Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2016	Dec. 31, 2017
Income Tax Disclosure [Line Items]
Income Tax Expense (Benefit)	$ 125	$ (38)	$ 251	$ 59
Tronox Litigation [Member] | Judicial Ruling [Member]
Income Tax Disclosure [Line Items]
Income Tax Expense (Benefit)			(346)	$ (346)
Unrecognized tax benefits	$ 1,200		$ 1,200			$ 1,200
Income tax refunds					$ 881