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Commitments and Contingencies - Additional Information (Detail) - USD ($)
 1 Months Ended 6 Months Ended 12 Months Ended
Jul. 28, 2016
Jun. 16, 2016
Jan. 31, 2017
Sep. 30, 2017
Mar. 31, 2014
Commitments And Contingencies [Line Items]          
Letters of credit outstanding, amount       $ 9,400,000  
Outstanding guarantees       0  
Contingently liable for performance, current       $ 21,100,000  
USG Corporation and United States Gypsum [Member]          
Commitments And Contingencies [Line Items]          
Litigation settlement amount         $ 48,000,000
Temple Inland Inc. [Member]          
Commitments And Contingencies [Line Items]          
Litigation settlement amount         $ 7,000,000
Lafarge North America [Member] | Direct Purchaser Class [Member]          
Commitments And Contingencies [Line Items]          
Litigation settlement amount   $ 23,000,000      
Lafarge North America [Member] | Indirect Purchaser Class [Member]          
Commitments And Contingencies [Line Items]          
Litigation settlement amount $ 5,200,000        
NCC [Member]          
Commitments And Contingencies [Line Items]          
Payment of penalty to reduce nitrous oxide emissions     $ 600,000    
Installation of emission control equipment and vehicle replacement period     2 years    
Anticipated cost of investment for new emission control equipment and vehicles     $ 3,000,000    
EPA notice of violation description       In January 2017, NCC entered into a Consent Decree in which NCC agreed to install at its Fernley, Nevada plant certain emission control equipment (selective non-catalytic reduction) to reduce nitrous oxide emissions and to pay a penalty of $0.6 million. NCC also agreed to replace two existing vehicles with two new vehicles with more efficient Tier 4 engines. Under the terms of the Consent Decree, NCC will complete the installation of the emission control equipment and vehicle replacement in approximately 2 years. It is anticipated that the investment in the new emission control equipment and vehicles will cost approximately $3.0 million. In the Consent Decree NCC denies all allegations set forth in the NOVs and the Complaint which was filed simultaneously with the entry of the Consent Decree, and the Consent Decree resolves all such claims by the government. The Consent Decree was signed by the EPA and the US Department of Justice and lodged in US District Court for the District of Nevada in May 2017. On October 4, 2017, the Consent Decree was entered by the Court and NCC paid the penalty in early October.