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Commitments and Contingencies Commitments and Contingencies (Details) $ in Millions |  | 3 Months Ended
--- | --- | ---
Apr. 03, 2018 | Mar. 31, 2018 USD ($) MMcf
Loss Contingencies [Line Items] |  |
Self-Insured Retention Expense | $ |  | $ 1.0
Subsequent Event [Member] |  |
Subsequent Event [Line Items] |  |
Subsequent Event, Description | On April 3, 2018, we filed formula rate mechanisms in our Mid-Tex and West Texas service areas, seeking increases in operating income |
Pending Litigation [Member] |  |
Loss Contingencies [Line Items] |  |
Loss Contingency, Damages Sought, Value | $ |  | $ 1.0
Loss Contingency, Lawsuit Filing Date |  | March 29, 2018
Inventories Under Indexed Contracts [Member] | Distribution Segment [Member] |  |
Long-term Purchase Commitment [Line Items] |  |
Long Term Purchase Commitment Minimum Quantity Required Within One Year | MMcf |  | 55,000
Long Term Purchase Commitment Minimum Quantity Required One To Three Years | MMcf |  | 64,700

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- Definition Volume that must be purchased within one to three years following the balance sheet date to avoid penalties or unfavorable effects on pricing, among other adverse consequences. + References No definition available. + Details
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- Definition Volume that must be purchased within one year of the balance sheet date to avoid penalties or unfavorable effects on pricing, among other adverse consequences. + References No definition available. + Details
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