| Goodwill |
Changes in the carrying amount of goodwill for the six months ended June 30, 2026 are summarized as follows (dollars in thousands): | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Packaging | | | | Specialty Products | | Total | | Balance, December 31, 2025 | $ | 293,720 | | | | | $ | 6,560 | | | $ | 300,280 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Foreign currency translation and other | (3,620) | | | | | — | | | (3,620) | | | Balance, June 30, 2026 | $ | 290,100 | | | | | $ | 6,560 | | | $ | 296,660 | | | | | | | | | | | Accumulated impairment losses at June 30, 2026 | $ | 58,660 | | | | | $ | — | | | $ | 58,660 | |
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| Schedule of Intangible Assets (excluding Goodwill) by Major Class |
The Company amortizes its other intangible assets over periods ranging from one to 30 years. The gross carrying amounts and accumulated amortization of the Company's other intangibles are summarized below (dollars in thousands): | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As of June 30, 2026 | | As of December 31, 2025 | | Intangible Category by Useful Life | | Gross Carrying Amount | | Accumulated Amortization | | Gross Carrying Amount | | Accumulated Amortization | | Finite-lived intangible assets: | | | | | | | | | Customer relationships, 5 – 12 years | | $ | 98,020 | | | $ | (73,300) | | | $ | 99,270 | | | $ | (71,810) | | Customer relationships, 15 – 25 years | | 39,280 | | | (39,280) | | | 39,280 | | | (39,280) | | | Total customer relationships | | 137,300 | | | (112,580) | | | 138,550 | | | (111,090) | | Technology and other, 1 – 15 years | | 13,540 | | | (12,240) | | | 13,630 | | | (12,140) | | Technology and other, 17 – 30 years | | 41,600 | | | (39,910) | | | 41,600 | | | (39,740) | | | Total technology and other | | 55,140 | | | (52,150) | | | 55,230 | | | (51,880) | | | Indefinite-lived intangible assets: | | | | | | | | | | Trademark/Trade names | | 45,260 | | | — | | | 45,740 | | | — | | | Total other intangible assets | | $ | 237,700 | | | $ | (164,730) | | | $ | 239,520 | | | $ | (162,970) | |
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| Schedule of Finite-Lived Intangible Assets, Amortization Expense |
Amortization expense related to intangible assets as included in the accompanying consolidated statement of income is summarized as follows (dollars in thousands): | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Three months ended June 30, | | Six months ended June 30, | | | 2026 | | 2025 | | 2026 | | 2025 | | Technology and other, included in cost of sales | | $ | 190 | | | $ | 190 | | | $ | 370 | | | $ | 360 | | | Customer relationships, included in selling, general and administrative expenses | | 990 | | | 1,490 | | | 2,250 | | | 2,910 | | | Total amortization expense | | $ | 1,180 | | | $ | 1,680 | | | $ | 2,620 | | | $ | 3,270 | |
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