DERIVATIVE INSTRUMENTS - Summary of Certain Characteristics of Futures Derivatives (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2026	Dec. 31, 2025
Futures contracts
Derivative [Line Items]
Weighted Average Years to Maturity	9 years 9 months 18 days	8 years 3 months 21 days
Futures contracts \| Notional - Long Positions
Derivative [Line Items]
Current notional	$ 1,000,000	$ 2,473,200
Futures contracts \| Notional - Short Positions
Derivative [Line Items]
Current notional	$ 17,787,900	$ 16,557,900
2-year swap equivalent SOFR contracts
Derivative [Line Items]
Maturity period	2 years	2 years
Weighted Average Years to Maturity	2 years	2 years
2-year swap equivalent SOFR contracts \| Notional - Long Positions
Derivative [Line Items]
Current notional	$ 1,000,000	$ 500,000
2-year swap equivalent SOFR contracts \| Notional - Short Positions
Derivative [Line Items]
Current notional	$ 1,000,000	$ 500,000
U.S. Treasury futures - 2 year
Derivative [Line Items]
Maturity period	2 years	2 years
Weighted Average Years to Maturity	2 years	1 year 10 months 24 days
U.S. Treasury futures - 2 year \| Notional - Long Positions
Derivative [Line Items]
Current notional	$ 0	$ 0
U.S. Treasury futures - 2 year \| Notional - Short Positions
Derivative [Line Items]
Current notional	$ 1,400,000	$ 3,658,000
U.S. Treasury futures - 5 year
Derivative [Line Items]
Maturity period	5 years	5 years
Weighted Average Years to Maturity	4 years 4 months 24 days	4 years 4 months 24 days
U.S. Treasury futures - 5 year \| Notional - Long Positions
Derivative [Line Items]
Current notional	$ 0	$ 1,973,200
U.S. Treasury futures - 5 year \| Notional - Short Positions
Derivative [Line Items]
Current notional	$ 825,000	$ 0
U.S. Treasury futures - 10 year and greater
Derivative [Line Items]
Maturity period	10 years	10 years
Weighted Average Years to Maturity	10 years 10 months 9 days	11 years 3 months 29 days
U.S. Treasury futures - 10 year and greater \| Notional - Long Positions
Derivative [Line Items]
Current notional	$ 0	$ 0
U.S. Treasury futures - 10 year and greater \| Notional - Short Positions
Derivative [Line Items]
Current notional	$ 14,452,900	$ 12,399,900
U.S. swap futures - 10 year and greater
Derivative [Line Items]
Weighted Average Years to Maturity	10 years 2 months 19 days
U.S. swap futures - 10 year and greater \| Notional - Long Positions
Derivative [Line Items]
Maturity period	10 years
Current notional	$ 0
U.S. swap futures - 10 year and greater \| Notional - Short Positions
Derivative [Line Items]
Current notional	$ 110,000

Average period remaining until maturity of derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-5

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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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-5A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481112/505-10-50-18

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 6A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480682/815-20-25-6A

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Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1A

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 181
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480401/815-10-55-181

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-1B

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Term of derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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