Policyholders' Liabilities (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period	[1]	$ 41,912,536
Transfer to (from) Policyholder Account Balance (to) from Separate Account		1,119,645	$ 371,965
Unearned revenue reserve		3,568,084	2,896,790
Other		102,815	98,896
Policyholder Account Balance, Total		$ 49,662,070	$ 40,752,545
Weighted-average crediting rate		2.15%	2.23%
Net amount at risk		$ 318,075,717	$ 300,034,197
Cash surrender value		40,991,161	32,097,177
Total
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period		38,744,221	33,233,826
Deposits		6,784,777	5,720,165
Interest credited		684,459	594,442
Policy charges		(1,379,610)	(1,349,471)
Surrenders and withdrawals		(1,093,317)	(824,869)
Benefit payments		(121,799)	(173,243)
Transfer to (from) Policyholder Account Balance (to) from Separate Account		1,119,645	371,965
Change in market value and other adjustments		1,252,795	184,044
Balance, end of period		45,991,171	37,756,859
Reinsurance and other recoverable		13,377,274	13,302,850
Policyholders' account balance net of reinsurance and other recoverables		32,613,897	24,454,009
Policyholder Account Balance, Total
Variable Annuities
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period		16,432,032	11,465,411
Deposits		3,439,562	3,742,495
Interest credited		194,853	120,516
Policy charges		(16,564)	(2,343)
Surrenders and withdrawals		(351,475)	(182,878)
Benefit payments		(22,285)	(28,907)
Transfer to (from) Policyholder Account Balance (to) from Separate Account		4,467	201,039
Change in market value and other adjustments		1,095,144	559,351
Balance, end of period		20,775,734	15,874,684
Reinsurance and other recoverable		495,506	328,079
Policyholders' account balance net of reinsurance and other recoverables		20,280,228	15,546,605
Policyholder Account Balance, Total		$ 3,004,628	$ 3,314,888
Weighted-average crediting rate		1.40%	1.18%
Net amount at risk		$ 0	$ 0
Cash surrender value		17,981,713	12,395,474
Variable/Universal Life
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period		18,736,365	18,762,548
Deposits		1,543,230	1,624,685
Interest credited		415,843	435,694
Policy charges		(1,357,363)	(1,343,735)
Surrenders and withdrawals		(579,913)	(597,867)
Benefit payments		(62,055)	(76,017)
Transfer to (from) Policyholder Account Balance (to) from Separate Account		1,115,178	170,926
Change in market value and other adjustments		76,107	(278,141)
Balance, end of period		19,887,392	18,698,093
Reinsurance and other recoverable		12,859,492	12,970,107
Policyholders' account balance net of reinsurance and other recoverables		7,027,900	5,727,986
Policyholder Account Balance, Total		$ 17,508,112	$ 16,620,170
Weighted-average crediting rate		2.87%	3.10%
Net amount at risk		$ 318,075,705	$ 300,033,962
Cash surrender value		18,517,769	17,084,598
Variable Life
Additional Liability, Long-Duration Insurance [Roll Forward]
Transfer to (from) Policyholder Account Balance (to) from Separate Account		1,115,178	170,926
Fixed Annuities
Additional Liability, Long-Duration Insurance [Roll Forward]
Balance, beginning of period		3,575,824	3,005,867
Deposits		1,801,985	352,985
Interest credited		73,763	38,232
Policy charges		(5,683)	(3,393)
Surrenders and withdrawals		(161,929)	(44,124)
Benefit payments		(37,459)	(68,319)
Transfer to (from) Policyholder Account Balance (to) from Separate Account		0	0
Change in market value and other adjustments		81,544	(97,166)
Balance, end of period		5,328,045	3,184,082
Reinsurance and other recoverable		22,276	4,664
Policyholders' account balance net of reinsurance and other recoverables		5,305,769	3,179,418
Policyholder Account Balance, Total		$ 2,025,288	$ 1,015,314
Weighted-average crediting rate		2.21%	1.65%
Net amount at risk		$ 12	$ 235
Cash surrender value		4,491,679	$ 2,617,105
Policy loans | Variable Life
Additional Liability, Long-Duration Insurance [Roll Forward]
Transfer to (from) Policyholder Account Balance (to) from Separate Account		$ 900,000

[1] Prior period amounts adjusted for the implementation of Accounting Standard Update ("ASU") 2018-12: Targeted Improvements to the Accounting for Long-Duration Contracts.