Concentration of Risk and Enterprise-Wide Disclosures (Tables)

9 Months Ended

Sep. 30, 2019

Trade and contract retainage receivables

Concentration Risk [Line Items]

Schedules of concentration of risk, by risk factor

	September 30, 2019				December 31, 2018
Federal Government	$	595	1	%	$	2,319	2	%
State Governments		4,279	3	%		916	1	%
Local Governments		40,006	28	%		30,187	28	%
Private Companies		97,213	68	%		74,953	69	%
Total receivables	$	142,093	100	%	$	108,375	100	%

Contract revenues

Concentration Risk [Line Items]

Schedules of concentration of risk, by risk factor

	Three months ended September 30,								Nine months ended September 30,
	2019		%		2018		%		2019		%		2018		%
Federal Government	$	13,564	7	%	$	18,072	15	%	$	36,142	7	%	$	47,170	11	%
State Governments		19,872	10	%		7,674	6	%		34,213	7	%		25,947	6	%
Local Government		54,654	27	%		25,546	20	%		150,683	30	%		69,298	17	%
Private Companies		111,417	56	%		73,781	59	%		287,559	57	%		279,267	66	%
Total contract revenues	$	199,507	100	%	$	125,073	100	%	$	508,597	100	%	$	421,682	100	%