Littelfuse (LFUS) 10-Q 28 Apr 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 27, 2021	Apr. 23, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 27, 2021
Document Transition Report	false
Entity File Number	0-20388
Entity Registrant Name	LITTELFUSE INC /DE
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-3795742
Entity Address, Address Line One	8755 West Higgins Road
Entity Address, Address Line Two	Suite 500
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60631
City Area Code	773
Local Phone Number	628-1000
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	LFUS
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		24,555,229
Entity Central Index Key	0000889331
Current Fiscal Year End Date	--12-26
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 27, 2021	Dec. 26, 2020
Current assets:
Cash and cash equivalents	$ 572,771	$ 687,525
Short-term investments	53	54
Trade receivables, less allowances of $42,624 and $45,237 at March 27, 2021 and December 26, 2020, respectively	276,687	232,760
Inventories	295,057	258,002
Prepaid income taxes and income taxes receivable	4,146	3,029
Prepaid expenses and other current assets	43,698	35,939
Total current assets	1,192,412	1,217,309
Net property, plant, and equipment	344,914	344,178
Intangible assets, net of amortization	317,294	291,887
Goodwill	845,586	816,812
Investments	37,285	30,547
Deferred income taxes	9,854	11,224
Right of use lease assets, net	19,560	17,615
Other assets	19,965	18,021
Total assets	2,786,870	2,747,593
Current liabilities:
Accounts payable	179,723	145,984
Accrued liabilities	98,354	110,478
Accrued income taxes	23,468	19,186
Current portion of long-term debt	25,000	0
Total current liabilities	326,545	275,648
Long-term debt, less current portion	623,865	687,034
Deferred income taxes	51,229	50,134
Accrued post-retirement benefits	42,894	45,802
Non-current operating lease liabilities	14,190	12,950
Other long-term liabilities	67,410	67,252
Shareholders’ equity:
Common stock, par value $0.01 per share: 34,000,000 shares authorized; shares issued, March 27, 2021–26,196,472; December 26, 2020–26,131,544	259	259
Additional paid-in capital	918,762	907,858
Treasury stock, at cost: 1,644,283 and 1,644,283 shares, respectively	(242,366)	(242,366)
Accumulated other comprehensive loss	(96,028)	(91,157)
Retained earnings	1,079,979	1,034,048
Littelfuse, Inc. shareholders’ equity	1,660,606	1,608,642
Non-controlling interest	131	131
Total equity	1,660,737	1,608,773
Total liabilities and equity	$ 2,786,870	$ 2,747,593

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Mar. 27, 2021	Dec. 26, 2020
Statement of Financial Position [Abstract]
Allowance for trade receivables	$ 42,624	$ 45,237
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock authorized (in shares)	34,000,000	34,000,000
Common stock issued (in shares)	26,196,472	26,131,544
Treasury stock (in shares)	1,644,283	1,644,283

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF NET INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Income Statement [Abstract]
Net sales	$ 463,794	$ 346,096
Cost of sales	303,328	221,740
Gross profit	160,466	124,356
Selling, general, and administrative expenses	58,288	51,200
Research and development expenses	14,739	14,463
Amortization of intangibles	10,521	9,981
Restructuring, impairment, and other charges	437	3,962
Total operating expenses	83,985	79,606
Operating income	76,481	44,750
Interest expense	4,673	5,418
Foreign exchange loss	6,837	2,584
Other (income) expense, net	(7,737)	1,249
Income before income taxes	72,708	35,499
Income taxes	14,995	10,855
Net income	$ 57,713	$ 24,644
Earnings per share:
Basic (in dollars per share)	$ 2.35	$ 1.01
Diluted (in dollars per share)	$ 2.32	$ 1
Weighted-average shares and equivalent shares outstanding:
Basic (in shares)	24,532	24,393
Diluted (in shares)	24,892	24,578

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 57,713	$ 24,644
Other comprehensive income (loss):
Pension and postemployment adjustment, net of tax	454	561
Foreign currency translation adjustments	(5,325)	(15,540)
Comprehensive income	$ 52,842	$ 9,665

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
OPERATING ACTIVITIES
Net income	$ 57,713	$ 24,644
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	13,677	13,821
Amortization of intangibles	10,521	9,981
Deferred revenue	(157)	(145)
Non-cash inventory charges	3,489	0
Impairment charges	0	2,237
Stock-based compensation	3,395	2,965
(Gain) loss on investments and other assets	(7,675)	2,604
Deferred income taxes	378	616
Other	8,537	3,547
Changes in operating assets and liabilities:
Trade receivables	(32,973)	(9,457)
Inventories	(6,152)	6,667
Accounts payable	17,070	(3,964)
Accrued liabilities and income taxes	(15,427)	(7,012)
Prepaid expenses and other assets	(2,230)	(1,225)
Net cash provided by operating activities	50,166	45,279
INVESTING ACTIVITIES
Acquisitions of businesses, net of cash acquired	(109,852)	0
Purchases of property, plant, and equipment	(14,721)	(16,586)
Net proceeds from sale of property, plant and equipment	2,553	50
Net cash used in investing activities	(122,020)	(16,536)
FINANCING ACTIVITIES
Proceeds of revolving credit facility	0	100,000
Payments of revolving credit facility	(30,000)	0
Payments of term loan	0	(2,500)
Net proceeds related to stock-based award activities	7,509	2,956
Purchases of common stock	0	(22,927)
Cash dividends paid	(11,782)	(11,725)
Net cash (used in) provided by financing activities	(34,273)	65,804
Effect of exchange rate changes on cash, cash equivalents, and restricted cash	(4,101)	(5,111)
(Decrease) increase in cash, cash equivalents, and restricted cash	(110,228)	89,436
Cash, cash equivalents, and restricted cash at beginning of period	687,525	531,139
Cash, cash equivalents, and restricted cash at end of period	577,297	620,575
Supplementary Cash Flow Information
Cash and cash equivalents	572,771	620,575
Restricted cash included in prepaid expenses and other current assets	3,462	0
Restricted cash included in other assets	1,064	0
Cash paid during the period for interest	6,235	7,354
Capital expenditures, not yet paid	$ 4,141	$ 5,832

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Addl. Paid in Capital	Treasury Stock	Accum. Other Comp. (Loss)	Retained Earnings	Non-controlling Interest
Balance at Dec. 28, 2019	$ 1,496,014	$ 256	$ 867,996	$ (216,447)	$ (106,823)	$ 950,901	$ 131
Increase (Decrease) in Stockholders' Equity
Net income	24,644					24,644
Total change in other comprehensive income (loss)	(14,979)				(14,979)
Stock-based compensation	2,965		2,965
Withheld shares on restricted share units for withholding taxes	(443)			(443)
Stock options exercised	3,399		3,399
Repurchases of common stock	(22,927)			(22,927)
Cash dividends paid	(11,725)					(11,725)
Balance at Mar. 28, 2020	1,476,948	256	874,360	(239,817)	(121,802)	963,820	131
Balance at Dec. 26, 2020	1,608,773	259	907,858	(242,366)	(91,157)	1,034,048	131
Increase (Decrease) in Stockholders' Equity
Net income	57,713					57,713
Total change in other comprehensive income (loss)	(4,871)				(4,871)
Stock-based compensation	3,395		3,395
Stock options exercised	7,509	0	7,509
Cash dividends paid	(11,782)					(11,782)
Balance at Mar. 27, 2021	$ 1,660,737	$ 259	$ 918,762	$ (242,366)	$ (96,028)	$ 1,079,979	$ 131

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parentheticals) - $ / shares	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Statement of Stockholders' Equity [Abstract]
Cash dividends paid, per share (in dollars per share)	$ 0.48	$ 0.48

Summary of Significant Accounti

Summary of Significant Accounting Policies and Other Information	3 Months Ended
	Mar. 27, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Other Information	Summary of Significant Accounting Policies and Other Information Nature of Operations Founded in 1927, Littelfuse is an industrial technology manufacturing company empowering a sustainable, connected, and safer world. Across more than 15 countries, and with 12,000 global associates, we partner with customers to design and deliver innovative, reliable solutions. Serving over 100,000 end customers, our products are found in a variety of industrial, transportation and electronics end markets – everywhere, every day. Basis of Presentation The Company’s accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with U.S. Generally Accepted Accounting Principles (“GAAP”) for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, certain information and disclosures normally included in the consolidated balance sheets, statements of net income and comprehensive income, statements of cash flows, and statement of stockholders' equity prepared in conformity with U.S. GAAP have been condensed or omitted as permitted by such rules and regulations, although the Company believes that the disclosures made are adequate to make the information not misleading. They have been prepared in accordance with accounting policies described in the Company’s Annual Report on Form 10-K for the fiscal year ended December 26, 2020 which should be read in conjunction with the disclosures therein. In the opinion of management, all adjustments considered necessary for a fair presentation have been included and are of a normal, recurring nature. Operating results for interim periods are not necessarily indicative of annual operating results. Revenue Recognition Revenue Disaggregation The following tables disaggregate the Company’s revenue by primary business units for the three months ended March 27, 2021 and March 28, 2020: Three Months Ended March 27, 2021 (in thousands) Electronics Automotive Industrial Electronics – Passive Products and Sensors $ 132,437 $ — $ — $ 132,437 Electronics – Semiconductor 154,098 — — 154,098 Passenger Car Products — 67,901 — 67,901 Automotive Sensors — 28,284 — 28,284 Commercial Vehicle Products — 32,344 — 32,344 Industrial Products — — 48,730 48,730 Total $ 286,535 $ 128,529 $ 48,730 $ 463,794 Three Months Ended March 28, 2020 (in thousands) Electronics Automotive Industrial Total Electronics – Passive Products and Sensors $ 84,598 $ — $ — $ 84,598 Electronics – Semiconductor 129,591 — — 129,591 Passenger Car Products — 52,645 — 52,645 Automotive Sensors — 24,174 — 24,174 Commercial Vehicle Products — 27,951 — 27,951 Industrial Products — — 27,137 27,137 Total $ 214,189 $ 104,770 $ 27,137 $ 346,096 See Note 15, Segment Information for net sales by segment and countries. Revenue Recognition The Company recognizes revenue on product sales in the period in which the Company satisfies its performance obligation and control of the product is transferred to the customer. The Company’s sales arrangements with customers are predominately short term in nature and generally provide for transfer of control at the time of shipment as this is the point at which title and risk of loss of the product transfers to the customer. At the end of each period, for those shipments where title to the products and the risk of loss and rewards of ownership do not transfer until the product has been received by the customer, the Company adjusts revenues and cost of sales for the delay between the time that the products are shipped and when they are received by the customer. The amount of revenue recorded reflects the consideration to which the Company expects to be entitled in exchange for goods and may include adjustments for customer allowance, rebates and price adjustments. The Company’s distribution channels are primarily through direct sales and independent third-party distributors. The Company elected the practical expedient under Accounting Standards Codification ("ASC") 340-40-25-4 to expense commissions when incurred as the amortization period of the commission asset the Company would have otherwise recognized is less than one year. Revenue and Billing The Company generally accepts orders from customers through receipt of purchase orders or electronic data interchange based on written sales agreements and purchasing contracts. Contract pricing and selling agreement terms are based on market factors, costs, and competition. Pricing is often negotiated as an adjustment (premium or discount) from the Company’s published price lists. The customer is invoiced when the Company’s products are shipped to them in accordance with the terms of the sales agreement. As the Company’s standard payment terms are less than one year, the Company elected the practical expedient under ASC 606-10-32-18 to not assess whether a contract has a significant financing component. The Company also elected the practical expedient provided in ASC 606-10-25-18B to treat all product shipping and handling activities as fulfillment activities, and therefore recognize the gross revenue associated with the contract, inclusive of any shipping and handling revenue. Ship and Debit Program Some of the terms of the Company’s sales agreements and normal business conditions provide customers (distributors) the ability to receive price adjustments on products previously shipped and invoiced. This practice is common in the industry and is referred to as a “ship and debit” program. This program allows the distributor to debit the Company for the difference between the distributors’ contracted price and a lower price for specific transactions. Under certain circumstances (usually in a competitive situation or large volume opportunity), a distributor will request authorization for pricing allowances to reduce its price. When the Company approves such a reduction, the distributor is authorized to “debit” its account for the difference between the contracted price and the lower approved price. The Company establishes reserves for this program based on historic activity, electronic distributor inventory levels and actual authorizations for the debit and recognizes these debits as a reduction of revenue. Return to Stock The Company has a return to stock policy whereby certain customers, with prior authorization from Littelfuse management, can return previously purchased goods for full or partial credit. The Company establishes an estimated allowance for these returns based on historic activity. Sales revenue and cost of sales are reduced to anticipate estimated returns. Volume Rebates The Company offers volume based sales incentives to certain customers to encourage greater product sales. If customers achieve their specific quarterly or annual sales targets, they are entitled to rebates. The Company estimates the projected amount of rebates that will be achieved by the customer and recognizes this estimated cost as a reduction to revenue as products are sold. Cash, Cash Equivalents and Restricted Cash The following table provides a reconciliation of cash, cash equivalents and restricted cash at March 27, 2021 and December 26, 2020 reported within the Condensed Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Condensed Consolidated Statement of Cash Flows. (in thousands) March 27, December 26, Cash and cash equivalents $ 572,771 $ 687,525 Restricted cash included in prepaid expenses and other current assets 3,462 — Restricted cash included in other assets 1,064 $ — Total cash, cash equivalents and restricted cash $ 577,297 $ 687,525 Recently Adopted Accounting Standards In December 2019, the Financial Accounting Standards Board (FASB) issued ASU No. 2019-12, "Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes" as part of its initiative to reduce complexity in the accounting standards. The guidance is effective for fiscal years beginning after December 15, 2020 with early adoption permitted. The adoption of ASU 2019-12 did not have a material impact on our Condensed Consolidated Financial Statements.

