Accounting Pronouncements (Effects of Adoption of ASU 2018-12 Balance Sheet) (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023
Statements Adjusted [Abstract]
Deferred policy acquisition costs, net	$ 119,806	$ 121,224
Assets	19,305,427	19,058,758		$ 18,614,034
Policy benefits and losses, claims and loss expenses payable	841,861	849,113
Deferred Income Tax Liabilities, Net	1,470,156	1,447,125
Total liabilities	11,954,986	11,886,313
Accumulated other comprehensive loss	(231,813)	(223,216)
Retained earnings	7,786,683	7,600,090
Stockholders' Equity Attributable to Parent	7,350,441	7,172,445
Liabilities and Equity		19,058,758	$ 19,305,427
Operating Segments [Member] | Life Insurance [Member]
Statements Adjusted [Abstract]
Assets	$ 2,957,781	$ 2,990,903