Restructuring (Narrative) (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) Employee	Sep. 30, 2014 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring Charges | $	$ 6	$ 8	$ 10	$ 16
2015 Acquisition Integration [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Number of Positions Eliminated			50
Restructuring and Related Cost, Number of Positions Eliminated			30
Restructuring Charges | $			$ 1
Restructuring and Related Cost, Expected Cost | $	$ 15		$ 15
2014 T15 Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Number of Positions Eliminated			320
Restructuring and Related Cost, Number of Positions Eliminated			295
Restructuring Charges | $			$ 9