Changes in and Reclassification out of Accumulated Other Comprehensive Loss by Component - Summary of Reclassification of Accumulated Other Comprehensive Loss by Component (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Accumulated Other Comprehensive Income Loss [Line Items]
Amount reclassified from accumulated other comprehensive loss, net of tax	$ 4	$ 7	$ 12	$ 19
Cash Flow Hedges
Accumulated Other Comprehensive Income Loss [Line Items]
Amount reclassified from accumulated other comprehensive loss, before tax	4	4	12	12
Amount reclassified from accumulated other comprehensive loss, tax	2	1	5	4
Amount reclassified from accumulated other comprehensive loss, net of tax	2	3	7	8
Post Employment Benefits
Accumulated Other Comprehensive Income Loss [Line Items]
Amount reclassified from accumulated other comprehensive loss, before tax	3	5	9	14
Amount reclassified from accumulated other comprehensive loss, tax	1	1	4	3
Amount reclassified from accumulated other comprehensive loss, net of tax	$ 2	$ 4	$ 5	$ 11