Market Risk Benefits - Market Risk Benefits In Asset and Liability Positions (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Liability for Future Policy Benefit, Activity [Line Items]
Direct and assumed	$ 1,269,533	$ 1,419,114
Ceded	1,264,807	1,131,050
Total market risk benefit assets	2,534,340	2,550,164	$ 2,637,363
Direct and assumed	4,422,992	4,085,018
Ceded	245,500	285,942
Total market risk benefit liabilities	4,668,492	4,370,960	4,281,244
Net liability	2,134,152	1,820,796
Variable Annuities
Liability for Future Policy Benefit, Activity [Line Items]
Net amount at risk	$ 8,238,438	$ 8,732,024
Weighted-average attained age of contractholders	72 years	71 years
Direct and assumed	$ 1,268,242	$ 1,419,114
Ceded	1,264,807	1,131,050
Total market risk benefit assets	2,533,049	2,550,164
Direct and assumed	4,259,146	4,085,018
Ceded	245,500	285,942
Total market risk benefit liabilities	4,504,646	4,370,960
Net liability	1,971,597	1,820,796	$ 2,488,463	$ 3,707,407
Fixed Annuities
Liability for Future Policy Benefit, Activity [Line Items]
Net amount at risk	$ 400,810
Weighted-average attained age of contractholders	67 years
Direct and assumed	$ 1,291	0
Ceded	0	0
Total market risk benefit assets	1,291	0
Direct and assumed	163,846	0
Ceded	0	0
Total market risk benefit liabilities	163,846	0
Net liability	$ 162,555	$ 0