| In millions, except per share items | Jun-30-23 | Mar-31-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 |
| | 10-Q | 10-Q | 10-K | 8-K | 10-Q | 10-Q | 10-K | 10-Q |
| Net revenues | | | | | | | | |
| Revenues | 246.9 | 243.5 | 269.1 | 294.0 | 266.8 | 206.6 | 189.9 | 189.6 |
| Revenues growth | -7.4% | 17.9% | 41.7% | 55.1% | 58.3% | 35.1% | 35.5% | 33.3% |
| Cost of sales: | | | | | | | | |
| Cost of materials and other | | | | | | | | |
| Operating expenses (excluding depreciation and amortization presented below) | 28.5 | 24.2 | 11.4 | 31.4 | 20.3 | 17.5 | 40.9 | 6.9 |
| Depreciation and amortization | 22.5 | 19.8 | | | 12.9 | 9.9 | 11.6 | 9.7 |
| Total cost of sales | 179.1 | 170.1 | | | 209.6 | 153.6 | 455.4 | 9.7 |
| Operating expenses related to wholesale business | 0.5 | 0.5 | | | 0.7 | 0.6 | | |
| General and administrative expenses | 6.6 | 7.5 | 3.4 | 12.0 | 13.8 | 5.1 | 4.4 | 6.1 |
| Depreciation and amortization | 1.3 | 1.3 | -40.5 | 19.5 | 0.5 | 0.5 | 0.4 | 0.5 |
| (Gain) loss on disposal of assets | -0.5 | 0.1 | 0.0 | -0.1 | | 0.0 | -0.1 | 0.3 |
| Total operating costs and expenses | 394.5 | 373.9 | 420.8 | 488.2 | 454.4 | 330.9 | 684.8 | 139.0 |
| Operating income | 59.9 | 63.9 | 61.6 | 59.0 | 42.2 | 46.8 | 49.4 | 50.6 |
| Operating margin | 24.3% | 26.3% | 22.9% | 20.1% | 15.8% | 22.7% | 26.0% | 26.7% |
| Interest expense, net | -35.1 | -32.6 | -28.7 | -22.6 | -16.8 | -14.3 | -14.3 | -14.5 |
| Income from equity method investments | -7.3 | -6.3 | -9.0 | -8.6 | -7.1 | -7.0 | -6.6 | -7.3 |
| Other income, net | 0.0 | 0.0 | -2.1 | 0.0 | 0.0 | 0.0 | 0.0 | -0.1 |
| Total non-operating expenses, net | 27.8 | 26.3 | 19.3 | 14.0 | 9.7 | 7.2 | 7.7 | 7.2 |
| Income before income tax expense | 32.2 | 37.7 | | | 32.5 | 39.6 | 41.7 | 43.4 |
| Income tax expense | 0.3 | 0.3 | -0.4 | 0.4 | 0.3 | 0.1 | 0.0 | -0.2 |
| Net income attributable to partners | 31.9 | 37.4 | 42.7 | 44.7 | 32.2 | 39.5 | 41.7 | 43.6 |
| Comprehensive income attributable to partners | 31.9 | 37.4 | 42.7 | 44.7 | 32.2 | 39.5 | 41.7 | 43.6 |
| |
| Net income per limited partner unit: | | | | | | | | |
| Basic (in dollars per unit) | $0.73 | $0.86 | ($43,477,797.34) | $43,485,779.00 | $0.74 | $0.91 | $0.96 | $1.00 |
| Diluted (in dollars per unit) | $0.73 | $0.86 | ($43,499,833.34) | $43,515,960.00 | $0.74 | $0.91 | $0.96 | $1.00 |
| |
| Weighted average limited partner units outstanding: | | | | | | | | |
| Basic (in units) | 43.6 | 43.6 | | | 43.5 | 43.5 | 43.4 | 43.5 |
| Diluted (in units) | 43.6 | 43.6 | | | 43.5 | 43.5 | 43.5 | 43.5 |
| Cash distributions per limited partner unit (in dollars per unit) | 0.0 | 0.0 | | | 0.0 | 0.0 | 0.0 | 0.0 |