Taxes on Income - Textual (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		1 Months Ended	3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Apr. 30, 2011 IRS [Member]	Jun. 30, 2011 IRS [Member]	Sep. 30, 2012 Canada Revenue Agency (CRA) [Member]
Income Taxes [Line Items]
Effective tax rate	20.50%	26.70%	27.80%	15.70%
Net reduction of deferred tax liabilities on intangibles established in purchase accounting due to tax rate changes				$ 230
Litigation charges				500
Net payments made to taxing authority for settlement of income tax examination					465		65
Decrease in unrecognized tax benefits resulting from prior period tax positions						$ 700	$ 112