| Condensed Consolidated Statements of Operations [Abstract] | |
| Net sales | 2.19B |
| Operating costs and expenses: | |
| Cost of products sold (exclusive of depreciation and amortization) | 1.8B |
| Direct operating expenses (exclusive of depreciation and amortization) | 121.86M |
| Selling, general, and administrative expenses | 26.55M |
| Maintenance turnaround expense | 43.17M |
| Depreciation and amortization | 24.33M |
| Total operating costs and expenses | 2.01B |
| Operating income | 173.12M |
| Other income (expense): | |
| Interest income | 151K |
| Interest expense and other financing costs | -17.99M |
| Amortization of loan fees | -1.6M |
| Loss on extinguishment of debt | -22.05M |
| Other, net | 197K |
| Income (loss) before income taxes | 131.83M |
| Provision for income taxes | -48.11M |
| Net income (loss) | 83.72M |
| Net earnings (loss) per share: | |
| Basic | 0.96 |
| Diluted | 0.81 |
| Weighted average common shares outstanding: | |
| Basic | 86.73M |
| Diluted | 109.1M |