Income taxes (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	3 Months Ended				9 Months Ended
	Jun. 15, 2012	Sep. 30, 2012	Jun. 30, 2012	Sep. 30, 2011	Jun. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Income Taxes [Line Items]
Effective Income Tax Rate, Continuing Operations		37.00%		34.50%		34.80%	41.90%
Increase Decrease In Effective Tax Rate		2.5				(7.1)
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions		$ 53				$ 53
Reversal of tax accruals no longer required and expiration of Statues of limitations		24
Tax provision recorded related to Mondelez and PMI tax matters		48				48
Portion Of Charge Recorded As (Benefit) Provision For Income Taxes			(75)		137	(75)	137
Interest Benefit From Lower than Estimated Interest on Tax Underpayment			(73)
Cash Payment for Federal taxes and Interest	456
Expected Cash Payment for State Taxes and Interest						50
Changes to Mondelez and PMI tax related receivables		48		19		48	19
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound		90				90
Interest On Tax Underpayments [Member]
Income Taxes [Line Items]
Portion Of Charge Recorded As (Benefit) Provision For Income Taxes					$ 312