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Interest Income (Expense), Net - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net Investment Income [Line Items]
Capitalized borrowing cost	$ 0	$ 0	$ 0
Floating Rate Notes [Member]
Net Investment Income [Line Items]
Interest income (expense), net	6,000,000	6,000,000	6,000,000
Senior Unsecured Convertible Debt [Member]
Net Investment Income [Line Items]
Interest expense	39,000,000	38,000,000	37,000,000
Non-cash interest expense accretion of discount on liability component	$ 37,000,000	$ 36,000,000	$ 33,000,000
Issued date of senior unsecured convertible bonds	Jul. 31, 2017	Jul. 31, 2014

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Amount recognized for the passage of time, typically for liabilities, that have been discounted to their net present values. Excludes accretion associated with asset retirement obligations.

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

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