Fair Value Measurements (Financial instruments level within the fair value hierarchy) (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Mar. 31, 2025
Assets:
Fixed maturities - available for sale	$ 2,501,436	$ 2,479,498
Preferred stock	8,075	22,136
Common stock	49,343	43,413
Derivatives	10,624	13,200
Total	21,500	2,558,247
Liabilities:
Derivatives	411	777
Guaranteed residual values of TRAC leases	8,966	8,693
Liabilities from investment contracts	2,406,345	2,436,537
Market risk benefits	12,123	13,432
Total	2,569,478	22,902
Level 1 [Member]
Assets:
Preferred stock	8,075	22,136
Common stock	49,343	43,413
Derivatives	8,314	8,819
Total		74,368
Liabilities:
Total	65,732
Level 2 [Member]
Assets:
Fixed maturities - available for sale	2,501,436	2,479,498
Derivatives	2,310	4,381
Total		2,483,879
Liabilities:
Derivatives	411	777
Total	2,503,746	777
Level 3 [Member]
Assets:
Total	21,089
Liabilities:
Guaranteed residual values of TRAC leases	8,966	8,693
Liabilities from investment contracts	2,406,345	2,436,537
Market risk benefits	$ 12,123	13,432
Total		$ 22,125