Concentration of Risk and Enterprise Wide Disclosures (Tables)

9 Months Ended

Sep. 30, 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 September 30, 2017 and December 31, 2016, respectively:

	September 30, 2017				December 31, 2016
Federal Government	$	4,238	4	%	$	5,542	4	%
State Governments	3,992		3	%	9,302		7	%
Local Governments	21,857		18	%	20,886		16	%
Private Companies	90,085		75	%	96,673		73	%
Total receivables	$	120,172	100	%	$	132,403	100	%

Contract revenues

Concentration Risk [Line Items]

Schedules of concentration of risk, by risk factor

Additionally, the table below represents concentrations of contract revenue by type of customer for the three and nine months ended September 30, 2017 and 2016, respectively:

	Three months ended September 30,								Nine months ended September 30,
	2017		%		2016		%		2017		%		2016		%
Federal Government	$	14,464	10	%	$	13,268	8	%	$	52,556	13	%	$	25,200	6	%
State Governments	9,185		7	%	13,285		8	%	33,910		8	%	29,114		7	%
Local Government	28,246		20	%	29,718		18	%	72,802		17	%	71,865		17	%
Private Companies	88,267		63	%	107,746		66	%	257,071		62	%	307,762		70	%
Total contract revenues	$	140,162	100	%	$	164,017	100	%	$	416,339	100	%	$	433,941	100	%