Accumulated Other Comprehensive Income (loss) - Reclassifications from Accumulated Other Comprehensive Income (Loss) to Income Statement (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Amortization of defined benefit pension:
Accumulated other comprehensive income, defined benefit pension, Tax Expense	$ (39)	$ (31)	$ (53)	$ (38)
Accumulated other comprehensive income, defined benefit pension net of tax	75	(76)	121	(43)
Amount Reclassified [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Amortization of defined benefit pension:
Accumulated other comprehensive income, defined benefit pension net of tax	4	4	9	8
Selling, General & Administrative Expense [Member] | Amount Reclassified [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Amortization of defined benefit pension:
Accumulated other comprehensive income, defined benefit pension, Selling, General and Administrative Expense	4	4	9	8
Tax expense [Member] | Amount Reclassified [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Amortization of defined benefit pension:
Accumulated other comprehensive income, defined benefit pension, Tax Expense
Interest expense [Member] | Amount Reclassified [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Amortization of defined benefit pension:
Interest rate swaps	$ 1		$ 1