,481)	(107,481)		1,158	(108,862)	223
Net income	59,825	57,484			57,484			2,341
Other comprehensive income:
Foreign currency translation adjustments	14,750	14,180					14,180	570
Realized and unrealized loss on derivative instruments	(5,673)	(5,676)					(5,676)	3
Change in unrealized gain (loss) on investments	(253)	(253)					(253)
Balance - end of period at Mar. 31, 2017	3,456,652	3,256,013	$ 107	4,400,389	(945,515)	47,266	(246,234)	200,639
Ending equity balance, shares at Mar. 31, 2017			106,511,052
Balance - beginning of period at Dec. 31, 2017	$ 3,411,385	3,192,261	$ 107	4,433,573	(1,052,064)	46,656	(236,011)	219,124
Beginning equity balance, shares at Dec. 31, 2017	106,922,616		106,922,616
W.P. Carey Stockholders
Shares issued upon delivery of vested restricted shares awards, value	$ (13,543)	(13,543)	$ 0	(13,543)
Shares issued upon delivery of vested restricted shares awards, shares			271,824
Delivery of deferred vested shares, net	0			10,509		(10,509)
Amortization of stock-based compensation expense	8,219	8,219		8,219
Distributions to noncontrolling interests	(5,224)							(5,224)
Distributions declared	(109,950)	(109,950)		675	(110,625)
Net income	68,066	65,274			65,274			2,792
Other comprehensive income:
Foreign currency translation adjustments	18,516	14,734					14,734	3,782
Realized and unrealized loss on derivative instruments	(8,392)	(8,389)					(8,389)	(3)
Change in unrealized gain (loss) on investments	428	428					428
Balance - end of period at Mar. 31, 2018	$ 3,369,505	$ 3,149,034	$ 107	$ 4,439,433	$ (1,097,415)	$ 36,147	$ (229,238)	$ 220,471
Ending equity balance, shares at Mar. 31, 2018	107,194,440		107,194,440