Additional Information to the Statements of Operations (Tables)
|12 Months Ended|
Dec. 31, 2017
|Additional Information to the Statements of Operations [Abstract]|
|Schedule of revenues in financial statements||
Tabular disclosure of revenue from external customers by geographic areas attributed to the entity's country of domicile and to foreign countries from which the entity derives revenue.
Reference 1: http://www.xbrl.org/2003/role/presentationRef