LOSS AND LOSS ADJUSTMENT EXPENSE RESERVES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Liability for Claims and Claims Adjustment Expense
Loss from catastrophes	$ 5,000	$ 27,015
Prior years	(2,489)	4,218
Operating Segments
Liability for Claims and Claims Adjustment Expense
Prior years	(2,489)	4,329
Operating Segments \| Open Market
Liability for Claims and Claims Adjustment Expense
Loss from catastrophes	5,000	27,015
Prior years	(2,847)	4,896
Operating Segments \| Innovations
Liability for Claims and Claims Adjustment Expense
Loss from catastrophes	0	0
Prior years	358	(567)
Operating Segments \| Reinsurance Contract [Axis]: Adverse Reserve Development \| Open Market
Liability for Claims and Claims Adjustment Expense
Prior years	3,000	23,200
Operating Segments \| Reinsurance Contract [Axis]: Adverse Reserve Development \| Innovations
Liability for Claims and Claims Adjustment Expense
Prior years	600
Operating Segments \| Reinsurance Contract [Axis]: Favorable Reserve Development \| Open Market
Liability for Claims and Claims Adjustment Expense
Prior years	(5,800)	$ (18,300)
Operating Segments \| Reinsurance Contract [Axis]: Favorable Reserve Development \| Innovations
Liability for Claims and Claims Adjustment Expense
Prior years	$ (300)

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- Definition

The charge against earnings in the period for the uninsured portion of a loss from a fire, explosion, or natural disaster (hurricane, earthquake).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(9))
-Publisher FASB
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- Definition

Amount, after effects of reinsurance, of expense (reversal of expense) for claims incurred in prior reporting periods and related claims settlement costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 55
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480046/944-40-55-7

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480081/944-40-50-3

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