Schedule of Goodwill by Segment (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2017 USD ($)
Goodwill [Line Items]
Balance as of December 31, 2016	$ 363
Acquisition	16
Balance as of September 30, 2017	379
Retail Division
Goodwill [Line Items]
Balance as of December 31, 2016	78
Balance as of September 30, 2017	78
Business Solutions Division
Goodwill [Line Items]
Balance as of December 31, 2016	285
Acquisition	16
Balance as of September 30, 2017	$ 301