Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Current portion of long-term debt:
Current portion of long-term debt	$ 26	$ 18
Non-current portion of long-term debt:
Debt issuance costs	(8)	(7)
Total	$ 1,596	1,237
1.125% Convertible Notes
Debt Instrument [Line Items]
Percentage of contractual interest rate	1.125%
5.375% Notes
Debt Instrument [Line Items]
Percentage of contractual interest rate	5.375%
4.875% Notes due 2025
Debt Instrument [Line Items]
Percentage of contractual interest rate	4.875%
Convertible Notes \| 1.125% Convertible Notes
Debt Instrument [Line Items]
Percentage of contractual interest rate	1.125%
Current portion of long-term debt:
Debt net of unamortized discount	$ 0	12
Term Loan Facility \| Term Loan Facility
Current portion of long-term debt:
Debt net of unamortized discount	26	6
Non-current portion of long-term debt:
Debt net of unamortized debt discount	$ 574	214
Senior Notes \| 5.375% Notes
Debt Instrument [Line Items]
Percentage of contractual interest rate	5.375%
Non-current portion of long-term debt:
Debt net of unamortized debt discount	$ 700	700
Senior Notes \| 4.875% Notes due 2025
Debt Instrument [Line Items]
Percentage of contractual interest rate	4.875%
Non-current portion of long-term debt:
Debt net of unamortized debt discount	$ 330	$ 330

Long-Term Debt, Current Maturities, Net Of Unamortized Premium (Discount)

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Long-Term Debt, Noncurrent, Net Of Unamortized Debt Discount

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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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Amount, after accumulated amortization, of debt issuance costs classified as noncurrent. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount of long-term debt and lease obligation, classified as current.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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