XML 81 R58.htm IDEA: XBRL DOCUMENT
v3.24.3

Regulatory Matters - Schedule of Regulatory Assets and Liabilities (Details) - USD ($) $ in Thousands | Sep. 30, 2024 | Sep. 30, 2023
--- | --- | ---
Regulatory Assets: |  |  |
Total Regulatory Assets |  | $ 231,974 | $ 184,796
Less: Amounts Included in Other Current Assets |  | (38,264) | (36,373)
Regulatory Liabilities: |  |  |
Total Regulatory Liabilities |  | 821,646 | 808,821
Less: Amounts included in Current and Accrued Liabilities |  | (72,072) | (97,124)
Total Long-Term Regulatory Liabilities |  | 749,574 | 711,697
Cost of Removal Regulatory Liability |  |  |
Regulatory Liabilities: |  |  |
Total Regulatory Liabilities |  | 292,477 | 277,694
Taxes Refundable to Customers |  |  |
Regulatory Liabilities: |  |  |
Total Regulatory Liabilities |  | 305,645 | 268,562
Post-Retirement Benefit Costs |  |  |
Regulatory Liabilities: |  |  |
Total Regulatory Liabilities | [1] | 141,199 | 159,760
Less: Amounts included in Current and Accrued Liabilities |  | (5,800) | (5,800)
Total Long-Term Regulatory Liabilities |  | 135,399 | 153,960
Amounts Payable to Customers |  |  |
Regulatory Liabilities: |  |  |
Total Regulatory Liabilities |  | 42,720 | 59,019
Environmental Site Remediation Costs |  |  |
Regulatory Liabilities: |  |  |
Total Regulatory Liabilities | [2] | 5,390 | 619
Other |  |  |
Regulatory Liabilities: |  |  |
Total Regulatory Liabilities | [3] | 34,215 | 43,167
Total Long-Term Regulatory Liabilities |  | 10,663 | 10,862
Other Accruals and Current Liabilities |  |  |
Regulatory Liabilities: |  |  |
Less: Amounts included in Current and Accrued Liabilities |  | (23,552) | (32,305)
Pension Costs |  |  |
Regulatory Assets: |  |  |
Total Regulatory Assets | [4] | 30,259 | 20,459
Post-Retirement Benefit Costs |  |  |
Regulatory Assets: |  |  |
Total Regulatory Assets | [4] | 7,932 | 2,536
Recoverable Future Taxes |  |  |
Regulatory Assets: |  |  |
Total Regulatory Assets |  | 80,084 | 69,045
System Modernization And Improvement Tracker |  |  |
Regulatory Assets: |  |  |
Total Regulatory Assets | [5] | 47,043 | 30,375
Less: Amounts Included in Other Current Assets |  | (15,681) | (19,584)
Total Long-Term Regulatory Assets |  | 31,362 | 10,791
Asset Retirement Obligations |  |  |
Regulatory Assets: |  |  |
Total Regulatory Assets | [4] | 21,951 | 19,384
Unamortized Debt Expense |  |  |
Regulatory Assets: |  |  |
Total Regulatory Assets |  | 5,604 | 7,240
Other |  |  |
Regulatory Assets: |  |  |
Total Regulatory Assets | [6] | 39,101 | 35,757
Total Long-Term Regulatory Assets |  | 16,518 | 18,968
Long-Term Regulatory Assets |  |  |
Regulatory Assets: |  |  |
Total Long-Term Regulatory Assets |  | 193,710 | 148,423
Other Current Assets |  |  |
Regulatory Assets: |  |  |
Less: Amounts Included in Other Current Assets |  | $ (22,583) | $ (16,789)
[1] | $5,800 is included in Other Accruals and Current Liabilities on the Consolidated Balance Sheets at both September 30, 2024 and 2023, since such amounts are expected to be passed back to ratepayers in the next 12 months. $135,399 and $153,960 are included in Other Regulatory Liabilities on the Consolidated Balance Sheets at September 30, 2024 and 2023, respectively.
[2] | Included in Other Regulatory Liabilities on the Consolidated Balance Sheets.
[3] | $23,552 and $32,305 are included in Other Accruals and Current Liabilities on the Consolidated Balance Sheets at September 30, 2024 and 2023, respectively, since such amounts are expected to be passed back to ratepayers in the next 12 months. $10,663 and $10,862 are included in Other Regulatory Liabilities on the Consolidated Balance Sheets at September 30, 2024 and 2023, respectively.
[4] | Included in Other Regulatory Assets on the Consolidated Balance Sheets.
[5] | $15,681 and $19,584 are included in Other Current Assets on the Consolidated Balance Sheets at September 30, 2024 and 2023, respectively, since such amounts are expected to be recovered from ratepayers in the next 12 months. $31,362 and $10,791 are included in Other Regulatory Assets on the Consolidated Balance Sheets at September 30, 2024 and 2023, respectively.
[6] | $22,583 and $16,789 are included in Other Current Assets on the Consolidated Balance Sheets at September 30, 2024 and 2023, respectively, since such amounts are expected to be recovered from ratepayers in the next 12 months. $16,518 and $18,968 are included in Other Regulatory Assets on the Consolidated Balance Sheets at September 30, 2024 and 2023, respectively.

X
- References No definition available. + Details
Name: | us-gaap_RegulatoryAssetAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 340 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478742/980-340-50-1 + Details
Name: | us-gaap_RegulatoryAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are expected to be recovered through revenue sources within one year or the normal operating cycle, if longer. Such costs are capitalized if they meet both of the following criteria: a. It is probable that future revenue in an amount at least equal to the capitalized cost will result from inclusion of that cost in allowable costs for rate-making purposes. b. Based on available evidence, the future revenue will be provided to permit recovery of the previously incurred cost rather than to provide for expected levels of similar future costs. If the revenue will be provided through an automatic rate-adjustment clause, this criterion requires that the regulator's intent clearly be to permit recovery of the previously incurred cost. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 340 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478742/980-340-50-1 + Details
Name: | us-gaap_RegulatoryAssetsCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 340 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478742/980-340-50-1 + Details
Name: | us-gaap_RegulatoryAssetsNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 405 -Name Accounting Standards Codification -Section 25 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477571/980-405-25-1 + Details
Name: | us-gaap_RegulatoryLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_RegulatoryLiabilityAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount for the individual regulatory current liability as itemized in a table of regulatory current liabilities as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 405 -Name Accounting Standards Codification -Section 25 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477571/980-405-25-1 + Details
Name: | us-gaap_RegulatoryLiabilityCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount for the individual regulatory noncurrent liability as itemized in a table of regulatory noncurrent liabilities as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(24)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_RegulatoryLiabilityNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=nfg_CostOfRemovalRegulatoryLiabilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=nfg_TaxesRefundableToCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_PostretirementBenefitCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=nfg_AmountsPayableToCustomersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_EnvironmentalRestorationCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=us-gaap_OtherRegulatoryAssetsLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryLiabilityAxis=nfg_OtherAccrualsAndCurrentLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_PensionCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_PostretirementBenefitCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=nfg_RecoverableFutureTaxesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=nfg_SystemModernizationAndImprovementTrackerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_AssetRetirementObligationCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=nfg_UnamortizedDebtExpenseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_OtherRegulatoryAssetsLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=nfg_LongTermRegulatoryAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=us-gaap_OtherCurrentAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |