Total Assets Fixed Assets Net and Total Fixed Asset Additions by Segment (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 32,555	$ 25,278
Property and equipment, net	7,060	4,417
Total property and equipment additions	4,317	3,044
North America
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	20,703	16,461
Property and equipment, net	5,481	3,413
Total property and equipment additions	3,348	2,259
International
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	11,852	8,817
Property and equipment, net	1,579	1,004
Total property and equipment additions	$ 969	$ 785