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Amount of distribution received from equity method investee for return on investment, classified as operating activities. Excludes distribution for return of investment, classified as investing activities.

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Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

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Investments - Schedule of Private Debt and Equity (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2026 USD ($) note	Jun. 30, 2025 USD ($)	Jun. 30, 2026 USD ($) note	Jun. 30, 2025 USD ($)	Dec. 31, 2025 USD ($)	Apr. 11, 2025 note
Net Investment Income [Line Items]
Carrying Value	$ 69,966		$ 69,966		$ 64,152
Investment Income	334	$ 986	2,149	$ 1,186
Renewable energy LLCs
Net Investment Income [Line Items]
Carrying Value	7,189		7,189		7,274
Investment Income	(4)	(320)	(34)	(320)
Limited partnerships
Net Investment Income [Line Items]
Carrying Value	14,921		14,921		13,477
Investment Income	(368)	851	806	860
Private debt
Net Investment Income [Line Items]
Carrying Value	47,856		47,856		43,401
Investment Income	706	455	1,377	646
Excess & Surplus Lines
Net Investment Income [Line Items]
Carrying Value	69,597		69,597		63,783
Investment Income	$ 334	986	$ 2,149	1,186
Excess & Surplus Lines \| TPG Credit
Net Investment Income [Line Items]
Number of notes maturing in 2031 \| note	2		2
Number of notes maturing in 2035 \| note	2		2			3
Number of notes maturing in 2064 \| note						3
Excess & Surplus Lines \| Notes receivable one \| TPG Credit
Net Investment Income [Line Items]
Rate of interest						6.79%
Excess & Surplus Lines \| Notes receivable two \| TPG Credit
Net Investment Income [Line Items]
Rate of interest						8.04%
Excess & Surplus Lines \| Notes receivable three \| TPG Credit
Net Investment Income [Line Items]
Rate of interest						9.04%
Excess & Surplus Lines \| Renewable energy LLCs
Net Investment Income [Line Items]
Carrying Value	$ 7,189		$ 7,189		7,274
Investment Income	$ (4)	(320)	(34)	(320)
Excess & Surplus Lines \| Renewable energy LLCs \| Investment in LLC
Net Investment Income [Line Items]
Cash distributions from LLCs			$ 50	48
Excess & Surplus Lines \| Renewable energy LLCs \| Minimum \| Investment in LLC \| Various LLCs
Net Investment Income [Line Items]
Ownership percentage	3.60%		3.60%
Excess & Surplus Lines \| Renewable energy LLCs \| Maximum \| Investment in LLC \| Various LLCs
Net Investment Income [Line Items]
Ownership percentage	5.10%		5.10%
Excess & Surplus Lines \| Limited partnerships
Net Investment Income [Line Items]
Carrying Value	$ 14,552		$ 14,552		13,108
Investment Income	(368)	851	806	860
Outstanding commitments to invest	10,800		10,800
Excess & Surplus Lines \| Private debt
Net Investment Income [Line Items]
Carrying Value	47,856		47,856		43,401
Investment Income	$ 706	455	$ 1,377	646
Excess & Surplus Lines \| Private Specialty Credit
Net Investment Income [Line Items]
Number of notes issued \| note	10		10
Commitment to invest in notes receivable	$ 75,300		$ 75,300
Excess & Surplus Lines \| Private Specialty Credit \| Notes receivable one
Net Investment Income [Line Items]
Rate of interest	4.25%		4.25%
Excess & Surplus Lines \| Private Specialty Credit \| Notes receivable two
Net Investment Income [Line Items]
Rate of interest	5.25%		5.25%
Excess & Surplus Lines \| Private Specialty Credit \| Notes receivable three
Net Investment Income [Line Items]
Rate of interest	6.50%		6.50%
Excess & Surplus Lines \| Private Specialty Credit \| Notes receivable four
Net Investment Income [Line Items]
Rate of interest	8.00%		8.00%
Excess & Surplus Lines \| Private Specialty Credit \| Notes Receivable Five
Net Investment Income [Line Items]
Rate of interest	6.00%		6.00%
Excess & Surplus Lines \| Private Specialty Credit \| Notes Receivable Six
Net Investment Income [Line Items]
Rate of interest	7.00%		7.00%
Excess & Surplus Lines \| Private Specialty Credit \| Notes Receivable Seven
Net Investment Income [Line Items]
Rate of interest	8.00%		8.00%
Corporate & Other
Net Investment Income [Line Items]
Carrying Value	$ 369		$ 369		369
Investment Income	0	0	0	0
Corporate & Other \| Renewable energy LLCs
Net Investment Income [Line Items]
Carrying Value	0		0		0
Investment Income	0	0	0	0
Corporate & Other \| Limited partnerships
Net Investment Income [Line Items]
Carrying Value	369		369		369
Investment Income	0	0	0	0
Corporate & Other \| Private debt
Net Investment Income [Line Items]
Carrying Value	0		0		$ 0
Investment Income	$ 0	$ 0	$ 0	$ 0