Schedule I - Summary of Investments Other Than investments in Related Parties (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Schedule of Investments [Line Items]
Fixed maturities, available-for-sale, amortized cost	$ 36,980,933	$ 27,538,066
Fair Value	34,986,160	26,131,780
Equity securities, at cost	2,650,542	824,270
Equity securities, at fair value (cost: 2024 – $2,650,189; 2023 – $819,617)	2,623,820	844,950
Fixed maturities, trading, amortized cost	4,415,277	3,476,746
Fixed maturities, trading, at fair value (amortized cost: 2024 – $4,391,322; 2023 – $3,451,001)	3,845,045	2,796,446
Commercial mortgage and other loans (net of $36,002 and $36,527 allowance for credit losses at December 31, 2024 and 2023, respectively)	7,759,323	6,122,721
Policy loans	1,541,480	1,472,677
Short-term Investments	517,386
Other invested assets (includes $12,999 and $80,638 of assets measured at fair value at December 31, 2024 and 2023, respectively)	1,582,094	1,222,985
Total Investment at Cost	55,447,035
Total investment per Balance Sheet	52,855,308	38,971,925
Equity securities
Schedule of Investments [Line Items]
Equity securities, at cost	2,650,542
Equity securities, at fair value (cost: 2024 – $2,650,189; 2023 – $819,617)	2,623,820
Available-for-sale | Fixed maturities
Schedule of Investments [Line Items]
Fixed maturities, available-for-sale, amortized cost	36,980,933
Fair Value	34,986,160
Trading | Fixed maturities
Schedule of Investments [Line Items]
Fixed maturities, trading, amortized cost	4,415,277
Fixed maturities, trading, at fair value (amortized cost: 2024 – $4,391,322; 2023 – $3,451,001)	3,845,045
U.S. Treasury securities and obligations of U.S. government authorities and agencies
Schedule of Investments [Line Items]
Fixed maturities, available-for-sale, amortized cost	1,199,628	1,009,937
Fair Value	1,099,241	975,287
U.S. Treasury securities and obligations of U.S. government authorities and agencies | Fixed maturities
Schedule of Investments [Line Items]
Fair Value	1,099,241
Obligations of U.S. states and their political subdivisions
Schedule of Investments [Line Items]
Fixed maturities, available-for-sale, amortized cost	570,253	789,856
Fair Value	541,066	776,627
Obligations of U.S. states and their political subdivisions | Fixed maturities
Schedule of Investments [Line Items]
Fair Value	541,066
Foreign government securities
Schedule of Investments [Line Items]
Fixed maturities, available-for-sale, amortized cost	362,154	330,830
Fair Value	310,334	281,986
Foreign government securities | Fixed maturities
Schedule of Investments [Line Items]
Fair Value	310,334
Asset-backed securities
Schedule of Investments [Line Items]
Fixed maturities, available-for-sale, amortized cost	3,728,073	2,016,028
Fair Value	3,750,663	2,027,550
Asset-backed securities | Fixed maturities
Schedule of Investments [Line Items]
Fair Value	3,750,663
Commercial mortgage-backed securities
Schedule of Investments [Line Items]
Fixed maturities, available-for-sale, amortized cost	944,652	913,347
Fair Value	895,775	851,778
Commercial mortgage-backed securities | Fixed maturities
Schedule of Investments [Line Items]
Fair Value	895,775
Residential mortgage-backed securities
Schedule of Investments [Line Items]
Fixed maturities, available-for-sale, amortized cost	367,005	399,542
Fair Value	356,072	396,070
Residential mortgage-backed securities | Fixed maturities
Schedule of Investments [Line Items]
Fair Value	356,072
Public utilities | Available-for-sale | Fixed maturities
Schedule of Investments [Line Items]
Fixed maturities, available-for-sale, amortized cost	2,869,299
Fair Value	2,613,495
All other corporate bonds | Available-for-sale | Fixed maturities
Schedule of Investments [Line Items]
Fixed maturities, available-for-sale, amortized cost	26,934,775
Fair Value	25,414,259
Redeemable preferred stock | Available-for-sale | Fixed maturities
Schedule of Investments [Line Items]
Fixed maturities, available-for-sale, amortized cost	5,094
Fair Value	5,255
Other common stocks | Equity securities
Schedule of Investments [Line Items]
Equity securities, at cost	2,452,942
Equity securities, at fair value (cost: 2024 – $2,650,189; 2023 – $819,617)	2,427,792
Mutual funds | Equity securities
Schedule of Investments [Line Items]
Equity securities, at cost	177,939
Equity securities, at fair value (cost: 2024 – $2,650,189; 2023 – $819,617)	175,882
Perpetual preferred stocks | Equity securities
Schedule of Investments [Line Items]
Equity securities, at cost	19,661
Equity securities, at fair value (cost: 2024 – $2,650,189; 2023 – $819,617)	20,146
Total Net Commercial Mortgage and Other Loans
Schedule of Investments [Line Items]
Commercial mortgage and other loans (net of $36,002 and $36,527 allowance for credit losses at December 31, 2024 and 2023, respectively)	$ 7,759,323	$ 6,122,721