Comprehensive Income - Summarizes of Changes in Accumulated Other Comprehensive Income (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Amounts reclassified from accumulated other comprehensive income, Cash Flow Hedges
Amounts reclassified from accumulated other comprehensive income, Defined benefit pension and postretirement benefit plans	1	1
Amounts reclassified from accumulated other comprehensive income	1
Beginning balance at December 31, 2012	(338)
Total before tax	(12)	39
Tax (expense) benefit
Net current year other comprehensive income	(12)	39
Ending balance at March 31, 2013	(350)
Other comprehensive income before reclassifications, Cash Flow Hedges	1	(1)
Other comprehensive income before reclassifications, Defined benefit pension and postretirement benefit plans
Other comprehensive income before reclassifications	(13)
Cash Flow Hedges [Member]
Amounts reclassified from accumulated other comprehensive income, Cash Flow Hedges
Beginning balance at December 31, 2012	(1)
Total before tax	1
Tax (expense) benefit
Net current year other comprehensive income	1
Ending balance at March 31, 2013
Other comprehensive income before reclassifications, Cash Flow Hedges	1
Defined benefit pension and postretirement benefit plans [Member]
Amounts reclassified from accumulated other comprehensive income, Defined benefit pension and postretirement benefit plans	1
Beginning balance at December 31, 2012	(86)
Total before tax	1
Tax (expense) benefit
Net current year other comprehensive income	1
Ending balance at March 31, 2013	(85)
Other comprehensive income before reclassifications, Defined benefit pension and postretirement benefit plans
Foreign Currency Translation Adjustments [Member]
Amounts reclassified from accumulated other comprehensive income, Foreign Currency Translation Adjustments
Beginning balance at December 31, 2012	(251)
Total before tax	(14)
Tax (expense) benefit
Net current year other comprehensive income	(14)
Ending balance at March 31, 2013	(265)
Other comprehensive income before reclassifications, Foreign Currency Translation Adjustments	$ (14)