Geographic and Business Segment Information - Revenues and Property and Equipment, Net for Each of Geographical Areas (Parenthetical) (Detail) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues		$ 686	$ 688	$ 733	$ 684	$ 670	$ 671	$ 725	$ 661	$ 2,791	$ 2,727	$ 2,688
Property and Equipment, net										185	227	226
Property and equipment, net classified as held for sale		31								31
United States [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	[1],[2]									2,618	2,580	2,524
United States [Member] | Laundry Operations [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues										13	13	13
Property and Equipment, net										5	$ 4	$ 3
South Africa [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Property and equipment, net classified as held for sale		$ 31								$ 31

[1] Excludes $31 million of property and equipment, net classified as held for sale as of December 31, 2017.

[2] Includes revenues of $13 million for each of the years ended December 31, 2017, 2016 and 2015, respectively, from our laundry operations which is not part of our segment. Also includes property and equipment, net of $5 million, $4 million and $3 million as of December 31, 2017, 2016 and 2015, respectively, from our laundry operations.