| Assets | — | — |
| Current assets | — | — |
| Cash and cash equivalents | 408.24a | 199.37a |
| Short-term investments | 51.99a | 81.93a |
| Accounts and notes receivable | — | — |
| Trade receivables, net | 136.75a | 147.61a |
| Other receivables, net | 25.9a | 12.77a |
| Inventories | 96.2a | 88.15a |
| Other current assets | 66.87a | 71.17a |
| Total current assets | 785.96a | 601.01a |
| Property, plant and equipment | — | — |
| Property, plant and equipment | 5,764.08a | 5,552.4a |
| Less - accumulated depreciation, depletion and amortization | 3,842.38a | 3,649.28a |
| Total property, plant and equipment - net | 1,921.7a | 1,903.12a |
| Other assets | — | — |
| Right of use asset - operating leases | 5.51a | 14.66a |
| Global water treatment trust fund | 12.05a | 0a |
| Salary retirement | 41.94a | 47.25a |
| Other noncurrent assets, net | 112.38a | 108.97a |
| Total other assets | 171.89a | 170.87a |
| Total assets | 2,879.54a | 2,675a |
| Liabilities and equity | — | — |
| Current liabilities | — | — |
| Accounts payable | 143.64a | 137.24a |
| Current portion of long-term debt | 112.87a | 11.11a |
| Operating lease liability, current portion | 0.61a | 4.77a |
| Other accrued liabilities | 261.57a | 290.61a |
| Total current liabilities | 518.68a | 443.72a |
| Long-term debt | — | — |
| Long-term debt | 79.52a | 181.89a |
| Finance lease obligations | 15.27a | 4.18a |
| Total long-term debt | 94.79a | 186.07a |
| Deferred credits and other liabilities | — | — |
| Postretirement benefits other than pensions | 176.25a | 207.91a |
| Pneumoconiosis benefits | 145.49a | 154.94a |
| Asset retirement obligations | 212.18a | 212.62a |
| Workers' compensation | 36.05a | 39.14a |
| Salary retirement | 20.07a | 20.81a |
| Operating lease liability | 5.47a | 10.39a |
| Deferred income taxes | 49.21a | 36.22a |
| Other noncurrent liabilities | 53.1a | 19.74a |
| Total deferred credits and other liabilities | 697.82a | 701.77a |
| Total liabilities | 1,311.3a | 1,331.56a |
| Stockholders' equity | — | — |
| Common stock | 0.29a | 0.3a |
| Capital in excess of par value | 540.41a | 547.86a |
| Retained earnings | 1,162.11a | 944.34a |
| Accumulated other comprehensive loss | -134.57a | -149.06a |
| Total equity | 1,568.25a | 1,343.44a |
| Total liabilities and equity | 2,879.54a | 2,675a |