Market Risk Benefits - Market Risk Benefits In Asset and Liability Positions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024	Dec. 31, 2023
Liability for Future Policy Benefit, Activity [Line Items]
Total market risk benefit assets	$ 2,508,967	$ 2,537,000	$ 2,637,363
Total market risk benefit liabilities	4,803,284	4,388,000	4,281,244
Variable Annuities
Liability for Future Policy Benefit, Activity [Line Items]
Net amount at risk	$ 9,113,461	$ 8,350,431
Weighted-average attained age of contractholders	71 years	70 years
Direct and assumed	$ 1,255,404	$ 1,472,957
Ceded	1,253,563	1,063,886
Total market risk benefit assets	2,508,967	2,536,843
Direct and assumed	4,549,121	4,088,679
Ceded	254,163	299,638
Total market risk benefit liabilities	4,803,284	4,388,317
Net liability	$ 2,294,317	$ 1,851,474	2,488,463	$ 3,707,407
Total, Net of Reinsurance
Liability for Future Policy Benefit, Activity [Line Items]
Net liability			$ 1,643,881	$ 2,789,615