Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959

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Period Type:	instant

- Definition

Fair value as of the balance sheet date of all foreign currency derivatives designated as cash flow hedging instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (a),(b),(c)(1)
-URI http://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cpa18_ForeignCurrencyCollarsMember
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- Details

Name:	srt_CurrencyAxis=currency_EUR
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- Details

Name:	srt_CurrencyAxis=currency_NOK
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Risk Management and Use of Derivative Financial Instruments - Foreign Currency Derivatives Details (Details) € in Thousands, kr in Thousands, $ in Thousands	Dec. 31, 2021 USD ($) derivative	Dec. 31, 2021 EUR (€) derivative	Dec. 31, 2021 NOK (kr) derivative
Derivative
Fair value	$ 594
Derivatives Designated as Hedging Instruments \| Designated as Cash Flow Hedging Instruments \| Foreign currency collars \| EUR
Derivative
Number of Instruments \| derivative	6	6	6
Notional Amount \| €		€ 3,900
Fair value	$ 524
Derivatives Designated as Hedging Instruments \| Designated as Cash Flow Hedging Instruments \| Foreign currency collars \| NOK
Derivative
Number of Instruments \| derivative	4	4	4
Notional Amount \| kr			kr 5,000
Fair value	$ 70