Fair Value of Assets and Liabilities (Changes in Level 3 Assets and Liabilities) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	$ 29,783	$ 8,005	$ 12,472	$ 7,889
Purchases	0	0	10,000	0
Sales	0	0	(230)	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Other	0	3,874	9,661	3,874
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	28,672	12,356	28,672	12,356
Total gains (losses) (realized/unrealized):
Included in earnings	(1,111)	477	(3,231)	593
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(1,110)	477	(3,249)	593
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)	477	(3,231)	593
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(1,110)	477	(3,249)	593
Equity securities | Interest credited to policyholders’ account balances
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 | 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	2,772	0	0	0
Purchases	0	0	2,766	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	(5,876)	0	(5,930)	0
Other	7,290	1,690	7,290	1,690
Transfers into Level 3	0	0	55	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	4,188	1,690	4,188	1,690
Total gains (losses) (realized/unrealized):
Included in earnings	2	0	7	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 | Interest credited to policyholders’ account balances
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	2	0	7	0
Other assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	75,858	0	72,937	0
Purchases	(24,914)	0	(23,673)	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	(104)	0	(2,761)	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	107,435	0	107,435	0
Total gains (losses) (realized/unrealized):
Included in earnings	56,595	0	60,932	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	56,700	0	63,692	0
Other assets | Realized investment gains (losses), net
Total gains (losses) (realized/unrealized):
Included in earnings	56,595	0	60,932	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	56,700	0	63,692	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 | Interest credited to policyholders’ account balances
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
Cash equivalents
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Other	0	1,230	0	1,230
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Fair Value, end of period	0	1,230	0	1,230
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
Cash equivalents | 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
Cash equivalents | 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
Cash equivalents | Interest credited to policyholders’ account balances
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
Cash equivalents | 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
Cash equivalents | 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	555,053	9,275,523	931,207	13,239,539
Purchases	33,413	36,892	102,753	592,758
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	475,186	939,489	475,186	939,489
Total gains (losses) (realized/unrealized):
Included in earnings	(113,280)	(8,372,926)	(558,774)	(12,892,808)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(109,508)	(32,262)	(535,503)	(524,521)
Reinsurance recoverables | Realized investment gains (losses), net
Total gains (losses) (realized/unrealized):
Included in earnings	(113,280)	(8,372,926)	(558,774)	(12,892,808)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(109,508)	(32,262)	(535,503)	(524,521)
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 | Interest credited to policyholders’ account balances
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
Separate account assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	0	0	0	0
Purchases	7,000	0	7,000	0
Sales	(3,000)	0	(3,000)	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	3,954	0	3,954	0
Total gains (losses) (realized/unrealized):
Included in earnings	(46)	0	(46)	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(46)	0	(46)	0
Separate account assets | 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
Separate account 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
Separate account assets | Interest credited to policyholders’ account balances
Total gains (losses) (realized/unrealized):
Included in earnings	(46)	0	(46)	0
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(46)	0	(46)	0
Separate account 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
Separate account assets | 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	(5,706,968)	(9,263,516)	(9,047,956)	(13,227,814)
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	(248,054)	(276,639)	(763,606)	(828,542)
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	(4,945,400)	(9,208,188)	(4,945,400)	(9,208,188)
Total gains (losses) (realized/unrealized):
Included in earnings	1,009,622	331,967	4,866,162	4,848,168
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	975,995	218,025	4,655,099	4,365,984
Future policy benefits | Realized investment gains (losses), net
Total gains (losses) (realized/unrealized):
Included in earnings	1,009,622	331,967	4,866,162	4,848,168
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	975,995	218,025	4,655,099	4,365,984
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 | Interest credited to policyholders’ account balances
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	(3,427,667)	(1,156,610)	(3,245,773)	(1,155,274)
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	(3,202)	0	0
Settlements	(433,009)	0	(824,375)	32,129
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	(3,642,839)	(1,154,423)	(3,642,839)	(1,154,423)
Total gains (losses) (realized/unrealized):
Included in earnings	217,837	5,389	188,287	(31,278)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	843,341	21,559	1,272,540	21,234
Policyholders' account balances | Realized investment gains (losses), net
Total gains (losses) (realized/unrealized):
Included in earnings	217,837	5,389	188,287	(31,278)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	843,341	21,559	1,272,540	21,234
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 | Interest credited to policyholders’ account balances
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	307	(1,656)	(16,505)	152
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	491	(1,678)	(13,988)	121
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 | Interest credited to policyholders’ account balances
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	(9,226)	(5,768)	(64,307)	(14,678)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(9,811)	(5,486)	(64,768)	(14,407)
Available-for-sale | Fixed maturities | Net investment income
Total gains (losses) (realized/unrealized):
Included in earnings	(1,272)	185	(942)	235
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	135	156	150	163
Purchases	501	0	501	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	724	152	724	152
Total gains (losses) (realized/unrealized):
Included in earnings	88	(4)	73	(11)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	86	(5)	71	(13)
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	317,878	170,830	385,634	174,776
Purchases	66,826	3,173	200,137	5,515
Sales	(11,975)	0	(24,363)	0
Issuances	0	0	0	0
Settlements	(54,455)	(7,907)	(87,790)	(12,280)
Other	106,408	119,218	106,408	119,218
Transfers into Level 3	6,259	4,106	6,259	9,223
Transfers out of Level 3	0	0	(106,124)	0
Fair Value, end of period	423,565	282,637	423,565	282,637
Total gains (losses) (realized/unrealized):
Included in earnings	(7,376)	(6,783)	(56,596)	(13,815)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(6,546)	(6,710)	(53,687)	(13,811)
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	123,288	27,179	173,944	2,065
Purchases	28,250	12,500	61,740	38,450
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	(403)	(308)	(1,476)	(1,131)
Other	0	19,859	0	19,859
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	(33,490)	(25,450)	(94,235)	(25,450)
Fair Value, end of period	114,742	33,328	114,742	33,328
Total gains (losses) (realized/unrealized):
Included in earnings	(2,903)	(452)	(25,231)	(465)
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	(2,860)	(449)	(25,140)	(462)
Trading | Fixed maturities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair Value, beginning of period	0	801	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	(801)	0	(801)
Fair Value, end of period	0	0	0	0
Total gains (losses) (realized/unrealized):
Included in earnings	0	0	0	46
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	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	0	0	46
Unrealized gains (losses) for assets/liabilities still held:
Included in earnings	0	0	0	46
Trading | Fixed maturities | Interest credited to policyholders’ account balances
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 | 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