Accounting Pronouncements (Adoption Of New Accounting Pronouncement Adjustments To Select Tables) (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022
Statements Adjusted [Abstract]
Assets	$ 19,021,450	$ 18,143,343		$ 18,100,734
Liabilities	11,991,072			11,596,543
Stockholders Equity Including Portion Attributable To Noncontrolling Interest	7,030,378	6,324,173	$ 6,777,757	6,504,191	$ 6,086,986	$ 5,894,075
Scenario Previously Reported [Member]
Statements Adjusted [Abstract]
Assets	18,124,648	17,299,581		18,124,648
Liabilities	11,596,313	11,347,089		$ 11,596,313
Stockholders Equity Including Portion Attributable To Noncontrolling Interest	6,528,335	5,952,492
Cumulative Effect Period Of Adoption Adjustment [Member] | Life And Annuity Insurance Product Line [Member]
Statements Adjusted [Abstract]
Derecognition of shadow reserves	(25,141)	26,131
Re-measurement due to discount rate	0	0
Other adjustments	1,227	1,471
Subtotal	(23,914)	27,602
After adoption	18,100,734	17,327,183
Cumulative Effect Of Adoption Liabilities [Member] | Life And Annuity Insurance Product Line [Member]
Statements Adjusted [Abstract]
Derecognition of FIT on shadow reserves	(5,280)	5,488
Re-measurement due to discount rate	(1,626)	87,258
Re-measurement due to discount rate FIT	342	(18,324)
Other adjustments	6,794	8,511
Subtotal	230	82,933
After adoption	11,596,543	11,430,022
Cumulative Effect Of Adoption Comprehensive Income [Member]
Statements Adjusted [Abstract]
Stockholders Equity Including Portion Attributable To Noncontrolling Interest	(267,046)	46,384
Cumulative Effect Of Adoption Comprehensive Income [Member] | Life And Annuity Insurance Product Line [Member]
Statements Adjusted [Abstract]
Derecognition of FIT on shadow reserves	(19,861)	20,644
Re-measurement due to discount rate	1,626	(87,258)
Re-measurement due to discount rate FIT	(342)	18,324
Other adjustments	0	0
Subtotal	(18,577)	(48,290)
After adoption	(285,623)	(1,906)
Cumulative Effect Of Adoption Stockholders Equity [Member] | Life And Annuity Insurance Product Line [Member]
Statements Adjusted [Abstract]
Derecognition of FIT on shadow reserves	(19,861)	20,644
Re-measurement due to discount rate FIT	1,284	(68,934)
Other adjustments	(5,567)	(7,042)
Subtotal	(24,144)	(55,332)
After adoption	$ 6,504,191	$ 5,897,160