Line of Credit	12 Months Ended
Dec. 31, 2017
Debt Disclosure [Abstract]
Line of Credit	Line of Credit The Company has a $10.0 million revolving line of credit with a domestic bank. At December 31, 2017 and 2016, there were no borrowings under the line. Under the terms of the line of credit, available borrowings are reduced by outstanding letters of credit. As of December 31, 2017, the Company had letters of credit outstanding of approximately $2.7 million under the facility and available borrowing of $7.3 million. The line is secured by substantially all of the assets of the Company, and bears interest at varying rates (currently LIBOR plus 1.25% or Prime less 0.50%). The line of credit matures on December 31, 2018, and requires monthly payments of interest only. The Company’s agreement with the bank requires it to comply with a maximum funded debt to earnings before interest, taxes, depreciation and amortization ("EBITDA") ratio, as defined, of no greater than 2.00 to 1.00 based upon a trailing twelve-month period. At December 31, 2017, the Company’s funded debt to EBITDA ratio was 0.34 to 1.00.

Line of Credit

12 Months Ended

Dec. 31, 2017

The Company has a $10.0 million revolving line of credit with a domestic bank. At December 31, 2017 and 2016, there were no borrowings under the line. Under the terms of the line of credit, available borrowings are reduced by outstanding letters of credit. As of December 31, 2017, the Company had letters of credit outstanding of approximately $2.7 million under the facility and available borrowing of $7.3 million. The line is secured by substantially all of the assets of the Company, and bears interest at varying rates (currently LIBOR plus 1.25% or Prime less 0.50%). The line of credit matures on December 31, 2018, and requires monthly payments of interest only. The Company’s agreement with the bank requires it to comply with a maximum funded debt to earnings before interest, taxes, depreciation and amortization ("EBITDA") ratio, as defined, of no greater than 2.00 to 1.00 based upon a trailing twelve-month period. At December 31, 2017, the Company’s funded debt to EBITDA ratio was 0.34 to 1.00.