Summary of Significant Accounting Policies and Other Information - Narrative (Details) customer in Thousands, associate in Thousands, € in Millions	3 Months Ended	12 Months Ended
	Jun. 27, 2020 USD ($)	Jan. 01, 2022 USD ($) country customer associate	Dec. 26, 2020 USD ($) reporting_unit	Dec. 28, 2019 USD ($)	Jan. 01, 2022 EUR (€) country associate	Sep. 25, 2021	Dec. 26, 2020 EUR (€)
Summary of Significant Accounting Policies and Other Information
Countries where product is used (country) | country		15			15
Number of customers (over) | customer		100
Global associates (associate) | associate		17			17
Cost of sales		$ 1,308,002,000	$ 944,523,000	$ 957,578,000
Equity investment		26,070,000	19,186,000
Gain (loss) from equity method investments		1,300,000	0
Equity method investments		12,400,000	11,400,000
Equity method investment, cost		0	500,000
Impairment of equity method investments		500,000	100,000
Goodwill impairment			33,841,000
Goodwill		929,790,000	$ 816,812,000	820,589,000
Number of reporting units | reporting_unit			7
Trade receivables, allowances		1,900,000	$ 1,400,000
Foreign exchange loss (gain)		17,158,000	(14,875,000)	5,224,000
Loss contingency accrual		2,100,000	2,900,000		€ 1.9		€ 2.3
Toll charge, noncurrent		17,800,000
Toll charge, current		(3,000,000)
Transportation Segment
Summary of Significant Accounting Policies and Other Information
Goodwill impairment	$ 33,800,000		33,841,000
Goodwill		192,378,000	101,931,000	131,321,000
90 days past due
Summary of Significant Accounting Policies and Other Information
Trade receivables, allowances		$ 2,100,000	1,000,000
Land use rights
Summary of Significant Accounting Policies and Other Information
Finite lived intangible asset weighted average useful life (years)		50 years
Electronics – Passive Products and Sensors
Summary of Significant Accounting Policies and Other Information
Percentage of fair value in excess of carrying value						380.00%
Electronics – Semiconductor
Summary of Significant Accounting Policies and Other Information
Percentage of fair value in excess of carrying value						104.00%
Passenger Car Products
Summary of Significant Accounting Policies and Other Information
Percentage of fair value in excess of carrying value						255.00%
Commercial Vehicle Products
Summary of Significant Accounting Policies and Other Information
Percentage of fair value in excess of carrying value						217.00%
Automotive Sensors
Summary of Significant Accounting Policies and Other Information
Goodwill impairment	$ 33,800,000
Goodwill		$ 9,200,000
Percentage of fair value in excess of carrying value						95.00%
Relay Unit
Summary of Significant Accounting Policies and Other Information
Percentage of fair value in excess of carrying value						144.00%
Fuse Unit
Summary of Significant Accounting Policies and Other Information
Percentage of fair value in excess of carrying value						231.00%
Minimum | Customer relationships
Summary of Significant Accounting Policies and Other Information
Finite lived intangible asset weighted average useful life (years)		5 years
Minimum | Trademarks and tradenames
Summary of Significant Accounting Policies and Other Information
Finite lived intangible asset weighted average useful life (years)		5 years
Minimum | Patents, licenses and software
Summary of Significant Accounting Policies and Other Information
Finite lived intangible asset weighted average useful life (years)		5 years
Minimum | Distribution network
Summary of Significant Accounting Policies and Other Information
Finite lived intangible asset weighted average useful life (years)		4 years
Maximum | Customer relationships
Summary of Significant Accounting Policies and Other Information
Finite lived intangible asset weighted average useful life (years)		20 years
Maximum | Trademarks and tradenames
Summary of Significant Accounting Policies and Other Information
Finite lived intangible asset weighted average useful life (years)		20 years
Maximum | Patents, licenses and software
Summary of Significant Accounting Policies and Other Information
Finite lived intangible asset weighted average useful life (years)		17 years
Maximum | Distribution network
Summary of Significant Accounting Policies and Other Information
Finite lived intangible asset weighted average useful life (years)		10 years
Building
Summary of Significant Accounting Policies and Other Information
Useful life (in years)		21 years
Equipment | Minimum
Summary of Significant Accounting Policies and Other Information
Useful life (in years)		3 years
Equipment | Maximum
Summary of Significant Accounting Policies and Other Information
Useful life (in years)		10 years
Furniture and Fixtures
Summary of Significant Accounting Policies and Other Information
Useful life (in years)		7 years
Tools, Dies and Molds
Summary of Significant Accounting Policies and Other Information
Useful life (in years)		5 years
Computer Equipment
Summary of Significant Accounting Policies and Other Information
Useful life (in years)		3 years
Selling, General and Administrative Expenses
Summary of Significant Accounting Policies and Other Information
Advertising expense		$ 2,100,000	2,100,000	2,700,000
Selling, General and Administrative Expenses | Shipping and handling cost and expenses
Summary of Significant Accounting Policies and Other Information
Cost of sales		15,400,000	11,100,000	$ 11,000,000
Other Assets
Summary of Significant Accounting Policies and Other Information
Equity method investment, cost			500,000
Other Noncurrent Assets
Summary of Significant Accounting Policies and Other Information
Marketable securities		$ 15,000,000	$ 13,200,000
Polytronics
Summary of Significant Accounting Policies and Other Information
Ownership percentage		6.80%	7.20%		6.80%		7.20%
Equity investment		$ 26,100,000	$ 19,200,000		€ 23.0		€ 15.7
Powersem | Equity Method
Summary of Significant Accounting Policies and Other Information
Ownership percentage		45.00%			45.00%
EB Tech | Equity Method
Summary of Significant Accounting Policies and Other Information
Ownership percentage		19.00%			19.00%
ATEC | Equity Method
Summary of Significant Accounting Policies and Other Information
Ownership percentage		24.00%			24.00%