Restructuring and Other Charges - Activity and Reserve Balances for Restructuring Charges (Parenthetical) (Detail) € in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2015 EUR (€)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Restructuring Cost and Reserve [Line Items]
Other layoff cost including reclassification in pension cost			$ 291	$ 246	$ 185
Restructuring and other charges	$ 735	€ 150	1,195	1,168	782
Pension Costs [Member]
Restructuring Cost and Reserve [Line Items]
Other layoff cost including reclassification in pension cost			35	26	92
Restructuring and other charges			30	26
Asset Retirement Obligations [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges			76	95	58
Environmental Remediation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges			$ 86	$ 47	$ 12