Acquisitions

Acquisitions	3 Months Ended
	Mar. 27, 2021
Business Combinations [Abstract]
Acquisitions	Acquisitions The Company accounts for acquisitions using the acquisition method in accordance with ASC 805, “Business Combinations,” in which assets acquired and liabilities assumed are recorded at fair value as of the date of acquisition. The operating results of the acquired business are included in the Company’s Consolidated Financial Statements from the date of the acquisition. Hartland Controls On January 28, 2021, the Company acquired Hartland Controls ("Hartland"), a manufacturer and leading supplier of electrical components used primarily in heating, ventilation, air conditioning (HVAC) and other industrial and control systems applications with annualized sales of approximately $70 million. The purchase price for Hartland was approximately $112.3 million and the operations of Hartland are included in the Industrial segment. The total purchase consideration of $109.9 million, net of cash, cash equivalents, and restricted cash has been allocated, on a preliminary basis, to assets acquired and liabilities assumed, as of the completion of the acquisition, based on preliminary estimated fair values. The purchase consideration is subject to change for the final working capital adjustments. As of March 27, 2021, the Company had restricted cash of $1.7 million in an escrow account for general indemnification purposes. The purchase price allocation is preliminary because the evaluations necessary to assess the fair values of the net assets acquired are still in process. The primary areas that are not yet finalized relate to the completion of the valuations of certain acquired income tax assets and liabilities. As a result, these allocations are subject to change during the purchase price allocation period as the valuations are finalized. The following table summarizes the purchase price allocation of the fair value of assets acquired and liabilities assumed in the Hartland acquisition: (in thousands) Purchase Price Total purchase consideration: Cash, net of cash acquired, and restricted cash $ 109,852 Allocation of consideration to assets acquired and liabilities assumed: Trade receivables, net 14,305 Inventories 36,306 Other current assets 2,384 Property, plant, and equipment 6,296 Intangible assets 39,660 Goodwill 38,929 Other non-current assets 3,542 Current liabilities (25,024) Other non-current liabilities (6,546) $ 109,852 All Hartland goodwill, other assets and liabilities were recorded in the Industrial segment and are primarily reflected in the Americas and Asia-Pacific geographic areas. The goodwill resulting from this acquisition consists largely of the Company’s expected future product sales and synergies from combining Hartland’s products and technology with the Company’s existing industrial products portfolio. Goodwill resulting from the Hartland acquisition is not expected to be deductible for tax purposes. Included in the Company’s Condensed Consolidated Statements of Net Income for the three months ended March 27, 2021 are net sales of approximately $16.7 million, and a loss before income taxes of $2.2 million, since the January 28, 2021 acquisition of Hartland. The Company recorded a $6.8 million step-up of inventory to its fair value as of the acquisition date based on the preliminary valuation. The step-up is being amortized as a non-cash charge to cost of goods sold during the first and second quarters of 2021, as the acquired inventory is sold, and reflected as other non-segment costs. During the three months ended March 27, 2021, the Company recognized a charge of $3.5 million for the amortization of this fair value inventory step-up. During the three months ended March 27, 2021, the Company incurred approximately $0.7 million of legal and professional fees related to this acquisition recognized as Selling, general, and administrative expenses . These costs were reflected as other non-segment costs. Pro Forma Results The following table summarizes, on an unaudited pro forma basis, the combined results of operations of the Company and Hartland as though the acquisition had occurred as of December 29, 2019. The pro forma amounts presented are not necessarily indicative of either the actual consolidated results had the Hartland acquisition occurred as of December 29, 2019 or of future consolidated operating results. For the Three Months Ended (in thousands, except per share amounts) March 27, March 28, 2020 Net sales $ 470,832 $ 363,617 Income before income taxes 77,288 31,431 Net income 61,317 21,438 Net income per share — basic 2.50 0.88 Net income per share — diluted 2.46 0.87 Pro forma results presented above primarily reflect the following adjustments: For the Three Months Ended (in thousands) March 27, March 28, 2020 Amortization (a) $ (279) $ (834) Depreciation 7 48 Transaction costs (b) 707 (707) Amortization of inventory step-up (c) 3,490 (5,137) Income tax (expense) benefit of above items (831) 1,398 (a) The amortization adjustment for the three months ended March 28, 2020 primarily reflects incremental amortization resulting for the measurement of intangibles at their fair values. (b) The transaction cost adjustments reflect the reversal of certain bank and attorney fees from the three months ended March 27, 2021 and recognition of those fees during the three months ended March 28, 2020. (c) The amortization of inventory step-up adjustment reflects the reversal of the amount recognized during the three months ended March 27, 2021 and the recognition of a full quarter of the amortization during the three months ended March 28, 2020. The inventory step-up was amortized over four months as the inventory was sold.

Inventories

Inventories	3 Months Ended
	Mar. 27, 2021
Inventory Disclosure [Abstract]
Inventories	Inventories The components of inventories at March 27, 2021 and December 26, 2020 are as follows: (in thousands) March 27, 2021 December 26, 2020 Raw materials $ 97,695 $ 85,394 Work in process 102,285 92,783 Finished goods 130,138 114,641 Inventory Reserves (35,061) (34,816) Total $ 295,057 $ 258,002

Property, Plant, and Equipment

Property, Plant, and Equipment	3 Months Ended
	Mar. 27, 2021
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment	Property, Plant, and Equipment The components of net property, plant, and equipment at March 27, 2021 and December 26, 2020 are as follows: (in thousands) March 27, 2021 December 26, 2020 Land $ 22,711 $ 22,851 Building 124,192 123,497 Equipment 687,563 678,220 Accumulated depreciation and amortization (489,552) (480,390) Total $ 344,914 $ 344,178 The Company recorded depreciation expense of $13.7 million and $13.8 million for the three months ended March 27, 2021 and March 28, 2020, respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	3 Months Ended
	Mar. 27, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets The amounts for goodwill and changes in the carrying value by segment for the three months ended March 27, 2021 are as follows: (in thousands) Electronics Automotive Industrial Total Net book value of goodwill as of December 26, 2020 Gross goodwill as of December 26, 2020 $ 676,325 $ 138,354 $ 47,551 $ 862,230 Accumulated impairment losses as of December 26, 2020 — (36,423) (8,995) (45,418) Total 676,325 101,931 38,556 816,812 Changes during 2021: Additions (a) — — 38,929 38,929 Currency translation (8,124) (2,012) (19) (10,155) Net book value of goodwill as of March 27, 2021 Gross goodwill as of March 27, 2021 668,201 136,229 86,461 890,891 Accumulated impairment losses as of March 27, 2021 — (36,310) (8,995) (45,305) Total $ 668,201 $ 99,919 $ 77,466 $ 845,586 (a) The additions resulted from the acquisition of Hartland. The components of other intangible assets as of March 27, 2021 and December 26, 2020 are as follows: As of March 27, 2021 (in thousands) Gross Accumulated Amortization Net Book Value Land use rights $ 10,251 $ 2,051 $ 8,200 Patents, licenses and software 142,732 94,636 48,096 Distribution network 43,704 39,307 4,397 Customer relationships, trademarks, and tradenames 400,253 143,652 256,601 Total $ 596,940 $ 279,646 $ 317,294 As of December 26, 2020 (in thousands) Gross Accumulated Amortization Net Book Value Land use rights $ 10,280 $ 2,007 $ 8,273 Patents, licenses and software 137,210 92,868 44,342 Distribution network 43,910 38,980 4,930 Customer relationships, trademarks, and tradenames 372,064 137,722 234,342 Total $ 563,464 $ 271,577 $ 291,887 During the three months ended March 27, 2021 and March 28, 2020, the Company recorded amortization expense of $10.5 million and $10.0 million, respectively. The Company recognized a $0.3 million non-cash impairment charge in the first quarter of 2020 on a certain patent triggered by the Company’s announcement to consolidate a manufacturing facility within the Industrial segment. During the three months ended March 27, 2021, the Company recorded additions to intangible assets of $39.7 million, related to the Hartland acquisition, the components of which were as follows: (in thousands) Weighted Average Useful Life Amount Patents, licenses and software 9.2 $ 7,559 Customer relationships, trademarks, and tradenames 13.7 32,101 Total $ 39,660 Estimated annual amortization expense related to intangible assets with definite lives as of March 27, 2021 is as follows: (in thousands) Amount 2021 $ 41,545 2022 40,791 2023 36,491 2024 33,054 2025 32,603 2026 and thereafter 143,331 Total $ 327,815

Accrued Liabilities

Accrued Liabilities	3 Months Ended
	Mar. 27, 2021
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities The components of accrued liabilities as of March 27, 2021 and December 26, 2020 are as follows: (in thousands) March 27, 2021 December 26, 2020 Employee-related liabilities $ 45,135 $ 50,689 Operating lease liability 7,177 6,811 Interest 2,636 4,517 Restructuring liability 2,588 4,195 Customer liability 794 3,858 Professional services 3,010 3,321 Deferred revenue 2,713 2,959 Other non-income taxes 1,903 2,126 Other 32,398 32,002 Total $ 98,354 $ 110,478 Employee-related liabilities consist primarily of payroll, sales commissions, bonus, employee benefit accruals and workers’ compensation. Bonus accruals include amounts earned pursuant to the Company’s primary employee incentive compensation plans. Other accrued liabilities include miscellaneous operating accruals and other client-related liabilities.

Restructuring, Impairment and O

Restructuring, Impairment and Other Charges	3 Months Ended
	Mar. 27, 2021
Restructuring and Related Activities [Abstract]
Restructuring, Impairment and Other Charges	Restructuring, Impairment and Other Charges The Company recorded restructuring, impairment and other charges for the three months ended March 27, 2021 and March 28, 2020 as follows: Three months ended March 27, 2021 (in thousands) Electronics Automotive Industrial Total Employee terminations $ 257 $ — $ 163 $ 420 Other restructuring charges — 17 — 17 Total restructuring charges 257 17 163 437 Impairment — — — — Total $ 257 $ 17 $ 163 $ 437 Three months ended March 28, 2020 (in thousands) Electronics Automotive Industrial Total Employee terminations $ 881 $ 399 $ 321 $ 1,601 Other restructuring charges 1 120 3 124 Total restructuring charges 882 519 324 1,725 Impairment — — 2,237 2,237 Total $ 882 $ 519 $ 2,561 $ 3,962 2021 For the three months ended March 27, 2021, the Company recorded total restructuring charges of $0.4 million, primarily for employee termination costs. These charges primarily related to the reorganization of certain manufacturing, selling and administrative functions within the Electronics and Industrial segments. 2020 For the three months ended March 28, 2020, the Company recorded total restructuring charges of $1.7 million, for employee termination costs and other restructuring charges. These charges primarily related to the reorganization of certain manufacturing, selling and administrative functions across all segments and the announced consolidation of a manufacturing facility within the Industrial segment. The Company also recognized $2.2 million of impairment charges related to the land and building associated with the Company’s announcement to consolidate a manufacturing facility within the Industrial segment. The restructuring liability as of March 27, 2021 and December 26, 2020 is $2.6 million and $4.2 million, respectively. The restructuring liability is included within accrued liabilities in the Condensed Consolidated Balance Sheets. The Company anticipates the remaining payments associated with employee terminations will primarily be completed by the first quarter of 2022.

