Allowance for Credit Losses (Reserve Allowance Various Credit Loss) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Dec. 31, 2022	Mar. 31, 2022
Valuation And Qualifying Accounts [Abstract]
March 31, 2022	$ 9,210	$ 6,242
Transition adjustment expected credit loss current	(2,442)	2,968
Write-offs against allowance	0	0
Recoveries	0	0
December 31, 2022	6,768	9,210
Trade Receivables
Valuation And Qualifying Accounts [Abstract]
March 31, 2022	8,649	4,421
Transition adjustment expected credit loss current	(4,630)	4,228
Write-offs against allowance	0	0
Recoveries	0	0
December 31, 2022	4,019	8,649
Investments, Fixed Maturities
Valuation And Qualifying Accounts [Abstract]
March 31, 2022	60	1,320
Transition adjustment expected credit loss current	2,183	(1,260)
Write-offs against allowance	0	0
Recoveries	0	0
December 31, 2022	2,243	60
Investments, Other
Valuation And Qualifying Accounts [Abstract]
March 31, 2022	501	501
Transition adjustment expected credit loss current	5	0
Write-offs against allowance	0	0
Recoveries	0	0
December 31, 2022	$ 506	$ 501