Summary of Property, Plant and Equipment |
Property, plant, and equipment on the Consolidated Balance Sheets is summarized as follows: | | | | | | | | | | | | December 31, | (Thousands) | | 2015 | | 2014 | Land | | $ | 7,457 |
| | $ | 7,458 |
| Buildings | | 133,427 |
| | 129,673 |
| Machinery and equipment | | 597,423 |
| | 579,906 |
| Software | | 38,505 |
| | 34,525 |
| Construction in progress | | 15,449 |
| | 16,818 |
| Allowances for depreciation | | (565,203 | ) | | (534,908 | ) | Subtotal | | 227,058 |
| | 233,472 |
| Capital leases | | 10,913 |
| | 10,912 |
| Allowances for depreciation | | (2,242 | ) | | (1,988 | ) | Subtotal | | 8,671 |
| | 8,924 |
| Mineral resources | | 4,979 |
| | 4,980 |
| Mine development | | 25,681 |
| | 16,399 |
| Allowances for amortization and depletion | | (2,760 | ) | | (16,187 | ) | Subtotal | | 27,900 |
| | 5,192 |
| Property, plant, and equipment — net | | $ | 263,629 |
| | $ | 247,588 |
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