Segment Reporting - Income From Investment Management (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenues
Revenues	$ 448,553	$ 383,622	$ 1,328,921	$ 1,076,457
Operating Expenses
Reimbursable costs from affiliates	97	344	322	2,414
Impairment charges — Investment Management goodwill	0	29,334	0	29,334
Merger and other expenses	4,152	17,667	5,595	17,329
Total operating expenses	256,590	246,811	735,022	632,189
Other Income and Expenses
Other gains and (losses)	2,859	(15,020)	9,593	(1,021)
Gain on change in control of interests	0	33,931	0	33,931
Earnings from equity method investments in the Managed Programs	4,978	11,304	14,569	23,477
Non-operating (loss) income	4,862	9,263	13,997	23,783
Total other income and expenses	(61,874)	(24,280)	459	(33,691)
Income (loss) before income taxes	130,089	112,531	594,358	410,577
Provision for income taxes	(5,090)	(8,263)	(30,338)	(21,598)
Net Income (Loss) from Investment Management Attributable to W. P. Carey	125,040	104,928	564,040	389,601
Investment Management
Revenues
Operating property revenues	291	1,541	1,158	10,498
Operating Expenses
Impairment charges — Investment Management goodwill		29,300		29,300
Investment Management | Operating Segments
Revenues
Revenues	291	1,541	1,158	10,498
Operating Expenses
Reimbursable costs from affiliates	97	344	322	2,414
Impairment charges — Investment Management goodwill	0	29,334	0	29,334
Merger and other expenses	0	0	0	3
Total operating expenses	97	29,678	322	31,751
Other Income and Expenses
Other gains and (losses)	679	(1,060)	717	(1,324)
Gain on change in control of interests	0	22,526	0	22,526
Earnings from equity method investments in the Managed Programs	0	4,857	0	13,288
Non-operating (loss) income	0	(1)	13	2
Total other income and expenses	679	26,322	730	34,492
Income (loss) before income taxes	873	(1,815)	1,566	13,239
Provision for income taxes	0	(4,632)	390	(5,099)
Net Income (Loss) from Investment Management Attributable to W. P. Carey	873	(6,447)	1,956	8,140
Asset management revenue | Investment Management
Revenues
Operating property revenues	194	1,197	836	8,084
Asset management revenue | Investment Management | Operating Segments
Revenues
Operating property revenues	194	1,197	836	8,084
Reimbursable costs from affiliates | Investment Management
Revenues
Operating property revenues	97	344	322	2,414
Reimbursable costs from affiliates | Investment Management | Operating Segments
Revenues
Operating property revenues	$ 97	$ 344	$ 322	$ 2,414