Derivative Instruments and Hedging Activities - Cash Flow Hedges Included in Accumulated Other Comprehensive Loss (Detail) - Interest Rate [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Accumulated Other Comprehensive Loss After-tax	$ 8	$ 9
Portion Expected to be Reclassified to Income during the Next 12 Months	$ 1	$ 1
Maximum Term	200 months	212 months