| In millions, except per share items | Jun-30-23 | Dec-31-22 | Sep-30-22 | Jun-30-22 | Mar-31-22 | Dec-31-21 | Sep-30-21 | Jun-30-21 |
| | 10-Q | 10-K | 10-Q | 10-Q | 10-Q | 10-K | 10-Q | 10-Q |
| Net income | | 387.9 | 135.5 | -45.3 | -133.1 | -133.5 | -216.4 | -135.1 |
| Depreciation and amortization [+] | | 111.2 | 110.5 | 110.2 | 99.7 | 89.1 | 79.6 | 71.0 |
| Depreciation | | 110.4 | 109.0 | 107.1 | 96.9 | 86.7 | 59.6 | 90.0 |
| Amortization of intangible assets | | | 1.5 | 3.1 | 2.8 | 2.4 | 1.7 | |
| Asset impairment charges | | | | | 5.2 | | | 101.1 |
| Stock-based compensation | | 6.7 | 6.1 | 11.0 | 10.6 | 10.5 | 10.5 | 5.4 |
| Change in working capital [+] | | -145.2 | -92.0 | -58.0 | -1.1 | -2.5 | 28.1 | 53.7 |
| Accounts receivable | | -182.7 | -133.3 | -83.7 | -27.1 | -16.5 | 21.8 | 49.9 |
| Deferred revenues | | 2.6 | 0.2 | | | -1.6 | 0.5 | |
| Other | | 34.9 | 41.0 | 24.3 | 24.6 | 15.6 | 5.7 | 6.8 |
| Other operating activities | | -74.6 | -82.7 | -58.4 | -56.2 | -43.3 | -22.8 | -30.2 |
| Cash from operations | | 287.8 | 79.0 | -38.8 | -75.0 | -76.2 | -31.7 | 65.9 |
| |
| Capital expenditures [+] | | -0.7 | -1.2 | -1.2 | 1.8 | -1.0 | -0.5 | -0.4 |
| Purchases of property and equipment | | -0.7 | -1.2 | -1.2 | 1.8 | -1.0 | -0.5 | -0.4 |
| Sales of property and equipment | | 116.0 | 121.4 | 107.7 | 112.7 | 78.0 | 47.8 | 33.2 |
| Purchases of short-term investments | | -105.0 | -80.0 | | | | | |
| Purchases of short-term investments | | -105.0 | -80.0 | | | | | |
| Other cash from investing | | 32.5 | 29.0 | 212.4 | 7.5 | 56.2 | 132.2 | 6.3 |
| Cash from investing | | 42.8 | 69.2 | 318.9 | 122.1 | 133.3 | 179.5 | 39.1 |
| |
| Cash dividends paid | | -69.8 | -17.8 | -46.5 | -42.2 | -40.9 | -39.6 | -6.7 |
| Repurchase of common stock, net | | | -36.7 | | | -16.7 | | |
| Financing costs | | 0.0 | 165.9 | -0.5 | | 0.0 | -166.6 | 0.0 |
| Other cash from financing | | -95.9 | 115.1 | -119.2 | -85.0 | -116.2 | -296.0 | -109.2 |
| Cash from financing | | -185.8 | -105.3 | -181.9 | -143.9 | -173.8 | -168.9 | -115.9 |
| |
| Free cash flow | | 287.1 | 77.8 | -40.0 | -73.2 | -77.2 | -32.1 | 65.5 |
| Per share (diluted) | | $5.77 | $1.66 | ($0.87) | ($1.80) | ($2.18) | ($0.98) | $2.33 |