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Significant Accounting Policies - Additional Information (Detail) $ in Millions | 6 Months Ended |
--- | --- | ---
Jun. 30, 2021 USD ($) Facility State Segment | Dec. 31, 2020 USD ($)
Accounting Policies [Abstract] |  |
Number of quarries and yards | Facility | 310 |
Number of states with aggregates business sales by destination | State | 26 |
Reportable business segments | Segment | 2 |
Restricted cash | $ | $ 17.2 | $ 97.1

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