Fair Value Measurements (Financial instruments level within the fair value hierarchy) (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Mar. 31, 2024
Assets:
Fixed maturities - available for sale	$ 2,437,923	$ 2,442,504
Preferred stock	21,766	21,260
Common stock	41,529	45,014
Derivatives	11,332	18,930
Total	2,414,464	2,527,708
Liabilities:
Derivatives	1,952
Guaranteed residual values of TRAC leases	9,406	9,300
Liabilities from investment contracts	2,389,751	2,290,096
Market risk benefits	13,355	13,400
Total	2,512,550	2,312,796
Level 1 [Member]
Assets:
Preferred stock	21,766	21,260
Common stock	41,529	45,014
Derivatives	8,210	10,538
Total		76,812
Liabilities:
Total	71,505
Level 2 [Member]
Assets:
Fixed maturities - available for sale	2,437,923	2,442,446
Derivatives	3,122	8,392
Total		2,450,838
Liabilities:
Derivatives	1,952
Total	2,441,045
Level 3 [Member]
Assets:
Fixed maturities - available for sale		58
Total	2,412,512	58
Liabilities:
Guaranteed residual values of TRAC leases	9,406	9,300
Liabilities from investment contracts	2,389,751	2,290,096
Market risk benefits	$ 13,355	13,400
Total		$ 2,312,796