Investments - Schedule of Available-for-Sale Allowance for Credit Losses Roll Forward (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 30,381	$ 33,554	$ 28,212	$ 45,721
Current Provision for Securities without Prior Allowance	1,135	2,128	2,828	4,894
Initial Allowance for Purchased Credit Deteriorated Assets with Credit Deterioration	0	0	0	0
Increase (Decrease) on Securities with Prior Allowance, excluding intent (or Requirement) to Sell Securities	98	(2,992)	1,055	(15,287)
Reductions for Securities Sold	(305)	(1,229)	(777)	(3,852)
Reductions for Securities Identified as Intent (or Requirement) to Sell during the Period	0	(36)	(9)	(51)
Ending Balance	31,309	31,425	31,309	31,425
Foreign government
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Roll Forward]
Beginning Balance	29	36	35	284
Current Provision for Securities without Prior Allowance	0	0	0	0
Initial Allowance for Purchased Credit Deteriorated Assets with Credit Deterioration	0	0	0	0
Increase (Decrease) on Securities with Prior Allowance, excluding intent (or Requirement) to Sell Securities	(3)	(2)	(3)	(250)
Reductions for Securities Sold	0	0	(6)	0
Reductions for Securities Identified as Intent (or Requirement) to Sell during the Period	0	0	0	0
Ending Balance	26	34	26	34
Obligations of states and political subdivisions
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Roll Forward]
Beginning Balance	695	737	669	1,024
Current Provision for Securities without Prior Allowance	18	67	37	67
Initial Allowance for Purchased Credit Deteriorated Assets with Credit Deterioration	0	0	0	0
Increase (Decrease) on Securities with Prior Allowance, excluding intent (or Requirement) to Sell Securities	(74)	(35)	(59)	(239)
Reductions for Securities Sold	0	0	(8)	(83)
Reductions for Securities Identified as Intent (or Requirement) to Sell during the Period	0	0	0	0
Ending Balance	639	769	639	769
Corporate securities
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Roll Forward]
Beginning Balance	15,442	16,756	12,999	30,330
Current Provision for Securities without Prior Allowance	846	1,438	2,362	4,141
Initial Allowance for Purchased Credit Deteriorated Assets with Credit Deterioration	0	0	0	0
Increase (Decrease) on Securities with Prior Allowance, excluding intent (or Requirement) to Sell Securities	(126)	(1,070)	1,166	(14,884)
Reductions for Securities Sold	(212)	(939)	(568)	(3,387)
Reductions for Securities Identified as Intent (or Requirement) to Sell during the Period	0	(36)	(9)	(51)
Ending Balance	15,950	16,149	15,950	16,149
CLO and other ABS
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Roll Forward]
Beginning Balance	2,627	3,895	2,854	2,375
Current Provision for Securities without Prior Allowance	271	622	427	677
Initial Allowance for Purchased Credit Deteriorated Assets with Credit Deterioration	0	0	0	0
Increase (Decrease) on Securities with Prior Allowance, excluding intent (or Requirement) to Sell Securities	126	(1,595)	(255)	(127)
Reductions for Securities Sold	(2)	(7)	(4)	(10)
Reductions for Securities Identified as Intent (or Requirement) to Sell during the Period	0	0	0	0
Ending Balance	3,022	2,915	3,022	2,915
RMBS
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Roll Forward]
Beginning Balance	11,580	11,740	11,649	11,597
Current Provision for Securities without Prior Allowance	0	1	0	8
Initial Allowance for Purchased Credit Deteriorated Assets with Credit Deterioration	0	0	0	0
Increase (Decrease) on Securities with Prior Allowance, excluding intent (or Requirement) to Sell Securities	171	(50)	202	174
Reductions for Securities Sold	(91)	(141)	(191)	(229)
Reductions for Securities Identified as Intent (or Requirement) to Sell during the Period	0	0	0	0
Ending Balance	11,660	11,550	11,660	11,550
CMBS
Debt Securities, Available-for-Sale, Allowance for Credit Loss [Roll Forward]
Beginning Balance	8	390	6	111
Current Provision for Securities without Prior Allowance	0	0	2	1
Initial Allowance for Purchased Credit Deteriorated Assets with Credit Deterioration	0	0	0	0
Increase (Decrease) on Securities with Prior Allowance, excluding intent (or Requirement) to Sell Securities	4	(240)	4	39
Reductions for Securities Sold	0	(142)	0	(143)
Reductions for Securities Identified as Intent (or Requirement) to Sell during the Period	0	0	0	0
Ending Balance	$ 12	$ 8	$ 12	$ 8