Investments - AFS Securities with Cost Basis in Excess of Fair Value - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale fixed-maturities with cost basis in excess of fair values, cost basis	$ 2,406,500,000	$ 2,713,800,000
Allowance for credit losses	0	0	$ 816,000
Available-for-sale credit (gains) losses	$ 2,200,000		$ 800,000
Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale credit (gains) losses		$ 100,000