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Stockholder's Equity - Accumulated Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2018 | Mar. 31, 2017
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), after Tax [Roll Forward] |  |
Beginning balance | $ (4,272) | $ (4,878)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax | (2,232) | 1,269
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax | 538 | (849)
Net current-period other comprehensive income (loss) | (1,694) | 420
Ending balance | (6,873) | (4,458)
Tax Cuts and Jobs Act, Reclassification from AOCI to Retained Earnings, Tax Effect | (907) |
UnrealizedGainsLossesFromDefinedBenefitPensionAndPostretirementPlanItems [Member] |  |
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), after Tax [Roll Forward] |  |
Beginning balance | (4,743) | (5,360)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax | 0 | (9)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax | 94 | 91
Net current-period other comprehensive income (loss) | 94 | 82
Ending balance | (5,671) | (5,278)
Tax Cuts and Jobs Act, Reclassification from AOCI to Retained Earnings, Tax Effect | (1,022) |
Accumulated (Gain) Loss from Commodity Contracts Cash Flows Hedges [Member] |  |
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), after Tax [Roll Forward] |  |
Beginning balance | 471 | 482
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax | (2,232) | 1,278
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax | 444 | (940)
Net current-period other comprehensive income (loss) | (1,788) | 338
Ending balance | (1,202) | $ 820
Tax Cuts and Jobs Act, Reclassification from AOCI to Retained Earnings, Tax Effect | $ 115 |

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- Definition Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14 -URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e681-108580 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669686-108580 + Details
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- Definition Amount after tax, before reclassification adjustments of other comprehensive income (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 55 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=84158357&loc=d3e1436-108581 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 14A -URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669686-108580 + Details
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