Debt

Debt	3 Months Ended
	Mar. 27, 2021
Debt Disclosure [Abstract]
Debt	Debt The carrying amounts of debt at March 27, 2021 and December 26, 2020 are as follows: (in thousands) March 27, December 26, Revolving Credit Facility $ 100,000 $ 130,000 Euro Senior Notes, Series A due 2023 138,039 142,679 Euro Senior Notes, Series B due 2028 112,083 115,850 U.S. Senior Notes, Series A due 2022 25,000 25,000 U.S. Senior Notes, Series B due 2027 100,000 100,000 U.S. Senior Notes, Series A due 2025 50,000 50,000 U.S. Senior Notes, Series B due 2030 125,000 125,000 Other 2,619 2,619 Unamortized debt issuance costs (3,876) (4,114) Total debt 648,865 687,034 Less: Current maturities (25,000) — Total long-term debt $ 623,865 $ 687,034 Revolving Credit Facility On April 3, 2020, the Company amended its Credit Agreement to effect certain changes, including, among others: (i) eliminating the $200.0 million unsecured term loan credit facility, the remaining outstanding balance ($140.0 million) of which was repaid in full on April 3, 2020 through the revolving credit facility; (ii) making certain financial and non-financial covenants less restrictive on the Company; (iii) modifying performance-based interest rate margins and undrawn fees; and (iv) extending the maturity date to April 3, 2025. The amended Credit Agreement also allows the Company to increase the size of the revolving credit facility or enter into one or more tranches of term loans if there is no event of default and the Company is in compliance with certain financial covenants. The Company made payments of $30.0 million on the amended revolving credit facility during the three months ended March 27, 2021. The balance under the facility was $100.0 million as of March 27, 2021. Outstanding borrowings under the amended Credit Agreement bears interest, at the Company’s option, at either LIBOR, fixed for interest periods of one, two, three or six-month periods, plus 1.25% to 2.00%, or at the bank’s Base Rate, as defined, plus 0.25% to 1.00%, based upon the Company’s Consolidated Leverage Ratio, as defined. The Company was also required to pay commitment fees on unused portions of the credit agreement ranging from 0.125% to 0.20%, based on the Consolidated Leverage Ratio, as defined in the agreement. The amended Credit Agreement included representations, covenants and events of default that are customary for financing transactions of this nature . The effective interest rate on outstanding borrowings under the credit facility was 1.61% at March 27, 2021. As of March 27, 2021, the Company had no amount outstanding in letters of credit and had available $571.3 million of borrowing capacity under the Revolving Credit Facility based on financial covenants. At March 27, 2021, the Company was in compliance with all covenants under the Credit Agreement. Senior Notes On December 8, 2016, the Company entered into a Note Purchase Agreement, pursuant to which the Company issued and sold €212 million aggregate principal amount of senior notes in two series. The funding date for the Euro denominated senior notes occurred on December 8, 2016 for €117 million in aggregate amount of 1.14% Senior Notes, Series A, due December 8, 2023 (“Euro Senior Notes, Series A due 2023”), and €95 million in aggregate amount of 1.83% Senior Notes, Series B due December 8, 2028 (“Euro Senior Notes, Series B due 2028”) (together, the “Euro Senior Notes”). Interest on the Euro Senior Notes is payable semiannually on June 8 and December 8, commencing June 8, 2017. On December 8, 2016, the Company entered into a Note Purchase Agreement, pursuant to which the Company issued and sold $125 million aggregate principal amount of senior notes in two series. On February 15, 2017, $25 million in aggregate principal amount of 3.03% Senior Notes, Series A, due February 15, 2022 (“U.S. Senior Notes, Series A due 2022”), and $100 million in aggregate principal amount of 3.74% Senior Notes, Series B, due February 15, 2027 (“U.S. Senior Notes, Series B due 2027”) (together, the “U.S. Senior Notes due 2022 and 2027”) were funded. Interest on the U.S. Senior Notes due 2022 and 2027 is payable semiannually on February 15 and August 15, commencing August 15, 2017. On November 15, 2017, the Company entered into a Note Purchase Agreement pursuant to which the Company issued and sold $175 million in aggregate principal amount of senior notes in two series. On January 16, 2018, $50 million aggregate principal amount of 3.48% Senior Notes, Series A, due February 15, 2025 (“U.S. Senior Notes, Series A due 2025”) and $125 million in aggregate principal amount of 3.78% Senior Notes, Series B, due February 15, 2030 (“U.S. Senior Notes, Series B due 2030”) (together the “U.S. Senior Notes due 2025 and 2030” and with the Euro Senior Notes and the U.S. Senior Notes due 2022 and 2027, the “Senior Notes”) were funded. Interest on the U.S. Senior Notes due 2025 and 2030 is payable semiannually on February 15 and August 15, commencing on August 15, 2018. The Senior Notes have not been registered under the Securities Act, or applicable state securities laws. The Senior Notes are general unsecured senior obligations and rank equal in right of payment with all existing and future unsecured unsubordinated indebtedness of the Company. The Senior Notes are subject to certain customary covenants, including limitations on the Company’s ability, with certain exceptions, to engage in mergers, consolidations, asset sales and transactions with affiliates, to engage in any business that would substantially change the general business of the Company, and to incur liens. In addition, the Company is required to satisfy certain financial covenants and tests relating to, among other matters, interest coverage and leverage. At March 27, 2021, the Company was in compliance with all covenants under the Senior Notes. The Company may redeem the Senior Notes upon the satisfaction of certain conditions and the payment of a make-whole amount to noteholders and are required to offer to repurchase the Senior Notes at par following certain events, including a change of control. Interest paid on all Company debt was $6.2 million and $7.4 million for the three months ended March 27, 2021 and March 28, 2020, respectively.

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	3 Months Ended
	Mar. 27, 2021
Fair Value Disclosures [Abstract]
Fair Value of Assets and Liabilities	Fair Value of Assets and Liabilities For assets and liabilities measured at fair value on a recurring and nonrecurring basis, a three-level hierarchy of measurements based upon observable and unobservable inputs is used to arrive at fair value. Observable inputs are developed based on market data obtained from independent sources, while unobservable inputs reflect the Company’s assumptions about valuation based on the best information available in the circumstances. Depending on the inputs, the Company classifies each fair value measurement as follows: Level 1 —Valuations based on unadjusted quoted prices for identical assets or liabilities in active markets; Level 2 —Valuations based upon quoted prices for similar instruments, prices for identical or similar instruments in markets that are not active, or model-derived valuations, all of whose significant inputs are observable, and Level 3 —Valuations based upon one or more significant unobservable inputs. Following is a description of the valuation methodologies used for instruments measured at fair value and their classification in the valuation hierarchy. Cash Equivalents Cash equivalents primarily consist of money market funds, which are held with an institution with sound credit rating and are highly liquid. The Company classified cash equivalents as Level 1 and are valued at cost which approximates fair value. Investments in Equity Securities Investments in equity securities listed on a national market or exchange are valued at the last sales price and classified within Level 1 of the valuation hierarchy and recorded in investments and other assets. Other Investments The Company has certain convertible debt and convertible preferred stock investments that are accounted for under the cost method reflected in other assets in the Condensed Consolidated Balance Sheets. As of March 27, 2021 and December 26, 2020, the balances of these investments were both $0.5 million. The fair value of these investments are measured on a nonrecurring basis using Level 3 inputs under the fair value hierarchy. The Company's accounting and finance management determines the valuation policies and procedures for Level 3 fair value measurements and is responsible for the development and determination of unobservable inputs. Mutual Funds The Company has a non-qualified Supplemental Retirement and Savings Plan which provides additional retirement benefits for certain management employees and named executive officers by allowing participants to defer a portion of their annual compensation. The Company maintains accounts for participants through which participants make investment elections. The marketable securities are classified as Level 1 under the fair value hierarchy as they are maintained in mutual funds with readily determinable fair value and recorded in other assets. There were no changes during the quarter ended March 27, 2021 to the Company’s valuation techniques used to measure asset and liability fair values on a recurring basis. As of March 27, 2021 and December 26, 2020, the Company did not hold any non-financial assets or liabilities that are required to be measured at fair value on a recurring basis. The following table presents assets measured at fair value by classification within the fair value hierarchy as of March 27, 2021: Fair Value Measurements Using (in thousands) Quoted Prices in Significant Significant Total Cash Equivalents $ 66,565 $ — $ — $ 66,565 Investments in equity securities 25,830 — — 25,830 Mutual funds 13,397 — — 13,397 Total $ 105,792 $ — $ — $ 105,792 The following table presents assets measured at fair value by classification within the fair value hierarchy as of December 26, 2020: Fair Value Measurements Using (in thousands) Quoted Prices in Significant Significant Total Cash Equivalents $ 73,461 $ — $ — $ 73,461 Investments in equity securities 19,186 — — 19,186 Mutual funds 13,249 — — 13,249 Total $ 105,896 $ — $ — $ 105,896 In addition to the methods and assumptions used for the financial instruments recorded at fair value as discussed above, the following methods and assumptions are used to estimate the fair value of other financial instruments that are not marked to market on a recurring basis. The Company’s other financial instruments include cash and cash equivalents, short-term investments, accounts receivable and its long-term debt. Due to their short-term maturity, the carrying amounts of cash and cash equivalents, short-term investments and accounts receivable approximate their fair values. The Company’s revolving credit facilities’ fair values approximate book value at March 27, 2021 and December 26, 2020, as the rates on these borrowings are variable in nature. The carrying value and estimated fair values of the Company’s Euro Senior Notes, Series A and Series B and USD Senior Notes, Series A and Series B, as of March 27, 2021 and December 26, 2020 were as follows: March 27, 2021 December 26, 2020 (in thousands) Carrying Estimated Carrying Estimated Euro Senior Notes, Series A due 2023 $ 138,039 $ 140,084 $ 142,679 $ 144,323 Euro Senior Notes, Series B due 2028 112,083 117,703 115,850 123,588 USD Senior Notes, Series A due 2022 25,000 25,375 25,000 25,437 USD Senior Notes, Series B due 2027 100,000 106,174 100,000 109,552 USD Senior Notes, Series A due 2025 50,000 52,817 50,000 53,474 USD Senior Notes, Series B due 2030 125,000 130,764 125,000 138,036 The Company recognized impairment charges of $1.9 million for the land and building and $0.3 million for a certain patent as a result of the Company’s announcement to consolidate a manufacturing facility within the Industrial segment during the first quarter of 2020. See Note 7, Restructuring, Impairment and Other Charges, for further discussion. The fair value of the land and building was valued using a real estate appraisal and classified as a Level 3 input under the fair value hierarchy.

Benefit Plans

Benefit Plans	3 Months Ended
	Mar. 27, 2021
Retirement Benefits [Abstract]
Benefit Plans	Benefit Plans The Company has company-sponsored defined benefit pension plans covering employees in the U.K., Germany, the Philippines, China, Japan, Mexico, Italy and France. The amount of the retirement benefits provided under the plans is based on years of service and final average pay. The Company recognizes interest cost, expected return on plan assets, and amortization of prior service, net within Other (income) expense, net in the Condensed Consolidated Statements of Net Income. The components of net periodic benefit cost for the three months ended March 27, 2021 and March 28, 2020 were as follows: For the Three Months Ended (in thousands) March 27, 2021 March 28, 2020 Components of net periodic benefit cost: Service cost $ 702 $ 618 Interest cost 440 658 Expected return on plan assets (367) (727) Amortization of prior service and net actuarial loss 331 145 Net periodic benefit cost $ 1,106 $ 694 The Company expects to make approximately $2.2 million of contributions to the plans and pay $3.8 million of benefits directly in 2021. The Company also sponsors certain post-employment plans in foreign countries and other statutory benefit plans. The Company recorded expense of $0.5 million for both the three months ended March 27, 2021 and March 28, 2020 , respectively, in Cost of Sales and Other (income) expense, net within the Condensed Consolidated Statements of Net Income. For the three months ended March 27, 2021 and March 28, 2020, the pre-tax amounts recognized in other comprehensive income (loss) as components of net periodic benefit costs for these plans were both $0.2 million. On April 7, 2020, the Company entered into a definitive agreement to purchase a group annuity contract, under which an insurance company will be required to directly pay and administer pension payments to certain of the Company’s U.K. pension plan participants, or their designated beneficiaries. The purchase of this group annuity contract will reduce the Company’s outstanding pension benefit obligation by approximately $55 million, representing approximately 37% of the total obligations of the Company’s qualified pension plans, and will be funded with pension plan assets and additional cash on hand. In connection with this transaction, the Company will record a one-time non-cash settlement charge currently estimated between $18 million and $22 million in the fourth quarter of 2021, reflecting the accelerated recognition of unamortized actuarial losses

