Revenue Recognition - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Revenue Recognition [Line Items]
Performance obligations, description of timing	Performance obligations within paving service agreements are satisfied over time, primarily ranging from one day to two years. For product revenues and freight revenues, customer payment terms are generally 30 days from invoice date. Customer payments for the paving operations are based on a contractual billing schedule and are due 30 days from invoice date.
Product and freight revenues customer payment terms	30 days
Customer payments terms based on contractual billing	30 days
Future revenues from unsatisfied performance obligations	$ 172.8	$ 212.7
Service revenues	982.4	958.2
Revenue recognized from contract liabilities	4.9	4.4
Retainage on contracts	7.5		$ 10.6
Service | COLORADO
Revenue Recognition [Line Items]
Service revenues	$ 8.8	$ 14.5
Minimum | Service
Revenue Recognition [Line Items]
Performance obligations, period	1 day
Maximum | Service
Revenue Recognition [Line Items]
Performance obligations, period	2 years