Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended			36 Months Ended	48 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2014
Income Tax Disclosure [Line Items]
One-time deferred tax benefit due to tax reform legislation	$ (1,168)	$ 0	$ 0
Unrecognized tax benefits	1,317	1,456	1,780	$ 1,456	$ 1,317	$ 1,687
Total income tax benefit recorded related to the Tronox-related contingent liability	1,477	1,021	$ 2,877
Income taxes receivable	154	247		247	154
Unrecognized tax benefits that would affect the effective tax rate on income if recognized	1,250				1,250
Accrued interest related to uncertain tax positions	86	31		31	86
Interest and penalties recognized in income tax expense (benefit)	55	21
Minimum [Member]
Income Tax Disclosure [Line Items]
Unrecognized tax benefits expected to reverse within the next 12 months due to expiration of statutes of limitation and audit settlements	20				20
Maximum [Member]
Income Tax Disclosure [Line Items]
Unrecognized tax benefits expected to reverse within the next 12 months due to expiration of statutes of limitation and audit settlements	50				50
Portion Of Unrecognized Tax Benefits With Highly Certain Deductibility [Member]
Income Tax Disclosure [Line Items]
Unrecognized tax benefits	1,290				1,290
Portion Of Unrecognized Tax Benefits With Highly Certain Deductibility And Uncertain Timing [Member]
Income Tax Disclosure [Line Items]
Unrecognized tax benefits	27				27
Tronox Litigation [Member] | Judicial Ruling [Member]
Income Tax Disclosure [Line Items]
Unrecognized tax benefits	1,200	1,300		1,300	1,200
Tentative tax refund received		$ 881
Total income tax benefit recorded related to the Tronox-related contingent liability				$ 576	$ 346
Foreign Tax Credits [Member]
Income Tax Disclosure [Line Items]
Increase in valuation allowance	$ 236