Earnings Per Share (Policies)

12 Months Ended

Dec. 31, 2017

Earnings Per Share [Abstract]

Discussion on convertible debt included in computation of earnings per share diluted

The Company's convertible debt instruments are only convertible for specified periods upon the occurrence of certain events.  The convertible debentures due 2042 became convertible subsequent to the December 31, 2016 evaluation of the conversion criteria, remained convertible subsequent to the April 1, 2017, July 1, 2017, and September 30, 2017 evaluations, and remain convertible subsequent to the December 31, 2017 evaluation.   The convertible debentures due 2040 became convertible subsequent to the September 30, 2017 evaluation of the conversion criteria and remain convertible subsequent to the December 31, 2017 evaluation.  In periods that the debentures are not convertible, the certain conditions which could trigger conversion of the remaining debentures have been deemed to be non-substantive, and accordingly, the Company assumes the conversion of these instruments in its diluted earnings per share computation during periods in which they are dilutive.

At the direction of its Board of Directors, the Company intends, upon conversion, to repay the principal amounts of the convertible senior debentures, due 2040, due 2041, and due 2042, in cash and settle any additional amounts in shares of Vishay common stock. Accordingly, the debentures are included in the diluted earnings per share computation using the "treasury stock method" (similar to options and warrants) rather than the "if converted method" otherwise required for convertible debt. Under the "treasury stock method," Vishay calculates the number of shares issuable under the terms of the debentures based on the average market price of Vishay common stock during the period, and that number is included in the total diluted shares figure for the period.  If the average market price is less than $12.95, no shares are included in the diluted earnings per share computation for the convertible senior debentures due 2040, if the average market price is less than $17.75, no shares are included in the diluted earnings per share computation for the convertible senior debentures due 2041, and if the average market price is less than $11.02, no shares are included in the diluted earnings per share computation for the convertible senior debentures due 2042.