Segments (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Restructuring charges	$ 0	$ 3	$ 10
Gypsum
Segment Reporting Information [Line Items]
Restructuring charges	0	3	8
Ceilings
Segment Reporting Information [Line Items]
Restructuring charges	0	0	0
Distribution
Segment Reporting Information [Line Items]
Restructuring charges	0	(1)	0
Corporate
Segment Reporting Information [Line Items]
Restructuring charges	$ 0	$ 1	$ 2