Concentration of Risk and Enterprise-Wide Disclosures

Accounts receivable include amounts billed to governmental agencies and private customers and do not bear interest. Balances billed to customers but not paid pursuant to retainage provisions generally become payable upon contract completion and acceptance by the owner. The table below presents the concentrations of current receivables (trade and retainage) at September 30, 2018 and December 31, 2017, respectively:



	September 30, 2018				December 31, 2017
Federal Government	$	6,168	5	%	$	3,509	3	%
State Governments	2,740		2	%	4,503		3	%
Local Governments	13,781		12	%	18,256		15	%
Private Companies	88,708		81	%	97,874		79	%
Total current receivables	$	111,397	100	%	$	124,142	100	%

At September 30, 2018 and December 31, 2017, no single customer accounted for more than 10% of total current receivables.

Additionally, the table below represents concentrations of contract revenue by type of customer for the three and nine months ended September 30, 2018 and 2017, respectively:



	Three months ended September 30,								Nine months ended September 30,
	2018		%		2017		%		2018		%		2017		%
Federal Government	$	18,072	15	%	$	14,464	10	%	$	47,170	11	%	$	52,556	13	%
State Governments	7,674		6	%	9,185		7	%	25,947		6	%	33,910		8	%
Local Governments	25,546		20	%	28,246		20	%	69,298		17	%	72,802		17	%
Private Companies	73,781		59	%	88,267		63	%	279,267		66	%	257,071		62	%
Total contract revenues	$	125,073	100	%	$	140,162	100	%	$	421,682	100	%	$	416,339	100	%

For the three months ended September 30, 2018 and September 30, 2017, no single customer accounted for more than 10% of total contract revenues. Additionally, for the nine months ended September 30, 2018 and September 30, 2017, no single customer accounted for more than 10% of total contract revenues.

The Company does not believe that the loss of any one of its customers would have a material adverse effect on the Company or its subsidiaries and affiliates since no single specific customer sustains such a large portion of receivables or contract revenue over time.

In addition, the concrete segment primarily purchases concrete from select suppliers. The loss of one of these suppliers could adversely impact short-term operations.