Note 10 - Retirement Plans (Tables)

12 Months Ended

Mar. 31, 2023

Notes Tables

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

	Fiscal Year:
	2023			2022
Change in benefit obligation
Benefit obligation at beginning of year	$	275,001		$	286,063
Service cost		7,429			8,483
Interest cost		9,254			7,721
Actuarial gain		(47,403	)		(972	)
Benefit payments and expenses		(9,243	)		(26,294	)
Benefit obligation at end of year	$	235,038		$	275,001
Change in plan assets
Fair value of plan assets at beginning of year	$	327,867		$	348,914
Actual return on plan assets		(23,169	)		6,666
Benefit payments and expenses		(10,356	)		(27,713	)
Fair value of plan assets at end of year	$	294,342		$	327,867
Funded status	$	59,304		$	52,866

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

	Fiscal Year:
	2023			2022			2021
Amounts Recognized in Accumulated Other Comprehensive Pre-Tax Loss
Prior service cost	$	(75	)	$	(167	)	$	(258	)
Net loss		(28,310	)		(36,136	)		(26,265	)
Accumulated other comprehensive pre-tax loss	$	(28,385	)	$	(36,303	)	$	(26,523	)

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

	Fiscal Year:
	2023			2022			2021
Service cost including administration	$	8,240		$	9,508		$	10,627
Interest cost		9,254			7,721			9,266
Expected return on plan assets		(16,104	)		(17,114	)		(15,804	)
Amortization of net loss		-			-			9,919
Prior service cost		91			91			91
Net periodic benefit cost	$	1,481		$	206		$	14,099

Defined Benefit Plan, Assumptions [Table Text Block]

	Fiscal Year:
	2023			2022			2021
Weighted Average Assumptions for Balance Sheet Liability at End of Year:
Discount rate - projected benefit obligation		5.04	%		3.81	%		3.43	%
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-2020
Weighted Average Assumptions for Benefit Cost at Beginning of Year:
Discount rate - benefit obligations		3.81	%		3.43	%		3.69	%
Discount rate - interest cost		3.52	%		2.68	%		3.30	%
Discount rate - service cost		3.93	%		3.75	%		3.87	%
Expected return on plan assets		5.00	%		5.00	%		7.25	%
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 2024			March 31, 2023			March 31, 2022
Equity securities		16	%		13	%		21	%
Debt securities		80	%		75	%		61	%
Real estate		2	%		8	%		7	%
Cash		1	%		1	%		7	%
Other		1	%		3	%		4	%
Total		100	%		100	%		100	%

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

	As of March 31, 2023
	Level 1		Level 2		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

	As of March 31, 2022
	Level 1		Level 2		Level 3		`	Subtotal		Measured at NAV (1)		Total
Equity securities	$	29,427	$	-	$	-		$	29,427	$	-	$	29,427
Held in common/collective trusts
Equity securities		-		-		-			-		40,969		40,969
Real estate		-		-		-			-		23,200		23,200
Debt securities		-		-		-			-		200,224		200,225
Cash/short-term investments (2)		-		-		-			-		22,224		22,224
Other investments		-		-		-			-		11,822		11,822
Fair value of plan assets	$	29,427	$	-	$	-		$	29,427	$	298,439	$	327,867

Schedule of Expected Contributions [Table Text Block]

Expected Employer Contributions	$	-
Expected Employee Contributions	$	-

Schedule of Expected Benefit Payments [Table Text Block]

2024			$	10,706
2025				11,446
2026				12,210
2027				12,975
2028				13,648
2029	-	2033		76,496