Concentration of Credit Risk (Tables)

12 Months Ended

Dec. 31, 2017

Risks and Uncertainties [Abstract]

Schedule of concentration of risk

We believe that a loss of any of those customers where we currently derive more than 10 percent of our revenues would not have a material adverse effect on our operations as shown in the table below:

Individual customer sales						Individual customer receivables in excess
in excess of 10% of revenues						of 10% of total receivables
for the year ended December 31,						at December 31,
2017		2016		2015		2017		2016		2015
22.8	%	18.2	%	24.4	%	19.1	%	20.9	%	20.3	%
17.1	%	16.5	%	13.8	%	15.0	%	14.0	%	16.5	%
10.8	%	15.9	%			11.1	%	10.1	%	12.7	%
10.7	%	10.6	%			10.4	%