Income Taxes - Additional Information (Detail) € in Millions, $ in Millions	3 Months Ended		6 Months Ended			12 Months Ended
	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 EUR (€)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Income Taxes [Line Items]
Provision for income taxes	$ (307)	$ (266)		$ (782)	$ (337)
Discrete tax expense (benefit)				(70)	41
Cash taxes paid, net of refunds	88	$ 65		226	$ 119	$ 380	$ 188
Tax contingencies	$ 1,600			$ 1,600		$ 1,600		$ 1,200
Internal Revenue Service (IRS)
Income Taxes [Line Items]
Description of the status of the tax examination			We are under examination, or may be subject to examination, by the Internal Revenue Service (“IRS”) for the calendar year 2005 and thereafter	We are under examination, or may be subject to examination, by the Internal Revenue Service (“IRS”) for the calendar year 2005 and thereafter
Tax examination, estimate of additional tax expense				$ 1,500
France
Income Taxes [Line Items]
Description of the status of the tax examination			Certain of our subsidiaries are under examination or investigation or may be subject to examination or investigation by the French Tax Administration (“FTA”) for calendar year 2006 and thereafter	Certain of our subsidiaries are under examination or investigation or may be subject to examination or investigation by the French Tax Administration (“FTA”) for calendar year 2006 and thereafter
Tax examination, estimate of additional tax expense | €			€ 196
European Union
Income Taxes [Line Items]
Description of the status of the tax examination			In addition, in October 2014, the European Commission opened a formal investigation to examine whether decisions by the tax authorities in Luxembourg with regard to the corporate income tax paid by certain of our subsidiaries comply with European Union rules on state aid.	In addition, in October 2014, the European Commission opened a formal investigation to examine whether decisions by the tax authorities in Luxembourg with regard to the corporate income tax paid by certain of our subsidiaries comply with European Union rules on state aid.
Other Foreign Jurisdictions
Income Taxes [Line Items]
Description of the status of the tax examination			We are also subject to taxation in various states and other foreign jurisdictions including Canada, China, Germany, India, Italy, Japan, Luxembourg, and the United Kingdom. We are under, or may be subject to, audit or examination and additional assessments by the relevant authorities in respect of these particular jurisdictions primarily for 2008 and thereafter.	We are also subject to taxation in various states and other foreign jurisdictions including Canada, China, Germany, India, Italy, Japan, Luxembourg, and the United Kingdom. We are under, or may be subject to, audit or examination and additional assessments by the relevant authorities in respect of these particular jurisdictions primarily for 2008 and thereafter.