Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended					6 Months Ended		12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 31, 2017	Dec. 31, 2016
Numerator for basic earnings per share:
Net earnings attributable to Vishay stockholders	$ 103,097	$ (177,657)	$ 64,404	$ 56,190	$ 36,719	$ 165,463	$ 92,909	$ (20,344)	$ 48,792
Denominator for basic earnings per share:
Weighted average shares	144,215			146,226		144,188	146,173
Outstanding phantom stock units	167			155		167	155
Adjusted weighted average shares (basic)	144,382			146,381		144,355	146,328
Effect of dilutive securities:
Convertible and exchangeable debt instruments	12,810			8,651		13,710	8,500
Restricted stock units	465			268		515	260
Dilutive potential common shares	13,275			8,919		14,225	8,760
Denominator for diluted earnings per share:
Adjusted weighted average shares (diluted)	157,657			155,300		158,580	155,088
Basic earnings per share attributable to Vishay stockholders (in dollars per share)	$ 0.71			$ 0.38		$ 1.15	$ 0.63
Diluted earnings per share attributable to Vishay stockholders (in dollars per share)	0.65			$ 0.36		1.04	$ 0.60
Convertible Senior Debentures, Due 2040 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Minimum market price of common stock for inclusion of shares issuable upon conversion of senior debentures for calculation of diluted earnings per share (in dollars per share)	$ 12.86					$ 12.86
Convertible Senior Debentures, Due 2041 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount (in shares)	0			8,371		0	8,356
Minimum market price of common stock for inclusion of shares issuable upon conversion of senior debentures for calculation of diluted earnings per share (in dollars per share)	$ 17.63					$ 17.63
Convertible Senior Debentures, Due 2042 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Minimum market price of common stock for inclusion of shares issuable upon conversion of senior debentures for calculation of diluted earnings per share (in dollars per share)	$ 10.94					$ 10.94
Weighted average other [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount (in shares)	307			581		307	581
Convertible Senior Notes, Due 2025 [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount (in shares)	3,769			0		1,885	0
Minimum market price of common stock for inclusion of shares issuable upon conversion of senior debentures for calculation of diluted earnings per share (in dollars per share)	$ 31.49					$ 31.49