Financial Instruments - Summary of Reconciliation of Net Carrying Amount of Derivative Financial Instruments (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Net derivative asset as of January 1	$ 10
Total gain for the period included in net loss	2
Total loss for period accounted through other comprehensive income	(1)
Payments for settlement of foreign exchange derivative contracts	(1)
Net derivative asset as of March 31	$ 10