Investments (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Schedule of Investments [Line Items]
Fixed Maturity Purchased with Credit Deterioration	$ 0	$ 0
Accrued Investment Income Write Down	0	0
Securities sold under agreements to repurchase	$ 0	$ 0
Commercial mortgage loans, Percentage	100.00%	100.00%
Write-downs charged against allowance	$ 9,367,000
Loans on non-accrual status recognized in interest income	700,000	$ 0.0
Loans on non-accrual status, do not have allowance for credit losses	2,000,000.0	1,300,000
Loans acquired	12,600,000	0.0
Loans sold	0	0
Commercial mortgage and other loans purchased with credit deterioration	0	0
Fixed maturities, available-for-sale, at fair value (allowance for credit losses: 2024 – $40,414; 2023 – $2,004) (amortized cost: 2024 – $33,648,311; 2023 – $24,872,031)	34,986,160,000	26,131,780,000
Fixed maturities, trading, at fair value (amortized cost: 2024 – $4,391,322; 2023 – $3,451,001)	3,845,045,000	2,796,446,000
Fair value of collateral that could be sold or repledged	0	25,000,000
Assets Deposited With Governmental Authorities	3,600,000	3,600,000
Gross Unrealized Losses	2,160,856,000	1,739,561,000
Twelve Months or More, Gross Unrealized Losses	$ 1,893,641,000	1,699,993,000
Commercial mortgage Loans | Extended Maturity
Schedule of Investments [Line Items]
Financing Receivable, Modified, Weighted Average Term Increase from Modification	1 year
Carrying value of non-income producing assets
Schedule of Investments [Line Items]
Fixed maturities, available-for-sale, at fair value (allowance for credit losses: 2024 – $40,414; 2023 – $2,004) (amortized cost: 2024 – $33,648,311; 2023 – $24,872,031)	$ 55,300,000
Fixed maturities, trading, at fair value (amortized cost: 2024 – $4,391,322; 2023 – $3,451,001)	900,000
Fixed maturities | Trading
Schedule of Investments [Line Items]
Fixed maturities, trading, at fair value (amortized cost: 2024 – $4,391,322; 2023 – $3,451,001)	3,845,045,000
NAIC high or highest quality rating | Fixed maturities
Schedule of Investments [Line Items]
Gross Unrealized Losses	2,059,000,000	1,634,000,000
NAIC other than high or highest quality rating | Fixed maturities
Schedule of Investments [Line Items]
Gross Unrealized Losses	$ 102,000,000	106,000,000
California
Schedule of Investments [Line Items]
Commercial mortgage loans, Percentage	25.00%
Florida
Schedule of Investments [Line Items]
Commercial mortgage loans, Percentage	9.00%
Texas
Schedule of Investments [Line Items]
Commercial mortgage loans, Percentage	8.00%
Europe
Schedule of Investments [Line Items]
Commercial mortgage loans, Percentage	8.00%
Mexico
Schedule of Investments [Line Items]
Commercial mortgage loans, Percentage	1.00%
Australia
Schedule of Investments [Line Items]
Commercial mortgage loans, Percentage	1.00%
Other Income | Fixed maturities | Trading
Schedule of Investments [Line Items]
Unrealized Gain (Loss) on Investments	$ (182,900,000)	65,600,000	$ (728,600,000)
Other Income | Equity securities
Schedule of Investments [Line Items]
Unrealized Gain (Loss) on Investments	(34,200,000)	25,800,000	$ (10,200,000)
Fixed maturities
Schedule of Investments [Line Items]
Twelve Months or More, Gross Unrealized Losses	$ 1,894,000,000	$ 1,700,000,000