DEBT AND CREDIT FACILITIES - Schedule Of Long-Term Debt (Details) - USD ($) $ in Millions |
Dec. 31, 2021 |
Sep. 30, 2021 |
Feb. 17, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Debt Instrument [Line Items] |
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Total Principal Amount |
$ 5,369
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Total Debt |
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$ 5,424
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Less: current |
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34
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Total long-term debt |
5,238
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$ 5,390
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AK Steel |
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Debt Instrument [Line Items] |
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Total Principal Amount |
$ 56
|
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4.875% 2024 Senior Secured Notes | ÐÇ¿Õ´«Ã½ Inc. |
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Debt Instrument [Line Items] |
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Stated interest rate |
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4.875%
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Annual Effective Interest Rate |
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5.00%
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Total Principal Amount |
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$ 395
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Unamortized Debt Issuance Costs |
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(3)
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Unamortized Discounts |
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(1)
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Total Debt |
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$ 391
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9.875% 2025 Senior Secured Notes | ÐÇ¿Õ´«Ã½ Inc. |
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Debt Instrument [Line Items] |
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Stated interest rate |
9.875%
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9.875%
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Annual Effective Interest Rate |
10.57%
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10.57%
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Total Principal Amount |
$ 607
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$ 955
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Unamortized Debt Issuance Costs |
(4)
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(8)
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Unamortized Discounts |
(13)
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(25)
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Total Debt |
$ 590
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$ 922
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6.750% 2026 Senior Secured Notes | ÐÇ¿Õ´«Ã½ Inc. |
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Debt Instrument [Line Items] |
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Stated interest rate |
6.75%
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6.75%
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Annual Effective Interest Rate |
6.99%
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6.99%
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Total Principal Amount |
$ 845
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$ 845
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Unamortized Debt Issuance Costs |
(16)
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(20)
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Unamortized Discounts |
(7)
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(9)
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Total Debt |
$ 822
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$ 816
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7.625% 2021 AK Senior Notes | AK Steel |
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Debt Instrument [Line Items] |
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Stated interest rate |
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7.625%
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Annual Effective Interest Rate |
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7.33%
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Total Principal Amount |
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$ 34
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Unamortized Debt Issuance Costs |
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0
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Unamortized Discounts |
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0
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Total Debt |
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$ 34
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7.500% 2023 AK Senior Notes | AK Steel |
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Debt Instrument [Line Items] |
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Stated interest rate |
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7.50%
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Annual Effective Interest Rate |
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6.17%
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Total Principal Amount |
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$ 13
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Unamortized Debt Issuance Costs |
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0
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Unamortized Discounts |
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0
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Total Debt |
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$ 13
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6.375% 2025 Senior Notes | ÐÇ¿Õ´«Ã½ Inc. |
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Debt Instrument [Line Items] |
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Stated interest rate |
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6.375%
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Annual Effective Interest Rate |
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8.11%
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Total Principal Amount |
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$ 64
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Unamortized Debt Issuance Costs |
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0
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Unamortized Discounts |
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(4)
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Total Debt |
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$ 60
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6.375% 2025 AK Senior Notes | AK Steel |
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Debt Instrument [Line Items] |
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Stated interest rate |
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6.375%
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Annual Effective Interest Rate |
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8.11%
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Total Principal Amount |
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$ 29
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Unamortized Debt Issuance Costs |
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0
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Unamortized Discounts |
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(2)
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Total Debt |
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$ 27
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1.500% 2025 Convertible Senior Notes | ÐÇ¿Õ´«Ã½ Inc. |
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Debt Instrument [Line Items] |
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Stated interest rate |
1.50%
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1.50%
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Annual Effective Interest Rate |
6.26%
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6.26%
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Total Principal Amount |
$ 294
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$ 296
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Unamortized Debt Issuance Costs |
(3)
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(4)
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Unamortized Discounts |
(39)
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(49)
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Total Debt |
$ 252
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$ 243
