Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended					9 Months Ended		12 Months Ended
	Sep. 29, 2018	Dec. 31, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Numerator for basic earnings per share:
Net earnings attributable to Vishay stockholders	$ 77,876	$ (177,657)	$ 64,404	$ 56,190	$ 36,719	$ 243,339	$ 157,313	$ (20,344)	$ 48,792
Denominator for basic earnings per share:
Weighted average shares	144,215		145,572			144,197	145,973
Outstanding phantom stock units	168		156			167	155
Adjusted weighted average shares (basic)	144,383		145,728			144,364	146,128
Effect of dilutive securities:
Convertible and exchangeable debt instruments	8,062		10,480			11,827	9,160
Restricted stock units	501		493			511	338
Dilutive potential common shares	8,563		10,973			12,338	9,498
Denominator for diluted earnings per share:
Adjusted weighted average shares (diluted)	152,946		156,701			156,702	155,626
Basic earnings per share attributable to Vishay stockholders (in dollars per share)	$ 0.54		$ 0.44			$ 1.69	$ 1.08
Diluted earnings per share attributable to Vishay stockholders (in dollars per share)	0.51		$ 0.41			1.55	$ 1.01
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)	$ 12.81					$ 12.81
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		8,401			0	8,371
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)	$ 17.56					$ 17.56
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)	$ 10.90					$ 10.90
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		379			307	514
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)	19,052		0			7,607	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