Line of Credit Facility, Maximum Borrowing Capacity, Increase

No definition available.

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Namespace Prefix:	nly_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number Of Closed Securitizations

+ References

No definition available.

+ Details

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Namespace Prefix:	nly_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: 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(22)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

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(19)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

+ Details

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

- Definition

This is the principal amount outstanding for securitized loans only (across all types of loans).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Subparagraph (a)
-Paragraph 4
-SubTopic 20
-Topic 860
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-4

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

+ Details

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Period Type:	duration

- Details

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Namespace Prefix:
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Balance Type:
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- Details

Name:	us-gaap_DebtInstrumentAxis=nly_MortgageServicingRightsCommittedCreditFacilityMember
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Balance Type:
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- Details

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- Details

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- Details

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SUBSEQUENT EVENTS (Details) $ in Millions	1 Months Ended
SUBSEQUENT EVENTS (Details) $ in Millions	Feb. 28, 2025 USD ($) securitization	Jan. 31, 2025 USD ($) securitization	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Line of Credit \| Mortgage Servicing Rights Committed Credit Facility
Subsequent Event [Line Items]
Credit facility, maximum borrowing capacity			$ 1,600.0	$ 1,250.0
Subsequent Event
Subsequent Event [Line Items]
Number of closed securitizations \| securitization	1	1
Subsequent Event \| Line of Credit \| Mortgage Servicing Rights Committed Credit Facility
Subsequent Event [Line Items]
Credit facility, maximum borrowing, increase		$ 250.0
Subsequent Event \| Line of Credit \| Residential mortgage loans
Subsequent Event [Line Items]
Credit facility, maximum borrowing capacity		300.0
OBX 2025-NQM1 \| Subsequent Event
Subsequent Event [Line Items]
Face value at closing		$ 618.4
OBX 2025-NQM2 \| Subsequent Event
Subsequent Event [Line Items]
Face value at closing	$ 719.2