Derivative Instruments and Hedging Activities - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Derivative
Notional amount of foreign exchange forward contracts	$ 98		$ 98		$ 102
Notional amount of foreign exchange forward contracts on a net basis	27		27		19
Fair value derivative liabilities	0		0		0
Fair value derivative assets	0		0		0
Fair value gain (loss) on foreign currency forward contracts	$ 0	$ 0	$ 0	$ 0