Summary of Significant Accounting Policies and Other Information - Narrative (Details) $ in Thousands, € in Millions		3 Months Ended						12 Months Ended
	Jan. 17, 2018 USD ($)	Dec. 28, 2019 USD ($)	Jun. 29, 2019 USD ($)	Mar. 30, 2019 USD ($)	Dec. 29, 2018 USD ($)	Sep. 29, 2018 USD ($)	Dec. 30, 2017 USD ($)	Dec. 28, 2019 USD ($) unit	Dec. 29, 2018 USD ($)	Jan. 17, 2018 USD ($)	Dec. 30, 2017 USD ($)	Dec. 28, 2019 EUR (€)	Dec. 28, 2019 USD ($)	Sep. 30, 2019	Dec. 30, 2018 USD ($)	Dec. 29, 2018 EUR (€)	Dec. 29, 2018 USD ($)
Summary of Significant Accounting Policies and Other Information [Line Items]
Investments in equity securities													$ 12,969				$ 10,312
Gain from equity method investments								$ (600)	$ 700
Equity method investments													11,100				11,600
Cost method investments													400				7,900
Impairment charges		$ 4,200	$ 200	$ 2,800				$ 322	2,218		$ 0
Number of reporting units | unit								7
Foreign exchange loss (gain)								$ 5,224	(863)		2,376
Loss contingency accrual												€ 0.6	700			€ 1.1	1,300
Provisional estimate of Tax Act							$ 47,000
Preliminary estimate of toll charge							49,000				49,000
Other net tax benefits							$ (2,000)
TCJA one-time charge					$ 3,200
Toll charge, noncurrent								(23,800)
Toll charge, current								3,000
Operating ROU assets													21,918				0
Operating lease liability													24,425
ASU 2016-02
Summary of Significant Accounting Policies and Other Information [Line Items]
Operating ROU assets															$ 26,100
Operating lease liability															$ 29,400
ASU 2016-01
Summary of Significant Accounting Policies and Other Information [Line Items]
Cumulative effect adjustment								(9,800)
Loss recognized on statement of income									(700)
Other Expense
Summary of Significant Accounting Policies and Other Information [Line Items]
Investments in equity securities													400
Impairment charges								7,300
Selling, General and Administrative Expenses
Summary of Significant Accounting Policies and Other Information [Line Items]
Advertising expense								2,700	2,800		2,900
Shipping and handling fees and costs								11,000	12,300		$ 10,900
Industrial
Summary of Significant Accounting Policies and Other Information [Line Items]
Impairment charges								$ 0	$ 2,130
Electronics Non Silicon Unit
Summary of Significant Accounting Policies and Other Information [Line Items]
Excess fair value over carrying value														217.00%
Electronics (Silicon) Unit
Summary of Significant Accounting Policies and Other Information [Line Items]
Excess fair value over carrying value														42.00%
Passenger Car
Summary of Significant Accounting Policies and Other Information [Line Items]
Excess fair value over carrying value														137.00%
Commercial Vehicle Products
Summary of Significant Accounting Policies and Other Information [Line Items]
Excess fair value over carrying value														213.00%
Sensors
Summary of Significant Accounting Policies and Other Information [Line Items]
Excess fair value over carrying value														40.00%
Relay Unit
Summary of Significant Accounting Policies and Other Information [Line Items]
Excess fair value over carrying value														89.00%
Fuse Unit
Summary of Significant Accounting Policies and Other Information [Line Items]
Excess fair value over carrying value														268.00%
Minimum | Trademarks and tradenames
Summary of Significant Accounting Policies and Other Information [Line Items]
Weighted average useful life (years)								5 years
Minimum | Patents, licenses and software
Summary of Significant Accounting Policies and Other Information [Line Items]
Weighted average useful life (years)								5 years
Minimum | Distribution network
Summary of Significant Accounting Policies and Other Information [Line Items]
Weighted average useful life (years)								4 years
Maximum | Trademarks and tradenames
Summary of Significant Accounting Policies and Other Information [Line Items]
Weighted average useful life (years)								20 years
Maximum | Patents, licenses and software
Summary of Significant Accounting Policies and Other Information [Line Items]
Weighted average useful life (years)								17 years
Maximum | Distribution network
Summary of Significant Accounting Policies and Other Information [Line Items]
Weighted average useful life (years)								10 years
Building
Summary of Significant Accounting Policies and Other Information [Line Items]
Useful life								21 years
Equipment | Minimum
Summary of Significant Accounting Policies and Other Information [Line Items]
Useful life								3 years
Equipment | Maximum
Summary of Significant Accounting Policies and Other Information [Line Items]
Useful life								10 years
Furniture and Fixtures
Summary of Significant Accounting Policies and Other Information [Line Items]
Useful life								7 years
Tools, Dies and Molds
Summary of Significant Accounting Policies and Other Information [Line Items]
Useful life								5 years
Computer Equipment
Summary of Significant Accounting Policies and Other Information [Line Items]
Useful life								3 years
Other Noncurrent Assets
Summary of Significant Accounting Policies and Other Information [Line Items]
Marketable securities													$ 10,500				9,100
ATEC
Summary of Significant Accounting Policies and Other Information [Line Items]
Ownership percentage												24.00%	24.00%
EB Tech
Summary of Significant Accounting Policies and Other Information [Line Items]
Ownership percentage												19.00%	19.00%
Powersem
Summary of Significant Accounting Policies and Other Information [Line Items]
Ownership percentage												45.00%	45.00%
Polytronics
Summary of Significant Accounting Policies and Other Information [Line Items]
Investments in equity securities												€ 11.6	$ 12,800			€ 8.9	$ 10,200
Ownership percentage												7.20%	7.20%
Toll Charge
Summary of Significant Accounting Policies and Other Information [Line Items]
TCJA one-time charge					2,300
Other Items
Summary of Significant Accounting Policies and Other Information [Line Items]
TCJA one-time charge					900
IXYS Corporation | Toll Charge
Summary of Significant Accounting Policies and Other Information [Line Items]
TCJA one-time charge	$ 7,000				$ (1,000)	$ (2,000)				$ 7,000