v3.21.1

Debt (Exchange and Issue) (Details) $ / shares in Units, $ in Millions			3 Months Ended		12 Months Ended
	Feb. 26, 2021 USD ($) $ / shares	Jan. 17, 2020 USD ($)	Mar. 31, 2021 USD ($) $ / shares	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Debt
Issuance of debt in exchange transactions			$ 294
Aggregate cash payment			12	$ 813
Proceeds from issuance of debt				$ 743
Exchanged
Debt
Issuance of debt in exchange transactions			294
Aggregate cash payment			$ 11
0.50% Exchangeable Senior Bonds due January 2023
Debt
Debt conversion ratio			0.09729756
Debt conversion (in dollars per share) | $ / shares			$ 10.28
Effective interest rate (as a percent)			0.50%
Fair value of debt			$ 104
Equity component of convertible debt instruments			$ 172		$ 172
Aggregate cash payment	$ 11
Original debt in exchange	323
Gains (losses) on restructuring	$ 51
Gains (losses) on restructuring (in dollars per share) | $ / shares	$ 0.08
4.00% Senior Guaranteed Exchangeable Bonds due December 2025
Debt
Debt conversion ratio			0.19047620
Debt conversion (in dollars per share) | $ / shares			$ 5.25
Effective interest rate (as a percent)			6.90%
Fair value of debt			$ 280
Equity component of convertible debt instruments	$ 260
Issuance of debt in exchange transactions	$ 294
2.50% Senior Guaranteed Exchangeable Bonds due January 2027
Debt
Debt conversion ratio			0.16216260
Debt conversion (in dollars per share) | $ / shares			$ 6.17
Effective interest rate (as a percent)			0.00%
Fair value of debt			$ 195
8.00% Senior Notes due February 2027
Debt
Debt instrument face value		$ 750
Proceeds from issuance of debt		$ 743
Redemption price of debt instrument (as a percent)		100.00%

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- Definition

Adjustment to additional paid in capital resulting from the recognition of convertible debt instruments as two separate components - a debt component and an equity component. This bifurcation may result in a basis difference associated with the liability component that represents a temporary difference for purposes of applying accounting for income taxes. The initial recognition of deferred taxes for the tax effect of that temporary difference is as an adjustment to additional paid in capital.

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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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The amount of the original debt being converted 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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The price per share of the conversion feature embedded in the debt instrument.

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Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

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Face (par) amount of debt instrument at time of issuance.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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For a debtor, the aggregate gain (loss) recognized on the restructuring of payables arises from the difference between the book value of the debt before the restructuring and the fair value of the payments on the debt after restructuring is complete.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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The cash inflow from additional borrowings, net of cash paid to third parties in connection with debt origination.

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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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Provide the per share amount of gain (loss), after the impact of income taxes, on restructuring of payables (or debt) for all restructuring gains (losses) (in aggregate) during the period.

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