Derivative instruments (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Notional Amount	$ 635,086		$ 635,086		$ 638,667
Asset Derivatives Fair Value	56,113		56,113		36,812
Liabilities Derivatives Fair Value	(2,638)		(2,638)		(212)
Derivative gain (loss)
Net Realized Gain (Loss)	$ 4,478	$ 10,427	$ 8,870	$ 14,113
Net Realized gain (loss) - Statement of Income	Realized Investment Gains (Losses)	Realized Investment Gains (Losses)	Realized Investment Gains (Losses)	Realized Investment Gains (Losses)
Unrealized Gain (Loss)	$ (1,803)	$ 2,489	$ 5,083	$ (6,432)
Unrealized gain (loss) - Statement of Income	Net unrealized gain (loss) on financial instruments	Net unrealized gain (loss) on financial instruments	Net unrealized gain (loss) on financial instruments	Net unrealized gain (loss) on financial instruments
Total change in OCI for period	$ (1,440)	$ 2,493	$ 4,805	$ (1,312)
Designated as Hedging
Derivative gain (loss)
Derivatives - effective portion reclassified from AOCI to income	(278)	(294)	(561)	(592)
Derivatives- effective portion recorded in OCI	(1,718)	2,199	4,244	(1,904)
Total change in OCI for period	(1,440)	2,493	4,805	(1,312)
Interest rate swaps
Asset Derivatives Fair Value	55,770		55,770		36,812
Liabilities Derivatives Fair Value	(2,038)		(2,038)
Derivative gain (loss)
Net Realized Gain (Loss)	3,566	9,682	7,958	13,368
Unrealized Gain (Loss)	(1,803)	3,853	5,083	(4,606)
Interest rate swaps \| Not Designated as Hedging \| Interest Rate Risk
Notional Amount	26,300		26,300		183,081
Asset Derivatives Fair Value	4,380		4,380		12,349
Interest rate swaps \| Designated as Hedging \| Interest Rate Risk
Notional Amount	546,620		546,620		416,139
Asset Derivatives Fair Value	51,390		51,390		24,463
Liabilities Derivatives Fair Value	(2,038)		(2,038)
FX forwards
Asset Derivatives Fair Value	343		343
Liabilities Derivatives Fair Value	(600)		(600)		(212)
Derivative gain (loss)
Net Realized Gain (Loss)	912	745	912	745
Unrealized Gain (Loss)		$ (1,364)		$ (1,826)
FX forwards \| Foreign Exchange Rate Risk
Notional Amount	62,166		62,166		39,447
Asset Derivatives Fair Value	343		343
Liabilities Derivatives Fair Value	$ (600)		$ (600)		$ (212)

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