Allowance for Credit Losses (Reserve Allowance Various Credit Loss) (Details) $ in Thousands	9 Months Ended
	Dec. 31, 2021 USD ($)
Valuation And Qualifying Accounts [Abstract]
March 31, 2020	$ 4,656
Transition adjustment expected credit loss current	204
Write-offs against allowance	0
Recoveries	0
December 31, 2020	4,860
Trade Receivables
Valuation And Qualifying Accounts [Abstract]
March 31, 2020	2,835
Transition adjustment expected credit loss current	1,510
Write-offs against allowance	0
Recoveries	0
December 31, 2020	4,345
Investments, Fixed Maturities
Valuation And Qualifying Accounts [Abstract]
March 31, 2020	1,320
Transition adjustment expected credit loss current	(1,320)
Write-offs against allowance	0
Recoveries	0
December 31, 2020	0
Investments, Other
Valuation And Qualifying Accounts [Abstract]
March 31, 2020	501
Transition adjustment expected credit loss current	14
Write-offs against allowance	0
Recoveries	0
December 31, 2020	$ 515