Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
U.S. federal statutory rate	35.00%	35.00%	35.00%	35.00%
Accounts Receivable Other [Member]
Income Tax Disclosure [Line Items]
Income taxes receivable	$ 959		$ 959
Tronox Litigation [Member] | Judicial Ruling [Member]
Income Tax Disclosure [Line Items]
Tax benefit related to the Tronox settlement	577		577
Uncertain tax position			1,300
Tronox Litigation [Member] | Judicial Ruling [Member] | Accounts Receivable Other [Member]
Income Tax Disclosure [Line Items]
Tax benefit related to the Tronox settlement	$ 887		$ 887