Accounting Pronouncements (Adoption Of New Accounting Pronouncement Adjustments To Select Tables) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Statements Adjusted [Abstract]
Assets	$ 18,100,734		$ 18,614,034	$ 17,793,811
Liabilities	11,596,543		11,836,277
Stockholders Equity Including Portion Attributable To Noncontrolling Interest	6,504,191	$ 5,894,075	$ 6,777,757	$ 6,086,986
Scenario Previously Reported [Member]
Statements Adjusted [Abstract]
Assets	18,124,648	17,299,581
Liabilities	11,596,313	11,347,089
Stockholders Equity Including Portion Attributable To Noncontrolling Interest	(267,046)	46,384
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] | Life And Annuity Insurance Product Line [Member]
Statements Adjusted [Abstract]
Derecognition of 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] | Scenario Previously Reported [Member]
Statements Adjusted [Abstract]
Stockholders Equity Including Portion Attributable To Noncontrolling Interest	6,528,335	5,952,492
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