Prepaid Expenses and Other Current Assets  | 
12 Months Ended | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Dec. 31, 2017  | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Prepaid Expenses and Other Current Assets | 
 Note 3 - Prepaid Expenses and Other Current Assets 
 Prepaid expenses and other current assets consisted of the following at December 31, 2017 and 2016: 
 
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