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v3.20.2

Fair Value Measurements - Level 3 Reconciliation (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Nordpool Power Price Swap [Member] |  |  |  |
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] |  |  |  |
Balance, beginning |  |  |  | $ 4.7
Total realized/unrealized gains (losses) |  |  |  |
Included in net income (loss) |  |  |  | (1.0)
Purchases, sales, settlements |  |  |  |
Purchases |  |  |  | 0.0
Sales |  |  |  | 0.0
Settlements |  |  |  | 0.0
Transfers into Level 3 |  |  |  | 0.0
Transfers out of Level 3 |  |  |  | (3.7)
Balance, ending |  | $ 0.0 |  | 0.0
Change in unrealized gains (losses) |  |  |  | (1.0)
LME Swap [Member] |  |  |  |
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] |  |  |  |
Balance, beginning | $ 6.1 |  | $ 10.6 |
Total realized/unrealized gains (losses) |  |  |  |
Included in net income (loss) | (4.2) |  | 0.8 |
Purchases, sales, settlements |  |  |  |
Purchases | 0.0 |  | 0.0 |
Sales | 0.0 |  | 0.0 |
Settlements | 0.0 |  | 0.0 |
Transfers into Level 3 | 4.7 |  | 4.7 |
Transfers out of Level 3 | 0.0 |  | (9.5) |
Balance, ending | 6.6 |  | 6.6 |
Change in unrealized gains (losses) | (4.2) |  | 0.8 |
Hawesville L4 Power Price Swaps [Member] |  |  |  |
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] |  |  |  |
Balance, beginning | (1.5) | (2.7) | (2.9) | 0.0
Total realized/unrealized gains (losses) |  |  |  |
Included in net income (loss) | (0.2) | 1.2 | (1.6) | 1.2
Purchases, sales, settlements |  |  |  |
Purchases | 0.0 | 0.0 | 0.0 | 0.0
Sales | 0.0 | 0.0 | 0.0 | 0.0
Settlements | 0.9 | 0.0 | 3.7 | 0.0
Transfers into Level 3 | 0.0 | 0.0 | 0.0 | (2.7)
Transfers out of Level 3 | 0.0 | 0.0 | 0.0 | 0.0
Balance, ending | (0.8) | (1.5) | (0.8) | (1.5)
Change in unrealized gains (losses) | $ 0.7 | 1.2 | $ 2.1 | (1.5)
FX Swap [Member] |  |  |  |
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] |  |  |  |
Balance, beginning |  |  |  | (0.3)
Total realized/unrealized gains (losses) |  |  |  |
Included in net income (loss) |  |  |  | (0.3)
Purchases, sales, settlements |  |  |  |
Purchases |  |  |  | 0.0
Sales |  |  |  | 0.0
Settlements |  |  |  | 0.0
Transfers into Level 3 |  |  |  | 0.0
Transfers out of Level 3 |  |  |  | 0.6
Balance, ending |  | 0.0 |  | 0.0
Change in unrealized gains (losses) |  |  |  | (0.3)
United States [Member] | LME Swap [Member] |  |  |  |
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] |  |  |  |
Balance, beginning |  | 6.9 |  | 0.3
Total realized/unrealized gains (losses) |  |  |  |
Included in net income (loss) |  | 8.8 |  | 15.6
Purchases, sales, settlements |  |  |  |
Purchases |  | 0.0 |  | 0.0
Sales |  | 0.0 |  | 0.0
Settlements |  | 0.0 |  | 0.0
Transfers into Level 3 |  | 0.0 |  | (0.2)
Transfers out of Level 3 |  | 0.0 |  | 0.0
Balance, ending |  | 15.7 |  | 15.7
Change in unrealized gains (losses) |  | 8.8 |  | 15.4
Iceland [Member] | LME Swap [Member] |  |  |  |
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] |  |  |  |
Balance, beginning |  |  |  | (0.2)
Total realized/unrealized gains (losses) |  |  |  |
Included in net income (loss) |  |  |  | (0.1)
Purchases, sales, settlements |  |  |  |
Purchases |  |  |  | 0.0
Sales |  |  |  | 0.0
Settlements |  |  |  | 0.0
Transfers into Level 3 |  |  |  | 0.0
Transfers out of Level 3 |  |  |  | 0.3
Balance, ending |  | $ 0.0 |  | 0.0
Change in unrealized gains (losses) |  |  |  | $ (0.1)

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- Definition Amount of gain (loss) recognized in income from derivative asset (liability) after deduction of derivative liability (asset), measured at fair value on recurring basis using unobservable input (level 3). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19279-110258 + Details
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- Definition Amount of purchases of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19279-110258 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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