Concentration of Risk and Enterprise Wide Disclosures (Tables)

12 Months Ended

Dec. 31, 2014

Accounts receivable

Concentration Risk [Line Items]

Schedules of concentration of risk, by risk factor

The table below presents the concentrations of receivables (trade and retainage) at December 31, 2014 and December 31, 2013, respectively:

	December 31, 2014				December 31, 2013
Federal Government	$	4,607	9	%	$	4,849	10	%
State Governments	476		1	%	4,002		8	%
Local Governments	13,927		26	%	8,857		18	%
Private Companies	33,778		64	%	31,829		64	%
Total receivables	$	52,788	100	%	$	49,537	100	%

Contract revenues

Concentration Risk [Line Items]

Schedules of concentration of risk, by risk factor

Additionally, the table below represents concentrations of revenue by type of customer for the years ended December 31, 2014, 2013 and 2012.

	Year ended December 31,
	2014		%		2013		%		2012		%
Federal	$	47,390	13	%	$	65,926	19	%	$	64,049	22	%
State	43,147		11	%	30,451		9	%	35,799		12	%
Local	97,145		25	%	54,702		15	%	44,626		15	%
Private	198,136		51	%	203,465		57	%	147,568		51	%
	$	385,818	100	%	$	354,544	100	%	$	292,042	100	%