Fair Value of Assets and Liabilities (Balances of Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	$ 14,438,956	$ 13,278,166
Fixed maturities, trading	1,814,999	3,302,392
Equity securities	229,268	111,267
Other invested assets	964,752	1,209,925
Other assets	986,295	1,140,948
Reinsurance recoverables	38,809,510	38,598,767
Receivables from parent and affiliates	197,904	278,131
Separate account assets	118,792,119	149,797,828
TOTAL ASSETS	190,435,117	221,661,364
Future policy benefits	24,112,142	27,927,029
Payables to parent and affiliates	72,102	31,775
Other Liabilities	3,203,069	2,264,477
Total liabilities	185,670,939	215,706,270
Future policy benefits
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative, Net Liability	5,707,000	9,048,000
Embedded Derivative, Fair Value of Embedded Derivative Gross Asset	714,000	610,000
Embedded Derivative, Fair Value of Embedded Derivative Gross Liability	6,421,000	9,658,000
Other Liabilities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative, Net Liability	24,000	13,000
Fair Value, Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	14,438,956	13,278,166
Fixed maturities, trading	1,814,999	3,302,392
Equity securities	229,268	111,267
Short-term Investments	141,881	145,437
Cash equivalents	917,443	436,632
Other invested assets	37,766	268,525
Other assets	75,858	72,937
Reinsurance recoverables	555,053	931,207
Receivables from parent and affiliates	150,946	162,045
Subtotal excluding separate account assets	18,362,170	18,708,608
Separate account assets	113,660,077	144,111,658
TOTAL ASSETS	132,022,247	162,820,266
Future policy benefits	5,706,968	9,047,956
Policyholders’ account balances	3,427,667	3,245,773
Payables to parent and affiliates	43,306	0
Other Liabilities	8,249	18,525
Total liabilities	9,186,190	12,312,254
Asset Netting	(7,317,530)	(6,818,009)
Liability Netting	(14,428,241)	(12,568,082)
Netting	(7,111,000)	(5,750,000)
Fair Value, Measurements, Recurring | Other invested assets
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Asset Netting	(7,317,530)	(6,818,009)
Fair Value, Measurements, Recurring | Payables to parent and affiliates
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liability Netting	(14,424,444)	(12,563,253)
Fair Value, Measurements, Recurring | Other Liabilities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liability Netting	(3,797)	(4,829)
Fair Value, Measurements, Recurring | U.S. Treasury securities and obligations of U.S. government authorities and agencies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	593,874	333,940
Fair Value, Measurements, Recurring | Obligations of U.S. states and their political subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	554,010	630,521
Fair Value, Measurements, Recurring | Foreign government bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	268,444	350,471
Fair Value, Measurements, Recurring | U.S. corporate public securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	5,328,017	5,131,872
Fair Value, Measurements, Recurring | U.S. corporate private securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	2,285,723	2,004,875
Fair Value, Measurements, Recurring | Foreign corporate public securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	1,089,063	929,902
Fair Value, Measurements, Recurring | Foreign corporate private securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	2,634,683	2,753,911
Fair Value, Measurements, Recurring | Asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	894,553	547,310
Fair Value, Measurements, Recurring | Commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	694,688	575,184
Fair Value, Measurements, Recurring | Residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	95,901	20,180
Fair Value, Measurements, Recurring | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fixed maturities, trading	0	0
Equity securities	184,148	58,160
Short-term Investments	0	9,997
Cash equivalents	0	13,999
Other invested assets	36,359	246,097
Other assets	0	0
Reinsurance recoverables	0	0
Receivables from parent and affiliates	0	0
Subtotal excluding separate account assets	220,507	328,253
Separate account assets	68,279	52,100
TOTAL ASSETS	288,786	380,353
Future policy benefits	0	0
Policyholders’ account balances	0	0
Payables to parent and affiliates	0	0
Other Liabilities	36,235	10,730
Total liabilities	36,235	10,730
Fair Value, Measurements, Recurring | Level 1 | U.S. Treasury securities and obligations of U.S. government authorities and agencies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 1 | Obligations of U.S. states and their political subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 1 | Foreign government bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. corporate public securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 1 | U.S. corporate private securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 1 | Foreign corporate public securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 1 | Foreign corporate private securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 1 | Asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 1 | Commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 1 | Residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	13,997,655	12,718,438
