Fair Value Measurements (Financial instruments level within the fair value hierarchy) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Assets:
Fixed maturities - available for sale	$ 2,442,504	$ 2,709,037
Preferred stock	21,260	21,982
Common stock	45,014	39,375
Derivatives	18,930	9,606
Total	2,527,708	2,780,000
Level 1 [Member]
Assets:
Fixed maturities - available for sale	0	251,832
Preferred stock	21,260	21,982
Common stock	45,014	39,735
Derivatives	10,538	4,295
Total	76,812	317,844
Level 2 [Member]
Assets:
Fixed maturities - available for sale	2,442,446	2,457,146
Preferred stock	0
Common stock	0
Derivatives	8,392	5,311
Total	2,450,838	2,462,457
Level 3 [Member]
Assets:
Fixed maturities - available for sale	58	59
Preferred stock	0
Common stock	0
Derivatives	0
Total	$ 58	$ 59