Selected Quarterly Financial Data (Unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Data
Revenues	$ 248,333	$ 195,945	$ 252,907	$ 209,008	$ 139,008	$ 132,592	$ 112,221	$ 106,030	$ 906,193	$ 489,851	$ 352,361
Expenses	176,236	128,178	161,359	171,605	105,076	91,625	80,811	75,194	637,378	352,706	299,491
Net income	33,463	28,316	66,972	117,318	48,860	21,650	45,816	15,839	246,069	132,165	62,779
Net loss (income) attributable to noncontrolling interests	(1,470)	(993)	(2,344)	(1,578)	(25,624)	(2,912)	(2,692)	(1,708)	(6,385)	(32,936)	(607)
Net (income) loss attributable to redeemable noncontrolling interests	279	14	111	(262)	(214)	(232)	43	50	142	(353)	(40)
Net Income Attributable to W. P. Carey	$ 32,272	$ 27,337	$ 64,739	$ 115,478	$ 23,022	$ 18,506	$ 43,167	$ 14,181	$ 239,826	$ 98,876	$ 62,132
Earnings per share attributable to W.P. Carey shareholders
Basic	$ 0.31	$ 0.27	$ 0.64	$ 1.29	$ 0.33	$ 0.27	$ 0.63	$ 0.20	$ 2.42	$ 1.43	$ 1.30
Diluted	$ 0.30	$ 0.27	$ 0.64	$ 1.27	$ 0.33	$ 0.27	$ 0.62	$ 0.20	$ 2.39	$ 1.41	$ 1.28
Per shares distributions declared	$ 0.950	$ 0.940	$ 0.900	$ 0.895	$ 0.980	$ 0.860	$ 0.840	$ 0.820	$ 3.685	$ 3.390	$ 2.440