XML 92 R78.htm IDEA: XBRL DOCUMENT
v3.26.1

Note 10 - Retirement Plans - Fair Value of Plan Assets (Details) - USD ($) $ in Thousands | Mar. 31, 2026 | Mar. 31, 2025 | Mar. 31, 2024
--- | --- | --- | ---
Plan Assets, Amount |  | $ 323,061 | $ 293,121 | $ 288,949
Defined Benefit Plan, Equity Securities [Member] |  |  |  |
Plan Assets, Amount |  | 70,860 | 42,767 |
Defined Benefit Plan, Equity Securities Held in Common Collective Trusts [Member] |  |  |  |
Plan Assets, Amount |  | 28,859 | 26,903 |
Defined Benefit Plan, Real Estate Held in Common Collective Trusts [Member] |  |  |  |
Plan Assets, Amount |  | 7,505 | 4,451 |
Defined Benefit Plan, Debt Security Held in Common Collective Trusts [Member] |  |  |  |
Plan Assets, Amount |  | 207,304 | 212,162 |
Defined Benefit Plan, Cash and Short-term Investments Held in Common Collective Trusts [Member] |  |  |  |
Plan Assets, Amount | [1] | 3,457 | 3,485 |
All Other Investments [Member] |  |  |  |
Plan Assets, Amount |  | 5,076 | 3,353 |
Fair Value, Inputs, Level 1 [Member] |  |  |  |
Plan Assets, Amount |  | 70,860 | 42,767 |
Fair Value, Inputs, Level 1 [Member] | Defined Benefit Plan, Equity Securities [Member] |  |  |  |
Plan Assets, Amount |  | 70,860 | 42,767 |
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] | All 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] | All Other Investments [Member] |  |  |  |
Plan Assets, Amount |  | 0 | 0 |
Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] |  |  |  |
Plan Assets, Amount |  | 70,860 | 42,767 |
Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] | Defined Benefit Plan, Equity Securities [Member] |  |  |  |
Plan Assets, Amount |  | 70,860 | 42,767 |
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] | All Other Investments [Member] |  |  |  |
Plan Assets, Amount |  | 0 | 0 |
Fair Value Measured at Net Asset Value Per Share [Member] |  |  |  |
Plan Assets, Amount | [2] | 252,201 | 250,354 |
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] | 28,859 | 26,903 |
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] | 7,505 | 4,451 |
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] | 207,304 | 212,162 |
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] | 3,457 | 3,485 |
Fair Value Measured at Net Asset Value Per Share [Member] | All Other Investments [Member] |  |  |  |
Plan Assets, Amount | [2] | $ 5,076 | $ 3,353 |
[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.

X
- Definition Amount of asset segregated and restricted to provide benefit under defined benefit plan. Asset includes, but is not limited to, stock, bond, other investment, earning from investment, and contribution by employer and employee. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (c)(ii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-5 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-5 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (c)(iv)(01) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-5 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (c)(iv)(01) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-5 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (c)(ii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-5 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 17 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480482/715-20-55-17 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(02) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 11: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 Reference 12: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480506/715-20-50-1 + Details
Name: | us-gaap_DefinedBenefitPlanFairValueOfPlanAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=us-gaap_DefinedBenefitPlanEquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=senea_DefinedBenefitPlanEquitySecuritiesHeldInCommonCollectiveTrustsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=senea_DefinedBenefitPlanRealEstateHeldInCommonCollectiveTrustsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=senea_DefinedBenefitPlanDebtSecurityHeldInCommonCollectiveTrustsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=senea_DefinedBenefitPlanCashAndShorttermInvestmentsHeldInCommonCollectiveTrustsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=senea_AllOtherInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=senea_FairValueInputsLevel2AndLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel12And3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |