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
	Mar. 31, 2014		Mar. 31, 2013
Amount reclassified from accumulated other comprehensive income, net of tax	$ 4		$ 5
Interest Rate Swap
Amount reclassified from accumulated other comprehensive income, before tax	4		4
Amount reclassified from accumulated other comprehensive income, tax	2		2
Amount reclassified from accumulated other comprehensive income, net of tax	2		2
Actuarial loss
Amount reclassified from accumulated other comprehensive income, before tax	3	[1]	4	[1]
Amount reclassified from accumulated other comprehensive income, tax	1		1
Amount reclassified from accumulated other comprehensive income, net of tax	$ 2		$ 3

[1] This accumulated other comprehensive loss component is included in the computation of net periodic pension cost.