Other Comprehensive Income

Other Comprehensive Income	3 Months Ended
	Mar. 27, 2021
Equity [Abstract]
Other Comprehensive Income	Other Comprehensive Income Changes in other comprehensive income (loss) by component were as follows: (in thousands) Three Months Ended Three Months Ended Pre-tax Tax Net of Tax Pre-tax Tax Net of Tax Defined benefit pension plan and other adjustments $ 506 $ 52 $ 454 $ 555 $ (6) $ 561 Foreign currency translation adjustments (5,325) — (5,325) (15,540) — (15,540) Total change in other comprehensive income (loss) $ (4,819) $ 52 $ (4,871) $ (14,985) $ (6) $ (14,979) The following tables set forth the changes in accumulated other comprehensive (loss) by component for the three months ended March 27, 2021 and March 28, 2020: (in thousands) Defined benefit pension plan and other adjustments Foreign currency Accumulated other Balance at December 26, 2020 $ (34,141) $ (57,016) $ (91,157) Activity in the period 454 (5,325) (4,871) Balance at March 27, 2021 $ (33,687) $ (62,341) $ (96,028) (in thousands) Defined benefit pension plan and other adjustments Foreign currency translation adjustment Accumulated other comprehensive (loss) Balance at December 28, 2019 $ (18,046) $ (88,777) $ (106,823) Activity in the period 561 (15,540) (14,979) Balance at March 28, 2020 $ (17,485) $ (104,317) $ (121,802) Amounts reclassified from accumulated other comprehensive (loss) to earnings for the three months ended March 27, 2021 and March 28, 2020 were as follows: Three Months Ended (in thousands) March 27, 2021 March 28, 2020 Pension and Postemployment plans: Amortization of prior service and net actuarial loss $ 504 $ 345 The Company recognizes the amortization of prior service costs in Other (income) expense, net within the Condensed Consolidated Statements of Net Income.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 27, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The effective tax rate for the three months ended March 27, 2021 was 20.6%, compared to the effective tax rate for the three months ended March 28, 2020 of 30.6%. The effective tax rate for the 2021 period is lower than the effective tax rate for the comparable 2020 period primarily due to an increase in the forecasted income earned in lower tax jurisdictions in 2021 as compared to 2020. The effective tax rate for the 2021 period is approximately the same as the applicable U.S. statutory rate.

Earnings Per Share

Earnings Per Share	3 Months Ended
	Mar. 27, 2021
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The following table sets forth the computation of basic and diluted earnings per share: Three Months Ended (in thousands, except per share amounts) March 27, 2021 March 28, 2020 Numerator: Net income as reported $ 57,713 $ 24,644 Denominator: Weighted average shares outstanding Basic 24,532 24,393 Effect of dilutive securities 360 185 Diluted 24,892 24,578 Earnings Per Share: Basic earnings per share $ 2.35 $ 1.01 Diluted earnings per share $ 2.32 $ 1.00 Potential shares of common stock relating to stock options and restricted share units excluded from the earnings per share calculation because their effect would be anti-dilutive were 15 and 153,836 for the three months ended March 27, 2021 and March 28, 2020, respectively. Share Repurchase Program On April 26, 2019, the Company's Board of Directors authorized a program to repurchase up to 1,000,000 shares of the Company's common stock for the period May 1, 2019 to April 30, 2020 ("2019 program"). On April 29, 2020, the Company announced that the Board of Directors authorized a new program to repurchase up to 1,000,000 shares of the Company's common stock for the period May 1, 2020 to April 30, 2021 (the "2020 program") to replace its previous expired 2019 program. On April, 28, 2021, the Company announced that the Board of Directors authorized a new three year program to repurchase up to $300.0 million in the aggregate of shares of the Company’s common stock for the period May 1, 2021 to April 30, 2024 to replace its previous 2020 program.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 27, 2021
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions The Company has equity ownership in various investments that are accounted for under the equity method. The following is a description of the investments and related party transactions. Powersem GmbH: The Company owns 45% of the outstanding equity of Powersem GmbH (“Powersem”), a module manufacturer based in Germany. EB-Tech Co., Ltd.: The Company owns approximately 19% of the outstanding equity of EB Tech Co., Ltd. (“EB Tech”), a company with expertise in radiation technology based in South Korea. Automated Technology (Phil), Inc. : The Company owns approximately 24% of the outstanding common shares of Automated Technology (Phil), Inc. (“ATEC”), a supplier located in the Philippines that provides assembly and test services. One member of the Company's Board of Directors serves on the Board of Directors of ATEC. For the Three Months Ended March 27, 2021 For the Three Months Ended March 28, 2020 (in millions) Powersem EB Tech ATEC Powersem EB Tech ATEC Sales to related party $ 0.2 $ — $ — $ 0.4 $ — $ — Purchase material/service from related party $ 1.1 $ 0.1 $ 3.0 $ 0.2 $ — $ 1.8 March 27, 2021 December 26, 2020 (in millions) Powersem EB Tech ATEC Powersem EB Tech ATEC Accounts Receivable balance $ — $ — $ — $ 0.1 $ — $ — Accounts Payable balance $ 0.2 $ — $ 0.3 $ 0.1 $ — $ 0.2 Additionally, the Company has certain cost method investments in VTOOL Ltd. and Securepush Ltd. with a total book value of $0.5 million as of March 27, 2021 and December 26, 2020 and one member of the Company’s Board of Directors is currently an investor and a director of VTOOL Ltd. and Securepush Ltd.

Segment Information

Segment Information	3 Months Ended
	Mar. 27, 2021
Segment Reporting [Abstract]
Segment Information	Segment Information The Company and its subsidiaries design, manufacture and sell components and modules empowering a sustainable, connected, and safer world. The Company reports its operations by the following segments: Electronics, Automotive, and Industrial. An operating segment is defined as a component of an enterprise that engages in business activities from which it may earn revenues and incur expenses, and about which separate financial information is regularly evaluated by the Chief Operating Decision Maker (“CODM”) in deciding how to allocate resources. The CODM is the Company’s President and Chief Executive Officer (“CEO”). The CODM allocates resources to and assesses the performance of each operating segment using information about its revenue and operating income (loss) before interest and taxes, but does not evaluate the operating segments using discrete balance sheet information. Sales, marketing, and research and development expenses are charged directly into each operating segment. Purchasing, logistics, customer service, finance, information technology, and human resources are shared functions that are allocated back to the three operating segments. The Company does not report inter-segment revenue because the operating segments do not record it. Certain expenses, determined by the CODM to be strategic in nature and not directly related to segments' current results, are not allocated but identified as “Other”. Additionally, the Company does not allocate interest and other income, interest expense, or taxes to operating segments. These costs are not allocated to the segments, as management excludes such costs when assessing the performance of the segments. Although the CODM uses operating income (loss) to evaluate the segments, operating costs included in one segment may benefit other segments. Except as discussed above, the accounting policies for segment reporting are the same as for the Company as a whole. • Electronics Segment : Consists of one of the broadest product offerings in the industry, including fuses and fuse accessories, positive temperature coefficient (“PTC”) resettable fuses, polymer electrostatic discharge (“ESD”) suppressors, varistors, reed switch based magnetic sensing, gas discharge tubes; semiconductor products such as discrete transient voltage suppressor (“TVS”) diodes, TVS diode arrays, protection and switching thyristors, metal-oxide-semiconductor field effect transistors (“MOSFETs”) and silicon carbide diodes; and insulated gate bipolar transistors (“IGBT”) technologies. The segment covers a broad range of end markets, including industrial motor drives and power conversion, automotive electronics, electric vehicle and related infrastructure, power supplies, data centers and telecommunications, medical devices, alternative energy, building and home automation, appliances, and mobile electronics. • Automotive Segment: Consists of a wide range of circuit protection, power control and sensing technologies for global original equipment manufacturers (“OEMs”), Tier-I suppliers and parts distributors in passenger car, heavy duty truck, off-road vehicles, material handling, agricultural, construction and other commercial vehicle end markets. Passenger car fuse products for internal combustion engine, hybrid and electric vehicles including blade fuses, battery cable protectors, resettable fuses, high-current fuses, and high-voltage fuses. Commercial vehicle products include fuses, switches, relays, and power distribution modules used in applications serving a number of end markets, including heavy truck, construction, agriculture and material handling. Automotive sensor products include a wide range of automotive and commercial vehicle products designed to monitor the passenger compartment occupant's safety and environment as well as the vehicle’s powertrain. • Industrial Segment: Consists of industrial circuit protection products (i.e. fuses, power distribution modules, switches) and industrial control products (i.e. relays, transformers, contactors, sensors). These products are used in a variety of applications and end-markets including: Renewable Energy, Energy Storage, HVAC, Electric Vehicle Infrastructure, Industrial Equipment, Industrial Automation, Construction, Mining, and Oil & Gas. Segment information is summarized as follows: Three Months Ended (in thousands) March 27, 2021 March 28, 2020 Net sales Electronics $ 286,535 $ 214,189 Automotive 128,529 104,770 Industrial 48,730 27,137 Total net sales $ 463,794 $ 346,096 Depreciation and amortization Electronics $ 15,381 $ 15,531 Automotive 7,073 7,187 Industrial 1,744 1,084 Total depreciation and amortization $ 24,198 $ 23,802 Operating income Electronics $ 55,523 $ 32,272 Automotive 20,316 14,116 Industrial 3,506 3,534 Other (a) (2,864) (5,172) Total operating income 76,481 44,750 Interest expense 4,673 5,418 Foreign exchange loss 6,837 2,584 Other (income) expense, net (7,737) 1,249 Income before income taxes $ 72,708 $ 35,499 (a) Included in “Other” Operating income for the first quarter of 2021 was $3.5 million of purchase accounting inventory step-up charges, $0.8 million of legal and professional fees and other expenses related to Hartland and other contemplated acquisitions and $0.4 million of restructuring, impairment and other charges, primarily related to employee termination costs. See Note 7, Restructuring, Impairment and Other Charges, for further discussion. In addition, there was a $1.9 million gain from the sale of a building within the Electronics segment. Included in "Other" Operating income for the first quarter of 2020 was $1.2 million of acquisition integration charges related to the IXYS acquisition and other contemplated acquisitions. In addition, there were $4.0 million of restructuring, impairment and other charges, primarily related to impairment charges of $2.2 million associated with the announced consolidation of a manufacturing facility within the Industrial segment and $1.7 million of employee termination costs and other restructuring charges. See Note 7, Restructuring, Impairment and Other Charges , for further discussion. The Company’s net sales by country were as follows: Three Months Ended (in thousands) March 27, 2021 March 28, 2020 Net sales United States $ 130,931 $ 102,910 China 139,158 86,015 Other countries (a) 193,705 157,171 Total net sales $ 463,794 $ 346,096 The Company’s long-lived assets by country were as follows: (in thousands) March 27, December 26, Long-lived assets United States $ 48,908 $ 46,132 China 85,280 85,876 Mexico 72,499 70,125 Germany 36,227 37,976 Philippines 66,956 66,994 Other countries (a) 35,044 37,075 Total long-lived assets $ 344,914 $ 344,178 The Company’s additions to long-lived assets by country were as follows: Three Months Ended (in thousands) March 27, 2021 March 28, 2020 Additions to long-lived assets United States $ 683 $ 580 China 2,142 1,657 Mexico 6,121 2,592 Germany 593 753 Philippines 2,443 3,218 Other countries (a) 754 2,508 Total additions to long-lived assets $ 12,736 $ 11,308 (a) Each country included in other countries is less than 10% of net sales.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies and Other Information (Policies)	3 Months Ended
	Mar. 27, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s accompanying unaudited Condensed Consolidated Financial Statements have been prepared in accordance with U.S. Generally Accepted Accounting Principles (“GAAP”) for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, certain information and disclosures normally included in the consolidated balance sheets, statements of net income and comprehensive income, statements of cash flows, and statement of stockholders' equity prepared in conformity with U.S. GAAP have been condensed or omitted as permitted by such rules and regulations, although the Company believes that the disclosures made are adequate to make the information not misleading. They have been prepared in accordance with accounting policies described in the Company’s Annual Report on Form 10-K for the fiscal year ended December 26, 2020 which should be read in conjunction with the disclosures therein. In the opinion of management, all adjustments considered necessary for a fair presentation have been included and are of a normal, recurring nature. Operating results for interim periods are not necessarily indicative of annual operating results.
Revenue Recognition	Revenue Recognition Revenue Disaggregation The following tables disaggregate the Company’s revenue by primary business units for the three months ended March 27, 2021 and March 28, 2020: Three Months Ended March 27, 2021 (in thousands) Electronics Automotive Industrial Electronics – Passive Products and Sensors $ 132,437 $ — $ — $ 132,437 Electronics – Semiconductor 154,098 — — 154,098 Passenger Car Products — 67,901 — 67,901 Automotive Sensors — 28,284 — 28,284 Commercial Vehicle Products — 32,344 — 32,344 Industrial Products — — 48,730 48,730 Total $ 286,535 $ 128,529 $ 48,730 $ 463,794 Three Months Ended March 28, 2020 (in thousands) Electronics Automotive Industrial Total Electronics – Passive Products and Sensors $ 84,598 $ — $ — $ 84,598 Electronics – Semiconductor 129,591 — — 129,591 Passenger Car Products — 52,645 — 52,645 Automotive Sensors — 24,174 — 24,174 Commercial Vehicle Products — 27,951 — 27,951 Industrial Products — — 27,137 27,137 Total $ 214,189 $ 104,770 $ 27,137 $ 346,096 See Note 15, Segment Information for net sales by segment and countries. Revenue Recognition The Company recognizes revenue on product sales in the period in which the Company satisfies its performance obligation and control of the product is transferred to the customer. The Company’s sales arrangements with customers are predominately short term in nature and generally provide for transfer of control at the time of shipment as this is the point at which title and risk of loss of the product transfers to the customer. At the end of each period, for those shipments where title to the products and the risk of loss and rewards of ownership do not transfer until the product has been received by the customer, the Company adjusts revenues and cost of sales for the delay between the time that the products are shipped and when they are received by the customer. The amount of revenue recorded reflects the consideration to which the Company expects to be entitled in exchange for goods and may include adjustments for customer allowance, rebates and price adjustments. The Company’s distribution channels are primarily through direct sales and independent third-party distributors. The Company elected the practical expedient under Accounting Standards Codification ("ASC") 340-40-25-4 to expense commissions when incurred as the amortization period of the commission asset the Company would have otherwise recognized is less than one year. Revenue and Billing The Company generally accepts orders from customers through receipt of purchase orders or electronic data interchange based on written sales agreements and purchasing contracts. Contract pricing and selling agreement terms are based on market factors, costs, and competition. Pricing is often negotiated as an adjustment (premium or discount) from the Company’s published price lists. The customer is invoiced when the Company’s products are shipped to them in accordance with the terms of the sales agreement. As the Company’s standard payment terms are less than one year, the Company elected the practical expedient under ASC 606-10-32-18 to not assess whether a contract has a significant financing component. The Company also elected the practical expedient provided in ASC 606-10-25-18B to treat all product shipping and handling activities as fulfillment activities, and therefore recognize the gross revenue associated with the contract, inclusive of any shipping and handling revenue. Ship and Debit Program Some of the terms of the Company’s sales agreements and normal business conditions provide customers (distributors) the ability to receive price adjustments on products previously shipped and invoiced. This practice is common in the industry and is referred to as a “ship and debit” program. This program allows the distributor to debit the Company for the difference between the distributors’ contracted price and a lower price for specific transactions. Under certain circumstances (usually in a competitive situation or large volume opportunity), a distributor will request authorization for pricing allowances to reduce its price. When the Company approves such a reduction, the distributor is authorized to “debit” its account for the difference between the contracted price and the lower approved price. The Company establishes reserves for this program based on historic activity, electronic distributor inventory levels and actual authorizations for the debit and recognizes these debits as a reduction of revenue. Return to Stock The Company has a return to stock policy whereby certain customers, with prior authorization from Littelfuse management, can return previously purchased goods for full or partial credit. The Company establishes an estimated allowance for these returns based on historic activity. Sales revenue and cost of sales are reduced to anticipate estimated returns. Volume Rebates The Company offers volume based sales incentives to certain customers to encourage greater product sales. If customers achieve their specific quarterly or annual sales targets, they are entitled to rebates. The Company estimates the projected amount of rebates that will be achieved by the customer and recognizes this estimated cost as a reduction to revenue as products are sold.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards In December 2019, the Financial Accounting Standards Board (FASB) issued ASU No. 2019-12, "Income Taxes (Topic 740) - Simplifying the Accounting for Income Taxes" as part of its initiative to reduce complexity in the accounting standards. The guidance is effective for fiscal years beginning after December 15, 2020 with early adoption permitted. The adoption of ASU 2019-12 did not have a material impact on our Condensed Consolidated Financial Statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies and Other Information (Tables)	3 Months Ended
	Mar. 27, 2021
Accounting Policies [Abstract]
Schedule of revenue disaggregation	The following tables disaggregate the Company’s revenue by primary business units for the three months ended March 27, 2021 and March 28, 2020: Three Months Ended March 27, 2021 (in thousands) Electronics Automotive Industrial Electronics – Passive Products and Sensors $ 132,437 $ — $ — $ 132,437 Electronics – Semiconductor 154,098 — — 154,098 Passenger Car Products — 67,901 — 67,901 Automotive Sensors — 28,284 — 28,284 Commercial Vehicle Products — 32,344 — 32,344 Industrial Products — — 48,730 48,730 Total $ 286,535 $ 128,529 $ 48,730 $ 463,794 Three Months Ended March 28, 2020 (in thousands) Electronics Automotive Industrial Total Electronics – Passive Products and Sensors $ 84,598 $ — $ — $ 84,598 Electronics – Semiconductor 129,591 — — 129,591 Passenger Car Products — 52,645 — 52,645 Automotive Sensors — 24,174 — 24,174 Commercial Vehicle Products — 27,951 — 27,951 Industrial Products — — 27,137 27,137 Total $ 214,189 $ 104,770 $ 27,137 $ 346,096
Schedule of cash and cash equivalents	The following table provides a reconciliation of cash, cash equivalents and restricted cash at March 27, 2021 and December 26, 2020 reported within the Condensed Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Condensed Consolidated Statement of Cash Flows. (in thousands) March 27, December 26, Cash and cash equivalents $ 572,771 $ 687,525 Restricted cash included in prepaid expenses and other current assets 3,462 — Restricted cash included in other assets 1,064 $ — Total cash, cash equivalents and restricted cash $ 577,297 $ 687,525
Schedule of restricted cash and cash equivalents	The following table provides a reconciliation of cash, cash equivalents and restricted cash at March 27, 2021 and December 26, 2020 reported within the Condensed Consolidated Balance Sheets that sum to the total of the same such amounts shown in the Condensed Consolidated Statement of Cash Flows. (in thousands) March 27, December 26, Cash and cash equivalents $ 572,771 $ 687,525 Restricted cash included in prepaid expenses and other current assets 3,462 — Restricted cash included in other assets 1,064 $ — Total cash, cash equivalents and restricted cash $ 577,297 $ 687,525

Acquisitions (Tables)

Acquisitions (Tables)	3 Months Ended
	Mar. 27, 2021
Business Combinations [Abstract]
Schedule of recognized identified assets acquired and liabilities assumed	The following table summarizes the purchase price allocation of the fair value of assets acquired and liabilities assumed in the Hartland acquisition: (in thousands) Purchase Price Total purchase consideration: Cash, net of cash acquired, and restricted cash $ 109,852 Allocation of consideration to assets acquired and liabilities assumed: Trade receivables, net 14,305 Inventories 36,306 Other current assets 2,384 Property, plant, and equipment 6,296 Intangible assets 39,660 Goodwill 38,929 Other non-current assets 3,542 Current liabilities (25,024) Other non-current liabilities (6,546) $ 109,852
Summary of business acquisition, pro forma information	The following table summarizes, on an unaudited pro forma basis, the combined results of operations of the Company and Hartland as though the acquisition had occurred as of December 29, 2019. The pro forma amounts presented are not necessarily indicative of either the actual consolidated results had the Hartland acquisition occurred as of December 29, 2019 or of future consolidated operating results. For the Three Months Ended (in thousands, except per share amounts) March 27, March 28, 2020 Net sales $ 470,832 $ 363,617 Income before income taxes 77,288 31,431 Net income 61,317 21,438 Net income per share — basic 2.50 0.88 Net income per share — diluted 2.46 0.87
Summary of business acquisition, pro forma information, nonrecurring adjustments	Pro forma results presented above primarily reflect the following adjustments: For the Three Months Ended (in thousands) March 27, March 28, 2020 Amortization (a) $ (279) $ (834) Depreciation 7 48 Transaction costs (b) 707 (707) Amortization of inventory step-up (c) 3,490 (5,137) Income tax (expense) benefit of above items (831) 1,398 (a) The amortization adjustment for the three months ended March 28, 2020 primarily reflects incremental amortization resulting for the measurement of intangibles at their fair values. (b) The transaction cost adjustments reflect the reversal of certain bank and attorney fees from the three months ended March 27, 2021 and recognition of those fees during the three months ended March 28, 2020. (c) The amortization of inventory step-up adjustment reflects the reversal of the amount recognized during the three months ended March 27, 2021 and the recognition of a full quarter of the amortization during the three months ended March 28, 2020. The inventory step-up was amortized over four months as the inventory was sold.

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 27, 2021
Inventory Disclosure [Abstract]
Schedule of inventory	The components of inventories at March 27, 2021 and December 26, 2020 are as follows: (in thousands) March 27, 2021 December 26, 2020 Raw materials $ 97,695 $ 85,394 Work in process 102,285 92,783 Finished goods 130,138 114,641 Inventory Reserves (35,061) (34,816) Total $ 295,057 $ 258,002

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	3 Months Ended
	Mar. 27, 2021
Property, Plant and Equipment [Abstract]
Schedule of components of net property, plant, and equipment	The components of net property, plant, and equipment at March 27, 2021 and December 26, 2020 are as follows: (in thousands) March 27, 2021 December 26, 2020 Land $ 22,711 $ 22,851 Building 124,192 123,497 Equipment 687,563 678,220 Accumulated depreciation and amortization (489,552) (480,390) Total $ 344,914 $ 344,178

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	3 Months Ended
	Mar. 27, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill	The amounts for goodwill and changes in the carrying value by segment for the three months ended March 27, 2021 are as follows: (in thousands) Electronics Automotive Industrial Total Net book value of goodwill as of December 26, 2020 Gross goodwill as of December 26, 2020 $ 676,325 $ 138,354 $ 47,551 $ 862,230 Accumulated impairment losses as of December 26, 2020 — (36,423) (8,995) (45,418) Total 676,325 101,931 38,556 816,812 Changes during 2021: Additions (a) — — 38,929 38,929 Currency translation (8,124) (2,012) (19) (10,155) Net book value of goodwill as of March 27, 2021 Gross goodwill as of March 27, 2021 668,201 136,229 86,461 890,891 Accumulated impairment losses as of March 27, 2021 — (36,310) (8,995) (45,305) Total $ 668,201 $ 99,919 $ 77,466 $ 845,586 (a) The additions resulted from the acquisition of Hartland.
Schedule of finite-lived intangible assets	The components of other intangible assets as of March 27, 2021 and December 26, 2020 are as follows: As of March 27, 2021 (in thousands) Gross Accumulated Amortization Net Book Value Land use rights $ 10,251 $ 2,051 $ 8,200 Patents, licenses and software 142,732 94,636 48,096 Distribution network 43,704 39,307 4,397 Customer relationships, trademarks, and tradenames 400,253 143,652 256,601 Total $ 596,940 $ 279,646 $ 317,294 As of December 26, 2020 (in thousands) Gross Accumulated Amortization Net Book Value Land use rights $ 10,280 $ 2,007 $ 8,273 Patents, licenses and software 137,210 92,868 44,342 Distribution network 43,910 38,980 4,930 Customer relationships, trademarks, and tradenames 372,064 137,722 234,342 Total $ 563,464 $ 271,577 $ 291,887 During the three months ended March 27, 2021, the Company recorded additions to intangible assets of $39.7 million, related to the Hartland acquisition, the components of which were as follows: (in thousands) Weighted Average Useful Life Amount Patents, licenses and software 9.2 $ 7,559 Customer relationships, trademarks, and tradenames 13.7 32,101 Total $ 39,660
Schedule of finite-lived intangible assets, future amortization expense	Estimated annual amortization expense related to intangible assets with definite lives as of March 27, 2021 is as follows: (in thousands) Amount 2021 $ 41,545 2022 40,791 2023 36,491 2024 33,054 2025 32,603 2026 and thereafter 143,331 Total $ 327,815

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	3 Months Ended
	Mar. 27, 2021
Payables and Accruals [Abstract]
Schedule of components of accrued liabilities	The components of accrued liabilities as of March 27, 2021 and December 26, 2020 are as follows: (in thousands) March 27, 2021 December 26, 2020 Employee-related liabilities $ 45,135 $ 50,689 Operating lease liability 7,177 6,811 Interest 2,636 4,517 Restructuring liability 2,588 4,195 Customer liability 794 3,858 Professional services 3,010 3,321 Deferred revenue 2,713 2,959 Other non-income taxes 1,903 2,126 Other 32,398 32,002 Total $ 98,354 $ 110,478

