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Inventories (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | Dec. 31, 2020
Inventory [Line Items] |  |  |  |  |
Raw materials and supplies | $ 195.5 |  | $ 195.5 |  | $ 207.6
Work-in-process | 804.0 |  | 804.0 |  | 690.7
Finished goods | 125.1 |  | 125.1 |  | 181.6
Total inventories at current cost | 1,124.6 |  | 1,124.6 |  | 1,079.9
Adjustment from current cost to LIFO cost basis | 0.3 |  | 0.3 |  | 44.1
Inventory valuation reserves | (69.1) |  | (69.1) |  | (126.9)
Total inventories, net | 1,055.8 |  | 1,055.8 |  | 997.1
LIFO benefit (charge) |  |  | (43.8) | $ 7.5 |
NRV benefit (charge) |  |  | 43.8 | (7.5) |
Net cost of sales impact | 0.0 | $ 0.0 | 0.0 | $ 0.0 |
Net Realizable Value Reserve [Member] |  |  |  |  |
Inventory [Line Items] |  |  |  |  |
Inventory valuation reserves | $ (0.3) |  | $ (0.3) |  | $ (44.1)

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