XML 43 R31.htm IDEA: XBRL DOCUMENT v3.21.1
Significant Accounting Policies - Additional Information (Detail)
$ in Millions
3 Months Ended
Mar. 31, 2021
USD ($)
Facility
State
Segment
Dec. 31, 2020
USD ($)
Accounting Policies [Abstract]    
Number of quarries and yards | Facility 290  
Number of states with aggregates business sales by destination | State 26  
Reportable business segments | Segment 2  
Restricted cash | $ $ 40.9 $ 97.1