INVESTMENT SECURITIES - Additional information (Details) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Mar. 31, 2023
INVESTMENT SECURITIES
Proceeds from the sale of investment securities	$ 0	$ 0
Gross realized gains on sales of investment securities	0	$ 0
Available for sale with amortized cost	225,156		$ 235,591
Available for sale, estimated fair value	193,984		211,499
Held to maturity, estimated fair value	193,283		210,214
Asset Pledged as Collateral.
INVESTMENT SECURITIES
Available for sale with amortized cost	2,900		3,200
Available for sale, estimated fair value	2,600		2,900
Held to maturity at amortized cost	11,700		12,300
Held to maturity, estimated fair value	$ 9,300		$ 10,400