Merger with CPA:16 Global - Narratives (Details) $ / shares in Units, $ in Thousands		3 Months Ended		5 Months Ended	6 Months Ended	12 Months Ended				13 Months Ended
	Jan. 31, 2014 USD ($) property loan investment $ / shares shares	Mar. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Jun. 30, 2014 USD ($)	Sep. 30, 2014 USD ($)	Dec. 31, 2016 USD ($) property	Dec. 31, 2015 USD ($) property	Dec. 31, 2014 USD ($) property	Dec. 31, 2013 USD ($)	Jan. 31, 2014 USD ($) property loan investment $ / shares shares
Merger Disclosure
Per share closing price | $ / shares	$ 59.08									$ 59.08
Cash consideration						$ 0	$ 0	$ 1,338
Non-recourse debt						1,706,921	2,269,421
Senior Unsecured Credit Facility - Revolver						676,715	485,021
Lease revenues						663,463	656,956	573,829
Income from operations						203,489	178,740	211,170
Merger and acquisition expense						5,377	(7,764)	34,465
Goodwill						635,920	681,809	692,415	$ 350,208
Gain on change in control of interests						$ 0	$ 0	105,947
Purchase on remaining interest								280,936
Additional Paid-in Capital
Merger Disclosure
Purchase on remaining interest								41,374
Hotel
Merger Disclosure
Number of real estate properties | property						2	2
Assets held-for-sale
Merger Disclosure
Number of real estate properties | property							2
CPA: 16 - Global
Merger Disclosure
Share per share exchange rate | $ / shares	0.1830									0.1830
Per share exchange rate | $ / shares	$ 11.25									$ 11.25
Merger consideration	$ 1,800,000
Shares issued as compensation, shares | shares	30,729,878
Fair value of W.P.Carey shares of common stock issued	$ 1,815,521									$ 1,815,521
Shares of acquired entity received | shares	168,041,772
Cash consideration	$ 1,338
Non-recourse debt	1,768,288									1,768,288
Senior Unsecured Credit Facility - Revolver	$ 170,000									$ 170,000
Number of unconsolidated investments | investment	18									18
Lease revenues				$ 251,500
Income from operations				91,100
Income attributable to noncontrolling interest				$ 2,400
Merger and acquisition expense								$ 30,500	$ 5,000	$ 10,600
Goodwill	$ 346,642									346,642
Carrying value of equity investment in CPA pre merger	$ 274,100									$ 274,100
Number of shares owned | shares	38,229,294									38,229,294
Fair value of noncontrolling interests acquired	$ 278,187									$ 278,187
Fair value equity interest in jointly-owned investments with equity investment prior to merger	$ 349,749
CPA: 16 - Global | Previously held equity interest
Merger Disclosure
Number of jointly owned investments with affiliate | investment	12									12
Gain on change in control of interests			$ 73,100
Carrying value of noncontrolling interest acquired from entity	$ 236,800									$ 236,800
CPA: 16 - Global | Jointly Owned Investments
Merger Disclosure
Number of jointly owned investments with affiliate | investment	9									9
Equity method investment, ownership percentage	100.00%									100.00%
Gain on change in control of interests			$ 30,200
Carrying value of equity investment in CPA pre merger	$ 142,500									$ 142,500
Fair value equity interest in jointly-owned investments with equity investment prior to merger	172,720
CPA: 16 - Global | Additional Paid-in Capital
Merger Disclosure
Purchase on remaining interest		$ 42,000
CPA: 16 - Global | Previously Reported
Merger Disclosure
Fair value equity interest in jointly-owned investments with equity investment prior to merger	347,200
CPA: 16 - Global | Measurement period adjustment
Merger Disclosure
Purchase on remaining interest	$ 600
Fair value of noncontrolling interests acquired							$ (600)
Fair value equity interest in jointly-owned investments with equity investment prior to merger					$ 2,600
CPA: 16 - Global | Assets held-for-sale | Discontinued Operations
Merger Disclosure
Number of real estate properties | property	10							10		10
CPA: 16 - Global | Assets held-for-sale | Discontinued Operations | Jointly Owned Investments
Merger Disclosure
Number of real estate properties | property	5									5
CPA: 16 - Global | Consolidated or partially leased investments
Merger Disclosure
Number of real estate properties | property	325									325
Weighted average lease term	10 years 4 months 24 days
Triple-net lease, current minimum base rent receivable	$ 300,100									$ 300,100
Interest Rate	5.60%
CPA: 16 - Global | Consolidated or partially leased investments | Hotel
Merger Disclosure
Number of real estate properties | property	2									2
CPA: 16 - Global | Consolidated or partially leased investments | Fixed interest rate
Merger Disclosure
Loans outstanding, count | loan	92									92
CPA: 16 - Global | Consolidated or partially leased investments | Variable interest rate
Merger Disclosure
Loans outstanding, count | loan	18									18
CPA: 16 - Global | Equity method investments
Merger Disclosure
Number of real estate properties | property	140									140
Non-recourse debt	$ 291,200									$ 291,200
Number of consolidated investments | investment	11									11
Number of jointly owned investments with affiliate | investment	2									2
Number of investments consolidated after merger | investment	5									5
Weighted average lease term	8 years 7 months 6 days
Triple-net lease, current minimum base rent receivable	$ 63,900									$ 63,900
Interest Rate	4.80%
CPA: 16 - Global | Equity method investments | Fixed interest rate
Merger Disclosure
Loans outstanding, count | loan	17									17
CPA: 16 - Global | Equity method investments | Variable interest rate
Merger Disclosure
Loans outstanding, count | loan	5									5