Policy Benefits And Losses Claims And Loss Expenses Payable (Balance Changes Liabilities Investment Contracts) (Details) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Policyholder Account Balance [Roll Forward]
Policyholder contract deposits account balance Beginning of year	$ 8,232
End of period	7,677
Deferred Fixed Annuity [Member]
Policyholder Account Balance [Roll Forward]
Policyholder contract deposits account balance Beginning of year	2,398,884	$ 2,336,238
Deposits received	125,122	169,008
Surrenders and withdrawals	(146,647)	(122,450)
Benefit payments	(20,761)	(18,334)
Interest credited	36,992	25,566
Other	0	0
End of period	$ 2,393,590	$ 2,390,028
Weighted average credited rate	3.09%	2.16%
Cash surrender value	$ 2,062,233	$ 2,082,936