Consolidated Statement of Equity (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 Merger,value	1,380,361		40	(40)
Exchange of shares of W. P. Carey & Co. LLC shares for shares of W.P.Carey Inc. in connection with the Merger, shares		(39,834,827)	39,834,827
Shares issued to stockholders of CPA:15 in connection with the Merger, value	237,359		28	1,380,333					1,380,361	237,513
Shares issued to stockholders of CPA:15 in connection with the Merger, shares			28,170,643
Purchase of noncontrilling interests in connection with merger				(154)					(154)
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 from the issuance of shares to third party, net, value	45,000		1	44,999					45,000
Cash proceeds from the issuance of shares to third party, net, shares			937,500
Grants issued in connection with services rendered - shares		427,425
Shares issued under share incentive plans - value	646			646					646
Shares issued under share incentive plans - shares		238,728
Contributions from noncontrolling interests	3,291									3,291
Forfeitures of shares - shares		(29,919)
Windfall tax benefit - share incentive plan	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 parties (Note 3), value	(45,270)							(45,270)	(45,270)
Purchase of treasury stock from related parties (Note 3), shares		(561,418)	(416,408)
Cancellation of shares, value				(25,000)				25,000
Cancellation of shares, shares			(85,671)
Net income	62,739				62,132				62,132	607
Other comprehensive loss
Foreign currency translation adjustments	7,721						6,127		6,127	1,594
Unrealized (loss)/gain on derivative instruments	(2,262)						(2,262)		(2,262)
Change in unrealized apprection 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
Shares issued under share incentive plans - value	(6,855)			(6,855)					(6,855)
Shares issued under share incentive plans - shares			275,956
Cash proceeds from the excerise of stock options, value	25			25					25
Cash proceeds from the excerise of stock options, shares			778
Contributions from noncontrolling interests	2,463									2,463
Windfall tax benefit - share incentive plan	10,764			10,764					10,764
Stock-based compensation expense	9,149			4,633		4,516			9,149
Redemption value adjustment	0
Distributions to noncontrolling interests	(9,181)									(9,181)
Distributions declared	(59,653)				(60,190)	537			(59,653)
Foreign currency translation	10									10
Net income					14,181				14,181	1,708
Other comprehensive loss
Foreign currency translation adjustments	(9,729)						(7,940)		(7,940)	(1,789)
Unrealized (loss)/gain on derivative instruments	3,175						3,175		3,175
Balance - end of period at Mar. 31, 2013	$ 2,213,380		$ 69	$ 2,184,387	$ (218,191)	$ 13,411	$ (9,414)	$ (20,270)	$ 1,949,992	$ 263,388
Ending equity balance - shares at Mar. 31, 2013			68,762,259