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v3.21.2

Fair Value Measurements - Level 3 Reconciliation (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020
Nord Pool Swap [Member] |  |  |  |
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] |  |  |  |
Balance, beginning | $ 1.5 |  | $ 0.0 |
Total realized/unrealized gains (losses) |  |  |  |
Included in net income (loss) | 0.0 |  | 0.0 |
Purchases, sales, settlements |  |  |  |
Purchases | 0.0 |  | 0.0 |
Sales | 0.0 |  | 0.0 |
Settlements | 0.0 |  | 0.0 |
Transfers into Level 3 | 0.0 |  | 1.5 |
Transfers out of Level 3 | (1.5) |  | (1.5) |
Balance, ending | 0.0 |  | 0.0 |
Change in unrealized gains (losses) | 0.0 |  | 0.0 |
LME Swap [Member] |  |  |  |
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] |  |  |  |
Balance, beginning | (17.9) | $ 6.1 | 2.9 | $ 10.6
Total realized/unrealized gains (losses) |  |  |  |
Included in net income (loss) | (7.7) | (4.2) | (28.0) | 0.8
Purchases, sales, settlements |  |  |  |
Purchases | 0.0 | 0.0 | 0.0 | 0.0
Sales | 0.0 | 0.0 | 0.0 | 0.0
Settlements | 0.0 |  | 0.0 | 0.0
Transfers into Level 3 | 0.0 | 4.7 | (1.0) | 4.7
Transfers out of Level 3 | 11.0 | 0.0 | 11.5 | (9.5)
Balance, ending | (14.6) | 6.6 | (14.6) | 6.6
Change in unrealized gains (losses) | (7.7) | (4.2) | (28.0) | 0.8
FX Swap [Member] |  |  |  |
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] |  |  |  |
Balance, beginning | (0.4) |  | 0.1 |
Total realized/unrealized gains (losses) |  |  |  |
Included in net income (loss) | (0.5) |  | (0.5) |
Purchases, sales, settlements |  |  |  |
Purchases | 0.0 |  | 0.0 |
Sales | 0.0 |  | 0.0 |
Settlements | 0.0 |  | 0.0 |
Transfers into Level 3 | 0.0 |  | (0.4) |
Transfers out of Level 3 | 0.0 |  | (0.1) |
Balance, ending | (0.9) |  | (0.9) |
Change in unrealized gains (losses) | $ (0.5) |  | $ (0.5) |
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) |  | (2.9)
Total realized/unrealized gains (losses) |  |  |  |
Included in net income (loss) |  | (0.2) |  | (1.6)
Purchases, sales, settlements |  |  |  |
Purchases |  | 0.0 |  | 0.0
Sales |  | 0.0 |  | 0.0
Settlements |  | 0.9 |  | 3.7
Transfers into Level 3 |  | 0.0 |  | 0.0
Transfers out of Level 3 |  | 0.0 |  | 0.0
Balance, ending |  | (0.8) |  | (0.8)
Change in unrealized gains (losses) |  | $ 0.7 |  | $ 2.1

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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=123874694&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=123874694&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=123874694&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=123874694&loc=d3e19207-110258 + Details
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- Definition Amount of sales 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 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 Reference 2: 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=123874694&loc=d3e19279-110258 + Details
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- Definition Amount of settlements of financial instrument classified as a derivative asset (liability) after deduction of derivative liability, 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=123874694&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=123874694&loc=d3e19207-110258 + Details
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- Definition Amount of transfers of financial instrument classified as a derivative asset (liability) after deduction of derivative liability (asset) into level 3 of the fair value hierarchy. + References Reference 1: 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=123874694&loc=d3e19279-110258 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=123874694&loc=d3e19207-110258 + Details
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