Organization - Narratives (Details) ft² in Millions, $ in Millions	3 Months Ended	73 Months Ended	135 Months Ended
Mar. 31, 2018 ft² segment property tenant	Jan. 31, 2013 USD ($)	Mar. 31, 2018 USD ($) ft² property tenant
Real Estate Properties
Capital interest in operating partnership	99.99%		99.99%
Number of real estate properties (properties)	411		411
Number of tenants \| tenant	114		114
Square footage of real estate properties \| ft²	44.4		44.4
Number of reportable segments \| segment	2
Proceeds from Senior Credit Facility \| $		$ 2,900.0
Proceeds from DRIP shares \| $			$ 701.1
Operating real estate
Real Estate Properties
Number of real estate properties (properties)	38		38
Square footage of operating properties \| ft²	2.7		2.7
Self storage
Real Estate Properties
Number of real estate properties (properties)	37		37
Hotel
Real Estate Properties
Number of real estate properties (properties)	1		1

The percentage of capital interest in the Operating Partnership by the general partner.

No definition available.

Name:	cpa17_CapitalInterestInOperatingPartnership
Namespace Prefix:	cpa17_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of tenants occupying the real estate properties owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	cpa17_NumberOfTenants
Namespace Prefix:	cpa17_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The total square footage of the operating properties owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	cpa17_SquareFootageOfOperatingProperties
Namespace Prefix:	cpa17_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

Area of a real estate property.

+ References

No definition available.

+ Details

Name:	us-gaap_AreaOfRealEstateProperty
Namespace Prefix:	us-gaap_
Data Type:	num:areaItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of real estate properties owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfRealEstateProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfReportableSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash inflow associated with the amount received from entity's first offering of stock to the public.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromIssuanceInitialPublicOffering
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cash inflow from capital contributions to an entity associated with a dividend reinvestment plan.

+ References

No definition available.

+ Details

Name:	us-gaap_ProceedsFromIssuanceOfCommonStockDividendReinvestmentPlan
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_RealEstatePropertiesAxis=cpa17_OperatingRealEstateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstatePropertiesAxis=cpa17_SelfStorageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RealEstatePropertiesAxis=us-gaap_HotelMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: