Segments - Product Information (Details) - 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
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net	$ 831	$ 795	$ 811	$ 767	$ 734	$ 767	$ 769	$ 747	$ 3,204	$ 3,017	$ 2,913
Gypsum
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net									2,331	2,169	2,105
Performance Materials
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net									373	357	321
Ceilings
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net									509	500	496
Consolidation, Eliminations
Segment Reporting Information [Line Items]
Sales Revenue, Goods, Net									$ (9)	$ (9)	$ (9)