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

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

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow from the acquisition of a piece of land, anything permanently fixed to it, including buildings, structures on it and so forth; includes real estate intended to generate income for the owner; excludes real estate acquired for use by the owner.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3213-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_BusinessAcquisitionAxis=cxp_TerminalWarehouseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=cxp_A201CaliforniaStreetMember
Namespace Prefix:
Data Type:	na
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Period Type:

- Details

Name:	us-gaap_BusinessAcquisitionAxis=cxp_A101FranklinStreetMember
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Transactions (Schedule of Properties Acquired) (Details) - USD ($) $ in Thousands	Mar. 13, 2020	Dec. 09, 2019	Dec. 02, 2019
Terminal Warehouse
Business Acquisition [Line Items]
Ownership Interest	8.65%
Purchase Price	$ 40,048
201 California Street
Business Acquisition [Line Items]
Ownership Interest		100.00%
Purchase Price		$ 238,900
101 Franklin Street
Business Acquisition [Line Items]
Ownership Interest			92.50%
Purchase Price			$ 205,500