Goodwill and Other Intangible Assets	9 Months Ended
Goodwill and Other Intangible Assets	Oct. 01, 2016
Goodwill and Other Intangible Assets [Abstract]
Goodwill and Other Intangible Assets	Note 3 – Goodwill and Other Intangible Assets Goodwill represents the excess of the cost of a business acquired over the fair value of the related net assets at the date of acquisition. Goodwill is not amortized but rather tested for impairment at least annually. Similarly, indefinite-lived intangible assets are not amortized, but rather tested for impairment at least annually. These impairment tests must be performed more frequently whenever events or changes in circumstances indicate that the asset might be impaired. The Company's business segments (see Note 11) represent its reporting units for goodwill impairment testing purposes. As a result of a review of recent financial results and outlook for the MOSFETs segment following the recent completion of the production transfers, Vishay determined that an interim indefinite-lived intangible asset impairment test was required for its Siliconix tradenames as of the end of the third fiscal quarter of 2016. As a result of this analysis, the Company determined that its Siliconix tradenames, with a carrying value of $20,359, were impaired. The Company recorded an impairment charge of $1,559 to write-down the tradenames to their fair value. The tradenames are no longer considered indefinite-lived and the remaining value will be amortized over the 10 year estimated remaining useful life. The fair value of indefinite-lived trademarks is measured as the discounted cash flow savings realized from owning such tradenames and not having to pay a royalty for their use. The evaluation of the fair value of indefinite-lived trademarks requires us to make significant estimates and assumptions. These estimates and assumptions primarily include, but are not limited to: the assumed market-royalty rate; the discount rate; terminal growth rates; and forecasts of revenue. Due to the inherent uncertainty involved in making these estimates, actual financial results could differ from those estimates. Changes in assumptions concerning future financial results or other underlying assumptions could have a significant impact on the fair value, whether an impairment is present, and the amount of the impairment charge, if applicable. In light of a sustained decline in market capitalization for Vishay and its peer group companies, and other factors (including the cost reduction programs announced during the third fiscal quarter of 2015 as described in Note 3), Vishay determined that interim impairment tests were required as of the end of the third fiscal quarter of 2015. The Company recorded impairment charges totaling $62,980 as a result of these tests. The recorded impairment charges are noncash in nature and do not affect Vishay's liquidity, cash flows from operating activities, or debt covenants, and will not have a material impact on future operations.

The entire disclosure for the aggregate amount of goodwill and a description of intangible assets, which may include (a) for amortizable intangible assets (also referred to as finite-lived intangible assets), the carrying amount, the amount of any significant residual value, and the weighted-average amortization period, (b) for intangible assets not subject to amortization (also referred to as indefinite-lived intangible assets), the carrying amount, and (c) the amount of research and development assets acquired and written off in the period, including the line item in the income statement in which the amounts written off are aggregated, if not readily apparent from the income statement. Also discloses (a) for amortizable intangibles assets in total and by major class, the gross carrying amount and accumulated amortization, the total amortization expense for the period, and the estimated aggregate amortization expense for each of the five succeeding fiscal years, (b) for intangible assets not subject to amortization the carrying amount in total and by major class, and (c) for goodwill, in total and for each reportable segment, the changes in the carrying amount of goodwill during the period (including the aggregate amount of goodwill acquired, the aggregate amount of impairment losses recognized, and the amount of goodwill included in the gain (loss) on disposal of a reporting unit). If any part of goodwill has not been allocated to a reportable segment, discloses the unallocated amount and the reasons for not allocating. For each impairment loss recognized related to an intangible asset (excluding goodwill), discloses: (a) a description of the impaired intangible asset and the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method for determining fair value, (c) the caption in the income statement or the statement of activities in which the impairment loss is aggregated, and (d) the segment in which the impaired intangible asset is reported. For each goodwill impairment loss recognized, discloses: (a) a description of the facts and circumstances leading to the impairment, (b) the amount of the impairment loss and the method of determining the fair value of the associated reporting unit, and (c) if a recognized impairment loss is an estimate not finalized and the reasons why the estimate is not final. May also disclose the nature and amount of any significant adjustments made to a previous estimate of an impairment loss.