XML 87 R72.htm IDEA: XBRL DOCUMENT v3.20.2
Segment Breakdown of Goodwill (Detail) - USD ($)
$ in Thousands
Sep. 30, 2020
Mar. 31, 2020
Segment Reporting Information [Line Items]    
Goodwill $ 329,137 $ 331,592
Cement [Member]    
Segment Reporting Information [Line Items]    
Goodwill 203,342 205,797
Concrete and Aggregates [Member]    
Segment Reporting Information [Line Items]    
Goodwill 1,639 1,639
Gypsum Wallboard [Member]    
Segment Reporting Information [Line Items]    
Goodwill 116,618 116,618
Paperboard [Member]    
Segment Reporting Information [Line Items]    
Goodwill $ 7,538 $ 7,538