| In millions, except per share items | Dec-31-22 | Dec-31-21 | Dec-31-20 | Dec-31-19 | Dec-31-18 | Dec-31-17 | Dec-31-16 | Dec-31-15 |
| | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K | 10-K |
| Cash Flows from Operating Activities: | | | | | | | | |
| Net income | 387.9 | -134.7 | -5.5 | -0.8 | -88.9 | -106.1 | | |
| Items included in net income not affecting cash flows: | | | | | | | | |
| Depreciation and amortization | 110.4 | 86.7 | | | | | | |
| Loss on write-down of vessels and other assets | 1.7 | 3.5 | 103.0 | | 19.0 | 88.4 | 79.2 | |
| Amortization of debt discount and other deferred financing costs | 5.2 | 2.3 | 2.9 | 6.9 | 6.2 | 6.4 | 6.6 | 5.8 |
| Amortization of time charter hire contracts acquired | 0.8 | 2.4 | | | | | | |
| Deferred financing costs write-off | 1.3 | 2.1 | 13.1 | 3.6 | 2.4 | 7.0 | | |
| Stock compensation | 6.7 | 10.5 | 5.6 | 4.3 | 3.2 | 3.8 | 2.8 | 2.8 |
| Earnings of affiliated companies | -10.3 | -21.8 | -4.0 | -30.3 | -29.2 | -49.4 | -17.8 | -38.7 |
| Other - net | -2.2 | 3.0 | 1.7 | 1.5 | 0.4 | 0.1 | 0.5 | 0.0 |
| Items included in net income/(loss) related to investing and financing activities: | | | | | | | | |
| Gain on disposal of vessels and other assets, net | -21.3 | -13.3 | -2.9 | 0.3 | 0.6 | -1.6 | 0.0 | -4.5 |
| Loss on sale of investment in affiliated companies | 9.5 | | | -3.0 | | | | |
| Cash distributions from affiliated companies | 3.1 | 9.8 | 4.6 | 13.9 | 43.6 | 21.2 | | |
| Payments for drydocking | -43.3 | -42.4 | -25.6 | -19.5 | -4.5 | -21.4 | -9.3 | -20.7 |
| Insurance claims proceeds related to vessel operations | 5.3 | 1.8 | 5.2 | 2.2 | 5.4 | 2.0 | 1.9 | |
| Changes in operating assets and liabilities: | | | | | | | | |
| Decrease/(increase) in receivables | -182.7 | -16.5 | 40.5 | 10.8 | -36.4 | 8.7 | 8.0 | 13.4 |
| Decrease in deferred revenue | 2.6 | -1.6 | 3.0 | 0.0 | -0.9 | -4.7 | 4.4 | |
| Net change in inventories, prepaid expenses and other current assets and accounts payable, accrued expense, and other current and long-term liabilities | 13.1 | -3.6 | -2.3 | 0.4 | -7.2 | -16.0 | -5.1 | 3.0 |
| Net cash provided by operating activities | 287.8 | -76.2 | 216.1 | 87.5 | -12.5 | 17.4 | 129.0 | 222.7 |
| |
| Cash Flows from Investing Activities: | | | | | | | | |
| Expenditures for vessels, vessel improvements and vessels under construction | -116.0 | -78.0 | -50.0 | | | | | |
| Proceeds from disposal of vessels and other assets | 99.2 | 165.8 | 73.1 | | | | | |
| Expenditures for other property | -0.7 | -1.0 | -0.5 | -0.6 | -1.1 | -0.4 | -0.9 | |
| Proceeds from sale of investment in affiliated companies | 139.0 | | | 122.8 | | | | |
| Investments in short term time deposits | -105.0 | | | | | | | |
| Proceeds from maturities of short term time deposits | 25.0 | | | | | | | |
| Net cash (used in)/provided by investing activities | 42.8 | 133.3 | 32.4 | 107.9 | 123.7 | -136.8 | 2.5 | 114.2 |
| |
| Cash Flows from Financing Activities: | | | | | | | | |
| Issuance of debt, net of issuance and deferred financing costs | | | | | | | | |
| Borrowings on long term debt, net of lenders' fees and deferred financing costs | 640.1 | 83.7 | 363.0 | | | | | |
| Repayments of debt | -798.7 | -619.3 | -504.9 | -49.9 | -71.6 | -55.0 | | |
| Proceeds from sale and leaseback financing, net of issuance and deferred financing costs | 108.0 | 447.1 | | | | | | |
| Cash dividends paid | -69.8 | -40.9 | -6.8 | | | | -202.0 | -200.0 |
| Repurchases of common stock | -20.0 | -16.7 | -30.0 | | | | | |
| Cash paid to tax authority upon vesting or exercise of stock-based compensation | -6.1 | -1.1 | -1.5 | -0.4 | -0.4 | -0.3 | 0.0 | |
| Net cash used in by financing activities | -185.8 | -173.8 | -183.1 | -162.8 | -64.2 | 98.0 | -357.3 | -206.3 |
| Net (decrease)/increase in cash, cash equivalents and restricted cash | 144.8 | -116.7 | 65.4 | | | | | |