Supplemental Balance Sheet Information (Details 1) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning balance	$ 123	$ 132
Accretion expense	4	4
Liabilities incurred	0	0
Changes in estimated cash flows	(1)	(10)	[1]
Liabilities settled	(1)	(2)
Foreign currency translation	(2)	(1)
Ending balance	$ 123	$ 123

[1] Changes in estimated cash flows for the six months ended June 30, 2014 included changes in estimates primarily for our gypsum quarry and ship loading facility in Windsor, Nova Scotia, Canada, which we permanently closed during the third quarter of 2011, and our mining operation in Little Narrows, Nova Scotia, Canada as a result of receiving regulatory approval of a revised reclamation plan in 2014.