Goodwill (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill And Intangible Assets Disclosure [Abstract]

Summary of Goodwill Identified by Segment

Goodwill is identified by segment as follows (in millions):

	United States		Canada		International			Total
Balance at December 31, 2015		—	$	88	$	117		$	205
Additions		117		—		—			117
Currency translation adjustments and other		—		3		(14	)		(11	)
Balance at December 31, 2016	$	117		91		103			311
Additions		2		—		—			2
Currency translation adjustments and other		—	$	7	$	8			15
Balance at December 31, 2017	$	119	$	98	$	111		$	328