Segment Reporting - Total Company (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting [Abstract]
Revenues	$ 228,780	$ 225,247	$ 217,266	$ 270,240	$ 265,250	$ 214,666	$ 238,079	$ 220,388	$ 941,533	$ 938,383	$ 908,446
Operating expenses	144,564	136,472	160,697	180,000	150,902	159,066	130,382	140,479	621,733	580,829	637,378
Other income and (expenses)									(113,023)	(141,193)	(42,289)
Provision for income taxes									(3,288)	(37,621)	(17,609)
Income from discontinued operations, net of tax									0	0	33,318
Gain on sale of real estate, net of tax		49,100
Gain on sale of real estate, net of tax									71,318	6,487	1,581
Net income attributable to noncontrolling interests	(766)	(1,359)	(1,510)	(3,425)	(5,095)	(1,833)	(3,575)	(2,466)	(7,060)	(12,969)	(6,385)
Net loss (income) attributable to redeemable noncontrolling interests									0	0	142
Net Income Attributable to W. P. Carey	$ 47,704	$ 110,943	$ 51,661	$ 57,439	$ 51,049	$ 21,745	$ 63,348	$ 36,116	$ 267,747	$ 172,258	$ 239,826