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Nature of Business - Reclassifications Out of Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
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Dec. 31, 2019 | Sep. 30, 2019 | Jun. 30, 2019 | Mar. 31, 2019 | Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Reclassification Adjustment Out of Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Cost of sales |  |  |  |  |  |  |  |  | $ (310,894) | $ (325,712) | $ (363,265)
Defined benefit plan adjustments – actuarial losses |  |  |  |  |  |  |  |  | 5,091 | 2,139 |
Income (Loss) Before Income Taxes |  |  |  |  |  |  |  |  | (24,777) | (33,371) | 44,687
Tax benefit (expense) |  |  |  |  |  |  |  |  | (28,205) | 14,029 | (20,847)
Total reclassifications for the period, net of tax | $ (11,624) | $ (46,123) | $ 3,995 | $ 770 | $ (8,447) | $ 7,589 | $ (7,670) | $ (10,814) | (52,982) | (19,342) | 23,840
Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member] |  |  |  |  |  |  |  |  |  |  |
Reclassification Adjustment Out of Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Defined benefit plan adjustments – actuarial losses |  |  |  |  |  |  |  |  | (771) | (196) | (406)
Income (Loss) Before Income Taxes |  |  |  |  |  |  |  |  | (374) | 608 | 3,381
Tax benefit (expense) |  |  |  |  |  |  |  |  | 136 | (148) | (1,423)
Total reclassifications for the period, net of tax |  |  |  |  |  |  |  |  | (238) | 460 | 1,958
Unrealized Gains (Losses) on Available-for-Sale Securities [Member] | Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member] |  |  |  |  |  |  |  |  |  |  |
Reclassification Adjustment Out of Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net investment gain (loss) |  |  |  |  |  |  |  |  | $ 397 | $ 804 | 4,864
Impairment Expense [Member] | Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member] |  |  |  |  |  |  |  |  |  |  |
Reclassification Adjustment Out of Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Net investment gain (loss) |  |  |  |  |  |  |  |  |  |  | (180)
Net Losses on Derivatives Designated as Hedging Instruments [Member] | Reclassification Out of Accumulated Other Comprehensive Income (Loss) [Member] |  |  |  |  |  |  |  |  |  |  |
Reclassification Adjustment Out of Accumulated Other Comprehensive Income (Loss) [Line Items] |  |  |  |  |  |  |  |  |  |  |
Cost of sales |  |  |  |  |  |  |  |  |  |  | $ (897)

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- Definition The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.2(a),(d)) -URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227 + Details
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- Definition Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920 + Details
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