Supplemental Balance Sheet Information (Tables)

3 Months Ended

Mar. 31, 2016

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of inventories

Total inventories consisted of the following:

(millions)	March 31, 2016		December 31, 2015
Finished goods	$	215	$	210
Work in progress	34		36
Raw materials	69		68
Total	$	318	$	314

Changes in the liability for asset retirement obligations

Changes in the liability for asset retirement obligations consisted of the following:

	Three months ended March 31,
(millions)	2016		2015
Balance as of January 1	$	119	$	123
Accretion expense	2		2
Foreign currency translation	1		(3		)
Balance as of March 31	$	122	$	122