The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Gross amount of debt extinguished.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

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Debt (Settled) (Details) - USD ($) $ in Millions		3 Months Ended	6 Months Ended
Debt (Settled) (Details) - USD ($) $ in Millions	Feb. 26, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Debt
Debt retirement			$ 324	$ 790
Aggregate cash payment			12	830
Aggregate principal amount of debt issued in exchanges			294
Aggregate net gain (loss)		$ 4	$ 51	(53)
6.50% Senior Notes due November 2020
Debt
Debt instrument interest rate stated percentage			6.50%
Debt retirement				8
6.375% Senior Notes due December 2021
Debt
Debt instrument interest rate stated percentage			6.375%
Debt retirement				38
3.80% Senior Notes due October 2022
Debt
Debt instrument interest rate stated percentage			3.80%
Debt retirement				8
0.50% Exchangeable Senior Bonds due January 2023
Debt
Debt instrument interest rate stated percentage			0.50%
Debt retirement			$ 323
Aggregate cash payment	$ 11
5.375% Senior Secured Notes due May 2023
Debt
Debt instrument interest rate stated percentage			5.375%
Debt retirement			$ 1	22
9.00% Senior Notes due July 2023
Debt
Debt instrument interest rate stated percentage			9.00%
Debt retirement				714
Redeemed
Debt
Debt retirement				714
Aggregate cash payment				767
Aggregate net gain (loss)				(65)
Redeemed \| 9.00% Senior Notes due July 2023
Debt
Debt retirement				714
Repurchased
Debt
Debt retirement			$ 1	76
Aggregate cash payment			1	63
Aggregate net gain (loss)				12
Repurchased \| 6.50% Senior Notes due November 2020
Debt
Debt retirement				8
Repurchased \| 6.375% Senior Notes due December 2021
Debt
Debt retirement				38
Repurchased \| 3.80% Senior Notes due October 2022
Debt
Debt retirement				8
Repurchased \| 5.375% Senior Secured Notes due May 2023
Debt
Debt retirement			1	$ 22
Exchanged
Debt
Debt retirement			323
Aggregate cash payment			11
Aggregate principal amount of debt issued in exchanges			294
Aggregate net gain (loss)			51
Exchanged \| 0.50% Exchangeable Senior Bonds due January 2023
Debt
Debt retirement			$ 323