Segments - Reportable Segments (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) segment	Sep. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			5
Net Sales:
Total net sales	$ 851	$ 795	$ 2,517	$ 2,373
Operating Profit (Loss):
Total	69	91	190	270
U.S. Wallboard and Surfaces
Net Sales:
Total net sales	456		1,348
U.S. Performance Materials
Net Sales:
Total net sales	95		279
U.S. Ceilings
Net Sales:
Total net sales	132		382
Canada
Net Sales:
Total net sales	102		317
Other
Net Sales:
Total net sales	66		191
Operating segments
Net Sales:
Total net sales	907		2,691
Operating segments | Wallboard
Net Sales:
Total net sales	338		996
Operating segments | Surfaces and industrial products
Net Sales:
Total net sales	173		529
Operating segments | Underlayment
Net Sales:
Total net sales	83		243
Operating segments | Building envelope and structural
Net Sales:
Total net sales	21		64
Operating segments | Ceiling tile and grid
Net Sales:
Total net sales	140		418
Operating segments | Specialty ceilings
Net Sales:
Total net sales	18		55
Operating segments | Other products
Net Sales:
Total net sales	46		137
Operating segments | Total product sales
Net Sales:
Total net sales	819		2,442
Operating segments | Other miscellaneous sales
Net Sales:
Total net sales	88		249
Operating segments | U.S. Wallboard and Surfaces
Net Sales:
Total net sales	487	466	1,440	1,417
Operating Profit (Loss):
Total	64	71	194	228
Operating segments | U.S. Wallboard and Surfaces | Wallboard
Net Sales:
Total net sales	253		743
Operating segments | U.S. Wallboard and Surfaces | Surfaces and industrial products
Net Sales:
Total net sales	145		441
Operating segments | U.S. Wallboard and Surfaces | Underlayment
Net Sales:
Total net sales	0		0
Operating segments | U.S. Wallboard and Surfaces | Building envelope and structural
Net Sales:
Total net sales	0		0
Operating segments | U.S. Wallboard and Surfaces | Ceiling tile and grid
Net Sales:
Total net sales	0		0
Operating segments | U.S. Wallboard and Surfaces | Specialty ceilings
Net Sales:
Total net sales	0		0
Operating segments | U.S. Wallboard and Surfaces | Other products
Net Sales:
Total net sales	25		75
Operating segments | U.S. Wallboard and Surfaces | Total product sales
Net Sales:
Total net sales	423		1,259
Operating segments | U.S. Wallboard and Surfaces | Other miscellaneous sales
Net Sales:
Total net sales	64		181
Operating segments | U.S. Performance Materials
Net Sales:
Total net sales	101	92	298	278
Operating Profit (Loss):
Total	(1)	6	(6)	20
Operating segments | U.S. Performance Materials | Wallboard
Net Sales:
Total net sales	0		0
Operating segments | U.S. Performance Materials | Surfaces and industrial products
Net Sales:
Total net sales	0		0
Operating segments | U.S. Performance Materials | Underlayment
Net Sales:
Total net sales	69		204
Operating segments | U.S. Performance Materials | Building envelope and structural
Net Sales:
Total net sales	21		62
Operating segments | U.S. Performance Materials | Ceiling tile and grid
Net Sales:
Total net sales	0		0
Operating segments | U.S. Performance Materials | Specialty ceilings
Net Sales:
Total net sales	0		0
Operating segments | U.S. Performance Materials | Other products
Net Sales:
Total net sales	0		0
Operating segments | U.S. Performance Materials | Total product sales
Net Sales:
Total net sales	90		266
Operating segments | U.S. Performance Materials | Other miscellaneous sales
Net Sales:
Total net sales	11		32
Operating segments | U.S. Ceilings
Net Sales:
Total net sales	143	125	420	355
Operating Profit (Loss):
Total	24	25	66	68
Operating segments | U.S. Ceilings | Wallboard
Net Sales:
Total net sales	0		0
Operating segments | U.S. Ceilings | Surfaces and industrial products
Net Sales:
Total net sales	0		0
Operating segments | U.S. Ceilings | Underlayment
Net Sales:
Total net sales	0		0
Operating segments | U.S. Ceilings | Building envelope and structural
Net Sales:
Total net sales	0		0
Operating segments | U.S. Ceilings | Ceiling tile and grid
Net Sales:
Total net sales	122		359
Operating segments | U.S. Ceilings | Specialty ceilings
Net Sales:
Total net sales	15		48
Operating segments | U.S. Ceilings | Other products
Net Sales:
Total net sales	1		1
Operating segments | U.S. Ceilings | Total product sales
Net Sales:
Total net sales	138		408
Operating segments | U.S. Ceilings | Other miscellaneous sales
Net Sales:
Total net sales	5		12
Operating segments | Canada
Net Sales:
Total net sales	110	100	342	300
Operating Profit (Loss):
Total	6	3	16	7
Operating segments | Canada | Wallboard
Net Sales:
Total net sales	65		196
Operating segments | Canada | Surfaces and industrial products
Net Sales:
Total net sales	21		67
Operating segments | Canada | Underlayment
Net Sales:
Total net sales	3		8
Operating segments | Canada | Building envelope and structural
Net Sales:
Total net sales	0		1
Operating segments | Canada | Ceiling tile and grid
Net Sales:
Total net sales	10		34
Operating segments | Canada | Specialty ceilings
Net Sales:
Total net sales	3		7
Operating segments | Canada | Other products
Net Sales:
Total net sales	2		10
Operating segments | Canada | Total product sales
Net Sales:
Total net sales	104		323
Operating segments | Canada | Other miscellaneous sales
Net Sales:
Total net sales	6		19
Operating segments | Other
Net Sales:
Total net sales	66	63	191	178
Operating Profit (Loss):
Total	4	6	12	8
Operating segments | Other | Wallboard
Net Sales:
Total net sales	20		57
Operating segments | Other | Surfaces and industrial products
Net Sales:
Total net sales	7		21
Operating segments | Other | Underlayment
Net Sales:
Total net sales	11		31
Operating segments | Other | Building envelope and structural
Net Sales:
Total net sales	0		1
Operating segments | Other | Ceiling tile and grid
Net Sales:
Total net sales	8		25
Operating segments | Other | Specialty ceilings
Net Sales:
Total net sales	0		0
Operating segments | Other | Other products
Net Sales:
Total net sales	18		51
Operating segments | Other | Total product sales
Net Sales:
Total net sales	64		186
Operating segments | Other | Other miscellaneous sales
Net Sales:
Total net sales	2		5
Eliminations
Net Sales:
Total net sales	(56)	(51)	(174)	(155)
Eliminations | U.S. Wallboard and Surfaces
Net Sales:
Total net sales	(31)		(92)
Eliminations | U.S. Performance Materials
Net Sales:
Total net sales	(6)		(19)
Eliminations | U.S. Ceilings
Net Sales:
Total net sales	(11)		(38)
Eliminations | Canada
Net Sales:
Total net sales	(8)		(25)
Eliminations | Other
Net Sales:
Total net sales	0		0
Corporate
Operating Profit (Loss):
Total	$ (28)	$ (20)	$ (92)	$ (61)