Restructuring, Impairment and_2

Restructuring, Impairment and Other Charges (Tables)	3 Months Ended
	Mar. 27, 2021
Restructuring and Related Activities [Abstract]
Schedule of restructuring, impairment and other charges	The Company recorded restructuring, impairment and other charges for the three months ended March 27, 2021 and March 28, 2020 as follows: Three months ended March 27, 2021 (in thousands) Electronics Automotive Industrial Total Employee terminations $ 257 $ — $ 163 $ 420 Other restructuring charges — 17 — 17 Total restructuring charges 257 17 163 437 Impairment — — — — Total $ 257 $ 17 $ 163 $ 437 Three months ended March 28, 2020 (in thousands) Electronics Automotive Industrial Total Employee terminations $ 881 $ 399 $ 321 $ 1,601 Other restructuring charges 1 120 3 124 Total restructuring charges 882 519 324 1,725 Impairment — — 2,237 2,237 Total $ 882 $ 519 $ 2,561 $ 3,962

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 27, 2021
Debt Disclosure [Abstract]
Schedule of long-term debt instruments	The carrying amounts of debt at March 27, 2021 and December 26, 2020 are as follows: (in thousands) March 27, December 26, Revolving Credit Facility $ 100,000 $ 130,000 Euro Senior Notes, Series A due 2023 138,039 142,679 Euro Senior Notes, Series B due 2028 112,083 115,850 U.S. Senior Notes, Series A due 2022 25,000 25,000 U.S. Senior Notes, Series B due 2027 100,000 100,000 U.S. Senior Notes, Series A due 2025 50,000 50,000 U.S. Senior Notes, Series B due 2030 125,000 125,000 Other 2,619 2,619 Unamortized debt issuance costs (3,876) (4,114) Total debt 648,865 687,034 Less: Current maturities (25,000) — Total long-term debt $ 623,865 $ 687,034

Fair Value of Assets and Liab_2

Fair Value of Assets and Liabilities (Tables)	3 Months Ended
	Mar. 27, 2021
Fair Value Disclosures [Abstract]
Schedule of fair value, assets measured on recurring basis	The following table presents assets measured at fair value by classification within the fair value hierarchy as of March 27, 2021: Fair Value Measurements Using (in thousands) Quoted Prices in Significant Significant Total Cash Equivalents $ 66,565 $ — $ — $ 66,565 Investments in equity securities 25,830 — — 25,830 Mutual funds 13,397 — — 13,397 Total $ 105,792 $ — $ — $ 105,792 The following table presents assets measured at fair value by classification within the fair value hierarchy as of December 26, 2020: Fair Value Measurements Using (in thousands) Quoted Prices in Significant Significant Total Cash Equivalents $ 73,461 $ — $ — $ 73,461 Investments in equity securities 19,186 — — 19,186 Mutual funds 13,249 — — 13,249 Total $ 105,896 $ — $ — $ 105,896
Schedule of fair value, by balance sheet grouping	The carrying value and estimated fair values of the Company’s Euro Senior Notes, Series A and Series B and USD Senior Notes, Series A and Series B, as of March 27, 2021 and December 26, 2020 were as follows: March 27, 2021 December 26, 2020 (in thousands) Carrying Estimated Carrying Estimated Euro Senior Notes, Series A due 2023 $ 138,039 $ 140,084 $ 142,679 $ 144,323 Euro Senior Notes, Series B due 2028 112,083 117,703 115,850 123,588 USD Senior Notes, Series A due 2022 25,000 25,375 25,000 25,437 USD Senior Notes, Series B due 2027 100,000 106,174 100,000 109,552 USD Senior Notes, Series A due 2025 50,000 52,817 50,000 53,474 USD Senior Notes, Series B due 2030 125,000 130,764 125,000 138,036

Benefit Plans (Tables)

Benefit Plans (Tables)	3 Months Ended
	Mar. 27, 2021
Retirement Benefits [Abstract]
Schedule of net benefit costs	The components of net periodic benefit cost for the three months ended March 27, 2021 and March 28, 2020 were as follows: For the Three Months Ended (in thousands) March 27, 2021 March 28, 2020 Components of net periodic benefit cost: Service cost $ 702 $ 618 Interest cost 440 658 Expected return on plan assets (367) (727) Amortization of prior service and net actuarial loss 331 145 Net periodic benefit cost $ 1,106 $ 694

Other Comprehensive Income (Tab

Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 27, 2021
Equity [Abstract]
Schedule of components of comprehensive income (loss)	Changes in other comprehensive income (loss) by component were as follows: (in thousands) Three Months Ended Three Months Ended Pre-tax Tax Net of Tax Pre-tax Tax Net of Tax Defined benefit pension plan and other adjustments $ 506 $ 52 $ 454 $ 555 $ (6) $ 561 Foreign currency translation adjustments (5,325) — (5,325) (15,540) — (15,540) Total change in other comprehensive income (loss) $ (4,819) $ 52 $ (4,871) $ (14,985) $ (6) $ (14,979)
Schedule of accumulated other comprehensive income (loss)	The following tables set forth the changes in accumulated other comprehensive (loss) by component for the three months ended March 27, 2021 and March 28, 2020: (in thousands) Defined benefit pension plan and other adjustments Foreign currency Accumulated other Balance at December 26, 2020 $ (34,141) $ (57,016) $ (91,157) Activity in the period 454 (5,325) (4,871) Balance at March 27, 2021 $ (33,687) $ (62,341) $ (96,028) (in thousands) Defined benefit pension plan and other adjustments Foreign currency translation adjustment Accumulated other comprehensive (loss) Balance at December 28, 2019 $ (18,046) $ (88,777) $ (106,823) Activity in the period 561 (15,540) (14,979) Balance at March 28, 2020 $ (17,485) $ (104,317) $ (121,802)
Summary of reclassification out of accumulated other comprehensive income	Amounts reclassified from accumulated other comprehensive (loss) to earnings for the three months ended March 27, 2021 and March 28, 2020 were as follows: Three Months Ended (in thousands) March 27, 2021 March 28, 2020 Pension and Postemployment plans: Amortization of prior service and net actuarial loss $ 504 $ 345

Earnings Per Share (Tables)

Earnings Per Share (Tables)	3 Months Ended
	Mar. 27, 2021
Earnings Per Share [Abstract]
Schedule of earnings per share, basic and diluted	The following table sets forth the computation of basic and diluted earnings per share: Three Months Ended (in thousands, except per share amounts) March 27, 2021 March 28, 2020 Numerator: Net income as reported $ 57,713 $ 24,644 Denominator: Weighted average shares outstanding Basic 24,532 24,393 Effect of dilutive securities 360 185 Diluted 24,892 24,578 Earnings Per Share: Basic earnings per share $ 2.35 $ 1.01 Diluted earnings per share $ 2.32 $ 1.00

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 27, 2021
Related Party Transactions [Abstract]
Schedule of related party transactions	For the Three Months Ended March 27, 2021 For the Three Months Ended March 28, 2020 (in millions) Powersem EB Tech ATEC Powersem EB Tech ATEC Sales to related party $ 0.2 $ — $ — $ 0.4 $ — $ — Purchase material/service from related party $ 1.1 $ 0.1 $ 3.0 $ 0.2 $ — $ 1.8 March 27, 2021 December 26, 2020 (in millions) Powersem EB Tech ATEC Powersem EB Tech ATEC Accounts Receivable balance $ — $ — $ — $ 0.1 $ — $ — Accounts Payable balance $ 0.2 $ — $ 0.3 $ 0.1 $ — $ 0.2

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 27, 2021
Segment Reporting [Abstract]
Schedule of segment reporting information, by segment	Segment information is summarized as follows: Three Months Ended (in thousands) March 27, 2021 March 28, 2020 Net sales Electronics $ 286,535 $ 214,189 Automotive 128,529 104,770 Industrial 48,730 27,137 Total net sales $ 463,794 $ 346,096 Depreciation and amortization Electronics $ 15,381 $ 15,531 Automotive 7,073 7,187 Industrial 1,744 1,084 Total depreciation and amortization $ 24,198 $ 23,802 Operating income Electronics $ 55,523 $ 32,272 Automotive 20,316 14,116 Industrial 3,506 3,534 Other (a) (2,864) (5,172) Total operating income 76,481 44,750 Interest expense 4,673 5,418 Foreign exchange loss 6,837 2,584 Other (income) expense, net (7,737) 1,249 Income before income taxes $ 72,708 $ 35,499 (a) Included in “Other” Operating income for the first quarter of 2021 was $3.5 million of purchase accounting inventory step-up charges, $0.8 million of legal and professional fees and other expenses related to Hartland and other contemplated acquisitions and $0.4 million of restructuring, impairment and other charges, primarily related to employee termination costs. See Note 7, Restructuring, Impairment and Other Charges, for further discussion. In addition, there was a $1.9 million gain from the sale of a building within the Electronics segment.
Schedule of disclosure on geographic areas, long-lived assets in individual foreign countries by country	The Company’s net sales by country were as follows: Three Months Ended (in thousands) March 27, 2021 March 28, 2020 Net sales United States $ 130,931 $ 102,910 China 139,158 86,015 Other countries (a) 193,705 157,171 Total net sales $ 463,794 $ 346,096 The Company’s long-lived assets by country were as follows: (in thousands) March 27, December 26, Long-lived assets United States $ 48,908 $ 46,132 China 85,280 85,876 Mexico 72,499 70,125 Germany 36,227 37,976 Philippines 66,956 66,994 Other countries (a) 35,044 37,075 Total long-lived assets $ 344,914 $ 344,178 The Company’s additions to long-lived assets by country were as follows: Three Months Ended (in thousands) March 27, 2021 March 28, 2020 Additions to long-lived assets United States $ 683 $ 580 China 2,142 1,657 Mexico 6,121 2,592 Germany 593 753 Philippines 2,443 3,218 Other countries (a) 754 2,508 Total additions to long-lived assets $ 12,736 $ 11,308 (a) Each country included in other countries is less than 10% of net sales.

Summary of Significant Accoun_4

Summary of Significant Accounting Policies and Other Information (Details Textual) customer in Thousands, associate in Thousands	3 Months Ended
	Mar. 27, 2021countryassociatecustomer
Accounting Policies [Abstract]
Countries where product is used (country) | country	15
Global associates (associate) | associate	12
Number of customers (over) | customer	100

Summary of Significant Accoun_5

Summary of Significant Accounting Policies and Other Information - Revenue Disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Disaggregation of Revenue
Net sales	$ 463,794	$ 346,096
Electronics – Passive Products and Sensors
Disaggregation of Revenue
Net sales	132,437	84,598
Electronics – Semiconductor
Disaggregation of Revenue
Net sales	154,098	129,591
Passenger Car Products
Disaggregation of Revenue
Net sales	67,901	52,645
Automotive Sensors
Disaggregation of Revenue
Net sales	28,284	24,174
Commercial Vehicle Products
Disaggregation of Revenue
Net sales	32,344	27,951
Industrial Products
Disaggregation of Revenue
Net sales	48,730	27,137
Electronics Segment
Disaggregation of Revenue
Net sales	286,535	214,189
Electronics Segment | Electronics – Passive Products and Sensors
Disaggregation of Revenue
Net sales	132,437	84,598
Electronics Segment | Electronics – Semiconductor
Disaggregation of Revenue
Net sales	154,098	129,591
Electronics Segment | Passenger Car Products
Disaggregation of Revenue
Net sales	0	0
Electronics Segment | Automotive Sensors
Disaggregation of Revenue
Net sales	0	0
Electronics Segment | Commercial Vehicle Products
Disaggregation of Revenue
Net sales	0	0
Electronics Segment | Industrial Products
Disaggregation of Revenue
Net sales	0	0
Automotive Segment
Disaggregation of Revenue
Net sales	128,529	104,770
Automotive Segment | Electronics – Passive Products and Sensors
Disaggregation of Revenue
Net sales	0	0
Automotive Segment | Electronics – Semiconductor
Disaggregation of Revenue
Net sales	0	0
Automotive Segment | Passenger Car Products
Disaggregation of Revenue
Net sales	67,901	52,645
Automotive Segment | Automotive Sensors
Disaggregation of Revenue
Net sales	28,284	24,174
Automotive Segment | Commercial Vehicle Products
Disaggregation of Revenue
Net sales	32,344	27,951
Automotive Segment | Industrial Products
Disaggregation of Revenue
Net sales	0	0
Industrial Segment
Disaggregation of Revenue
Net sales	48,730	27,137
Industrial Segment | Electronics – Passive Products and Sensors
Disaggregation of Revenue
Net sales	0	0
Industrial Segment | Electronics – Semiconductor
Disaggregation of Revenue
Net sales	0	0
Industrial Segment | Passenger Car Products
Disaggregation of Revenue
Net sales	0	0
Industrial Segment | Automotive Sensors
Disaggregation of Revenue
Net sales	0	0
Industrial Segment | Commercial Vehicle Products
Disaggregation of Revenue
Net sales	0	0
Industrial Segment | Industrial Products
Disaggregation of Revenue
Net sales	$ 48,730	$ 27,137

