Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629

Reference 5: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69C
-URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 55
-Paragraph 69B
-URI https://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, after accumulated amortization, of debt discount (premium).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=124435984&loc=d3e28555-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI https://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 4
-URI https://asc.fasb.org/extlink&oid=124435984&loc=d3e28567-108399

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI https://asc.fasb.org/extlink&oid=124435984&loc=d3e28541-108399

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1D
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI https://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentUnamortizedDiscountPremiumNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1D
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 3
-URI https://asc.fasb.org/extlink&oid=124435984&loc=d3e28555-108399

+ Details

Name:	us-gaap_DeferredFinanceCostsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_SeniorLongtermNotesCurrentAndNoncurrentAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Principal Amount Of Debt Outstanding

+ References

No definition available.

+ Details

Name:	wpc_PrincipalAmountOfDebtOutstanding
Namespace Prefix:	wpc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Debt - Summary of Senior Unsecured Notes (Details)	Sep. 30, 2022 USD ($)	Sep. 30, 2022 EUR (€)	Sep. 28, 2022 USD ($)	Dec. 31, 2021 USD ($)
Senior Unsecured Notes
Unamortized deferred financing costs	$ 26,390,000
Unamortized discount, net	37,597,000
Unsecured Senior Notes
Senior Unsecured Notes
Principal Amount	5,700,000,000
Principal amount of debt outstanding	5,702,550,000			$ 5,759,815,000
Unamortized deferred financing costs	26,300,000		$ 2,300,000	28,700,000
Unamortized discount, net	$ 24,400,000			29,200,000
Unsecured Senior Notes \| 4.6% Senior Notes due 2024
Senior Unsecured Notes
Coupon rate (percentage)	4.60%	4.60%
Principal Amount	$ 500,000,000
Principal amount of debt outstanding	$ 500,000,000			500,000,000
Unsecured Senior Notes \| 2.25% Senior Notes due 2024
Senior Unsecured Notes
Coupon rate (percentage)	2.25%	2.25%
Principal Amount \| €		€ 500,000,000
Principal amount of debt outstanding	$ 487,400,000			566,300,000
Unsecured Senior Notes \| 4.0% Senior Notes due 2025
Senior Unsecured Notes
Coupon rate (percentage)	4.00%	4.00%
Principal Amount	$ 450,000,000
Principal amount of debt outstanding	$ 450,000,000			450,000,000
Unsecured Senior Notes \| 2.250% Senior Notes due 2026
Senior Unsecured Notes
Coupon rate (percentage)	2.25%	2.25%
Principal Amount \| €		€ 500,000,000
Principal amount of debt outstanding	$ 487,400,000			566,300,000
Unsecured Senior Notes \| 4.25% Senior Notes due 2026
Senior Unsecured Notes
Coupon rate (percentage)	4.25%	4.25%
Principal Amount	$ 350,000,000
Principal amount of debt outstanding	$ 350,000,000			350,000,000
Unsecured Senior Notes \| 2.125% Senior Notes due 2027
Senior Unsecured Notes
Coupon rate (percentage)	2.125%	2.125%
Principal Amount \| €		€ 500,000,000
Principal amount of debt outstanding	$ 487,400,000			566,300,000
Unsecured Senior Notes \| 1.350% Senior Notes due 2028
Senior Unsecured Notes
Coupon rate (percentage)	1.35%	1.35%
Principal Amount \| €		€ 500,000,000
Principal amount of debt outstanding	$ 487,400,000			566,300,000
Unsecured Senior Notes \| 3.850% Senior Notes due 2029
Senior Unsecured Notes
Coupon rate (percentage)	3.85%	3.85%
Principal Amount	$ 325,000,000
Principal amount of debt outstanding	$ 325,000,000			325,000,000
Unsecured Senior Notes \| 3.41% Senior Notes due 2029
Senior Unsecured Notes
Coupon rate (percentage)	3.41%	3.41%
Principal Amount \| €		€ 150,000,000
Principal amount of debt outstanding	$ 146,220,000			0
Unsecured Senior Notes \| 0.950% Senior Notes due 2030
Senior Unsecured Notes
Coupon rate (percentage)	0.95%	0.95%
Principal Amount \| €		€ 525,000,000
Principal amount of debt outstanding	$ 511,770,000			594,615,000
Unsecured Senior Notes \| 2.400% Senior Notes due 2031
Senior Unsecured Notes
Coupon rate (percentage)	2.40%	2.40%
Principal Amount	$ 500,000,000
Principal amount of debt outstanding	$ 500,000,000			500,000,000
Unsecured Senior Notes \| 2.450% Senior Notes due 2032
Senior Unsecured Notes
Coupon rate (percentage)	2.45%	2.45%
Principal Amount	$ 350,000,000
Principal amount of debt outstanding	$ 350,000,000			350,000,000
Unsecured Senior Notes \| 3.70% Senior Notes due 2032
Senior Unsecured Notes
Coupon rate (percentage)	3.70%	3.70%
Principal Amount \| €		€ 200,000,000
Principal amount of debt outstanding	$ 194,960,000			0
Unsecured Senior Notes \| 2.250% Senior Notes due 2033
Senior Unsecured Notes
Coupon rate (percentage)	2.25%	2.25%
Principal Amount	$ 425,000,000
Principal amount of debt outstanding	$ 425,000,000			$ 425,000,000