Fair Values of Financial Instruments (Reconciliation of Beginning and Ending Balances of Level 3 Assets and Liabilities) (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Funds withheld liability - embedded derivative
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	$ (441,864)	$ 0
Transfers in	0	0
Change in fair value, net	64,380	0
Ending balance	(377,484)	0
Fixed index annuities - embedded derivatives
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	4,820,845	7,964,961
Premiums less benefits	(121,181)	114,077
Change in fair value, net	205,469	(1,308,123)
Ending balance	4,905,133	6,770,915
Other investments
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	0	6,349
Transfers in	0	0
Transfers out	0	0
Included in net income	0	(2,482)
Included in other comprehensive income (loss)	0	0
Ending balance	0	3,867
Real estate investments
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	940,559	337,939
Purchases and sales, net	120,908	109,835
Included in net income	(7,836)	4,161
Ending balance	1,053,631	451,935
Equity Method Investments
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	64,209	0
Purchases and sales, net	94,137	58,253
Included in net income	5,981	0
Ending balance	164,327	58,253
Fixed maturity securities, available for sale - States, municipalities and territories
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	402,348	0
Purchases and sales, net	(26,278)	0
Transfers in	347	0
Transfers out	0	0
Included in net income	0	0
Included in other comprehensive income (loss)	(1,120)	0
Ending balance	375,297	0
Fixed maturity securities, available for sale - Corporate securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	0	0
Purchases and sales, net	0	0
Transfers in	97,659	0
Transfers out	0	0
Included in net income	0	0
Included in other comprehensive income (loss)	0	0
Ending balance	97,659	0
Other asset backed securities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	442,918	0
Purchases and sales, net	227,032	0
Transfers in	130,502	0
Transfers out	0	0
Included in net income	0	0
Included in other comprehensive income (loss)	7,776	0
Ending balance	$ 808,228	$ 0