Merger with CPA:18 – Global - Narratives (Details) $ / shares in Units, $ in Thousands, ft² in Millions		1 Months Ended		2 Months Ended		3 Months Ended		9 Months Ended
	Aug. 01, 2022 USD ($) ft² property $ / shares shares	Oct. 31, 2023 USD ($) property	Aug. 31, 2022 USD ($) property	Sep. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) ft² property shares	Sep. 30, 2022 USD ($) property	Sep. 30, 2023 USD ($) ft² property shares	Sep. 30, 2022 USD ($) property	Mar. 31, 2023 property	Dec. 31, 2022 USD ($) property shares	Jul. 31, 2022 shares
Business Acquisition
Common stock shares, outstanding (in shares) | shares						213,925,817		213,925,817			210,620,949
Cash consideration paid								$ 0	$ 423,435
Non-recourse mortgages, net						$ 784,750		$ 784,750			$ 1,132,417
Weighted average interest rate (as a percent)						4.70%		4.70%
Proceeds from sales of real estate								$ 187,678	170,341
Goodwill						$ 1,034,183		1,034,183			$ 1,037,412
Gain on change in control of interests						$ 0	$ 33,931	$ 0	$ 33,931
Asset Held for Sale, Not in Discontinued Operations
Business Acquisition
Number of properties (property) | property						8		8			3
Properties Disposed of by Sale
Business Acquisition
Number of properties (property) | property										2
Number of properties sold | property						6	3	14	17
Proceeds from sales of real estate						$ 143,600	$ 55,200	$ 187,700	$ 170,300
Losses on sales of property						$ (14,100)	4,700	$ (17,500)	$ (37,600)
Properties Disposed of by Sale | Subsequent Events
Business Acquisition
Number of properties sold | property		7
Proceeds from sales of real estate		$ 101,900
Real Estate
Business Acquisition
Number of properties (property) | property						1,472		1,472
Lease term (in years)						11 years		11 years
Occupancy rate (as a percent)								98.90%
Square footage of real estate properties | ft²						179.0		179.0
Real Estate | Asset Held for Sale, Not in Discontinued Operations
Business Acquisition
Number of properties (property) | property						6		6
CPA:18 | Affiliated Entity
Business Acquisition
Jointly owned investments, count | property	4
Real Estate | CPA:18 | Affiliated Entity
Business Acquisition
Number of properties (property) | property	7
Operating Properties | Real Estate
Business Acquisition
Number of properties (property) | property						98		98
Square footage of real estate properties | ft²						7.5		7.5
Self- Storage | Real Estate
Business Acquisition
Number of properties (property) | property						86		86
CPA:18
Business Acquisition
Common stock shares, outstanding (in shares) | shares												141,099,002
Number of properties (property) | property	42
Lease term (in years)	7 years
Occupancy rate (as a percent)	99.30%
Contractual minimum annualized base rent	$ 81,000
Non-recourse mortgages, net	$ 900,200
Weighted average interest rate (as a percent)	5.10%
CPA:18 | Self- Storage
Business Acquisition
Number of properties (property) | property	65
CPA:18 | Student Housing
Business Acquisition
Number of properties (property) | property	2
CPA:18
Business Acquisition
Share price (usd per share) | $ / shares	$ 87.46
Fair value of W. P. Carey shares of common stock issued	$ 1,600,000
Shares issued as compensation in acquisition (shares) | shares	13,786,302
Fair value of shares issued	$ 1,200,000
Actual revenue from acquiree					$ 16,500
Actual net loss from acquiree					(500)
Merger related costs								$ 17,100
Goodwill	172,300
Gain on change in control of interests							22,500
Fair value of our equity interest in jointly owned investments with CPA:18 – Global prior to the CPA:18 Merger	88,300
CPA:18 | Jointly Owned Investments
Business Acquisition
Gain on change in control of interests							$ 11,400
CPA:18 | Carrying Value
Business Acquisition
Fair value of our equity interest in jointly owned investments with CPA:18 – Global prior to the CPA:18 Merger	65,800
CPA:18 | Carrying Value | Jointly Owned Investments
Business Acquisition
Fair value of our equity interest in jointly owned investments with CPA:18 – Global prior to the CPA:18 Merger	17,200
CPA:18 | Fair Value | Jointly Owned Investments
Business Acquisition
Fair value of our equity interest in jointly owned investments with CPA:18 – Global prior to the CPA:18 Merger	$ 28,600
CPA:18 | Operating Properties
Business Acquisition
Square footage of real estate properties | ft²	5.1
CPA:18 | Operating Properties | Real Estate
Business Acquisition
Actual revenue from acquiree					$ 15,400
CPA:18 | $0.001 Par Value Common Stock
Business Acquisition
Share conversion rate (usd per share) | $ / shares	$ 0.0978
Share price (usd per share) | $ / shares	$ 3.00
Shares of acquiree held prior to merger (shares) | shares	8,556,732
CPA 18 Merger
Business Acquisition
Cash consideration paid	$ 423,300
Cash paid for fractional shares	$ 100
CPA 18 Merger | Asset Held for Sale, Not in Discontinued Operations
Business Acquisition
Number of properties (property) | property	2
Assets held for sale	$ 85,000
CPA 18 Merger | Properties Disposed of by Sale
Business Acquisition
Number of properties sold | property			1
Proceeds from sales of real estate			$ 44,500
Losses on sales of property				$ 200
CPA 18 Merger | Properties Disposed of by Sale | Subsequent Events
Business Acquisition
Proceeds from sales of real estate		$ 30,400
CPA 18 Merger | Real Estate
Business Acquisition
Lease revenues				$ 2,100