Debt - Schedule of Long-Term Debt (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Unamortized discounts and deferred financing costs	$ (39)	$ (33)
Long-term debt	1,802	1,404
Less: amount due within one year	1	16
Long-term debt non current	1,801	1,388
6.75% Notes, due 2024 [Member]
Debt Instrument [Line Items]
Long-term debt	750	750
7.00% Notes, due 2026 [Member]
Debt Instrument [Line Items]
Long-term debt	500	500
6.125% Notes, due 2028 [Member]
Debt Instrument [Line Items]
Long-term debt	500
BNDES Loans [member]
Debt Instrument [Line Items]
Long-term debt		137
Other [Member]
Debt Instrument [Line Items]
Long-term debt	$ 91	$ 50

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount of unamortized debt discount (premium) and debt issuance costs.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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