Real Estate, net and Real Estate Held for Sale - Minimum Future Rents (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract]
Remainder of 2020	$ 25,288
2021	98,543	$ 120,967
2022	92,488	113,170
2023	78,687	102,314
2024	69,665	85,367
2025 and thereafter	467,422
Total	832,093	$ 942,344
Minimum future rents for real estate, held for sale through 2029	$ 40,400

Lessor, Operating Lease, Payment to be Received, After Year Four

No definition available.

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- Definition

Lessor, Operating Lease, Payments to be Received, Ten Years, Real Estate Held-for-sale

+ References

No definition available.

+ Details

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Namespace Prefix:	clnc_
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- References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Amount of lease payments to be received by lessor for operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121576215&loc=SL77919396-209981

+ Details

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

- Definition

Amount of lease payment to be received by lessor for operating lease in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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

- Definition

Amount of lease payment to be received by lessor for operating lease in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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

- Definition

Amount of lease payment to be received by lessor for operating lease in remainder of current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 30
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121576215&loc=SL77919396-209981

+ Details

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

- Definition

Amount of lease payment to be received by lessor for operating lease in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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

- Definition

Amount of lease payment to be received by lessor for operating lease in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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