Revenue Recognition - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
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 20 months. 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 term based on contractual billing			30 days
Future revenues from unsatisfied performance obligations	$ 111,721,000	$ 107,953,000	$ 111,721,000	$ 107,953,000
Service revenues	1,219,640,000	1,087,732,000	3,224,047,000	2,995,116,000
Revenue recognized from contract liabilities	6,203,000	4,439,000	6,816,000	8,231,000
Retainage on contracts	8,733,000	7,680,000	8,733,000	7,680,000	$ 9,029,000
Service | COLORADO
Revenue Recognition [Line Items]
Service revenues	$ 82,232,000,000	$ 94,503,000,000	$ 162,944,000,000	$ 179,553,000,000
Minimum [Member]
Revenue Recognition [Line Items]
Performance obligations, customer satisfaction period	1 month	1 month	1 month	1 month
Construction contracts warranty provisions period			9 months
Minimum [Member] | Service
Revenue Recognition [Line Items]
Performance obligations, period			1 day
Maximum [Member]
Revenue Recognition [Line Items]
Performance obligations, customer satisfaction period	27 months	21 months	27 months	21 months
Construction contracts warranty provisions period			1 year
Maximum [Member] | Service
Revenue Recognition [Line Items]
Performance obligations, period			20 months