Fair Value of Assets and Liabilities (Changes in Level 3 Assets and Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	$ 11,463	$ 7,678	$ 12,472	$ 7,889
Purchases	10,000	0	10,000	0
Sales	(230)	0	(230)	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Other	9,661	0	9,661	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	29,783	8,005	29,783	8,005
Total gains (losses) (realized/unrealized):
Included in earnings	(1,111)	327	(2,120)	116
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(1,129)	327	(2,138)	116
Equity securities | Realized investment gains (losses), net
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Equity securities | Other income
Total gains (losses) (realized/unrealized):
Included in earnings	(1,111)	327	(2,120)	116
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(1,129)	327	(2,138)	116
Equity securities | Included in other comprehensive income (loss)
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Equity securities | Net investment income
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Short-term investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	0	0	0	0
Purchases	2,766	0	2,766	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	(54)	0	(54)	0
Other	0	0	0	0
Transfers into Level 3	55	0	55	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	2,772	0	2,772	0
Total gains (losses) (realized/unrealized):
Included in earnings	5	0	5	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Short-term investments | Realized investment gains (losses), net
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Short-term investments | Other income
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Short-term investments | Included in other comprehensive income (loss)
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Short-term investments | Net investment income
Total gains (losses) (realized/unrealized):
Included in earnings	5	0	5	0
Other assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	75,201	0	72,937	0
Purchases	(6,574)	0	1,241	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	(819)	0	(2,657)	0
Other	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	75,858	0	75,858	0
Total gains (losses) (realized/unrealized):
Included in earnings	8,050	0	4,337	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	7,231	0	1,679	0
Other assets | Realized investment gains (losses), net
Total gains (losses) (realized/unrealized):
Included in earnings	8,050	0	4,337	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	7,231	0	1,679	0
Other assets | Other income
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Other assets | Included in other comprehensive income (loss)
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Other assets | Net investment income
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Reinsurance recoverables
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	700,700	7,447,863	931,207	13,239,539
Purchases	34,038	277,633	69,340	555,866
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Other	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	555,053	9,275,523	555,053	9,275,523
Total gains (losses) (realized/unrealized):
Included in earnings	(179,685)	1,550,027	(445,494)	(4,519,882)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(174,545)	1,638,970	(430,193)	(4,201,349)
Reinsurance recoverables | Realized investment gains (losses), net
Total gains (losses) (realized/unrealized):
Included in earnings	(179,685)	1,550,027	(445,494)	(4,519,882)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(174,545)	1,638,970	(430,193)	(4,201,349)
Reinsurance recoverables | Other income
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Reinsurance recoverables | Included in other comprehensive income (loss)
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Reinsurance recoverables | Net investment income
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Future policy benefits
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	(6,964,587)	(7,435,081)	(9,047,956)	(13,227,814)
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	(252,534)	(275,654)	(515,552)	(551,903)
Settlements	0	0	0	0
Other	0	0	0	0
Transfers Into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	(5,706,968)	(9,263,516)	(5,706,968)	(9,263,516)
Total gains (losses) (realized/unrealized):
Included in earnings	1,510,153	(1,552,781)	3,856,540	4,516,201
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	1,460,746	(1,640,666)	3,702,735	4,197,669
Future policy benefits | Realized investment gains (losses), net
Total gains (losses) (realized/unrealized):
Included in earnings	1,510,153	(1,552,781)	3,856,540	4,516,201
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	1,460,746	(1,640,666)	3,702,735	4,197,669
Future policy benefits | Other income
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Future policy benefits | Included in other comprehensive income (loss)
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Future policy benefits | Net investment income
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Policyholders' account balances
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	(3,260,195)	(1,031,525)	(3,245,773)	(1,155,274)
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	(238,575)	21,839	(391,366)	35,331
Other	0	0	239,022	0
Transfers Into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	(3,427,667)	(1,156,610)	(3,427,667)	(1,156,610)
Total gains (losses) (realized/unrealized):
Included in earnings	71,103	(146,924)	(29,550)	(36,667)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(341,035)	(128,815)	(492,251)	(325)
Policyholders' account balances | Realized investment gains (losses), net
Total gains (losses) (realized/unrealized):
Included in earnings	71,103	(146,924)	(29,550)	(36,667)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(341,035)	(128,815)	(492,251)	(325)
Policyholders' account balances | Other income
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Policyholders' account balances | Included in other comprehensive income (loss)
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Policyholders' account balances | Net investment income
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Available-for-sale | Fixed maturities | Realized investment gains (losses), net
Total gains (losses) (realized/unrealized):
Included in earnings	(1,909)	2,316	(16,812)	1,808
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	631	2,300	(14,380)	1,799
Available-for-sale | Fixed maturities | Other income
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Available-for-sale | Fixed maturities | Included in other comprehensive income (loss)
Total gains (losses) (realized/unrealized):
Included in earnings	(21,240)	2,708	(55,081)	(8,910)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(21,518)	2,700	(54,957)	(8,921)
Available-for-sale | Fixed maturities | Net investment income
Total gains (losses) (realized/unrealized):
Included in earnings	(53)	27	330	50
Available-for-sale | Fixed maturities | US government
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	0	55,000	0	55,000
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Other	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	0	55,000	0	55,000
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Available-for-sale | Fixed maturities | Foreign government bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	140	157	150	163
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Other	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	135	156	135	156
Total gains (losses) (realized/unrealized):
Included in earnings	(5)	(1)	(15)	(7)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(5)	(1)	(15)	(8)
Available-for-sale | Fixed maturities | Corporate securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	385,358	165,491	385,634	174,776
Purchases	83,901	23	133,311	2,342
Sales	(11,217)	0	(12,388)	0
Issuances	0	0	0	0
Settlements	(21,195)	(2,208)	(33,335)	(4,373)
Other	0	0	0	0
Transfers into Level 3	0	2,474	0	5,117
Transfers out of Level 3	(106,124)	0	(106,124)	0
Fair Value, end of period	317,878	170,830	317,878	170,830
Total gains (losses) (realized/unrealized):
Included in earnings	(12,845)	5,050	(49,220)	(7,032)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(10,577)	5,000	(47,042)	(7,101)
Available-for-sale | Fixed maturities | Structured securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	112,116	2,134	173,944	2,065
Purchases	33,490	25,450	33,490	25,950
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	(571)	(407)	(1,073)	(823)
Other	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	(11,395)	0	(60,745)	0
Fair Value, end of period	123,288	27,179	123,288	27,179
Total gains (losses) (realized/unrealized):
Included in earnings	(10,352)	2	(22,328)	(13)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(10,305)	1	(22,280)	(13)
Trading | Fixed maturities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	0	767	0	755
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Other	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	0	801	0	801
Total gains (losses) (realized/unrealized):
Included in earnings	0	34	0	46
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	33	0	46
Trading | Fixed maturities | Realized investment gains (losses), net
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Trading | Fixed maturities | Other income
Total gains (losses) (realized/unrealized):
Included in earnings	0	34	0	46
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	33	0	46
Trading | Fixed maturities | Included in other comprehensive income (loss)
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	0
Trading | Fixed maturities | Net investment income
Total gains (losses) (realized/unrealized):
Included in earnings	$ 0	$ 0	$ 0	$ 0