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Debt - Public Debt (Details) - USD ($) |  |  |  |  |  |  | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Sep. 02, 2021 | Sep. 01, 2021 | May 03, 2021 | Jan. 15, 2021 | May 21, 2020 | Apr. 06, 2020 | Dec. 31, 2021 | Sep. 30, 2021 | Jun. 30, 2021 | Jun. 30, 2020 | Sep. 30, 2020 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | Apr. 24, 2020
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Early redemption of debt | $ 600,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Early termination premium |  |  |  |  |  |  |  |  |  | $ 35,000,000 |  |  |  |  |
Debt prepayment cost |  |  |  |  |  |  |  |  |  |  |  | $ 138,000,000 | $ 59,000,000 | $ 0 |
Interest expense |  |  |  |  |  |  |  |  |  |  | $ 17,000,000 |  |  |  |
5.125% Notes, due 2024 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Early redemption of debt |  |  |  |  |  |  | $ 100,000,000 | $ 100,000,000 |  |  |  |  |  |  |
Long- term debt, interest rate |  |  |  |  |  |  | 5.125% | 5.125% |  |  |  | 5.125% |  |  |
Repurchase of debt |  |  |  |  |  |  | $ 111,000,000 | $ 111,000,000 |  |  |  |  |  |  |
Early termination premium |  |  |  |  |  |  | 10,000,000 | 10,000,000 |  |  |  |  |  |  |
Interest expense |  |  |  |  |  |  | $ 1,000,000 | $ 1,000,000 |  |  |  |  |  |  |
6.875% Notes, due 2025 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long- term debt, interest rate | 6.875% |  |  |  |  |  | 6.875% |  |  |  |  | 6.875% |  |  | 6.875%
Early termination premium | $ 105,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest expense | $ 14,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,200,000,000
Deferred financing costs |  |  |  |  |  |  |  |  |  | 14,000,000 |  |  |  |  |
3.000% Notes due 2029 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Early redemption of debt |  | $ 700,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Long- term debt, interest rate |  | 3.00% |  |  |  |  |  |  |  |  |  |  |  |  |
5.870% Notes, due 2022(2) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Early redemption of debt |  |  | $ 476,000,000 |  | $ 151,000,000 |  |  |  |  |  |  |  |  |  |
Long- term debt, interest rate |  |  |  |  | 5.87% |  |  |  |  |  |  |  | 5.87% |  |
Early termination premium |  |  |  |  |  |  |  |  | $ 23,000,000 |  |  |  |  |  |
Debt prepayment cost |  |  | 503,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Debt prepayment, accrued interest |  |  | $ 5,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Interest expense |  |  |  |  |  |  |  |  |  |  | $ 4,000,000 |  |  |  |
5.400% Notes, due 2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Early redemption of debt |  |  |  | $ 361,000,000 | $ 589,000,000 | $ 300,000,000 |  |  |  |  |  |  |  |  |
Long- term debt, interest rate |  |  |  | 5.40% | 5.40% | 5.40% |  |  |  |  |  |  | 5.40% |  |
Early termination premium |  |  |  | $ 5,000,000 |  |  |  |  |  |  |  |  |  |  |
Debt prepayment cost |  |  |  |  |  | $ 315,000,000 |  |  |  |  |  |  |  |  |
Interest expense |  |  |  |  |  |  |  |  |  | $ 24,000,000 |  |  |  |  |
6.150% Notes, due 2020 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Early redemption of debt |  |  |  |  |  | $ 1,000,000,000 |  |  |  |  |  |  |  |  |
Long- term debt, interest rate |  |  |  |  |  | 6.15% |  |  |  |  |  |  |  |  |
Debt prepayment cost |  |  |  |  |  | $ 1,020,000,000 |  |  |  |  |  |  |  |  |

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