New Accounting Standards - Schedule of Balance Sheets (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Jan. 01, 2021	Dec. 31, 2020
Assets:
Other receivables	$ 601,787	$ 589,079
Deferred acquisition costs	5,778,732	5,535,697	$ 5,306,420	$ 4,587,547	$ 4,595,444
Liabilities:
Future policy benefits at current discount rates: (at original rates: 2023—$16,598,663; 2022—$16,306,870)	18,746,514	18,040,042
Unearned and advance premium	266,710	253,140		243,369	61,728
Policy claims and other benefits payable	510,929	507,219		$ 473,524	$ 399,507
Accrued Income Taxes	404,480	434,649
Shareholders' equity:
Accumulated other comprehensive income	(2,943,897)	(2,790,313)
Retained earnings	$ 7,285,809	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—$16,598,663; 2022—$16,306,870)		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		104,192
Deferred acquisition costs		285,790
Liabilities:
Future policy benefits at current discount rates: (at original rates: 2023—$16,598,663; 2022—$16,306,870)		1,318,196
Unearned and advance premium		192,398
Policy claims and other benefits payable		77,192
Accrued Income Taxes		(251,523)
Shareholders' equity:
Accumulated other comprehensive income		(1,374,599)
Retained earnings		$ 428,315