Life Insurance Liability - (Balance Changes Liabilities Investment Contracts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Policyholder Account Balance [Roll Forward]
Policyholder contract deposits account balance Beginning of year	$ 8,232
End of period	18,070	$ 8,232
Deferred Fixed Annuity Member
Policyholder Account Balance [Roll Forward]
Policyholder contract deposits account balance Beginning of year	2,398,884	2,336,238
Deposits received	360,124	326,465
Surrenders and withdrawals	(379,099)	(287,796)
Benefit payments	(39,990)	(33,548)
Interest credited	71,433	57,525
End of period	$ 2,411,352	$ 2,398,884
Weighted average credited rate	3.03%	2.43%
Cash surrender value	$ 2,104,617	$ 2,067,735