Summary of Significant Accoun_6

Summary of Significant Accounting Policies and Other Information - Cash and cash equivalents (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Dec. 26, 2020	Mar. 28, 2020	Dec. 28, 2019
Accounting Policies [Abstract]
Cash and cash equivalents	$ 572,771	$ 687,525	$ 620,575
Restricted cash included in prepaid expenses and other current assets	3,462	0	0
Restricted cash included in other assets	1,064	0	0
Total cash, cash equivalents and restricted cash	$ 577,297	$ 687,525	$ 620,575	$ 531,139

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - USD ($) $ in Thousands	Jan. 28, 2021	Mar. 27, 2021	Mar. 28, 2020
Business Acquisition
Cash, net of cash acquired, and restricted cash		$ 109,852	$ 0
Restricted cash		1,700
Acquisition related costs		700
Inventory amortization period (in years)			4 months
Hartland Controls
Business Acquisition
Annualized sales	$ 70,000
Hartland Controls
Business Acquisition
Cash acquired from acquisition	112,300
Cash, net of cash acquired, and restricted cash	109,852
Net sales		16,700
Income (loss) before income taxes		(2,200)
Inventory adjustment	$ 6,800	$ 3,500

Acquisitions - Preliminary Pric

Acquisitions - Preliminary Price Allocation (Details) - USD ($) $ in Thousands	Jan. 28, 2021	Mar. 27, 2021	Mar. 28, 2020	Dec. 26, 2020
Total purchase consideration:
Cash, net of cash acquired, and restricted cash		$ 109,852	$ 0
Allocation of consideration to assets acquired and liabilities assumed:
Goodwill		$ 845,586		$ 816,812
Hartland Controls
Total purchase consideration:
Cash, net of cash acquired, and restricted cash	$ 109,852
Allocation of consideration to assets acquired and liabilities assumed:
Trade receivables, net	14,305
Inventories	36,306
Other current assets	2,384
Property, plant, and equipment	6,296
Intangible assets	39,660
Goodwill	38,929
Other non-current assets	3,542
Current liabilities	(25,024)
Other non-current liabilities	(6,546)
Assets acquired and liabilities assumed	$ 109,852

Acquisitions - Business Acquisi

Acquisitions - Business Acquisition Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Business Combinations [Abstract]
Net sales	$ 470,832	$ 363,617
Income before income taxes	77,288	31,431
Net income	$ 61,317	$ 21,438
Net income per share — basic (in dollars per share)	$ 2.50	$ 0.88
Net income per share — diluted (in dollars per share)	$ 2.46	$ 0.87

Acquisitions - Pro Forma Inform

Acquisitions - Pro Forma Information Adjustments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment
Net income	$ 61,317	$ 21,438
Amortization
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment
Net income	(279)	(834)
Depreciation
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment
Net income	7	48
Transaction costs
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment
Net income	707	(707)
Amortization of inventory step-up
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment
Net income	3,490	(5,137)
Income tax (expense) benefit of above items
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment
Net income	$ (831)	$ 1,398

Inventories - Components of Inv

Inventories - Components of Inventories (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Dec. 26, 2020
Inventory Disclosure [Abstract]
Raw materials	$ 97,695	$ 85,394
Work in process	102,285	92,783
Finished goods	130,138	114,641
Inventory Reserves	(35,061)	(34,816)
Total	$ 295,057	$ 258,002

Property, Plant, and Equipmen_2

Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Dec. 26, 2020
Property, Plant and Equipment
Accumulated depreciation and amortization	$ (489,552)	$ (480,390)
Total	344,914	344,178
Land
Property, Plant and Equipment
Property, plant, and equipment, gross	22,711	22,851
Building
Property, Plant and Equipment
Property, plant, and equipment, gross	124,192	123,497
Equipment
Property, Plant and Equipment
Property, plant, and equipment, gross	$ 687,563	$ 678,220

Property, Plant, and Equipmen_3

Property, Plant, and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Property, Plant and Equipment [Abstract]
Depreciation	$ 13,677	$ 13,821

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Amounts for Goodwill and Changes in Carrying Value by Operating Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Dec. 26, 2020
Goodwill
Gross goodwill	$ 890,891	$ 862,230
Accumulated impairment losses	(45,305)	(45,418)
Net goodwill	845,586	816,812
Additions	38,929
Currency translation	(10,155)
Electronics
Goodwill
Gross goodwill	668,201	676,325
Accumulated impairment losses	0	0
Net goodwill	668,201	676,325
Additions	0
Currency translation	(8,124)
Automotive
Goodwill
Gross goodwill	136,229	138,354
Accumulated impairment losses	(36,310)	(36,423)
Net goodwill	99,919	101,931
Additions	0
Currency translation	(2,012)
Industrial
Goodwill
Gross goodwill	86,461	47,551
Accumulated impairment losses	(8,995)	(8,995)
Net goodwill	77,466	$ 38,556
Additions	38,929
Currency translation	$ (19)

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Details of Other Intangible Assets and Related Future Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Dec. 26, 2020
Finite-Lived Intangible Assets
Gross Carrying Value	$ 596,940	$ 563,464
Accumulated Amortization	279,646	271,577
Net Book Value	$ 317,294	291,887
Weighted Average Useful Life
Amount	$ 39,660
Land use rights
Finite-Lived Intangible Assets
Gross Carrying Value	10,251	10,280
Accumulated Amortization	2,051	2,007
Net Book Value	8,200	8,273
Patents, licenses and software
Finite-Lived Intangible Assets
Gross Carrying Value	142,732	137,210
Accumulated Amortization	94,636	92,868
Net Book Value	$ 48,096	44,342
Weighted Average Useful Life	9 years 2 months 12 days
Amount	$ 7,559
Distribution network
Finite-Lived Intangible Assets
Gross Carrying Value	43,704	43,910
Accumulated Amortization	39,307	38,980
Net Book Value	4,397	4,930
Customer relationships, trademarks, and tradenames
Finite-Lived Intangible Assets
Gross Carrying Value	400,253	372,064
Accumulated Amortization	143,652	137,722
Net Book Value	$ 256,601	$ 234,342
Weighted Average Useful Life	13 years 8 months 12 days
Amount	$ 32,101

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangibles	$ 10,521	$ 9,981
Impairment of intangibles		$ 300
Finite-Lived Intangible Assets
Acquired finite lived intangibles	38,929
Hartland Controls
Finite-Lived Intangible Assets
Acquired finite lived intangibles	$ 39,700

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Estimated Amortization Expense Related to Intangible Assets with Definite Lives (Details) $ in Thousands	Mar. 27, 2021USD ($)
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity
2021	$ 41,545
2022	40,791
2023	36,491
2024	33,054
2025	32,603
2026 and thereafter	143,331
Total	$ 327,815

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Dec. 26, 2020
Payables and Accruals [Abstract]
Employee-related liabilities	$ 45,135	$ 50,689
Operating lease liability	7,177	6,811
Interest	2,636	4,517
Restructuring liability	2,588	4,195
Customer liability	794	3,858
Professional services	3,010	3,321
Deferred revenue	2,713	2,959
Other non-income taxes	1,903	2,126
Other	32,398	32,002
Accrued liabilities	$ 98,354	$ 110,478

Restructuring, Impairment and_3

Restructuring, Impairment and Other Charges (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020	Dec. 26, 2020
Restructuring Cost and Reserve
Total restructuring charges	$ 437	$ 1,725
Impairment charges	0	2,237
Restructuring costs	437	3,962
Restructuring reserves	2,600		$ 4,200
Employee terminations
Restructuring Cost and Reserve
Total restructuring charges	420	1,601
Other restructuring charges
Restructuring Cost and Reserve
Total restructuring charges	17	124
Electronics
Restructuring Cost and Reserve
Total restructuring charges	257	882
Impairment charges	0	0
Restructuring costs	257	882
Electronics | Employee terminations
Restructuring Cost and Reserve
Total restructuring charges	257	881
Electronics | Other restructuring charges
Restructuring Cost and Reserve
Total restructuring charges	0	1
Automotive
Restructuring Cost and Reserve
Total restructuring charges	17	519
Impairment charges	0	0
Restructuring costs	17	519
Automotive | Employee terminations
Restructuring Cost and Reserve
Total restructuring charges	0	399
Automotive | Other restructuring charges
Restructuring Cost and Reserve
Total restructuring charges	17	120
Industrial
Restructuring Cost and Reserve
Total restructuring charges	163	324
Impairment charges	0	2,237
Restructuring costs	163	2,561
Industrial | Employee terminations
Restructuring Cost and Reserve
Total restructuring charges	163	321
Industrial | Other restructuring charges
Restructuring Cost and Reserve
Total restructuring charges	$ 0	3
Industrial | Facility Closing
Restructuring Cost and Reserve
Impairment charges		$ 2,200

Debt - Carrying Amounts of Long

Debt - Carrying Amounts of Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Dec. 26, 2020
Debt Instrument
Unamortized debt issuance costs	$ (3,876)	$ (4,114)
Total debt	648,865	687,034
Less: Current maturities	(25,000)	0
Total long-term debt	623,865	687,034
Revolving Credit Facility
Debt Instrument
Long-term debt, gross	100,000	130,000
Senior Notes | Euro Senior Notes, Series A due 2023
Debt Instrument
Long-term debt, gross	138,039	142,679
Senior Notes | Euro Senior Notes, Series B due 2028
Debt Instrument
Long-term debt, gross	112,083	115,850
Senior Notes | U.S. Senior Notes, Series A due 2022
Debt Instrument
Long-term debt, gross	25,000	25,000
Senior Notes | U.S. Senior Notes, Series B due 2027
Debt Instrument
Long-term debt, gross	100,000	100,000
Senior Notes | U.S. Senior Notes, Series A due 2025
Debt Instrument
Long-term debt, gross	50,000	50,000
Senior Notes | U.S. Senior Notes, Series B due 2030
Debt Instrument
Long-term debt, gross	125,000	125,000
Other
Debt Instrument
Long-term debt, gross	$ 2,619	$ 2,619

Debt - Narrative (Details)

Debt - Narrative (Details)	Apr. 03, 2020USD ($)	Mar. 04, 2016	Mar. 27, 2021USD ($)	Mar. 28, 2020USD ($)	Dec. 26, 2020USD ($)	Apr. 02, 2020USD ($)	Jan. 16, 2018USD ($)	Nov. 15, 2017USD ($)series	Feb. 15, 2017USD ($)	Dec. 08, 2016USD ($)series	Dec. 08, 2016EUR (€)series
Debt Instrument
Payments of revolving credit facility			$ (30,000,000)	$ 0
Cash paid during the period for interest			$ 6,235,000	$ 7,354,000
Credit Agreement
Debt Instrument
Effective interest rate (percent)			1.61%
Letter of credit outstanding (less than)			$ 0
Credit Agreement | Minimum
Debt Instrument
Commitment fee (percent)		0.125%
Credit Agreement | Maximum
Debt Instrument
Commitment fee (percent)		0.20%
Credit Agreement | LIBOR | Minimum
Debt Instrument
Basis spread on variable rate (percent)		1.25%
Credit Agreement | LIBOR | Maximum
Debt Instrument
Basis spread on variable rate (percent)		2.00%
Credit Agreement | Base Rate | Minimum
Debt Instrument
Basis spread on variable rate (percent)		0.25%
Credit Agreement | Base Rate | Maximum
Debt Instrument
Basis spread on variable rate (percent)		1.00%
Credit Agreement | Revolving Credit Facility
Debt Instrument
Remaining borrowing capacity			571,300,000
Term Loan
Debt Instrument
Elimination of unsecured team loan facility	$ 200,000,000
Long-term debt, gross						$ 140,000,000
Senior Notes | Euro Senior Notes, Series A and B
Debt Instrument
Face amount of debt | €											€ 212,000,000
Number of series | series										2	2
Senior Notes | Euro Senior Notes, Series A due 2023
Debt Instrument
Long-term debt, gross			138,039,000		$ 142,679,000
Face amount of debt | €											€ 117,000,000
Stated interest rate (percent)										1.14%	1.14%
Senior Notes | Euro Senior Notes, Series B due 2028
Debt Instrument
Long-term debt, gross			112,083,000		115,850,000
Face amount of debt | €											€ 95,000,000
Stated interest rate (percent)										1.83%	1.83%
Senior Notes | U.S. Senior Notes, Series A and B
Debt Instrument
Face amount of debt										$ 125,000,000
Number of series | series										2	2
Senior Notes | U.S. Senior Notes, Series A
Debt Instrument
Face amount of debt									$ 25,000,000
Stated interest rate (percent)									3.03%
Senior Notes | U.S. Senior Notes, Series B
Debt Instrument
Face amount of debt									$ 100,000,000
Stated interest rate (percent)									3.74%
Senior Notes | US Senior Notes A and B Due 2025 and 2030
Debt Instrument
Face amount of debt								$ 175,000,000
Number of series | series								2
Senior Notes | U.S. Senior Notes, Series A due 2025
Debt Instrument
Long-term debt, gross			50,000,000		50,000,000
Face amount of debt							$ 50,000,000
Stated interest rate (percent)							3.48%
Senior Notes | U.S. Senior Notes, Series B due 2030
Debt Instrument
Long-term debt, gross			$ 125,000,000		$ 125,000,000
Face amount of debt							$ 125,000,000
Stated interest rate (percent)							3.78%