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5.750% 2025 Senior Notes | ÐÇ¿Õ´«Ã½ Inc. |
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Debt Instrument [Line Items] |
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Stated interest rate |
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5.75%
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Annual Effective Interest Rate |
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6.01%
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Total Principal Amount |
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$ 396
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Unamortized Debt Issuance Costs |
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(3)
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Unamortized Discounts |
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(4)
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Total Debt |
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$ 389
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7.000% 2027 Senior Notes | ÐÇ¿Õ´«Ã½ Inc. |
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Debt Instrument [Line Items] |
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Stated interest rate |
7.00%
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7.00%
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Annual Effective Interest Rate |
9.24%
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9.24%
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Total Principal Amount |
$ 73
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$ 73
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Unamortized Debt Issuance Costs |
0
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0
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Unamortized Discounts |
(7)
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(8)
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Total Debt |
$ 66
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$ 65
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7.000% 2027 AK Senior Notes | AK Steel |
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Debt Instrument [Line Items] |
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Stated interest rate |
7.00%
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7.00%
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Annual Effective Interest Rate |
9.24%
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9.24%
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Total Principal Amount |
$ 56
|
$ 80
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$ 56
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Unamortized Debt Issuance Costs |
0
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0
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Unamortized Discounts |
(5)
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(6)
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Total Debt |
$ 51
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|
$ 50
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5.875% 2027 Senior Notes | ÐÇ¿Õ´«Ã½ Inc. |
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Debt Instrument [Line Items] |
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Stated interest rate |
5.875%
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5.875%
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Annual Effective Interest Rate |
6.49%
|
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|
6.49%
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Total Principal Amount |
$ 556
|
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$ 556
|
$ 750
|
Unamortized Debt Issuance Costs |
(3)
|
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(4)
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Unamortized Discounts |
(15)
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|
(18)
|
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Total Debt |
$ 538
|
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|
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|
$ 534
|
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4.625% 2029 Senior Notes | ÐÇ¿Õ´«Ã½ Inc. |
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Debt Instrument [Line Items] |
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Stated interest rate |
4.625%
|
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Annual Effective Interest Rate |
4.63%
|
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Total Principal Amount |
$ 500
|
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|
$ 500
|
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Unamortized Debt Issuance Costs |
(8)
|
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Unamortized Discounts |
0
|
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|
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|
Ìý
|
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|
Total Debt |
$ 492
|
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|
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|
Ìý
|
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4.875% 2031 Senior Notes | ÐÇ¿Õ´«Ã½ Inc. |
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|
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|
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Debt Instrument [Line Items] |
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Stated interest rate |
4.875%
|
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|
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|
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Annual Effective Interest Rate |
4.88%
|
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|
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|
Ìý
|
Ìý
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Total Principal Amount |
$ 500
|
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|
$ 500
|
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Unamortized Debt Issuance Costs |
(8)
|
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|
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|
Ìý
|
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Unamortized Discounts |
0
|
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|
Ìý
|
Ìý
|
Ìý
|
Total Debt |
$ 492
|
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|
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|
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|
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6.250% 2040 Senior Notes | ÐÇ¿Õ´«Ã½ Inc. |
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Debt Instrument [Line Items] |
Ìý
|
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|
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|
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|
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Stated interest rate |
6.25%
|
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|
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|
6.25%
|
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Annual Effective Interest Rate |
6.34%
|
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|
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|
6.34%
|
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|
Total Principal Amount |
$ 263
|
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|
Ìý
|
$ 263
|
Ìý
|
Unamortized Debt Issuance Costs |
(2)
|
Ìý
|
Ìý
|
(2)
|
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|
Unamortized Discounts |
(3)
|
Ìý
|
Ìý
|
(3)
|
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|
Total Debt |
258
|
Ìý
|
Ìý
|
258
|
Ìý
|
Industrial Revenue Bonds | AK Steel |
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|
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Debt Instrument [Line Items] |
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Total Principal Amount |
66
|
Ìý
|
Ìý
|
92
|
Ìý
|
Unamortized Debt Issuance Costs |
0
|
Ìý
|
Ìý
|
0
|
Ìý
|
Unamortized Premiums |
2
|
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|
Ìý
|
2
|
Ìý
|
Total Debt |
68
|
Ìý
|
Ìý
|
$ 94
|
Ìý
|
EDC Revolving Credit Facility | ÐÇ¿Õ´«Ã½ Inc. |
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Debt Instrument [Line Items] |
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Annual Effective Interest Rate |
Ìý
|
Ìý
|
Ìý
|
3.25%
|
Ìý
|
Credit facility, maximum borrowing capacity |
Ìý
|
Ìý
|
Ìý
|
$ 40
|
Ìý
|
Credit facility, amount outstanding |
Ìý
|
Ìý
|
Ìý
|
$ 18
|
Ìý
|
ABL Facility |
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Debt Instrument [Line Items] |
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Credit facility, amount outstanding |
$ 1,609
|
Ìý
|
Ìý
|
Ìý
|
Ìý
|
ABL Facility | ÐÇ¿Õ´«Ã½ Inc. |
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Debt Instrument [Line Items] |
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Ìý
|
Annual Effective Interest Rate |
1.87%
|
Ìý
|
Ìý
|
2.15%
|
Ìý
|
Credit facility, maximum borrowing capacity |
$ 4,500
|
Ìý
|
Ìý
|
$ 3,500
|
Ìý
|
Credit facility, amount outstanding |
$ 1,609
|
Ìý
|
Ìý
|
$ 1,510
|
Ìý
|