Schedule of Reconciliation of Obligations and Fair Values of Plan Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Benefit Obligation at April 1,	$ 36,701	$ 33,730
Service Cost - Benefits Earned During the Period		339	$ 399
Interest Cost on Projected Benefit Obligation	1,216	1,351	1,347
Actuarial (Gain) Loss	1,714	2,464
Benefits Paid	(1,251)	(1,183)
Sale of Business	(2,536)
Benefit Obligation at March 31,	35,844	36,701	33,730
Fair Value of Plan Assets at April 1,	39,009	36,541
Actual Return on Plan Assets	2,939	3,651
Benefits Paid	(1,251)	(1,183)
Sale of Business	(2,790)
Fair Value of Plan Assets at March 31,	37,907	39,009	$ 36,541
Funded Status at March 31,	2,063	2,308
Other Assets	2,063	2,308
Accumulated Other Comprehensive Losses - Net Actuarial Loss	4,524	4,709
Accumulated Other Comprehensive Losses	4,524	4,709
Tax impact	(1,086)	(1,128)
Accumulated Other Comprehensive Losses, net of tax	$ 3,438	$ 3,581