Segments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Net Sales:
Net sales	$ 970	$ 909
Operating Profit (Loss):
Operating profit	127	76
Operating segments | Gypsum
Net Sales:
Net sales	635	577
Operating Profit (Loss):
Operating profit	111	68
Operating segments | Ceilings
Net Sales:
Net sales	125	123
Operating Profit (Loss):
Operating profit	29	21
Operating segments | Distribution
Net Sales:
Net sales	357	334
Operating Profit (Loss):
Operating profit	11	4
Corporate
Operating Profit (Loss):
Operating profit	(21)	(23)
Eliminations
Net Sales:
Net sales	(147)	(125)
Operating Profit (Loss):
Operating profit	$ (3)	$ 6