Fair Value of Assets and Liab_3

Fair Value of Assets and Liabilities - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 27, 2021	Dec. 26, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Investments in equity securities		$ 25,830	$ 19,186
Patents
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Impairment charges	$ 300
Land and Building
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Impairment charges	$ 1,900
Other Expense (Income)
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Investments in equity securities		$ 500	$ 500

Fair Value of Assets and Liab_4

Fair Value of Assets and Liabilities - Assets Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Dec. 26, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash Equivalents	$ 66,565	$ 73,461
Investments in equity securities	25,830	19,186
Mutual funds	13,397	13,249
Total	105,792	105,896
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash Equivalents	66,565	73,461
Investments in equity securities	25,830	19,186
Mutual funds	13,397	13,249
Total	105,792	105,896
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash Equivalents	0	0
Investments in equity securities	0	0
Mutual funds	0	0
Total	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash Equivalents	0	0
Investments in equity securities	0	0
Mutual funds	0	0
Total	$ 0	$ 0

Fair Value of Assets and Liab_5

Fair Value of Assets and Liabilities - Carrying Value and Estimated Fair Value of Senior Notes (Details) - Senior Notes - USD ($) $ in Thousands	Mar. 27, 2021	Dec. 26, 2020
Carrying Value | Euro Senior Notes, Series A due 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt fair value	$ 138,039	$ 142,679
Carrying Value | Euro Senior Notes, Series B due 2028
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt fair value	112,083	115,850
Carrying Value | U.S. Senior Notes, Series A due 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt fair value	25,000	25,000
Carrying Value | U.S. Senior Notes, Series B due 2027
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt fair value	100,000	100,000
Carrying Value | U.S. Senior Notes, Series A due 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt fair value	50,000	50,000
Carrying Value | U.S. Senior Notes, Series B due 2030
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt fair value	125,000	125,000
Estimated Fair Value | Euro Senior Notes, Series A due 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt fair value	140,084	144,323
Estimated Fair Value | Euro Senior Notes, Series B due 2028
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt fair value	117,703	123,588
Estimated Fair Value | U.S. Senior Notes, Series A due 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt fair value	25,375	25,437
Estimated Fair Value | U.S. Senior Notes, Series B due 2027
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt fair value	106,174	109,552
Estimated Fair Value | U.S. Senior Notes, Series A due 2025
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt fair value	52,817	53,474
Estimated Fair Value | U.S. Senior Notes, Series B due 2030
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt fair value	$ 130,764	$ 138,036

Benefit Plans - Benefit Plan Ex

Benefit Plans - Benefit Plan Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Retirement Benefits [Abstract]
Service cost	$ 702	$ 618
Interest cost	440	658
Expected return on plan assets	(367)	(727)
Amortization of prior service and net actuarial loss	331	145
Net periodic benefit cost	$ 1,106	$ 694

Benefit Plans - Narrative (Deta

Benefit Plans - Narrative (Details) $ in Thousands, £ in Millions	Apr. 06, 2020GBP (£)	Dec. 31, 2021USD ($)	Mar. 27, 2021USD ($)	Jun. 27, 2020USD ($)	Jun. 27, 2020GBP (£)	Mar. 28, 2020USD ($)	Apr. 07, 2020USD ($)
Defined Benefit Plan Disclosure
Contributions expected			$ 2,200
Expected direct payments			3,800
Defined benefit plan expense			1,106			$ 694
Estimated decrease in pension cost							$ 55,000
Estimated percent reduction in pension costs							37.00%
Benefit obligation, unamortized actuarial loss | £	£ 13.4
Cash contribution				$ 10,400	£ 8.4
Defined benefit pension plan and other adjustments
Defined Benefit Plan Disclosure
Benefit obligation, unamortized actuarial loss | £	£ 10.9
Forecast | Minimum
Defined Benefit Plan Disclosure
Estimated settlement charge		$ 18,000
Forecast | Maximum
Defined Benefit Plan Disclosure
Estimated settlement charge		$ 22,000
Foreign Plan
Defined Benefit Plan Disclosure
Defined benefit plan expense			500			500
Other comprehensive income as component of net period benefit cost, before tax			$ 200			$ 200

Other Comprehensive Income - Sc

Other Comprehensive Income - Schedule of Components of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Other Comprehensive Income (Loss)
Pre-tax	$ (4,819)	$ (14,985)
Tax	52	(6)
Total change in other comprehensive income (loss)	(4,871)	(14,979)
Defined benefit pension plan and other adjustments
Other Comprehensive Income (Loss)
Pre-tax	506	555
Tax	52	(6)
Total change in other comprehensive income (loss)	454	561
Foreign currency translation adjustment
Other Comprehensive Income (Loss)
Pre-tax	(5,325)	(15,540)
Tax	0	0
Total change in other comprehensive income (loss)	$ (5,325)	$ (15,540)

Other Comprehensive Income - _2

Other Comprehensive Income - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Balance	$ 1,608,773	$ 1,496,014
Other comprehensive loss, net of tax	(4,871)	(14,979)
Balance	1,660,737	1,476,948
Accumulated other comprehensive (loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Balance	(91,157)	(106,823)
Other comprehensive loss, net of tax	(4,871)	(14,979)
Balance	(96,028)	(121,802)
Defined benefit pension plan and other adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Balance	(34,141)	(18,046)
Other comprehensive loss, net of tax	454	561
Balance	(33,687)	(17,485)
Foreign currency translation adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax
Balance	(57,016)	(88,777)
Other comprehensive loss, net of tax	(5,325)	(15,540)
Balance	$ (62,341)	$ (104,317)

Other Comprehensive Income - Re

Other Comprehensive Income - Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Amortization of prior service and net actuarial loss | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Amortization of prior service and net actuarial loss	$ 504	$ 345

Income Taxes (Details Textual)

Income Taxes (Details Textual)	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Income Tax Disclosure [Abstract]
Effective tax rate (percent)	20.60%	30.60%

Earnings Per Share - Computatio

Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Numerator:
Net income as reported	$ 57,713	$ 24,644
Weighted average shares outstanding
Basic (in shares)	24,532	24,393
Effect of dilutive securities (in shares)	360	185
Diluted (in shares)	24,892	24,578
Earnings Per Share:
Basic (loss) earnings per share (in dollars per share)	$ 2.35	$ 1.01
Diluted (loss) earnings per share (in dollars per share)	$ 2.32	$ 1

Earnings Per Share - Narrative

Earnings Per Share - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020	Apr. 28, 2021	Apr. 29, 2020	Apr. 26, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share
Antidilutive securities excluded (in shares)	15	153,836
Shares repurchased (in shares)	0	175,110
Repurchases of common stock		$ 22,927
2019 Share Repurchase Program
Antidilutive Securities Excluded from Computation of Earnings Per Share
Repurchase authorized (in shares)					1,000,000
2020 Share Repurchase Program
Antidilutive Securities Excluded from Computation of Earnings Per Share
Repurchase authorized (in shares)				1,000,000
2020 Share Repurchase Program | Subsequent Event
Antidilutive Securities Excluded from Computation of Earnings Per Share
Repurchase authorized (in shares)			300,000,000

Related Party Transactions (Det

Related Party Transactions (Details) - Equity Method Investee - USD ($) $ in Millions	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020	Dec. 26, 2020
Powersem
Related Party Transaction
Ownership percentage (percent)	45.00%
Sales to related party	$ 0.2	$ 0.4
Purchase material/service from related party	1.1	0.2
Accounts Receivable balance	0		$ 0.1
Accounts Payable balance	$ 0.2		0.1
EB Tech
Related Party Transaction
Ownership percentage (percent)	19.00%
Sales to related party	$ 0	0
Purchase material/service from related party	0.1	0
Accounts Receivable balance	0		0
Accounts Payable balance	$ 0		0
ATEC
Related Party Transaction
Ownership percentage (percent)	24.00%
Sales to related party	$ 0	0
Purchase material/service from related party	3	$ 1.8
Accounts Receivable balance	0		0
Accounts Payable balance	0.3		0.2
VTOOL Ltd. and Securepush Ltd.
Related Party Transaction
Cost method investments	$ 0.5		$ 0.5

Segment Information (Details)

Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Segment Reporting Information
Net sales	$ 463,794	$ 346,096
Depreciation and amortization	24,198	23,802
Operating income	76,481	44,750
Interest expense	4,673	5,418
Foreign exchange loss	6,837	2,584
Other (income) expense, net	(7,737)	1,249
Income before income taxes	72,708	35,499
Electronics
Segment Reporting Information
Net sales	286,535	214,189
Depreciation and amortization	15,381	15,531
Electronics | Operating Segments
Segment Reporting Information
Operating income	55,523	32,272
Automotive
Segment Reporting Information
Net sales	128,529	104,770
Depreciation and amortization	7,073	7,187
Automotive | Operating Segments
Segment Reporting Information
Operating income	20,316	14,116
Industrial
Segment Reporting Information
Net sales	48,730	27,137
Depreciation and amortization	1,744	1,084
Industrial | Operating Segments
Segment Reporting Information
Operating income	3,506	3,534
Other | Corporate Non-Segment
Segment Reporting Information
Operating income	$ (2,864)	$ (5,172)

Segment Information - Narrative

Segment Information - Narrative (Details) $ in Thousands	Jan. 28, 2021USD ($)	Mar. 27, 2021USD ($)segment	Mar. 28, 2020USD ($)
Segment Reporting Information
Number of operating segments | segment		3
Acquisition related costs		$ 700
Restructuring charges		437	$ 1,725
Impairment charges		0	2,237
Hartland Controls
Segment Reporting Information
Inventory adjustment	$ 6,800	3,500
Operating Income (Loss) | IXYS
Segment Reporting Information
Acquisition related costs			1,200
Operating Income (Loss) | Corporate Non-Segment | Hartland Controls
Segment Reporting Information
Inventory adjustment		3,500
Other | Operating Income (Loss)
Segment Reporting Information
Restructuring charges		400
Other | Operating Income (Loss) | Hartland Controls
Segment Reporting Information
Acquisition related costs		800
Industrial
Segment Reporting Information
Restructuring charges		163	324
Impairment charges		0	2,237
Electronics
Segment Reporting Information
Restructuring charges		257	882
Gain (loss) on sale of properties		1,900
Impairment charges		0	0
Facility Closing | Industrial
Segment Reporting Information
Impairment charges			2,200
Employee terminations
Segment Reporting Information
Restructuring charges		420	1,601
Employee terminations | IXYS
Segment Reporting Information
Restructuring charges			4,000
Employee terminations | Industrial
Segment Reporting Information
Restructuring charges		163	321
Employee terminations | Electronics
Segment Reporting Information
Restructuring charges		$ 257	$ 881

Segment Information - Revenues

Segment Information - Revenues and Long-lived Assets by Geographical Area (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020	Dec. 26, 2020
Segment Reporting Information
Net sales	$ 463,794	$ 346,096
Long-lived assets	344,914		$ 344,178
Additions to long-lived assets	12,736	11,308
United States
Segment Reporting Information
Net sales	130,931	102,910
Long-lived assets	48,908		46,132
Additions to long-lived assets	683	580
China
Segment Reporting Information
Net sales	139,158	86,015
Long-lived assets	85,280		85,876
Additions to long-lived assets	2,142	1,657
Mexico
Segment Reporting Information
Long-lived assets	72,499		70,125
Additions to long-lived assets	6,121	2,592
Germany
Segment Reporting Information
Long-lived assets	36,227		37,976
Additions to long-lived assets	593	753
Philippines
Segment Reporting Information
Long-lived assets	66,956		66,994
Additions to long-lived assets	2,443	3,218
Other countries
Segment Reporting Information
Net sales	193,705	157,171
Long-lived assets	35,044		$ 37,075
Additions to long-lived assets	$ 754	$ 2,508