Supplemental Cash Flow Information - Supplemental Information (Details) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
|
| Supplemental cash flow information | |||
| Cash paid for interest, net of amount capitalized | $ 653.4 | $ 485.2 | $ 473.8 |
| Cash paid (received) for income taxes, net | (58.9) | 52.4 | 33.8 |
| Cash received for sale of PTCs to a third party | 75.0 | ||
| Significant non-cash investing and financing transactions | |||
| Accounts payable related to construction costs | 171.3 | 197.4 | 127.8 |
| Increase in receivables related to insurance proceeds | 3.5 | 0.0 | 41.7 |
| Liabilities accrued for software licensing agreement | $ 0.0 | $ 7.4 | $ 0.0 |