Reinsurance (Reinsurance Recoverable by Counterparty) (Details) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Effects of Reinsurance [Line Items]
Total reinsurance recoverable and deposit receivables	$ 50,219,999	$ 48,247,817
PAR U
Effects of Reinsurance [Line Items]
Total reinsurance recoverable and deposit receivables	11,457,858	11,426,975
Prudential Insurance
Effects of Reinsurance [Line Items]
Total reinsurance recoverable and deposit receivables	8,234,784	7,507,414
PURE
Effects of Reinsurance [Line Items]
Total reinsurance recoverable and deposit receivables	8,087,723	7,951,965
PARCC
Effects of Reinsurance [Line Items]
Total reinsurance recoverable and deposit receivables	6,974,568	7,049,164
Lotus Re
Effects of Reinsurance [Line Items]
Total reinsurance recoverable and deposit receivables	3,061,586	2,130,095
Prudential of Japan
Effects of Reinsurance [Line Items]
Total reinsurance recoverable and deposit receivables	10,876	0
Unaffiliated
Effects of Reinsurance [Line Items]
Total reinsurance recoverable and deposit receivables	$ 12,392,604	$ 12,182,204