Mortgage-Backed Securities - Collateral Characteristics of Non-Agency Residential MBS (Details) - Non-Agency RMBS - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Investment Holdings [Line Items]
Weighted average maturity (years)	21 years 7 months 6 days	22 years 2 months 12 days
Weighted average amortized loan to value	60.60%	61.40%
Weighted average FICO	708	714
Weighted average loan balance (in thousands)	$ 263	$ 291
Weighted average percentage owner-occupied	83.70%	81.80%
Weighted average percentage single family residence	61.80%	61.70%
Weighted average current credit enhancement	1.10%	0.90%
CA
Investment Holdings [Line Items]
Weighted average geographic concentration of top four states	31.50%	33.80%
NY
Investment Holdings [Line Items]
Weighted average geographic concentration of top four states	10.00%	8.70%
FL
Investment Holdings [Line Items]
Weighted average geographic concentration of top four states	8.00%	7.90%
NJ
Investment Holdings [Line Items]
Weighted average geographic concentration of top four states	4.50%	4.30%

The weighted average maturity period of underlying mortgages, which is based on their current face amounts.

No definition available.

Name:	cim_UnderlyingMortgageWeightedAverageMaturityPeriod
Namespace Prefix:	cim_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

As of the balance sheet date, the weighted average of underlying mortgages at amortized cost to their fair values determined using defined pricing methodologies.

+ References

No definition available.

+ Details

Name:	cim_UnderlyingMortgagesWeightedAverageAmortizedLoanToValue
Namespace Prefix:	cim_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

As of the balance sheet date, the weighted average credit score of underlying mortgages based on their FICO ratings.

+ References

No definition available.

+ Details

Name:	cim_UnderlyingMortgagesWeightedAverageFairIsaacsCorporationCreditScore
Namespace Prefix:	cim_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

As of the balance sheet date, the percentage of unpaid principal amount of underlying mortgages originated in a specified territory.

+ References

No definition available.

+ Details

Name:	cim_UnderlyingMortgagesWeightedAverageGeographicPercentagePeriodEnd
Namespace Prefix:	cim_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

As of the balance sheet date, the weighted average of unpaid principal amounts of underlying mortgages.

+ References

No definition available.

+ Details

Name:	cim_UnderlyingMortgagesWeightedAverageLoanBalance
Namespace Prefix:	cim_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

As of the balance sheet date, the weighted average of underlying mortgages that are additionally secured in whole or in part with credit enhancements provided by third parties.

+ References

No definition available.

+ Details

Name:	cim_UnderlyingMortgagesWeightedAveragePercentageHavingCreditEnhancements
Namespace Prefix:	cim_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

As of the balance sheet date, the weighted average of underlying mortgages that are owner occupied.

+ References

No definition available.

+ Details

Name:	cim_UnderlyingMortgagesWeightedAveragePercentageOwnerOccupied
Namespace Prefix:	cim_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

As of the balance sheet date, the weighted average of underlying mortgages that are single family residences.

+ References

No definition available.

+ Details

Name:	cim_UnderlyingMortgagesWeightedAveragePercentageSingleFamilyResidence
Namespace Prefix:	cim_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

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

- Details

Name:	us-gaap_InvestmentTypeAxis=cim_NonAgencyResidentialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_CA
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_NY
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_FL
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementGeographicalAxis=stpr_NJ
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: