Reinsurance (Reinsurance Recoverable and Deposit Receivables by Counterparty) (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Effects of Reinsurance [Line Items]
Total reinsurance recoverables and deposit receivables	$ 48,247,817	$ 40,256,800
PAR U
Effects of Reinsurance [Line Items]
Total reinsurance recoverables and deposit receivables	11,426,975	15,722,061
PURC
Effects of Reinsurance [Line Items]
Total reinsurance recoverables and deposit receivables	0	7,565,968
PARCC
Effects of Reinsurance [Line Items]
Total reinsurance recoverables and deposit receivables	7,049,164	2,304,270
GUL Re
Effects of Reinsurance [Line Items]
Total reinsurance recoverables and deposit receivables	0	3,211,899
PAR Term
Effects of Reinsurance [Line Items]
Total reinsurance recoverables and deposit receivables	0	2,101,004
Prudential Insurance
Effects of Reinsurance [Line Items]
Total reinsurance recoverables and deposit receivables	7,507,414	1,331,202
Term Re
Effects of Reinsurance [Line Items]
Total reinsurance recoverables and deposit receivables	0	2,080,564
Lotus Re
Effects of Reinsurance [Line Items]
Total reinsurance recoverables and deposit receivables	2,130,095	2,051,831
DART
Effects of Reinsurance [Line Items]
Total reinsurance recoverables and deposit receivables	0	744,043
PURE
Effects of Reinsurance [Line Items]
Total reinsurance recoverables and deposit receivables	7,951,965	0
Unaffiliated activity
Effects of Reinsurance [Line Items]
Total reinsurance recoverables and deposit receivables	$ 12,182,204	$ 3,143,958