Future Minimum Payments Under Non-Cancelable Operating Leases, Along with Sublease Income Amounts (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Schedule of Operating Leases [Line Items]
Operating Leases	$ 2,954
Sub-lease Income	75
Net Operating Leases	2,879
2012
Schedule of Operating Leases [Line Items]
Operating Leases	389
Sub-lease Income	17
Net Operating Leases	372
2013
Schedule of Operating Leases [Line Items]
Operating Leases	377
Sub-lease Income	16
Net Operating Leases	361
2014
Schedule of Operating Leases [Line Items]
Operating Leases	357
Sub-lease Income	14
Net Operating Leases	343
2015
Schedule of Operating Leases [Line Items]
Operating Leases	311
Sub-lease Income	13
Net Operating Leases	298
2016
Schedule of Operating Leases [Line Items]
Operating Leases	256
Sub-lease Income	10
Net Operating Leases	246
Thereafter
Schedule of Operating Leases [Line Items]
Operating Leases	1,264
Sub-lease Income	5
Net Operating Leases	$ 1,259