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The pretax net amount of gains and losses that are not yet recognized as a component of net periodic benefit cost, and that are recognized as increases or decreases in other comprehensive income or regulatory assets and regulatory liabilities as they arise. Gains and losses are due to changes in the value of either the benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption, or the consequence of a decision to temporarily deviate from the substantive plan.

No definition available.

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Amount related to the pretax cost of benefit changes attributable to plan participants' prior service pursuant to a plan amendment or a plan initiation, which has not yet been recognized as components of net periodic benefit cost.

No definition available.

Name:	nfg_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeRegulatoryAssetRegulatoryLiabilityNetPriorServiceCostCreditBeforeTax
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The pretax cost (credit) of benefit changes attributable to plan participants' prior service resulting from a plan amendment or plan initiation that occurred during the period. The cost has not yet been recognized in net periodic benefit cost. A plan amendment includes provisions that grant increased (decreased) benefits based on services rendered in prior periods.

No definition available.

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Amounts recognized in other comprehensive income (but not yet recognized in net periodic benefit cost), including the net gain (loss) and net prior service cost (credit), or regulatory assets and regulatory liabilities arising during the period. Also includes reclassification adjustments out of other comprehensive income as a result of being recognized as components of net periodic benefit cost for the period.

No definition available.

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Pretax change in the value of either the benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption, or the consequence of a decision to temporarily deviate from the substantive plan, that has not been recognized in net periodic benefit cost.

No definition available.

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Before tax amount of the income statement impact or change in regulatory assets and regulatory liabilities of the reclassification adjustment for actuarial gain (loss) recognized as a component of net periodic benefit cost.

No definition available.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.