Receivables, Net (Tables)

6 Months Ended

Jun. 30, 2018

Receivables [Abstract]

Summary of Receivables

(in thousands)	June 30, 2018		December 31, 2017		June 30, 2017
Construction contracts completed and in progress:
Billed	$	340,548	$	252,467	$	208,635
Unbilled		71,464		77,135		135,072
Retentions		—		91,135		75,891
Total construction contracts completed and in progress		412,012		420,737		419,598
Construction material sales		64,128		42,192		54,165
Other		16,644		17,014		10,892
Total gross receivables		492,784		479,943		484,655
Less: allowance for doubtful accounts		66		152		410
Total net receivables	$	492,718	$	479,791	$	484,245