Note 10 - Retirement Plans (Tables)

12 Months Ended

Mar. 31, 2024

Notes Tables

Schedule of Changes in Projected Benefit Obligations [Table Text Block]

	Fiscal Year:
	2024			2023
Change in benefit obligation
Benefit obligation at beginning of year	$	235,038		$	275,001
Service cost (excluding expenses)		5,505			7,429
Interest cost		11,388			9,254
Actuarial gain		(4,674	)		(47,403	)
Benefit payments		(10,750	)		(9,243	)
Benefit obligation at end of year	$	236,507		$	235,038
Change in plan assets
Fair value of plan assets at beginning of year	$	294,342		$	327,867
Actual return on plan assets		6,428			(23,169	)
Benefit payments and expenses		(11,821	)		(10,356	)
Fair value of plan assets at end of year	$	288,949		$	294,342
Funded status	$	52,442		$	59,304

Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year [Table Text Block]

	Fiscal Year:
	2024			2023			2022
Amounts Recognized in Accumulated Other Comprehensive Pre-Tax Loss
Prior service cost	$	(9	)	$	(75	)	$	(167	)
Net loss		(34,883	)		(28,310	)		(36,136	)
Accumulated other comprehensive pre-tax loss	$	(34,892	)	$	(28,385	)	$	(36,303	)

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

	Fiscal Year:
	2024			2023			2022
Service cost including administrative expenses	$	6,405		$	8,240		$	9,508
Interest cost		11,388			9,254			7,721
Expected return on plan assets		(17,725	)		(16,104	)		(17,114	)
Amortization of net loss		220			-			-
Amortization of prior service cost		66			91			91
Net periodic benefit cost	$	354		$	1,481		$	206

Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]

	Fiscal Year:
	2024			2023			2022
Other Changes in Plan Assets and Benefit Obligation Recognized in Other Comprehensive Income
Net actuarial loss (gain)	$	6,792		$	(7,827	)	$	9,871
Amortization of:
Prior service (cost) credit		(65	)		(91	)		(91	)
Actuarial (loss) gain		(220	)		-			-
Total recognized in other comprehensive income	$	6,507		$	(7,918	)	$	9,780

Defined Benefit Plan, Assumptions [Table Text Block]

	Fiscal Year:
	2024			2023			2022
Weighted Average Assumptions for Balance Sheet Liability at End of Year:
Discount rate - projected benefit obligation		5.31	%		5.04	%		3.81	%
Rate of compensation increase		3.00	%		3.00	%		3.00	%
Mortality table	Pri-2012 Blue Collar Generational Table Improvement Scale MP-2021			Pri-2012 Blue Collar Generational Table Improvement Scale MP-2021			Pri-2012 Blue Collar Generational Table Improvement Scale MP-2021
Weighted Average Assumptions for Benefit Cost at Beginning of Year:
Discount rate - benefit obligations		5.04	%		3.81	%		3.43	%
Discount rate - interest cost		4.90	%		3.52	%		2.68	%
Discount rate - service cost		5.16	%		3.93	%		3.75	%
Expected return on plan assets		6.15	%		5.00	%		5.00	%
Rate of compensation increase		3.00	%		3.00	%		3.00	%

Schedule of Allocation of Plan Assets [Table Text Block]

	Target Allocation for:			Percentage of Plan Assets as of:
	Fiscal Year 2025			March 31, 2024			March 31, 2023
Equity securities		16	%		15	%		13	%
Debt securities		80	%		80	%		75	%
Real estate		2	%		2	%		8	%
Cash		1	%		1	%		1	%
Other		1	%		2	%		3	%
Total		100	%		100	%		100	%

Defined Benefit Plan, Plan Assets, Category [Table Text Block]

	As of March 31, 2024
	Level 1		Level 2 and Level 3		Subtotal		Measured at NAV (1)		Total
Equity securities	$	26,371	$	-	$	26,371	$	-	$	26,371
Held in common/collective trusts:
Equity securities		-		-		-		17,730		17,730
Real estate		-		-		-		4,509		4,509
Debt securities		-		-		-		231,904		231,904
Cash/short-term investments (2)		-		-		-		3,388		3,388
Other investments		-		-		-		5,047		5,047
Fair value of plan assets	$	26,371	$	-	$	26,371	$	262,578	$	288,949

	As of March 31, 2023
	Level 1		Level 2 and Level 3		Subtotal		Measured at NAV (1)		Total
Equity securities	$	25,045	$	-	$	25,045	$	-	$	25,045
Held in common/collective trusts:
Equity securities		-		-		-		12,639		12,639
Real estate		-		-		-		24,766		24,766
Debt securities		-		-		-		219,767		219,767
Cash/short-term investments (2)		-		-		-		2,799		2,799
Other investments		-		-		-		9,326		9,326
Fair value of plan assets	$	25,045	$	-	$	25,045	$	269,297	$	294,342

Schedule of Expected Contributions [Table Text Block]

Expected Employer Contributions	$	-
Expected Employee Contributions	$	-

Schedule of Expected Benefit Payments [Table Text Block]

2025			$	11,422
2026				12,231
2027				13,041
2028				13,807
2029				14,465
2030	-	2034		79,850