Revenue - Summary of Information about Receivables, Revenue Earned on Contracts in Progress in Excess of Billings, Which are Included Within Accounts Receivable, and Amounts Billed in Excess of Revenue Earned on Contracts (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Contracts receivable, net	$ 130,288
Centuri Construction Group Inc [Member]
Disaggregation of Revenue [Line Items]
Contracts receivable, net	130,288	$ 221,859
Revenue earned on contracts in progress in excess of billings	57,745	5,768
Amounts billed in excess of revenue earned on contracts	$ 8,102	$ 9,602