Intangible Assets - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Customer loyalty payments in cash	$ 78	$ 47	$ 65
Balance of accrued commission and incentives	253	211
Other current asset reclassified as customers loyalty payment with in other intangible assets		50
Other non-current assets reclassified as customers loyalty payments with in other intangible assets		68
Customer Relationships [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Amortization expense	80	82	88
Customer Loyalty Payments [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Balance of accrued commission and incentives	35	15
Amortization expense	$ 63	$ 62	$ 74