Net Investment and Interest Income (Details) - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2022
Net Investment Income [Line Items]
Investment income	$ 154,734	$ 185,014	$ 155,541
Less: investment expenses	(8,266)	(8,335)	(7,280)
Net investment and interest income	146,468	176,679	148,261
Fixed Maturities [Member]
Net Investment Income [Line Items]
Investment income	105,089	171,814	111,625
Insurance policy loans [Member]
Net Investment Income [Line Items]
Investment income	669	869	705
Mortgage loans [Member]
Net Investment Income [Line Items]
Investment income	28,599	23,854	25,850
Short-term, amounts held by ceding reinsurers, net and other investments [Member]
Net Investment Income [Line Items]
Investment income	$ 20,377	$ 11,523	$ 17,361

Amount before accretion (amortization) of purchase discount (premium) of interest income and dividend income on nonoperating securities.

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