Allowance For Credit Losses (Reserve Allowance For Various Credit Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Valuation And Qualifying Accounts [Abstract]
March 31, 2023		$ 9,210
Transition adjustment current expected credit losses	$ 437	(2,803)
Write-offs against allowance	0	0
Recoveries	0	0
June 30, 2023	6,844	6,407
Trade Receivables
Valuation And Qualifying Accounts [Abstract]
March 31, 2023		8,649
Transition adjustment current expected credit losses	591	(4,860)
Write-offs against allowance	0	0
Recoveries	0	0
June 30, 2023	4,380	3,789
Investments, Fixed Maturities
Valuation And Qualifying Accounts [Abstract]
March 31, 2023		60
Transition adjustment current expected credit losses	(455)	2,041
Write-offs against allowance	0	0
Recoveries	0	0
June 30, 2023	1,646	2,101
Investments, Other
Valuation And Qualifying Accounts [Abstract]
March 31, 2023		501
Transition adjustment current expected credit losses	301	16
Write-offs against allowance	0	0
Recoveries	0	0
June 30, 2023	$ 818	$ 517