Amortization Expense Related to Amortizable Intangible Assets (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Charged to cost of sales	$ 13	$ 13	$ 15
Charged to amortization of intangibles	74	77	61
Total amortization	$ 87	$ 90	$ 76

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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The amount of expense recognized in the current period that reflects the allocation of the costs of intangible assets over the expected benefit period of such assets. This element applies only to intangible assets used in the production of goods.

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