v3.25.1
Note 9 - Retirement Plans - Fair Value of Plan Assets (Details) - USD ($)
$ in Thousands
Mar. 31, 2025
Mar. 31, 2024
Mar. 31, 2023
Plan Assets, Amount $ 293,121 $ 288,949 $ 294,342
Defined Benefit Plan, Equity Securities [Member]      
Plan Assets, Amount 42,767 26,371  
Defined Benefit Plan, Equity Securities Held in Common Collective Trusts [Member]      
Plan Assets, Amount 26,903 17,730  
Defined Benefit Plan, Real Estate Held in Common Collective Trusts [Member]      
Plan Assets, Amount 4,451 4,509  
Defined Benefit Plan, Debt Security Held in Common Collective Trusts [Member]      
Plan Assets, Amount 212,162 231,904  
Defined Benefit Plan, Cash and Short-term Investments Held in Common Collective Trusts [Member]      
Plan Assets, Amount [1] 3,485 3,388  
Other Investments [Member]      
Plan Assets, Amount 3,353 5,047  
Fair Value, Inputs, Level 1 [Member]      
Plan Assets, Amount 42,767 26,371  
Fair Value, Inputs, Level 1 [Member] | Defined Benefit Plan, Equity Securities [Member]      
Plan Assets, Amount 42,767 26,371  
Fair Value, Inputs, Level 1 [Member] | Defined Benefit Plan, Equity Securities Held in Common Collective Trusts [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 1 [Member] | Defined Benefit Plan, Real Estate Held in Common Collective Trusts [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 1 [Member] | Defined Benefit Plan, Debt Security Held in Common Collective Trusts [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 1 [Member] | Defined Benefit Plan, Cash and Short-term Investments Held in Common Collective Trusts [Member]      
Plan Assets, Amount [1] 0 0  
Fair Value, Inputs, Level 1 [Member] | Other Investments [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 2 and Level 3 [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 2 and Level 3 [Member] | Defined Benefit Plan, Equity Securities [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 2 and Level 3 [Member] | Defined Benefit Plan, Equity Securities Held in Common Collective Trusts [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 2 and Level 3 [Member] | Defined Benefit Plan, Real Estate Held in Common Collective Trusts [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 2 and Level 3 [Member] | Defined Benefit Plan, Debt Security Held in Common Collective Trusts [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 2 and Level 3 [Member] | Defined Benefit Plan, Cash and Short-term Investments Held in Common Collective Trusts [Member]      
Plan Assets, Amount [1] 0 0  
Fair Value, Inputs, Level 2 and Level 3 [Member] | Other Investments [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member]      
Plan Assets, Amount 42,767 26,371  
Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Defined Benefit Plan, Equity Securities [Member]      
Plan Assets, Amount 42,767 26,371  
Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Defined Benefit Plan, Equity Securities Held in Common Collective Trusts [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Defined Benefit Plan, Real Estate Held in Common Collective Trusts [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Defined Benefit Plan, Debt Security Held in Common Collective Trusts [Member]      
Plan Assets, Amount 0 0  
Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Defined Benefit Plan, Cash and Short-term Investments Held in Common Collective Trusts [Member]      
Plan Assets, Amount [1] 0 0  
Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Other Investments [Member]      
Plan Assets, Amount 0 0  
Fair Value Measured at Net Asset Value Per Share [Member]      
Plan Assets, Amount [2] 250,354 262,578  
Fair Value Measured at Net Asset Value Per Share [Member] | Defined Benefit Plan, Equity Securities [Member]      
Plan Assets, Amount [2] 0 0  
Fair Value Measured at Net Asset Value Per Share [Member] | Defined Benefit Plan, Equity Securities Held in Common Collective Trusts [Member]      
Plan Assets, Amount [2] 26,903 17,730  
Fair Value Measured at Net Asset Value Per Share [Member] | Defined Benefit Plan, Real Estate Held in Common Collective Trusts [Member]      
Plan Assets, Amount [2] 4,451 4,509  
Fair Value Measured at Net Asset Value Per Share [Member] | Defined Benefit Plan, Debt Security Held in Common Collective Trusts [Member]      
Plan Assets, Amount [2] 212,162 231,904  
Fair Value Measured at Net Asset Value Per Share [Member] | Defined Benefit Plan, Cash and Short-term Investments Held in Common Collective Trusts [Member]      
Plan Assets, Amount [1],[2] 3,485 3,388  
Fair Value Measured at Net Asset Value Per Share [Member] | Other Investments [Member]      
Plan Assets, Amount [2] $ 3,353 $ 5,047  
[1] The cash/short term investments consist of a money market fund that holds individual, high quality, short duration fixed income investments, however the fund does not trade on public markets. The Company elected to consistently apply the practical expedient to all investments within common/collective trusts, and therefore, the fair value of this fund is measured at net asset value per share.
[2] Certain investments that are measured at fair value using the net asset value (“NAV”) per share (or its equivalent) practical expedient have not been categorized in the fair value hierarchy but are included to reconcile to the amounts presented in the benefit obligations and funded status table.