Consolidated Statement of Equity (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	Total USD ($)	No Par Value Common Stock	$0.001 Par Value Common Stock USD ($)	Additional Paid-in Capital USD ($)	Distributions in Excess of Accumulated Earnings USD ($)	Deferred Compensation Obligation USD ($)	Accumulated Other Comprehensive Loss USD ($)	Treasury Stock USD ($)	Total W.P. Carey Members USD ($)	Noncontrolling Interest USD ($)
Balance - beginning of period at Dec. 31, 2011	$ 716,402		$ 0	$ 779,071	$ (95,046)	$ 7,063	$ (8,507)	$ 0	$ 682,581	$ 33,821
Beginning equity balance - shares at Dec. 31, 2011		39,729,018	0
W.P. Carey Stockholders
Exchange of shares of W. P. Carey & Co. LLC shares for shares of W.P.Carey Inc. in connection with the CPA:15 Merger,value			40	(40)
Exchange of shares of W. P. Carey & Co. LLC shares for shares of W.P.Carey Inc. in connection with the CPA:15 Merger, shares		(39,834,827)	39,834,827
Shares issued to stockholders of CPA:15 in connection with the CPA:15 Merger, value	1,380,361		28	1,380,333					1,380,361
Shares issued to stockholders of CPA:15 in connection with the CPA:15 Merger, shares			28,170,643
Purchase of noncontrolling interests in connection with CPA:15 Merger	237,359			(154)					(154)	237,513
Reclassification of Estate shareholder shares	(40,000)			(40,000)					(40,000)
Exercise of stock options and employee purchase under the employee share purchase plan, value	1,553			1,553					1,553
Exercise of stock options and employee purchase under the employee share purchase plan, shares		30,993	13,768
Cash proceeds on issuance of shares to third party, net, value	45,000		1	44,999					45,000
Cash proceeds on issuance of shares to third party, net, shares			937,500
Grants issued in connection with services rendered - shares		427,425	3,822
Shares issued under share incentive plans - value	646			646					646
Shares issued under share incentive plans - shares		238,728	27,044
Contributions from noncontrolling interests	3,291									3,291
Forfeitures of shares - shares		(29,919)
Windfall tax benefit - share incentive plans	10,185			10,185					10,185
Stock-based compensation expense	26,038			25,067		971			26,038
Redemption value adjustment	(840)			(840)					(840)
Distributions to noncontrolling interests	(6,649)									(6,649)
Distributions declared	(138,944)				(139,268)	324			(138,944)
Purchase of treasury stock from related party (Note 3), value	(45,270)							(45,270)	(45,270)
Purchase of treasury stock from related parties (Note 3), shares		(561,418)	(416,408)
Cancelation of shares, value				(25,000)				25,000
Cancelation of shares, shares			(85,671)
Net income	62,739				62,132				62,132	607
Other comprehensive income
Foreign currency translation adjustments	7,721						6,127		6,127	1,594
Unrealized gain (loss) on derivative instruments	(2,262)						(2,262)		(2,262)
Change in unrealized appreciation on marketable securities	(7)						(7)		(7)
Balance - end of period at Dec. 31, 2012	2,257,323		69	2,175,820	(172,182)	8,358	(4,649)	(20,270)	1,987,146	270,177
Ending equity balance - shares at Dec. 31, 2012		0	68,485,525
W.P. Carey Stockholders
Reclassification of Estate shareholder shares	40,000			40,000					40,000
Exercise of stock options and employee purchase under the employee share purchase plan, value	1,970			1,970					1,970
Exercise of stock options and employee purchase under the employee share purchase plan, shares			49,054
Shares issued under share incentive plans - value	(7,958)			(7,958)					(7,958)
Shares issued under share incentive plans - shares			299,581
Contributions from noncontrolling interests	2,830									2,830
Windfall tax benefit - share incentive plans	11,556			11,556					11,556
Stock-based compensation expense	17,578			13,062		4,516			17,578
Redemption value adjustment	0
Distributions to noncontrolling interests	(14,913)									(14,913)
Distributions declared	(117,736)				(118,273)	537			(117,736)
Purchase of treasury stock from related party (Note 3), value	(40,000)							(40,000)	(40,000)
Purchase of treasury stock from related parties (Note 3), shares			(616,971)
Foreign currency translation	18									18
Net income	61,748				57,348				57,348	4,400
Other comprehensive income
Foreign currency translation adjustments	(4,637)						(3,590)		(3,590)	(1,047)
Unrealized gain (loss) on derivative instruments	5,255						5,255		5,255
Balance - end of period at Jun. 30, 2013	$ 2,213,034		$ 69	$ 2,234,450	$ (233,107)	$ 13,411	$ (2,984)	$ (60,270)	$ 1,951,569	$ 261,465
Ending equity balance - shares at Jun. 30, 2013			68,217,189