Investments - Unrealized Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Amortized Cost
Total Amortized Cost	$ 2,509,253	$ 1,801,109
Fair value
Total Fair Value	2,353,044	1,660,674
Unrealized Loss
Total Unrealized Loss	$ (156,209)	$ (140,435)
Percent to Total	100.00%
NAIC Rating 1 | AAA/AA/A | Aaa/Aa/A
Amortized Cost
Total Amortized Cost	$ 1,987,281
Fair value
Total Fair Value	1,850,834
Unrealized Loss
Total Unrealized Loss	$ (136,447)
Percent to Total	87.30%
NAIC Rating 2 | BBB | Baa
Amortized Cost
Total Amortized Cost	$ 423,761
Fair value
Total Fair Value	407,998
Unrealized Loss
Total Unrealized Loss	$ (15,763)
Percent to Total	10.10%
NAIC Rating 3 | BB | Ba
Amortized Cost
Total Amortized Cost	$ 50,929
Fair value
Total Fair Value	49,650
Unrealized Loss
Total Unrealized Loss	$ (1,279)
Percent to Total	0.80%
NAIC Rating 4 | B | B
Amortized Cost
Total Amortized Cost	$ 43,657
Fair value
Total Fair Value	41,522
Unrealized Loss
Total Unrealized Loss	$ (2,135)
Percent to Total	1.40%
NAIC Rating 5 | CCC | Caa
Amortized Cost
Total Amortized Cost	$ 3,625
Fair value
Total Fair Value	3,040
Unrealized Loss
Total Unrealized Loss	$ (585)
Percent to Total	0.40%
NAIC Rating 6 | CC Or Lower | Ca or lower
Unrealized Loss
Percent to Total	0.00%