Derivatives And Hedging Activities - Schedule of Outstanding Commodity Price Hedge Contracts (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Unrealized net loss recorded in “Accumulated other comprehensive loss”	$ (2)	$ (2)
Commodity Contracts [Member]
Derivative [Line Items]
Combined notional value	21	28
Commodity Contracts [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Combined notional value	$ 21	$ 28