Fixed maturities, trading	1,814,999	3,302,392
Equity securities	15,337	40,635
Short-term Investments	139,109	135,440
Cash equivalents	917,443	422,633
Other invested assets	7,318,937	6,840,437
Other assets	0	0
Reinsurance recoverables	0	0
Receivables from parent and affiliates	150,946	162,045
Subtotal excluding separate account assets	24,354,426	23,622,020
Separate account assets	113,591,798	144,059,558
TOTAL ASSETS	137,946,224	167,681,578
Future policy benefits	0	0
Policyholders’ account balances	0	0
Payables to parent and affiliates	14,467,750	12,563,253
Other Liabilities	(24,189)	12,624
Total liabilities	14,443,561	12,575,877
Fair Value, Measurements, Recurring | Level 2 | U.S. Treasury securities and obligations of U.S. government authorities and agencies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	593,874	333,940
Fair Value, Measurements, Recurring | Level 2 | Obligations of U.S. states and their political subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	554,010	630,521
Fair Value, Measurements, Recurring | Level 2 | Foreign government bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	268,309	350,321
Fair Value, Measurements, Recurring | Level 2 | U.S. corporate public securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	5,328,017	5,131,872
Fair Value, Measurements, Recurring | Level 2 | U.S. corporate private securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	2,112,731	1,873,370
Fair Value, Measurements, Recurring | Level 2 | Foreign corporate public securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	1,081,970	921,008
Fair Value, Measurements, Recurring | Level 2 | Foreign corporate private securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	2,496,890	2,508,676
Fair Value, Measurements, Recurring | Level 2 | Asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	860,209	484,861
Fair Value, Measurements, Recurring | Level 2 | Commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	605,744	463,689
Fair Value, Measurements, Recurring | Level 2 | Residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	95,901	20,180
Fair Value, Measurements, Recurring | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	441,301	559,728
Fixed maturities, trading	0	0
Equity securities	29,783	12,472
Short-term Investments	2,772	0
Cash equivalents	0	0
Other invested assets	0	0
Other assets	75,858	72,937
Reinsurance recoverables	555,053	931,207
Receivables from parent and affiliates	0	0
Subtotal excluding separate account assets	1,104,767	1,576,344
Separate account assets	0	0
TOTAL ASSETS	1,104,767	1,576,344
Future policy benefits	5,706,968	9,047,956
Policyholders’ account balances	3,427,667	3,245,773
Payables to parent and affiliates	0	0
Other Liabilities	0	0
Total liabilities	9,134,635	12,293,729
Fair Value, Measurements, Recurring | Level 3 | U.S. Treasury securities and obligations of U.S. government authorities and agencies
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 3 | Obligations of U.S. states and their political subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 3 | Foreign government bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	135	150
Fair Value, Measurements, Recurring | Level 3 | U.S. corporate public securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Fair Value, Measurements, Recurring | Level 3 | U.S. corporate private securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	172,992	131,505
Fair Value, Measurements, Recurring | Level 3 | Foreign corporate public securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	7,093	8,894
Fair Value, Measurements, Recurring | Level 3 | Foreign corporate private securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	137,793	245,235
Fair Value, Measurements, Recurring | Level 3 | Asset-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	34,344	62,449
Fair Value, Measurements, Recurring | Level 3 | Commercial mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	88,944	111,495
Fair Value, Measurements, Recurring | Level 3 | Residential mortgage-backed securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fixed maturities, available-for-sale	0	0
Other invested assets
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value investment measured at NAV per share	76,000	79,000
Separate Account Assets
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value investment measured at NAV per share	$ 5,132,000	$ 5,686,000