Reserve for Unpaid Losses and Loss Adjustment Expenses (Tables)

9 Months Ended

Sep. 30, 2025

Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block]

Unfavorable (Favorable) Prior Accident Year Development

	For the nine months ended September 30,
	2025		2024
Workers’ compensation	$	(188)	$	(188)
Workers’ compensation discount accretion	34		34
General liability	—		81
Marine	—		(1)
Package business	—		(6)
Commercial property	(28)		(7)
Professional liability	(11)		(7)
Bond	(22)		(22)
Assumed reinsurance	—		24
Commercial automobile liability	—		26
Personal automobile liability	(55)		(13)
Homeowners	(36)		(15)
Net asbestos and environmental ("A&E") reserves	—		—
Catastrophes	(39)		(38)
Uncollectible reinsurance	6		—
Other reserve re-estimates, net	(9)		(2)
Prior accident year development before change in deferred gain	(348)		(134)
Change in deferred gain on retroactive reinsurance included in other liabilities [1]	(64)		(87)
Total prior accident year development	$	(412)	$	(221)

[1]The $64 and $87 change in deferred gain on retroactive reinsurance for the nine months ended September 30, 2025 and 2024, respectively, is related to amortization of the Navigators ADC deferred gain. For additional information regarding the ADC reinsurance agreement, refer to "Change in Deferred Gain on Retroactive Reinsurance" discussion below.

Property, Liability and Casualty Insurance Product Line

Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block]

Rollforward of Liabilities for Unpaid Losses and Loss Adjustment Expenses

	For the nine months ended September 30,
	2025		2024
Beginning liabilities for unpaid losses and loss adjustment expenses, gross	$	36,404	$	34,044
Reinsurance and other recoverables	6,753		6,696
Beginning liabilities for unpaid losses and loss adjustment expenses, net	29,651		27,348
Provision for unpaid losses and loss adjustment expenses
Current accident year	8,401		7,799
Prior accident year development [1]	(412)		(221)
Total provision for unpaid losses and loss adjustment expenses	7,989		7,578
Change in deferred gain on retroactive reinsurance included in other liabilities [1]	64		87
Payments
Current accident year	(2,038)		(1,852)
Prior accident years	(4,586)		(4,078)
Total payments	(6,624)		(5,930)
Foreign currency adjustment	32		(9)
Ending liabilities for unpaid losses and loss adjustment expenses, net	31,112		29,092
Reinsurance and other recoverables	6,627		6,603
Ending liabilities for unpaid losses and loss adjustment expenses, gross	$	37,739	$	35,695

[1] Prior accident year development for the nine months ended September 30, 2025 and 2024 included a $64 and $87 benefit for amortization of a deferred gain under retroactive reinsurance accounting, respectively, related to the Navigators Adverse Development Cover (the "Navigator's ADC"). For additional information regarding the ADC reinsurance agreement, refer to "Change in Deferred Gain on Retroactive Reinsurance" discussion below.

Group Insurance Policy [Member]

Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block]

Rollforward of Liabilities for Unpaid Losses and Loss Adjustment Expenses

	For the nine months ended September 30,
	2025		2024
Beginning liabilities for unpaid losses and loss adjustment expenses, gross	$	8,206	$	8,274
Reinsurance recoverables	282		254
Beginning liabilities for unpaid losses and loss adjustment expenses, net	7,924		8,020
Provision for unpaid losses and loss adjustment expenses
Current incurral year	3,949		3,929
Prior year's discount accretion	153		149
Prior incurral year development [1]	(486)		(460)
Total provision for unpaid losses and loss adjustment expenses [2]	3,616		3,618
Payments
Current incurral year	(1,899)		(1,885)
Prior incurral years	(1,841)		(1,846)
Total payments	(3,740)		(3,731)
Ending liabilities for unpaid losses and loss adjustment expenses, net	7,800		7,907
Reinsurance recoverables	281		279
Ending liabilities for unpaid losses and loss adjustment expenses, gross	$	8,081	$	8,186

[1]Prior incurral year development represents the change in estimated ultimate incurred losses and loss adjustment expenses for prior incurral years on a discounted basis.

[2]Includes unallocated loss adjustment expenses ("ULAE") of $129 and $130 for the nine months ended September 30, 2025 and 2024, respectively, that are recorded in insurance operating costs and other expenses in the Condensed Consolidated Statements of Operations