Concentration of Risk and Enterprise Wide Disclosures (Tables)

12 Months Ended

Dec. 31, 2017

Accounts receivable

Concentration Risk [Line Items]

Schedules of concentration of risk, by risk factor

The table below presents the concentrations of current receivables (trade and retainage) at December 31, 2017 and December 31, 2016, respectively:

	December 31, 2017				December 31, 2016
Federal Government	$	3,509	3	%	$	5,542	4	%
State Governments	4,503		3	%	9,302		7	%
Local Governments	18,256		15	%	20,886		16	%
Private Companies	97,874		79	%	96,673		73	%
Total receivables	$	124,142	100	%	$	132,403	100	%

Contract revenues

Concentration Risk [Line Items]

Schedules of concentration of risk, by risk factor

dditionally, the table below represents concentrations of contract revenue by type of customer for the years ended December 31, 2017, 2016 and 2015.

	2017		%		2016		%		2015		%
Federal Government	$	63,823	11	%	$	40,361	7	%	$	45,439	10	%
State Governments	42,613		7	%	37,700		7	%	42,026		9	%
Local Governments	91,592		16	%	94,461		16	%	130,187		28	%
Private Companies	380,525		66	%	405,714		70	%	248,846		53	%
Total contract revenues	$	578,553	100	%	$	578,236	100	%	$	466,498	100	%