Concentration of Risk and Enterprise Wide Disclosures (Tables)

9 Months Ended

Sep. 30, 2020

Trade and contract retainage receivables

Concentration Risk [Line Items]

Schedules of concentration of risk, by risk factor

	September 30, 2020				December 31, 2019
Federal Government	$	258	-	%	$	4,765	3	%
State Governments		382	-	%		5,864	4	%
Local Governments		22,870	18	%		41,944	26	%
Private Companies		103,743	82	%		109,114	67	%
Gross receivables		127,253	100	%		161,687	100	%
Allowance for credit losses		(411)				(2,600)
Net receivables	$	126,842			$	159,087

Contract revenues

Concentration Risk [Line Items]

Schedules of concentration of risk, by risk factor

	Three months ended September 30,								Nine months ended September 30,
	2020		%		2019		%		2020		%		2019		%
Federal Government	$	16,499	9	%	$	13,564	7	%	$	32,720	6	%	$	36,142	7	%
State Governments		6,322	3	%		19,872	10	%		27,646	5	%		34,213	7	%
Local Government		54,316	29	%		54,654	27	%		158,176	29	%		150,683	30	%
Private Companies		112,296	59	%		111,417	56	%		321,224	60	%		287,559	56	%
Total contract revenues	$	189,433	100	%	$	199,507	100	%	$	539,766	100	%	$	508,597	100	%