Quarterly report pursuant to Section 13 or 15(d)

Property, Plant, and Equipment - Additional Information (Detail)

v3.19.3.a.u2
Property, Plant, and Equipment - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Property, Plant and Equipment [Abstract]    
Depreciation and depletion expense $ 9.4 $ 6.9