Income Taxes - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Income Taxes [Line Items]
Provision for income taxes	$ (71)	$ (73)
Cash taxes paid, net of refunds	55	38	194	121
Tax contingencies	726		726		710
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
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 or thereafter
Tax examination, estimate of additional tax expense	$ 250
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.
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, Japan, Luxembourg, and the United Kingdom. We are under, or may be subject to, audit or examination and additional assessments in respect of these particular jurisdictions for 2003 and thereafter.