Contracts Receivable and Retainage - Additional Information (Detail) (USD $)			6 Months Ended
	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2014 Top 3 Customer [Member] Customer
Long-term Contracts or Programs Disclosure [Line Items]
Contract receivable	$ 64,476,000	$ 98,579,000	$ 45,200,000
Number of major customers account for 70.1% of contract receivable			3
Percentage of contract receivable			70.10%
Reserve for bad debt included in contracts receivable balance	$ 900,000