Segments - Product Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net sales	$ 819	$ 851	$ 880	$ 786	$ 831	$ 795	$ 811	$ 767	$ 3,336	$ 3,204	$ 3,017
U.S. Wallboard and Surfaces
Segment Reporting Information [Line Items]
Net sales									1,803
U.S. Performance Materials
Segment Reporting Information [Line Items]
Net sales									372
U.S. Ceilings
Segment Reporting Information [Line Items]
Net sales									493
Canada
Segment Reporting Information [Line Items]
Net sales									417
Other
Segment Reporting Information [Line Items]
Net sales									251
Operating Segments
Segment Reporting Information [Line Items]
Net sales									3,560
Operating Segments | Wallboard
Segment Reporting Information [Line Items]
Net sales									1,322
Operating Segments | Surfaces and industrial products
Segment Reporting Information [Line Items]
Net sales									697
Operating Segments | Underlayment
Segment Reporting Information [Line Items]
Net sales									351
Operating Segments | Building envelope and structural
Segment Reporting Information [Line Items]
Net sales									84
Operating Segments | Ceiling tile and grid
Segment Reporting Information [Line Items]
Net sales									542
Operating Segments | Specialty ceilings
Segment Reporting Information [Line Items]
Net sales									28
Operating Segments | Other products
Segment Reporting Information [Line Items]
Net sales									197
Operating Segments | Total product sales
Segment Reporting Information [Line Items]
Net sales									3,221
Operating Segments | Other miscellaneous sales
Segment Reporting Information [Line Items]
Net sales									339
Operating Segments | U.S. Wallboard and Surfaces
Segment Reporting Information [Line Items]
Net sales									1,927	1,916	1,778
Operating Segments | U.S. Wallboard and Surfaces | Wallboard
Segment Reporting Information [Line Items]
Net sales									994
Operating Segments | U.S. Wallboard and Surfaces | Surfaces and industrial products
Segment Reporting Information [Line Items]
Net sales									580
Operating Segments | U.S. Wallboard and Surfaces | Underlayment
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Wallboard and Surfaces | Building envelope and structural
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Wallboard and Surfaces | Ceiling tile and grid
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Wallboard and Surfaces | Specialty ceilings
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Wallboard and Surfaces | Other products
Segment Reporting Information [Line Items]
Net sales									103
Operating Segments | U.S. Wallboard and Surfaces | Total product sales
Segment Reporting Information [Line Items]
Net sales									1,677
Operating Segments | U.S. Wallboard and Surfaces | Other miscellaneous sales
Segment Reporting Information [Line Items]
Net sales									250
Operating Segments | U.S. Performance Materials
Segment Reporting Information [Line Items]
Net sales									392	373	357
Operating Segments | U.S. Performance Materials | Wallboard
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Performance Materials | Surfaces and industrial products
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Performance Materials | Underlayment
Segment Reporting Information [Line Items]
Net sales									303
Operating Segments | U.S. Performance Materials | Building envelope and structural
Segment Reporting Information [Line Items]
Net sales									81
Operating Segments | U.S. Performance Materials | Ceiling tile and grid
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Performance Materials | Specialty ceilings
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Performance Materials | Other products
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Performance Materials | Total product sales
Segment Reporting Information [Line Items]
Net sales									384
Operating Segments | U.S. Performance Materials | Other miscellaneous sales
Segment Reporting Information [Line Items]
Net sales									8
Operating Segments | U.S. Ceilings
Segment Reporting Information [Line Items]
Net sales									541	477	467
Operating Segments | U.S. Ceilings | Wallboard
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Ceilings | Surfaces and industrial products
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Ceilings | Underlayment
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Ceilings | Building envelope and structural
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | U.S. Ceilings | Ceiling tile and grid
Segment Reporting Information [Line Items]
Net sales									464
Operating Segments | U.S. Ceilings | Specialty ceilings
Segment Reporting Information [Line Items]
Net sales									20
Operating Segments | U.S. Ceilings | Other products
Segment Reporting Information [Line Items]
Net sales									3
Operating Segments | U.S. Ceilings | Total product sales
Segment Reporting Information [Line Items]
Net sales									487
Operating Segments | U.S. Ceilings | Other miscellaneous sales
Segment Reporting Information [Line Items]
Net sales									54
Operating Segments | Canada
Segment Reporting Information [Line Items]
Net sales									448	405	389
Operating Segments | Canada | Wallboard
Segment Reporting Information [Line Items]
Net sales									258
Operating Segments | Canada | Surfaces and industrial products
Segment Reporting Information [Line Items]
Net sales									89
Operating Segments | Canada | Underlayment
Segment Reporting Information [Line Items]
Net sales									10
Operating Segments | Canada | Building envelope and structural
Segment Reporting Information [Line Items]
Net sales									2
Operating Segments | Canada | Ceiling tile and grid
Segment Reporting Information [Line Items]
Net sales									44
Operating Segments | Canada | Specialty ceilings
Segment Reporting Information [Line Items]
Net sales									8
Operating Segments | Canada | Other products
Segment Reporting Information [Line Items]
Net sales									13
Operating Segments | Canada | Total product sales
Segment Reporting Information [Line Items]
Net sales									424
Operating Segments | Canada | Other miscellaneous sales
Segment Reporting Information [Line Items]
Net sales									24
Operating Segments | Other
Segment Reporting Information [Line Items]
Net sales									252	245	220
Operating Segments | Other | Wallboard
Segment Reporting Information [Line Items]
Net sales									70
Operating Segments | Other | Surfaces and industrial products
Segment Reporting Information [Line Items]
Net sales									28
Operating Segments | Other | Underlayment
Segment Reporting Information [Line Items]
Net sales									38
Operating Segments | Other | Building envelope and structural
Segment Reporting Information [Line Items]
Net sales									1
Operating Segments | Other | Ceiling tile and grid
Segment Reporting Information [Line Items]
Net sales									34
Operating Segments | Other | Specialty ceilings
Segment Reporting Information [Line Items]
Net sales									0
Operating Segments | Other | Other products
Segment Reporting Information [Line Items]
Net sales									78
Operating Segments | Other | Total product sales
Segment Reporting Information [Line Items]
Net sales									249
Operating Segments | Other | Other miscellaneous sales
Segment Reporting Information [Line Items]
Net sales									3
Eliminations
Segment Reporting Information [Line Items]
Net sales									(224)	$ (212)	$ (194)
Eliminations | U.S. Wallboard and Surfaces
Segment Reporting Information [Line Items]
Net sales									(124)
Eliminations | U.S. Performance Materials
Segment Reporting Information [Line Items]
Net sales									(20)
Eliminations | U.S. Ceilings
Segment Reporting Information [Line Items]
Net sales									(48)
Eliminations | Canada
Segment Reporting Information [Line Items]
Net sales									(31)
Eliminations | Other
Segment Reporting Information [Line Items]
Net sales									$ (1)