Significant Accounting Policies - Schedule of Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2021	Dec. 31, 2020
Assets:
Other receivables	$ 630,223	$ 589,171
Deferred acquisition costs	6,009,477	5,535,697	$ 5,067,539	$ 4,587,547
Liabilities:
Future policy benefits at current discount rates: (at original rates: 2023—$16,984,615; 2022—$16,355,726)		18,097,341
Unearned and advance premium	254,567	253,360		243,612	$ 61,971
Policy claims and other benefits payable	514,875	509,356		$ 476,710	$ 402,693
Accrued Income Taxes	494,639	434,649
Shareholders' equity:
Accumulated other comprehensive income	(2,772,419)	(2,790,313)
Retained earnings	$ 7,478,813	6,894,535
As Previously Reported
Assets:
Other receivables		484,887
Deferred acquisition costs		5,249,907
Liabilities:
Future policy benefits at current discount rates: (at original rates: 2023—$16,984,615; 2022—$16,355,726)		16,721,846
Unearned and advance premium		60,742
Policy claims and other benefits payable		430,027
Accrued Income Taxes		686,172
Shareholders' equity:
Accumulated other comprehensive income		(1,415,714)
Retained earnings		6,466,220
Adoption Impact
Assets:
Other receivables		104,284
Deferred acquisition costs		285,790
Liabilities:
Future policy benefits at current discount rates: (at original rates: 2023—$16,984,615; 2022—$16,355,726)		1,375,495
Unearned and advance premium		192,618
Policy claims and other benefits payable		79,329
Accrued Income Taxes		(251,523)
Shareholders' equity:
Accumulated other comprehensive income		(1,374,599)
Retained earnings		$ 428,315