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Fair Value Measurements (Narrative) (Detail) $ in Thousands | Dec. 31, 2021 USD ($) | Dec. 31, 2020 Grade
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Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Financial instruments using fair value measurement option | $ | $ 0 |
Commodity Swaps And Options [Member] | Level 3 [Member] |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Weighted Average Risk Grade | Grade |  | 14.0
Weighted average loss severity in the event of default on commodity swaps |  | 10.00%

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