Investments - Gross Unrealized Losses and Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Marketable Securities
Estimated Fair Value, Less than 12 Months	$ 301,386	$ 95,416
Estimated Fair Value, 12 Months or More	634,845	805,448
Estimated Fair Value, Total	936,231	900,864
Unrealized Losses, Less than 12 Months	9,375	4,933
Unrealized Losses, 12 Months or More	68,080	78,314
Unrealized Losses, Total	77,455	83,247
Residential mortgage backed securities, fair value	47,341
Subtotal, fixed maturity securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	252,118	61,144
Estimated Fair Value, 12 Months or More	613,560	759,651
Estimated Fair Value, Total	865,678	820,795
Unrealized Losses, Less than 12 Months	5,345	1,854
Unrealized Losses, 12 Months or More	63,030	71,899
Unrealized Losses, Total	68,375	73,753
U.S. Treasury securities
Fixed Maturity Securities
Estimated Fair Value, 12 Months or More	1,742	1,708
Estimated Fair Value, Total	1,742	1,708
Unrealized Losses, 12 Months or More	77	115
Unrealized Losses, Total	77	115
Obligations of states and political subdivisions
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	13,289	403
Estimated Fair Value, 12 Months or More	19,209	28,893
Estimated Fair Value, Total	32,498	29,296
Unrealized Losses, Less than 12 Months	315	17
Unrealized Losses, 12 Months or More	2,270	2,404
Unrealized Losses, Total	2,585	2,421
Residential mortgage-backed securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	94,528	11,248
Estimated Fair Value, 12 Months or More	162,260	182,794
Estimated Fair Value, Total	256,788	194,042
Unrealized Losses, Less than 12 Months	2,401	167
Unrealized Losses, 12 Months or More	24,134	21,812
Unrealized Losses, Total	26,535	21,979
Commercial mortgage-backed securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	3,050	4,067
Estimated Fair Value, 12 Months or More	121,152	130,493
Estimated Fair Value, Total	124,202	134,560
Unrealized Losses, Less than 12 Months	9	108
Unrealized Losses, 12 Months or More	10,831	14,165
Unrealized Losses, Total	10,840	14,273
Other asset-backed securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	11,298	5,973
Estimated Fair Value, 12 Months or More	22,018	46,600
Estimated Fair Value, Total	33,316	52,573
Unrealized Losses, Less than 12 Months	278	224
Unrealized Losses, 12 Months or More	1,616	2,703
Unrealized Losses, Total	1,894	2,927
Corporate and other securities
Fixed Maturity Securities
Estimated Fair Value, Less than 12 Months	129,953	39,453
Estimated Fair Value, 12 Months or More	287,179	369,163
Estimated Fair Value, Total	417,132	408,616
Unrealized Losses, Less than 12 Months	2,342	1,338
Unrealized Losses, 12 Months or More	24,102	30,700
Unrealized Losses, Total	26,444	32,038
Equity securities
Equity Securities
Estimated Fair Value, Less than 12 Months	49,268	34,272
Estimated Fair Value, 12 Months or More	21,285	45,797
Estimated Fair Value, Total	70,553	80,069
Unrealized Losses, Less than 12 Months	4,030	3,079
Unrealized Losses, 12 Months or More	5,050	6,415
Unrealized Losses, Total	$ 9,080	$ 9,494

SAFETY INSURANCE GROUP INC 10-K