XML 62 R51.htm IDEA: XBRL DOCUMENT
v3.25.3

Equity and Earnings per Common Share, Common Stock ATM Program, Common Stock and Preferred Stock Repurchase Program (Details) - USD ($) | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Aug. 31, 2024 | Nov. 30, 2022 | Aug. 31, 2018 | Sep. 30, 2025 | Jun. 30, 2025 | Mar. 31, 2025 | Sep. 30, 2024 | Jun. 30, 2024 | Mar. 31, 2024 | Sep. 30, 2025 | Sep. 30, 2024 | Dec. 31, 2024 | Sep. 30, 2019
Class of Stock Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common stock, net of offering costs |  |  |  |  |  |  |  |  |  | $ 14,606,000 | $ 5,433,000 |  |
Stock Repurchase Program [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Gain on repurchase of preferred stock |  |  |  | $ 0 |  |  | $ 0 |  |  | 0 | $ 78,000 |  |
Series A Preferred Stock [Member] | Preferred Stock ATM Program [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common stock (in shares) |  |  |  |  |  |  |  |  |  |  |  | 0 |
Preferred stock value authorized |  |  |  |  |  |  |  |  |  | $ 35,000,000 |  |  |
Common Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common stock (in shares) |  |  |  | 694,446 | 3,414,173 | 1,005,846 | 1,530,917 | 60,187 | 0 |  |  |  |
Stock Repurchase Program [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Share repurchase program, authorized amount |  |  |  |  |  |  |  |  |  |  |  |  | $ 10,000,000
Number of shares repurchased (in shares) |  |  |  | 0 |  |  |  |  |  | 0 |  | 0 |
Common Stock [Member] | Common Stock ATM Program [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock value authorized | $ 150,000,000 | $ 150,000,000 | $ 50,000,000 |  |  |  |  |  |  |  |  |  |
Common stock value remaining |  |  |  |  |  |  |  |  |  | $ 34,600,000 |  |  |
Issuance of common stock (in shares) |  |  |  | 674,204 |  |  |  |  |  | 4,909,053 |  | 1,544,917 |
Weighted average price (in dollars per share) |  |  |  | $ 2.9 |  |  |  |  |  | $ 3 |  | $ 3.59 |
Issuance of common stock, net of offering costs |  |  |  | $ 2,000,000 |  |  |  |  |  | $ 14,700,000 |  | $ 5,600,000 |
Stock issuance fee |  |  |  | $ 39,000 |  |  |  |  |  | $ 293,000 |  | $ 111,000 |
Preferred Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Issuance of common stock (in shares) |  |  |  | 0 | 0 | 0 | 0 | 0 | 0 |  |  |  |
Stock Repurchase Program [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Share repurchase program, authorized amount |  |  |  |  |  |  |  | $ 50,000,000 |  |  |  |  |
Number of shares repurchased (in shares) |  |  |  | 0 |  |  |  |  |  | 0 |  |  |
Preferred Stock [Member] | Series B Preferred Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Class of Stock Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Weighted average price (in dollars per share) |  |  |  |  |  |  |  |  |  |  |  | $ 23.77 |
Stock Repurchase Program [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares repurchased (in shares) |  |  |  |  |  |  |  |  |  |  |  | 395,897 |
Gain on repurchase of preferred stock |  |  |  |  |  |  |  |  |  |  |  | $ 78,000 |
Brokerage commissions |  |  |  |  |  |  |  |  |  |  |  | $ 11,900 |

X
- Definition The amount of commissions paid to brokers for share repurchases. + References No definition available. + Details
Name: | chmi_BrokerageCommissions
Namespace Prefix: | chmi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The value of common shares authorized to be issued by an entity's charter and bylaws. + References No definition available. + Details
Name: | chmi_CommonStockValueAuthorized
Namespace Prefix: | chmi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The value of remaining common shares authorized to be issued by an entity's charter and bylaws. + References No definition available. + Details
Name: | chmi_CommonStockValueAuthorizedRemaining
Namespace Prefix: | chmi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount of gain on repurchase and retirement of preferred stock. + References No definition available. + Details
Name: | chmi_GainOnRepurchaseAndRetirementOfPreferredStock
Namespace Prefix: | chmi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The value of shares authorized to be issued by an entity's charter and bylaws. + References No definition available. + Details
Name: | chmi_PreferredStockValueAuthorized
Namespace Prefix: | chmi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The weighted average price per share for shares issued and sold under the program. + References No definition available. + Details
Name: | chmi_SharesIssuedAndSoldWeightedAveragePricePerShare
Namespace Prefix: | chmi_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount of fee for stock issuance. + References No definition available. + Details
Name: | chmi_StockIssuanceFee
Namespace Prefix: | chmi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- References No definition available. + Details
Name: | srt_ShareRepurchaseProgramAbstract
Namespace Prefix: | srt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount authorized for purchase of share under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 505 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481520/505-30-50-4 + Details
Name: | srt_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix: | srt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_ClassOfStockDisclosuresAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The cash inflow from the additional capital contribution to the entity. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 14 -Subparagraph (a) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-14 + Details
Name: | us-gaap_ProceedsFromIssuanceOfCommonStock
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of new stock issued during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 505 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478448/946-505-50-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(4)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-03(i)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479886/946-10-S99-3 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 505 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478448/946-505-50-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(4)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-03(i)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479886/946-10-S99-3 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_StockRepurchasedDuringPeriodShares
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_SeriesAPreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=chmi_PreferredStockATMProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=chmi_CommonStockATMProgramMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_PreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=us-gaap_SeriesBPreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |