Littelfuse (LFUS) 10-Q 1 Aug 18 2018 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 27, 2018
Document Information [Line Items]
Entity Registrant Name	LITTELFUSE INC /DE
Entity Central Index Key	889,331
Trading Symbol	lfus
Current Fiscal Year End Date	--12-29
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Entity Common Stock, Shares Outstanding (in shares)		25,080,569
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Current assets:
Cash and cash equivalents	$ 408,147	$ 429,676
Short-term investments	34	35
Trade receivables, less allowances (June 30, 2018 - $34,724; December 30, 2017 - $27,516)	260,444	182,699
Inventories	239,201	140,789
Prepaid income taxes and income taxes receivable	4,648	1,689
Prepaid expenses and other current assets	45,727	37,452
Total current assets	958,201	792,340
Property, plant, and equipment:
Land	29,198	9,547
Buildings	118,432	86,599
Equipment	558,855	505,838
Accumulated depreciation and amortization	(367,730)	(351,407)
Net property, plant, and equipment	338,755	250,577
Intangible assets, net of amortization	390,052	203,850
Goodwill	832,227	453,414
Investments	31,326	10,993
Deferred income taxes	10,320	11,858
Other assets	27,113	17,070
Total assets	2,587,994	1,740,102
Current liabilities:
Accounts payable	127,290	101,844
Accrued payroll	43,047	49,962
Accrued expenses	66,341	48,994
Accrued severance	1,049	1,459
Accrued income taxes	19,376	16,285
Current portion of long-term debt	10,060	6,250
Total current liabilities	267,163	224,794
Long-term debt, less current portion	687,538	489,361
Deferred income taxes	(53,996)	(17,069)
Accrued post-retirement benefits	33,210	18,742
Other long-term liabilities	76,067	62,580
Shareholders’ equity:
Common stock, par value $0.01 per share: 34,000,000 shares authorized; shares issued, June 30, 2018–25,070,738; December 30, 2017 –22,713,198	253	229
Treasury stock, at cost: 475,061 and 439,598 shares, respectively	(48,336)	(41,294)
Additional paid-in capital	815,826	310,012
Accumulated other comprehensive income	(89,684)	(63,668)
Retained earnings	791,831	722,140
Littelfuse, Inc. shareholders’ equity	1,469,890	927,419
Non-controlling interest	130	137
Total equity	1,470,020	927,556
Total liabilities and equity	$ 2,587,994	$ 1,740,102

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Trade receivables, allowances	$ 34,724	$ 27,516
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	34,000,000	34,000,000
Common stock, shares issued (in shares)	25,070,738	22,713,198
Treasury stock, shares (in shares)	475,061	439,598

Condensed Consolidated Statemen

Condensed Consolidated Statements of Net Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Net sales	$ 459,183	$ 313,355	$ 876,996	$ 598,797
Cost of sales	290,196	180,747	558,386	352,539
Gross profit	168,987	132,608	318,610	246,258
Selling, general, and administrative expenses	73,244	53,438	150,758	100,139
Research and development expenses	22,748	12,729	45,288	24,881
Amortization of intangibles	13,373	6,171	25,371	12,115
Total operating expenses	109,365	72,338	221,417	137,135
Operating income	59,622	60,270	97,193	109,123
Interest expense	5,782	3,281	11,205	6,401
Foreign exchange loss (gain)	3,200	(558)	(7,354)	(2,115)
Other (income) expense, net	(1,678)	190	(3,621)	52
Income before income taxes	52,318	57,357	96,963	104,785
Income taxes	9,992	8,719	18,609	17,255
Net income	$ 42,326	$ 48,638	$ 78,354	$ 87,530
Income per share:
Basic (in dollars per share)	$ 1.69	$ 2.13	$ 3.18	$ 3.84
Diluted (in dollars per share)	$ 1.67	$ 2.11	$ 3.12	$ 3.80
Weighted-average shares and equivalent shares outstanding:
Basic (in shares)	25,004	22,822	24,671	22,785
Diluted (in shares)	25,401	23,023	25,086	23,005

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Net income	$ 42,326	$ 48,638	$ 78,354	$ 87,530
Other comprehensive income (loss):
Pension and postemployment liability adjustments (net of tax expense (benefit) of $42 and $23 for the three months ended 2018 and 2017, and ($18) and $55 for the six months ended 2018 and 2017, respectively)	590	(19)	402	(200)
Pension and postemployment reclassification adjustments (net of tax expense (benefit) of ($5) and $28 for the three months ended 2018 and 2017, and ($11) and $64 for the six months ended 2018 and 2017, respectively)	176	(80)	361	(181)
Unrealized gain (loss) on investments		(472)		475
Foreign currency translation adjustments	(16,708)	(3,582)	(16,984)	1,380
Comprehensive income	$ 26,384	$ 44,485	$ 62,133	$ 89,004

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parentheticals) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Pension and postemployment liability adjustments, tax	$ 42	$ 23	$ (18)	$ 55
Pension and postemployment reclassification adjustments, tax	$ (5)	$ 28	$ (11)	$ 64

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Operating activities
Net income	$ 78,354	$ 87,530
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	24,431	18,575
Amortization of intangibles	25,371	12,115
Provision for bad debts	(2)	1,895
Deferred revenue	1,921
Non-cash inventory charges	36,927
Impairment charges	1,125
Loss on sale of property, plant, and equipment	780	593
Stock-based compensation	15,883	8,590
Unrealized gain on investments	(3,311)
Deferred income taxes	2,434	1,514
Changes in operating assets and liabilities:
Accounts receivables	(33,481)	(32,039)
Inventories	(1,502)	(8,739)
Accounts payable	13,684	7,985
Accrued expenses (including post-retirement)	3,773	3,912
Accrued payroll and severance	(13,745)	(13,190)
Accrued taxes	(6,411)	515
Prepaid expenses and other	(5,316)	4,317
Net cash provided by operating activities	140,915	93,573
Investing activities
Acquisitions of businesses, net of cash acquired	(310,487)	(14,172)
Proceeds from maturities of short-term investments		3,739
Decrease in entrusted loan		2,416
Purchases of property, plant, and equipment	(40,315)	(28,278)
Proceeds from sale of property, plant, and equipment	68	178
Net cash used in investing activities	(350,734)	(36,117)
Financing activities:
Proceeds of revolving credit facility	60,000
Proceeds of term loan	75,000
Net proceeds from senior notes payable	175,000	125,000
Payments of term loan	(40,025)	(3,125)
Payments of revolving credit facility	(60,000)	(112,500)
Net proceeds (payments) related to stock-based award activities	(5,568)	2,074
Payments of entrusted loan		(2,416)
Debt issuance costs	(878)	(1)
Cash dividends paid	(18,458)	(14,963)
Net cash provided by (used in) financing activities	196,207	(10,079)
Effect of exchange rate changes on cash and cash equivalents	(7,917)	(608)
Increase (decrease) in cash and cash equivalents	(21,529)	46,769
Cash and cash equivalents at beginning of period	429,676	275,124
Cash and cash equivalents at end of period	408,147	321,893
Supplemental disclosure of non-cash investing activities:
Fair value of commitment to purchase non-controlling interest of Monolith		$ 9,000

Note 1 - Summary of Significant

Note 1 - Summary of Significant Accounting Policies and Other Information	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Significant Accounting Policies [Text Block]	1. Nature of Operations Littelfuse, Inc. and subsidiaries (the “Company”) is a global leader in circuit protection products with advancing platforms in power control and sensor technologies, serving customers in the electronics, automotive, and industrial markets. With a diverse and extensive product portfolio of fuses, semiconductors, polymers, ceramics, relays and sensors, the Company works with its customers to build safer, more reliable and more efficient products for the connected world in virtually every market that uses electrical energy, ranging across consumer electronics, IT and telecommunication applications, industrial electronics, automobiles and other transportation, and heavy industrial applications. The Company has a network of global engineering centers and labs that develop new products and product enhancements, provides customer application support and test products for safety, reliability, and regulatory compliance. 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 10 X. not 10 December 30, 2017, not Revenue Recognition Adoption On December 31, 2017, not Revenue Disaggregation The following table disaggregates the Company’s revenue by primary business units for the three six June 30, 2018: For the three months ended June 30, 2018 (in thousands) Electronics Segment Automotive Segment Industrial Segment Total Electronics – Passive Products and Sensors $ 128,321 $ — $ — $ 128,321 Electronics – Semiconductor 171,036 — — 171,036 Passenger Car Products — 63,581 — 63,581 Automotive Sensors — 30,729 — 30,729 Commercial Vehicle Products — 32,862 — 32,862 Industrial Products — — 32,654 32,654 Total $ 299,357 $ 127,172 $ 32,654 $ 459,183 For the six months ended June 30, 2018 (in thousands) Electronics Segment Automotive Segment Industrial Segment Total Electronics – Passive Products and Sensors $ 242,816 $ — $ — $ 242,816 Electronics – Semiconductor 320,952 — — 320,952 Passenger Car Products — 127,160 — 127,160 Automotive Sensors — 62,052 — 62,052 Commercial Vehicle Products — 64,090 — 64,090 Industrial Products — — 59,926 59,926 Total $ 563,768 $ 253,302 $ 59,926 $ 876,996 See Note 12, Segment Information 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 may third The Company has elected the practical expedient under ASC 340 40 25 4 one 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 606 10 32 18 not 606 10 25 18B 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 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 In March 2017, No. 2017 07 715 No. 2017 07 first 2018 December 31, 2017. In January 2016, No. 2016 01, December 31, 2017, $9.8 six June 30, 2018, $2.8 In May 2014, No. 2014 09, 606 605, two one one December 31, 2017 no not Revenue Recognition In October 2016, No. 2016 16, 740 December 31, 2017 not Recently Issued Accounting Standards In February 2016, No. 2016 02, 842 twelve December 15, 2018, first 2019. not In January 2018, 2017 not not In February 2018, No. 2018 02 220 not 2018 02 first 2019; 2018 02

Note 2 - Acquisitions

Note 2 - Acquisitions	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Mergers, Acquisitions and Dispositions Disclosures [Text Block]	2. The Company accounts for acquisitions using the acquisition method in accordance with ASC 805, IXYS Corporation On January 17, 2018, 3,500 Upon completion of the acquisition, at IXYS stockholders’ election and subject to proration, each share of IXYS common stock, par value $0.01 $23.00 0.1265 $0.01 0.1265, 0.1265, Based on the $207.5 January 17, 2018, $814.8 $380.6 $434.2 $41.7 $856.5 The total purchase price of $856.5 not The following table summarizes the purchase price allocation of the fair value of assets acquired and liabilities assumed in the IXYS acquisition: (in thousands) Purchase Price Allocation Total purchase consideration: Cash, net of cash acquired $ 302,865 Cash settled stock options 3,622 Littelfuse stock 434,192 Converted stock options 38,109 Total purchase consideration $ 778,788 Allocation of consideration to assets acquired and liabilities assumed: Current assets, net $ 155,959 Property, plant, and equipment 77,442 Intangible assets 212,720 Goodwill 382,317 Other non-current assets 31,570 Other non-current liabilities (81,220 ) $ 778,788 Included in IXYS’s current assets, net was approximately $49.1 not Included in the Company’s Condensed Consolidated Statements of Net Income for the three six June 30, 2018 $100.2 $186.5 $13.9 $31.7 January 17, 2018 $1.6 $7.5 three six June 30, 2018, $4.5 As required by purchase accounting rules, the Company recorded a $36.9 first second 2018, three six June 30, 2018, $19.0 $36.9 During the three six June 30, 2018, $0.8 $11.0 selling, general, and administrative expenses 2017 Acquisitions U.S. Sensor On July 7, 2017, $24.3 fourth 2017, The following table summarizes the purchase price allocation of the fair value of assets acquired and liabilities assumed in the U.S. Sensor acquisition: (in thousands) Purchase Price Allocation Total purchase consideration: Cash $ 24,340 Allocation of consideration to assets acquired and liabilities assumed: Current assets, net $ 4,635 Patented and unpatented technologies 1,090 Trademarks and tradenames 200 Non-compete agreement 50 Customer relationships 2,830 Goodwill 16,075 Current liabilities (540 ) $ 24,340 Included in U.S. Sensor’s current assets, net was approximately $1.5 As required by purchase accounting rules, the Company recorded a $1.6 third 2017, Monolith In December 2015, $3.5 12% $3.5 December 31, 2016. On February 28, 2017, 62% $15 first 2018, April 2018 19% $5 $4 19% $0.5 $5 no June 30, 2019. The additional investment, in the first 2017, $3.5 no $3.5 $14.2 $9.0 $26.7 Commencing March 1, 2017, January 1, 2017, not The following table summarizes the purchase price allocation of the fair value of assets acquired and liabilities assumed in the Monolith acquisition: (in thousands) Purchase Price Allocation Total purchase consideration: Original investment $ 3,500 Cash, net of cash acquired 14,172 Non-cash, fair value of commitment to purchase non-controlling interest 9,000 Total purchase consideration $ 26,672 Allocation of consideration to assets acquired and liabilities assumed: Current assets, net $ 891 Property, plant, and equipment 789 Patented and unpatented technologies 6,720 Non-compete agreement 140 Goodwill 20,641 Current liabilities (639 ) Other non-current liabilities (1,870 ) $ 26,672 Included in Monolith’s current assets, net was approximately $0.7 not Pro Forma Results The following table summarizes, on a pro forma basis, the combined results of operations of the Company and IXYS as though the acquisition had occurred as of January 1, 2017. not not not January 1, 2017 For the Three Months Ended (in thousands, except per share amounts) July 1 , 2017 Net sales $ 396,897 Income before income taxes 40,312 Net income 37,442 Net income per share — basic 1.50 Net income per share — diluted 1.48 For the Six Months Ended (in thousands , except per share amounts ) June 30, 2018 July 1, 2017 Net sales $ 893,709 $ 765,710 Income before income taxes 134,227 51,546 Net income 106,247 55,043 Net income — basic 4.26 2.21 Net income — diluted 4.22 2.18 Pro forma results presented above primarily reflect the following adjustments: For the Three Months Ended For the Six Months Ended (in thousands) July 1, 2017 June 30, 2018 July 1, 2017 Amortization (a) $ (6,305 ) $ 5,185 $ (12,601 ) Depreciation 139 — 278 Transaction costs (b) — 9,976 (9,976 ) Amortization of inventory step-up (c) (14,771 ) 36,927 (36,927 ) Stock compensation (d) (767 ) 4,689 (5,780 ) Interest expense (e) (2,582 ) — (5,164 ) Income tax impact of above items 7,596 (13,329 ) 22,896 (a) The amortization adjustment for the six June 30, 2018 twelve 2017 three six July 1, 2017 (b) The transaction cost adjustments reflect the reversal of certain bank and attorney fees from the six June 30, 2018 six July 1, 2017. (c) The amortization of inventory step-up adjustment reflects the reversal of the amount recognized during the six June 30, 2018 six July 1, 2017. five (d) The stock compensation adjustment reflects the reversal of the portion of stock compensation for IXYS stock options that were converted to Littelfuse stock options and expensed immediately during the six June 30, 2018. six July 1, 2017 (e) The interest expense adjustment reflects incremental interest expense related to the financing of the transaction.

Note 3 - Inventories

Note 3 - Inventories	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Inventory Disclosure [Text Block]	3. The components of inventories at June 30, 2018 December 30, 2017 (in thousands) June 30 , 201 8 December 30 , 201 7 Raw materials $ 65,607 $ 39,030 Work in process 81,448 27,454 Finished goods 92,146 74,305 Total $ 239,201 $ 140,789

Note 4 - Goodwill and Other Int

Note 4 - Goodwill and Other Intangible Assets	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Goodwill and Intangible Assets Disclosure [Text Block]	4. The amounts for goodwill and changes in the carrying value by segment for the six June 30, 2018 (in thousands) Electronics Automotive Industrial Total As of December 30, 2017 $ 278,959 $ 135,829 $ 38,626 $ 453,414 Additions (a) 382,317 — — 382,317 Currency translation (1,558 ) (1,748 ) (198 ) (3,504 ) As of June 30, 2018 $ 659,718 $ 134,081 $ 38,428 $ 832,227 (a) The additions resulted from the acquisition of IXYS. The components of other intangible assets at June 30, 2018 (in thousands, except weighted average useful life) Weighted Average Useful Life Gross Carrying Value Accumulated Amortization Net Book Value Patents, licenses and software 10.6 $ 192,326 $ 67,528 $ 124,798 Distribution network 12.6 44,001 33,567 10,434 Customer relationships, trademarks, and tradenames 18.1 311,333 63,326 248,007 Order backlog 1.0 12,420 5,607 6,813 Total $ 560,080 $ 170,028 $ 390,052 During the six June 30, 2018, $212.7 (in thousands, except weighted average useful life) Weighted Average Useful Life Amount Patents, licenses and software 8.0 $ 51,500 Customer relationships, trademarks, and tradenames 17.2 148,800 Order backlog 1.0 12,420 Total $ 212,720 During the three six June 30, 2018 July 1, 2017, $13.4 $6.2 $25.4 $12.1 Estimated annual amortization expense related to intangible assets with definite lives as of June 30, 2018 (in thousands) Amount 2018 $ 53,440 2019 40,511 2020 40,240 2021 38,457 2022 37,456 2023 and thereafter 206,466 Total $ 416,570

Note 5 - Debt

Note 5 - Debt	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Debt Disclosure [Text Block]	5. The carrying amounts of debt at June 30, 2018 December 30, 2017 (in thousands) June 30, 2018 December 30, 2017 Revolving Credit Facility $ — $ — Term Loan 157,500 122,500 Euro Senior Notes, Series A due 2023 135,335 139,623 Euro Senior Notes, Series B due 2028 109,887 113,369 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 — U.S. Senior Notes, Series B due 2030 125,000 — Other 60 — Unamortized debt issuance costs (5,184 ) (4,881 ) Total debt 697,598 495,611 Less: Current maturities (10,060 ) (6,250 ) Total long-term debt $ 687,538 $ 489,361 Revolving Credit Facility / Term Loan On March 4, 2016, five $700.0 $575.0 $125.0 $150.0 $25.0 On October 13, 2017, $575.0 $700.0 $125.0 $200.0 March 4, 2021 October 13, 2022. $300.0 may two first $125.0 October 13, 2017 second $75.0 January 16, 2018. 1.25% $2.5 second January 16, 2018) October 13, 2022. $35.0 three June 30, 2018. Outstanding borrowings under the Credit Agreement bear interest, at the Company’s option, at either LIBOR, fixed for interest periods of one, two, three six 1.00% 2.00%, 0.00% 1.00%, 0.15% 0.25%, 3.59% June 30, 2018. As of June 30, 2018, $0.1 $699.9 June 30, 2018, Senior Notes On December 8, 2016, €212 two December 8, 2016 €117 1.14% December 8, 2023 ( 2023” €95 1.83% December 8, 2028 ( 2028” June 8 December 8, June 8, 2017. On December 8, 2016, $125 two February 15, 2017, $25 3.03% February 15, 2022 ( 2022” $100 3.74% February 15, 2027 ( 2027” 2022 2027” 2022 2027 February 15 August 15, August 15, 2017. On November 15, 2017, $175 two January 16, 2018, $50 3.48% February 15, 2025 ( 2025” $125 3.78% February 15, 2030 ( 2030” 2025 2030” 2022 2027, 2025 2030 February 15 August 15, August 15, 2018. The Senior Notes have not 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 June 30, 2018, The Company may

Note 6 - Fair Value of Assets a

Note 6 - Fair Value of Assets and Liabilities	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Fair Value Disclosures [Text Block]	6. For assets and liabilities measured at fair value on a recurring and nonrecurring basis, a three Level 1 Level 2 not Level 3 one Following is a description of the valuation methodologies used for instruments measured at fair value and their classification in the valuation hierarchy. 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 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 There were no June 30, 2018 June 30, 2018, December 30, 2017, not The following table presents assets measured at fair value by classification within the fair value hierarchy as of June 30, 2018: Fair Value Measurements Using (in thousands) Quoted Prices in Significant Significant Total Investments in equity securities $ 15,328 $ — $ — $ 15,328 Mutual funds 9,950 — — 9,950 The following table presents assets measured at fair value by classification within the fair value hierarchy as of December 30, 2017: Fair Value Measurements Using (in thousands) Quoted Prices in Significant Significant Total Investments in equity securities $ 10,993 $ — $ — $ 10,993 Mutual funds 7,962 — — 7,962 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 June 30, 2018 December 30, 2017, 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 June 30, 2018 December 30, 2017 June 30 , 2018 December 30, 2017 (in thousands) Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Euro Senior Notes, Series A due 2023 $ 135,335 $ 134,332 $ 139,623 $ 138,294 Euro Senior Notes, Series B due 2028 109,887 107,963 113,369 111,579 USD Senior Notes, Series A due 2022 25,000 24,154 25,000 24,737 USD Senior Notes, Series B due 2027 100,000 95,711 100,000 99,992 USD Senior Notes, Series A due 2025 50,000 47,769 — — USD Senior Notes, Series B due 2030 125,000 117,300 — —

Note 7 - Benefit Plans

Note 7 - Benefit Plans	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Pension and Other Postretirement Benefits Disclosure [Text Block]	7 . Benefit Plans The Company has company-sponsored defined benefit pension plans covering employees in the U.K., Germany, the Philippines, China, Japan, 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 costs, expected return on plan assets, and amortization, net within Other (income) expense, net three six June 30, 2018 July 1, 2017 For the Three Months Ended For the Six Months Ended (in thousands) June 30 , 201 8 July 1 , 201 7 June 30 , 201 8 July 1 , 201 7 Components of net periodic benefit cost: Service cost $ 533 $ 408 $ 1,066 $ 816 Interest cost 501 360 1,002 720 Expected return on plan assets (540 ) (476 ) (1,080 ) (952 ) Amortization of prior service (credit) 74 84 148 168 Net periodic benefit cost $ 568 $ 376 $ 1,136 $ 752 The Company expects to make approximately $2.3 2018.

Note 8 - Shareholders' Equity

Note 8 - Shareholders' Equity	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	8. The following table sets forth the changes in shareholders’ equity for the six June 30, 2018: (in thousands) Littelfuse, Inc. Shareholders’ Equity Non- controlling Interest Total Balance at December 30, 2017 $ 927,419 $ 137 $ 927,556 Net income 78,354 — 78,354 Other comprehensive income (loss) (16,221 ) — (16,221 ) Stock-based compensation 15,883 — 15,883 Withheld shares on restricted share units for withholding taxes (7,042 ) — (7,042 ) Stock options exercised 17,654 — 17,654 Issuance of common stock (a) 472,301 — 472,301 Cash dividends paid ($0.37 per share) (18,458 ) — (18,458 ) Non-controlling interest — (7 ) (7 ) Balance at June 30, 2018 $ 1,469,890 $ 130 $ 1,470,020 (a) The issuance of common stock ( 2,092,491 six June 30, 2018 2, Acquisitions The following table sets forth the changes in the components of Accumulated Other Comprehensive Income (Loss) by component for the three June 30, 2018: (in thousands) Pension and postretirement liability and reclassification adjustments (a) Unrealized gain/(loss) on investments Foreign currency translation adjustment Accumulated other comprehensive income (loss) Balance at December 30, 2017 $ (10,836 ) $ 9,795 $ (62,627 ) $ (63,668 ) Cumulative effect adjustment (b) — (9,795 ) — (9,795 ) Activity in the period 763 — (16,984 ) (16,221 ) Balance at June 30, 2018 $ (10,073 ) $ — $ (79,611 ) $ (89,684 ) (a) The balances at June 30, 2018 December 30, 2017 $0.4 $1.4 (b) The Company adopted ASU 2016 01 December 31, 2017 $9.8 1, Summary of Significant Accounting Policies and Other Information

Note 9 - Income Taxes

Note 9 - Income Taxes	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Income Tax Disclosure [Text Block]	9. The effective tax rates for the three six June 30, 2018 19.1% 19.2%, three six July 1, 2017 15.2% 16.5%, The effective tax rates for the 2018 2017 2017 35% On December 22, 2017, 35% 21%, one 2017 2018 In accordance with the guidance provided in SEC Staff Accounting Bulletin (“SAB”) No. 118, fourth 2017 $47 $49 $2 not first six 2018. $10 2017 No. 118 may may The Company will elect to pay the 2017 2018 eight $38.5 2017 2018 first second $3.4 June 30, 2018. The Company recognized deferred tax liabilities of $12.0 $11.8 $0.2 December 30, 2017 not may no December 30, 2017, no first six 2018. 2017 One of the base broadening provisions of the Tax Act is commonly referred to as the “GILTI” provisions. In accordance with guidance issued by the FASB staff, the Company has not 118. not second first six 2018. Although certain administrative guidance has been issued, the appropriate application of many provisions of the Tax Act remain uncertain. The Company used its best judgement as to the application of these provisions in determining its income tax expense for the second first 2018. first 2018 may

Note 10 - Earnings Per Share

Note 10 - Earnings Per Share	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Earnings Per Share [Text Block]	10 . Earnings Per Share The following table sets forth the computation of basic and diluted earnings per share: For the Three Months Ended For the Six Months Ended (in thousands, except per share amounts) June 30 , 201 8 July 1 , 201 7 June 30 , 201 8 July 1 , 201 7 Numerator: Net income as reported $ 42,326 $ 48,638 $ 78,354 $ 87,530 Denominator: Weighted average shares outstanding Basic 25,004 22,822 24,671 22,785 Effect of dilutive securities 397 201 415 220 Diluted 25,401 23,023 25,086 23,005 Earnings Per Share: Basic earnings per share $ 1.69 $ 2.13 $ 3.18 $ 3.84 Diluted earnings per share $ 1.67 $ 2.11 $ 3.12 $ 3.80 Potential shares of common stock relating to stock options excluded from the earnings per share calculation because their effect would be anti-dilutive were 47,849 46,100 three June 30, 2018 July 1, 2017, 23,659 21,896 six June 30, 2018 July 1, 2017,

Note 11 - Related Party Transac

Note 11 - Related Party Transactions	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Related Party Transactions Disclosure [Text Block]	11. As a result of the Company’s acquisition of IXYS, the Company has equity ownerships 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: 45% three six June 30, 2018, $0.3 $0.4 three six June 30, 2018, $1.0 $2.1 June 30, 2018, $0.1 $0.3 EB Tech Ltd.: 20% three six June 30, 2018 $0.1 $0.2 June 30, 2018, Automated Technology, Inc. 24% three six June 30, 2018, $2.8 $5.2 June 30, 2018, $0.7

Note 12 - Segment Information

Note 12 - Segment Information	6 Months Ended
	Jun. 30, 2018
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	12. The Company and its subsidiaries design, manufacture and sell components and modules for circuit protection, power control and sensing throughout the 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 not Sales, marketing, and research and development expenses are charged directly into each operating segment. Manufacturing, purchasing, logistics, customer service, finance, information technology, and human resources are shared functions that are allocated back to the three not not not not not not one may ● Electronics Segment one ● Automotive Segment: ● Industrial Segment: Segment information is summarized as follows: For the Three Months Ended For the Six Months Ended (in thousands) June 30 , 201 8 July 1 , 201 7 June 30 , 201 8 July 1 , 201 7 Net sales Electronics $ 299,357 $ 169,387 $ 563,768 $ 323,154 Automotive 127,172 116,457 253,302 224,297 Industrial 32,654 27,511 59,926 51,346 Total net sales $ 459,183 $ 313,355 $ 876,996 $ 598,797 Depreciation and amortization Electronics $ 15,651 $ 8,707 $ 29,329 $ 17,095 Automotive 5,969 5,580 11,939 10,950 Industrial 1,467 1,330 2,927 2,645 Other 3,103 - 5,607 - Total depreciation and amortization $ 26,190 $ 15,617 $ 49,802 $ 30,690 Operating income (loss) Electronics $ 67,311 $ 42,967 $ 121,275 $ 78,173 Automotive 15,711 15,713 34,102 30,778 Industrial 5,279 1,905 9,988 2,012 Other (a) (28,679 ) (315 ) (68,172 ) (1,840 ) Total operating income 59,622 60,270 97,193 109,123 Interest expense 5,782 3,281 11,205 6,401 Foreign exchange loss (gain) 3,200 (558 ) (7,354 ) (2,115 ) Other expense (income), net (1,678 ) 190 (3,621 ) 52 Income before income taxes $ 52,318 $ 57,357 $ 96,963 $ 104,785 (a) Included in “Other” Operating income (loss) for the 2018 second $24.4 $63.2 $19.0 $36.9 $2.3 $14.1 $3.1 $5.6 $4.5 $2.1 $3.2 $3.9 $1.1 $1.1 Included in “Other” Operating income (loss) for the 2017 second $0.3 $1.8 2016 The Company’s net sales by country are as follows: For the Three Months Ended For the Six Months Ended (in thousands) June 30 , 201 8 July 1 , 201 7 June 30 , 201 8 July 1 , 201 7 Net sales United States $ 137,236 $ 100,648 $ 261,112 $ 187,306 China (a) 127,776 86,891 234,284 165,111 Other countries (b) 194,171 125,816 381,600 246,380 Total net sales $ 459,183 $ 313,355 $ 876,996 $ 598,797 (a) Includes mainland China, Taiwan, and Hong Kong. 10% The Company’s long-lived assets by country, as of June 30, 2018 December 30, 2017, (in thousands) June 30, 2018 December 30, 2017 Long-lived assets United States $ 59,097 $ 23,490 China (a) 92,832 86,866 Mexico 66,063 62,510 Germany 35,013 1,082 Philippines 31,481 31,129 Other countries 54,269 45,500 Total long-lived assets $ 338,755 $ 250,577 (a) Includes mainland China, Taiwan, and Hong Kong. The Company’s additions to long-lived assets by country were as follows: For the Six Months Ended (in thousands) June 30 , 2018 July 1, 2017 Additions to long-lived assets United States $ 4,234 $ 1,149 China (a) 14,711 10,200 Mexico 8,874 10,925 Germany 5,182 - Philippines 4,241 1,345 Other countries 3,073 5,259 Total additions to long-lived assets $ 40,315 $ 28,878 (a) Includes mainland China, Taiwan, and Hong Kong.

Significant Accounting Policies

Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	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 10 X. not 10 December 30, 2017, not
Revenue from Contract with Customer [Policy Text Block]	Revenue Recognition Adoption On December 31, 2017, not Revenue Disaggregation The following table disaggregates the Company’s revenue by primary business units for the three six June 30, 2018: For the three months ended June 30, 2018 (in thousands) Electronics Segment Automotive Segment Industrial Segment Total Electronics – Passive Products and Sensors $ 128,321 $ — $ — $ 128,321 Electronics – Semiconductor 171,036 — — 171,036 Passenger Car Products — 63,581 — 63,581 Automotive Sensors — 30,729 — 30,729 Commercial Vehicle Products — 32,862 — 32,862 Industrial Products — — 32,654 32,654 Total $ 299,357 $ 127,172 $ 32,654 $ 459,183 For the six months ended June 30, 2018 (in thousands) Electronics Segment Automotive Segment Industrial Segment Total Electronics – Passive Products and Sensors $ 242,816 $ — $ — $ 242,816 Electronics – Semiconductor 320,952 — — 320,952 Passenger Car Products — 127,160 — 127,160 Automotive Sensors — 62,052 — 62,052 Commercial Vehicle Products — 64,090 — 64,090 Industrial Products — — 59,926 59,926 Total $ 563,768 $ 253,302 $ 59,926 $ 876,996 See Note 12, Segment Information
Revenue Recognition, Policy [Policy Text Block]	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 may third The Company has elected the practical expedient under ASC 340 40 25 4 one
Revenue Recognition And Billing [Policy Text Block]	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 606 10 32 18 not 606 10 25 18B
Revenue Recognition, Sales Returns [Policy Text Block]	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 and actual authorizations for the debit and recognizes these debits as a reduction of revenue.
Revenue Recognition Return to Stock [Policy Text Block]	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.
Revenue Recognition, Rebates [Policy Text Block]	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.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Adopted Accounting Standards In March 2017, No. 2017 07 715 No. 2017 07 first 2018 December 31, 2017. In January 2016, No. 2016 01, December 31, 2017, $9.8 six June 30, 2018, $2.8 In May 2014, No. 2014 09, 606 605, two one one December 31, 2017 no not Revenue Recognition In October 2016, No. 2016 16, 740 December 31, 2017 not Recently Issued Accounting Standards In February 2016, No. 2016 02, 842 twelve December 15, 2018, first 2019. not In January 2018, 2017 not not In February 2018, No. 2018 02 220 not 2018 02 first 2019; 2018 02

Note 1 - Summary of Significa21

Note 1 - Summary of Significant Accounting Policies and Other Information (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Disaggregation of Revenue [Table Text Block]	For the three months ended June 30, 2018 (in thousands) Electronics Segment Automotive Segment Industrial Segment Total Electronics – Passive Products and Sensors $ 128,321 $ — $ — $ 128,321 Electronics – Semiconductor 171,036 — — 171,036 Passenger Car Products — 63,581 — 63,581 Automotive Sensors — 30,729 — 30,729 Commercial Vehicle Products — 32,862 — 32,862 Industrial Products — — 32,654 32,654 Total $ 299,357 $ 127,172 $ 32,654 $ 459,183 For the six months ended June 30, 2018 (in thousands) Electronics Segment Automotive Segment Industrial Segment Total Electronics – Passive Products and Sensors $ 242,816 $ — $ — $ 242,816 Electronics – Semiconductor 320,952 — — 320,952 Passenger Car Products — 127,160 — 127,160 Automotive Sensors — 62,052 — 62,052 Commercial Vehicle Products — 64,090 — 64,090 Industrial Products — — 59,926 59,926 Total $ 563,768 $ 253,302 $ 59,926 $ 876,996

Note 2 - Acquisitions (Tables)

Note 2 - Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	(in thousands) Purchase Price Allocation Total purchase consideration: Cash, net of cash acquired $ 302,865 Cash settled stock options 3,622 Littelfuse stock 434,192 Converted stock options 38,109 Total purchase consideration $ 778,788 Allocation of consideration to assets acquired and liabilities assumed: Current assets, net $ 155,959 Property, plant, and equipment 77,442 Intangible assets 212,720 Goodwill 382,317 Other non-current assets 31,570 Other non-current liabilities (81,220 ) $ 778,788 (in thousands) Purchase Price Allocation Total purchase consideration: Cash $ 24,340 Allocation of consideration to assets acquired and liabilities assumed: Current assets, net $ 4,635 Patented and unpatented technologies 1,090 Trademarks and tradenames 200 Non-compete agreement 50 Customer relationships 2,830 Goodwill 16,075 Current liabilities (540 ) $ 24,340 (in thousands) Purchase Price Allocation Total purchase consideration: Original investment $ 3,500 Cash, net of cash acquired 14,172 Non-cash, fair value of commitment to purchase non-controlling interest 9,000 Total purchase consideration $ 26,672 Allocation of consideration to assets acquired and liabilities assumed: Current assets, net $ 891 Property, plant, and equipment 789 Patented and unpatented technologies 6,720 Non-compete agreement 140 Goodwill 20,641 Current liabilities (639 ) Other non-current liabilities (1,870 ) $ 26,672
Business Acquisition, Pro Forma Information [Table Text Block]	For the Three Months Ended (in thousands, except per share amounts) July 1 , 2017 Net sales $ 396,897 Income before income taxes 40,312 Net income 37,442 Net income per share — basic 1.50 Net income per share — diluted 1.48 For the Six Months Ended (in thousands , except per share amounts ) June 30, 2018 July 1, 2017 Net sales $ 893,709 $ 765,710 Income before income taxes 134,227 51,546 Net income 106,247 55,043 Net income — basic 4.26 2.21 Net income — diluted 4.22 2.18
Business Acquisition, Pro Forma Information, Nonrecurring Adjustments [Table Text Block]	For the Three Months Ended For the Six Months Ended (in thousands) July 1, 2017 June 30, 2018 July 1, 2017 Amortization (a) $ (6,305 ) $ 5,185 $ (12,601 ) Depreciation 139 — 278 Transaction costs (b) — 9,976 (9,976 ) Amortization of inventory step-up (c) (14,771 ) 36,927 (36,927 ) Stock compensation (d) (767 ) 4,689 (5,780 ) Interest expense (e) (2,582 ) — (5,164 ) Income tax impact of above items 7,596 (13,329 ) 22,896

Note 3 - Inventories (Tables)

Note 3 - Inventories (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Schedule of Inventory, Current [Table Text Block]	(in thousands) June 30 , 201 8 December 30 , 201 7 Raw materials $ 65,607 $ 39,030 Work in process 81,448 27,454 Finished goods 92,146 74,305 Total $ 239,201 $ 140,789

Note 4 - Goodwill and Other I24

Note 4 - Goodwill and Other Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Schedule of Goodwill [Table Text Block]	(in thousands) Electronics Automotive Industrial Total As of December 30, 2017 $ 278,959 $ 135,829 $ 38,626 $ 453,414 Additions (a) 382,317 — — 382,317 Currency translation (1,558 ) (1,748 ) (198 ) (3,504 ) As of June 30, 2018 $ 659,718 $ 134,081 $ 38,428 $ 832,227
Schedule of Finite-Lived Intangible Assets [Table Text Block]	(in thousands, except weighted average useful life) Weighted Average Useful Life Gross Carrying Value Accumulated Amortization Net Book Value Patents, licenses and software 10.6 $ 192,326 $ 67,528 $ 124,798 Distribution network 12.6 44,001 33,567 10,434 Customer relationships, trademarks, and tradenames 18.1 311,333 63,326 248,007 Order backlog 1.0 12,420 5,607 6,813 Total $ 560,080 $ 170,028 $ 390,052 (in thousands, except weighted average useful life) Weighted Average Useful Life Amount Patents, licenses and software 8.0 $ 51,500 Customer relationships, trademarks, and tradenames 17.2 148,800 Order backlog 1.0 12,420 Total $ 212,720
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	(in thousands) Amount 2018 $ 53,440 2019 40,511 2020 40,240 2021 38,457 2022 37,456 2023 and thereafter 206,466 Total $ 416,570

Note 5 - Debt (Tables)

Note 5 - Debt (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Schedule of Long-term Debt Instruments [Table Text Block]	(in thousands) June 30, 2018 December 30, 2017 Revolving Credit Facility $ — $ — Term Loan 157,500 122,500 Euro Senior Notes, Series A due 2023 135,335 139,623 Euro Senior Notes, Series B due 2028 109,887 113,369 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 — U.S. Senior Notes, Series B due 2030 125,000 — Other 60 — Unamortized debt issuance costs (5,184 ) (4,881 ) Total debt 697,598 495,611 Less: Current maturities (10,060 ) (6,250 ) Total long-term debt $ 687,538 $ 489,361

Note 6 - Fair Value of Assets26

Note 6 - Fair Value of Assets and Liabilities (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Fair Value, Assets Measured on Recurring Basis [Table Text Block]	Fair Value Measurements Using (in thousands) Quoted Prices in Significant Significant Total Investments in equity securities $ 15,328 $ — $ — $ 15,328 Mutual funds 9,950 — — 9,950 Fair Value Measurements Using (in thousands) Quoted Prices in Significant Significant Total Investments in equity securities $ 10,993 $ — $ — $ 10,993 Mutual funds 7,962 — — 7,962
Fair Value, by Balance Sheet Grouping [Table Text Block]	June 30 , 2018 December 30, 2017 (in thousands) Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value Euro Senior Notes, Series A due 2023 $ 135,335 $ 134,332 $ 139,623 $ 138,294 Euro Senior Notes, Series B due 2028 109,887 107,963 113,369 111,579 USD Senior Notes, Series A due 2022 25,000 24,154 25,000 24,737 USD Senior Notes, Series B due 2027 100,000 95,711 100,000 99,992 USD Senior Notes, Series A due 2025 50,000 47,769 — — USD Senior Notes, Series B due 2030 125,000 117,300 — —

Note 7 - Benefit Plans (Tables)

Note 7 - Benefit Plans (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Schedule of Net Benefit Costs [Table Text Block]	For the Three Months Ended For the Six Months Ended (in thousands) June 30 , 201 8 July 1 , 201 7 June 30 , 201 8 July 1 , 201 7 Components of net periodic benefit cost: Service cost $ 533 $ 408 $ 1,066 $ 816 Interest cost 501 360 1,002 720 Expected return on plan assets (540 ) (476 ) (1,080 ) (952 ) Amortization of prior service (credit) 74 84 148 168 Net periodic benefit cost $ 568 $ 376 $ 1,136 $ 752

Note 8 - Shareholders' Equity (

Note 8 - Shareholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Schedule of Stockholders Equity [Table Text Block]	(in thousands) Littelfuse, Inc. Shareholders’ Equity Non- controlling Interest Total Balance at December 30, 2017 $ 927,419 $ 137 $ 927,556 Net income 78,354 — 78,354 Other comprehensive income (loss) (16,221 ) — (16,221 ) Stock-based compensation 15,883 — 15,883 Withheld shares on restricted share units for withholding taxes (7,042 ) — (7,042 ) Stock options exercised 17,654 — 17,654 Issuance of common stock (a) 472,301 — 472,301 Cash dividends paid ($0.37 per share) (18,458 ) — (18,458 ) Non-controlling interest — (7 ) (7 ) Balance at June 30, 2018 $ 1,469,890 $ 130 $ 1,470,020
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	(in thousands) Pension and postretirement liability and reclassification adjustments (a) Unrealized gain/(loss) on investments Foreign currency translation adjustment Accumulated other comprehensive income (loss) Balance at December 30, 2017 $ (10,836 ) $ 9,795 $ (62,627 ) $ (63,668 ) Cumulative effect adjustment (b) — (9,795 ) — (9,795 ) Activity in the period 763 — (16,984 ) (16,221 ) Balance at June 30, 2018 $ (10,073 ) $ — $ (79,611 ) $ (89,684 )

Note 10 - Earnings Per Share (T

Note 10 - Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	For the Three Months Ended For the Six Months Ended (in thousands, except per share amounts) June 30 , 201 8 July 1 , 201 7 June 30 , 201 8 July 1 , 201 7 Numerator: Net income as reported $ 42,326 $ 48,638 $ 78,354 $ 87,530 Denominator: Weighted average shares outstanding Basic 25,004 22,822 24,671 22,785 Effect of dilutive securities 397 201 415 220 Diluted 25,401 23,023 25,086 23,005 Earnings Per Share: Basic earnings per share $ 1.69 $ 2.13 $ 3.18 $ 3.84 Diluted earnings per share $ 1.67 $ 2.11 $ 3.12 $ 3.80

Note 12 - Segment Information (

Note 12 - Segment Information (Tables)	6 Months Ended
	Jun. 30, 2018
Notes Tables
Schedule of Segment Reporting Information, by Segment [Table Text Block]	For the Three Months Ended For the Six Months Ended (in thousands) June 30 , 201 8 July 1 , 201 7 June 30 , 201 8 July 1 , 201 7 Net sales Electronics $ 299,357 $ 169,387 $ 563,768 $ 323,154 Automotive 127,172 116,457 253,302 224,297 Industrial 32,654 27,511 59,926 51,346 Total net sales $ 459,183 $ 313,355 $ 876,996 $ 598,797 Depreciation and amortization Electronics $ 15,651 $ 8,707 $ 29,329 $ 17,095 Automotive 5,969 5,580 11,939 10,950 Industrial 1,467 1,330 2,927 2,645 Other 3,103 - 5,607 - Total depreciation and amortization $ 26,190 $ 15,617 $ 49,802 $ 30,690 Operating income (loss) Electronics $ 67,311 $ 42,967 $ 121,275 $ 78,173 Automotive 15,711 15,713 34,102 30,778 Industrial 5,279 1,905 9,988 2,012 Other (a) (28,679 ) (315 ) (68,172 ) (1,840 ) Total operating income 59,622 60,270 97,193 109,123 Interest expense 5,782 3,281 11,205 6,401 Foreign exchange loss (gain) 3,200 (558 ) (7,354 ) (2,115 ) Other expense (income), net (1,678 ) 190 (3,621 ) 52 Income before income taxes $ 52,318 $ 57,357 $ 96,963 $ 104,785
Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block]	For the Three Months Ended For the Six Months Ended (in thousands) June 30 , 201 8 July 1 , 201 7 June 30 , 201 8 July 1 , 201 7 Net sales United States $ 137,236 $ 100,648 $ 261,112 $ 187,306 China (a) 127,776 86,891 234,284 165,111 Other countries (b) 194,171 125,816 381,600 246,380 Total net sales $ 459,183 $ 313,355 $ 876,996 $ 598,797 (in thousands) June 30, 2018 December 30, 2017 Long-lived assets United States $ 59,097 $ 23,490 China (a) 92,832 86,866 Mexico 66,063 62,510 Germany 35,013 1,082 Philippines 31,481 31,129 Other countries 54,269 45,500 Total long-lived assets $ 338,755 $ 250,577 For the Six Months Ended (in thousands) June 30 , 2018 July 1, 2017 Additions to long-lived assets United States $ 4,234 $ 1,149 China (a) 14,711 10,200 Mexico 8,874 10,925 Germany 5,182 - Philippines 4,241 1,345 Other countries 3,073 5,259 Total additions to long-lived assets $ 40,315 $ 28,878

Note 1 - Summary of Significa31

Note 1 - Summary of Significant Accounting Policies and Other Information (Details Textual) - Accounting Standards Update 2016-01 [Member] $ in Millions	6 Months Ended
	Jun. 30, 2018USD ($)
Cumulative Effect on Retained Earnings, Net of Tax, Total	$ 9.8
Equity Securities, FV-NI, Unrealized Gain (Loss), Total	$ 2.8

Note 1 - Summary of Significa32

Note 1 - Summary of Significant Accounting Policies and Other Information - Revenue Disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Revenue	$ 459,183	$ 313,355	$ 876,996	$ 598,797
Electronics - Passive Products and Sensors [Member]
Revenue	128,321		242,816
Electronics - Semiconductor [Member]
Revenue	171,036		320,952
Passenger Car Products [Member]
Revenue	63,581		127,160
Automotive Sensors [Member]
Revenue	30,729		62,052
Commercial Vehicle Products [Member]
Revenue	32,862		64,090
Industrial Products [Member]
Revenue	32,654		59,926
Electronics [Member]
Revenue	299,357	169,387	563,768	323,154
Electronics [Member] | Electronics - Passive Products and Sensors [Member]
Revenue	128,321		242,816
Electronics [Member] | Electronics - Semiconductor [Member]
Revenue	171,036		320,952
Electronics [Member] | Passenger Car Products [Member]
Revenue
Electronics [Member] | Automotive Sensors [Member]
Revenue
Electronics [Member] | Commercial Vehicle Products [Member]
Revenue
Electronics [Member] | Industrial Products [Member]
Revenue
Automotive [Member]
Revenue	127,172	116,457	253,302	224,297
Automotive [Member] | Electronics - Passive Products and Sensors [Member]
Revenue
Automotive [Member] | Electronics - Semiconductor [Member]
Revenue
Automotive [Member] | Passenger Car Products [Member]
Revenue	63,581		127,160
Automotive [Member] | Automotive Sensors [Member]
Revenue	30,729		62,052
Automotive [Member] | Commercial Vehicle Products [Member]
Revenue	32,862		64,090
Automotive [Member] | Industrial Products [Member]
Revenue
Industrial [Member]
Revenue	32,654	$ 27,511	59,926	$ 51,346
Industrial [Member] | Electronics - Passive Products and Sensors [Member]
Revenue
Industrial [Member] | Electronics - Semiconductor [Member]
Revenue
Industrial [Member] | Passenger Car Products [Member]
Revenue
Industrial [Member] | Automotive Sensors [Member]
Revenue
Industrial [Member] | Commercial Vehicle Products [Member]
Revenue
Industrial [Member] | Industrial Products [Member]
Revenue	$ 32,654		$ 59,926

Note 2 - Acquisitions (Details

Note 2 - Acquisitions (Details Textual) $ / shares in Units, $ in Thousands	Jan. 17, 2018USD ($)$ / shares	Jul. 07, 2017USD ($)	Mar. 01, 2017USD ($)	Feb. 28, 2017USD ($)	Apr. 30, 2018USD ($)	Jun. 30, 2018USD ($)$ / shares	Jun. 30, 2018USD ($)$ / shares	Jun. 30, 2018USD ($)$ / shares	Jul. 01, 2017USD ($)	Dec. 30, 2017$ / shares	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Common Stock, Par or Stated Value Per Share | $ / shares						$ 0.01	$ 0.01	$ 0.01		$ 0.01
Share Price | $ / shares	$ 207.50
Inventory Charge Related to Step-up in Cost Basis								$ 36,927
Payments to Acquire Businesses, Net of Cash Acquired, Total								310,487	14,172
Business Combination, Consideration Transferred, Commitment to Purchase Noncontrolling Interest									$ 9,000
Inventory, Amortization Period								150 days
Order or Production Backlog [Member]
Finite-Lived Intangible Asset, Useful Life								1 year
Monolith [Member]
Cost Method Investments											$ 3,500	$ 3,500
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners												12.00%
IXYS Corporation [Member]
Business Acquisition, Share Price | $ / shares	$ 23
Business Acquisition, Share Exchange Ratio	0.1265
Business Combination, Consideration Transferred, Excluding Value of Stock Options Converted	$ 814,800
Payments to Acquire Businesses, Gross	380,600
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	434,192
Business Combination, Value of Stock Options Converted to Company’s Stock Options	41,700
Business Combination, Consideration Transferred, Total	856,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	49,100
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual						$ 100,200	$ 186,500
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual						13,900	$ 31,700
Business Combination, Step Up of Inventory at Acquisition Date	36,900
Inventory Charge Related to Step-up in Cost Basis						19,000		$ 36,900
Payments to Acquire Businesses, Net of Cash Acquired, Total	302,865
IXYS Corporation [Member] | Selling, General and Administrative Expenses [Member]
Business Combination, Acquisition Related Costs						800		11,000
IXYS Corporation [Member] | Employee Stock Option [Member]
Allocated Share-based Compensation Expense, Total	$ 4,500					$ 1,600		$ 7,500
U.S. Sensor [Member]
Payments to Acquire Businesses, Gross		$ 24,340
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables		1,500
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory		$ 1,600
Monolith [Member]
Business Combination, Consideration Transferred, Total				$ 15,000	$ 5,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables				$ 700
Business Acquisition, Percentage of Voting Interests Acquired				62.00%	19.00%
Business Combination, Step Acquisition, Remaining Interest Percentage					19.00%
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low				$ 500
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High				5,000
Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value			$ 3,500	3,500
Payments to Acquire Businesses, Net of Cash Acquired, Total			14,172	14,200
Business Combination, Consideration Transferred, Commitment to Purchase Noncontrolling Interest			9,000	9,000
Business Combination, Consideration Transferred, Including Equity Interest in Acquiree Held Prior to Combination, Total			$ 26,672	$ 26,700
Monolith [Member] | Stockholders of Monolith [Member]
Business Combination, Consideration Transferred, Total					$ 4,000
IXYS Corporation [Member]
Number of Customers	3,500
Common Stock, Par or Stated Value Per Share | $ / shares	$ 0.01

Note 2 - Acquisitions - Prelimi

Note 2 - Acquisitions - Preliminary Price Allocation (Details) - USD ($) $ in Thousands	Jan. 17, 2018	Jul. 07, 2017	Mar. 01, 2017	Feb. 28, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 30, 2017
Cash, net of cash acquired					$ 310,487	$ 14,172
Goodwill					832,227		$ 453,414
Goodwill					832,227		$ 453,414
Cash, net of cash acquired					310,487	14,172
Non-cash, fair value of commitment to purchase non-controlling interest						$ 9,000
IXYS Corporation [Member]
Cash, net of cash acquired	$ 302,865
Cash settled stock options	3,622
Littelfuse stock	434,192
Converted stock options	38,109
Total purchase consideration	778,788
Current assets, net	155,959
Property, plant, and equipment	77,442
Intangible assets	212,720
Goodwill	382,317
Other non-current assets	31,570
Other non-current liabilities	(81,220)
	778,788
Cash	380,600
Current assets, net	155,959
Intangible assets, other than goodwill	212,720
Goodwill	382,317
	778,788
Cash, net of cash acquired	302,865
Property, plant, and equipment	$ 77,442
U.S. Sensor [Member]
Current assets, net		$ 4,635
Goodwill		16,075
		24,340
Cash		24,340
Current assets, net		4,635
Goodwill		16,075
Current liabilities		(540)
		24,340
U.S. Sensor [Member] | Patented and Unpatented Technologies [Member]
Intangible assets		1,090
Intangible assets, other than goodwill		1,090
U.S. Sensor [Member] | Trademarks and Trade Names [Member]
Intangible assets		200
Intangible assets, other than goodwill		200
U.S. Sensor [Member] | Noncompete Agreements [Member]
Intangible assets		50
Intangible assets, other than goodwill		50
U.S. Sensor [Member] | Customer Relationships [Member]
Intangible assets		2,830
Intangible assets, other than goodwill		$ 2,830
Monolith [Member]
Cash, net of cash acquired			$ 14,172	$ 14,200
Current assets, net			891
Property, plant, and equipment			789
Goodwill			20,641
Other non-current liabilities			(1,870)
Current assets, net			891
Goodwill			20,641
Current liabilities			(639)
Original investment			3,500	3,500
Cash, net of cash acquired			14,172	14,200
Non-cash, fair value of commitment to purchase non-controlling interest			9,000	9,000
Total purchase consideration			26,672	$ 26,700
Property, plant, and equipment			789
			26,672
Monolith [Member] | Patented and Unpatented Technologies [Member]
Intangible assets			6,720
Intangible assets, other than goodwill			6,720
Monolith [Member] | Noncompete Agreements [Member]
Intangible assets			140
Intangible assets, other than goodwill			$ 140

Note 2 - Acquisitions - Busines

Note 2 - Acquisitions - Business Acquisition Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Net sales	$ 396,897	$ 893,709	$ 765,710
Income before income taxes	40,312	134,227	51,546
Net income	$ 37,442	$ 106,247	$ 55,043
Net income per share — basic (in dollars per share)	$ 1.50	$ 4.26	$ 2.21
Net income per share — diluted (in dollars per share)	$ 1.48	$ 4.22	$ 2.18

Note 2 - Acquisition - Pro Form

Note 2 - Acquisition - Pro Forma Information Adjustments (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Net income			$ 37,442	$ 106,247	$ 55,043
Adjustment to Amortization [Member]
Net income	[1]	$ 5,185	(6,305)		(12,601)
Adjustment to Depreciation [Member]
Net income			139		278
Acquisition-related Costs [Member]
Net income	[2]	9,976			(9,976)
Amortization of Inventory Step Up [Member]
Net income	[3]	36,927	(14,771)		(36,927)
Adjustment to Stock Compensation [Member]
Net income	[4]	4,689	(767)		(5,780)
Adjustment to Interest Expense [Member]
Net income	[5]		(2,582)		(5,164)
Adjustment to Income Tax [Member]
Net income		$ (13,329)	$ 7,596		$ 22,896
[1]	The amortization adjustment for the six months ended June 30, 2018 primarily reflects the reduction of amortization expense in the period related to the Order backlog intangible asset. The Order backlog has a useful life of twelve months and will be fully amortized in the fiscal 2017 pro forma results. The amortization adjustment for the three and six months ended July 1, 2017 reflects incremental amortization resulting for the measurement of intangibles at their fair values.
[2]	The transaction cost adjustments reflect the reversal of certain bank and attorney fees from the six months ended June 30, 2018 and recognition of those fees during the six months ended July 1, 2017.
[3]	The amortization of inventory step-up adjustment reflects the reversal of the amount recognized during the six months ended June 30, 2018 and the recognition of the full amortization during the six months end July 1, 2017. The inventory step-up was amortized over five months as the inventory is sold.
[4]	The stock compensation adjustment reflects the reversal of the portion of stock compensation for IXYS stock options that were converted to Littelfuse stock options and expensed immediately during the six months ended June 30, 2018. The adjustment for the six months ended July 1, 2017 reflect the incremental stock compensation for the converted stock options.
[5]	The interest expense adjustment reflects incremental interest expense related to the financing of the transaction.

Note 3 - Inventories - Componen

Note 3 - Inventories - Components of Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Raw materials	$ 65,607	$ 39,030
Work in process	81,448	27,454
Finished goods	92,146	74,305
Total	$ 239,201	$ 140,789

Note 4 - Goodwill and Other I38

Note 4 - Goodwill and Other Intangible Assets (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Finite-lived Intangible Assets Acquired			$ 212,720
Amortization of Intangible Assets, Total	$ 13,373	$ 6,171	25,371	$ 12,115
IXYS Corporation [Member]
Finite-lived Intangible Assets Acquired			$ 212,700

Note 4 - Goodwill and Other I39

Note 4 - Goodwill and Other Intangible Assets - Amounts for Goodwill and Changes in Carrying Value by Operating Segment (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)
Balance	$ 453,414
Additions	382,317	[1]
Currency translation	(3,504)
Balance	832,227
Electronics [Member]
Balance	278,959
Additions	382,317	[1]
Currency translation	(1,558)
Balance	659,718
Automotive [Member]
Balance	135,829
Additions		[1]
Currency translation	(1,748)
Balance	134,081
Industrial [Member]
Balance	38,626
Additions		[1]
Currency translation	(198)
Balance	$ 38,428
[1]	The additions resulted from the acquisition of IXYS.

Note 4 - Goodwill and Other I40

Note 4 - Goodwill and Other Intangible Assets - Details of Other Intangible Assets and Related Future Amortization Expense (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)
Finite-lived intangible assets, gross	$ 560,080
Finite-lived intangible assets, accumulated amortization	170,028
Finite-lived intangible assets, Net Book Value	390,052
Finite-lived Intangible Assets Acquired	$ 212,720
Patents, Licenses, and Software [Member]
Finite-Lived Intangible Asset, Useful Life	10 years 219 days
Finite-lived intangible assets, gross	$ 192,326
Finite-lived intangible assets, accumulated amortization	67,528
Finite-lived intangible assets, Net Book Value	$ 124,798
Finite-lived intangible assets, useful life (Year)	8 years
Finite-lived Intangible Assets Acquired	$ 51,500
Distribution Rights [Member]
Finite-Lived Intangible Asset, Useful Life	12 years 219 days
Finite-lived intangible assets, gross	$ 44,001
Finite-lived intangible assets, accumulated amortization	33,567
Finite-lived intangible assets, Net Book Value	$ 10,434
Customer Lists, Trademarks, and Trade Names [Member]
Finite-Lived Intangible Asset, Useful Life	18 years 36 days
Finite-lived intangible assets, gross	$ 311,333
Finite-lived intangible assets, accumulated amortization	63,326
Finite-lived intangible assets, Net Book Value	$ 248,007
Finite-lived intangible assets, useful life (Year)	17 years 73 days
Finite-lived Intangible Assets Acquired	$ 148,800
Order or Production Backlog [Member]
Finite-Lived Intangible Asset, Useful Life	1 year
Finite-lived intangible assets, gross	$ 12,420
Finite-lived intangible assets, accumulated amortization	5,607
Finite-lived intangible assets, Net Book Value	$ 6,813
Finite-lived intangible assets, useful life (Year)	1 year
Finite-lived Intangible Assets Acquired	$ 12,420

Note 4 - Goodwill and Other I41

Note 4 - Goodwill and Other Intangible Assets - Estimated Amortization Expense Related to Intangible Assets with Definite Lives (Details) $ in Thousands	Jun. 30, 2018USD ($)
2,018	$ 53,440
2,019	40,511
2,020	40,240
2,021	38,457
2,022	37,456
2023 and thereafter	206,466
Total	$ 416,570

Note 5 - Debt (Details Textual)

Note 5 - Debt (Details Textual) € in Millions, $ in Millions	Jan. 16, 2018USD ($)	Oct. 13, 2017USD ($)	Mar. 04, 2016USD ($)	Jun. 30, 2018USD ($)	Dec. 30, 2017	Nov. 15, 2017USD ($)	Oct. 12, 2017USD ($)	Feb. 15, 2017USD ($)	Dec. 08, 2016USD ($)	Dec. 08, 2016EUR (€)
Euro Senior Notes, Series A and B [Member]
Debt Instrument, Face Amount | €										€ 212
Euro Senior Notes, Series A [Member]
Debt Instrument, Face Amount									$ 117
Debt Instrument, Interest Rate, Stated Percentage									1.14%	1.14%
Euro Senior Notes, Series B [Member]
Debt Instrument, Face Amount | €										€ 95
Debt Instrument, Interest Rate, Stated Percentage									1.83%	1.83%
U.S. Senior Notes, Series A and B [Member]
Debt Instrument, Face Amount									$ 125
U.S. Senior Notes, Series A [Member]
Debt Instrument, Face Amount								$ 25
Debt Instrument, Interest Rate, Stated Percentage								3.03%
U.S. Senior Notes, Series B [Member]
Debt Instrument, Face Amount								$ 100
Debt Instrument, Interest Rate, Stated Percentage								3.74%
US Senior Notes A and B Due 2025 and 2030 [Member]
Debt Instrument, Face Amount						$ 175
US Senior Notes, Series A Due 2025 [Member]
Debt Instrument, Face Amount	$ 50
Debt Instrument, Interest Rate, Stated Percentage	3.48%
US Senior Notes, Series B Due 2030 [Member]
Debt Instrument, Face Amount	$ 125
Debt Instrument, Interest Rate, Stated Percentage	3.78%
Credit Agreement [Member]
Debt Instrument, Term			5 years
Debt Agreement, Maximum Borrowing Capacity			$ 700
Line of Credit Facility, Additional Uncommitted Borrowing Capacity		$ 300	150
Line of Credit Facility, Additional Uncommitted Borrowing Capacity, Minimum Increments			$ 25
Number of Advances		2
Debt Instrument, Interest Rate, Effective Percentage				3.59%
Letters of Credit Outstanding, Amount				$ 0.1
Credit Agreement [Member] | Minimum [Member]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage			0.15%
Credit Agreement [Member] | Maximum [Member]
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage			0.25%
Credit Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Debt Instrument, Basis Spread on Variable Rate			1.00%
Credit Agreement [Member] | London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member]
Debt Instrument, Basis Spread on Variable Rate			2.00%
Credit Agreement [Member] | Base Rate [Member] | Minimum [Member]
Debt Instrument, Basis Spread on Variable Rate			0.00%
Credit Agreement [Member] | Base Rate [Member] | Maximum [Member]
Debt Instrument, Basis Spread on Variable Rate			1.00%
Credit Agreement [Member] | Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity		$ 700	$ 575				$ 575
Line of Credit Facility, Remaining Borrowing Capacity				699.9
Credit Agreement [Member] | Term Loan Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity		200	$ 125				$ 125
Proceeds from Issuance of Long-term Debt, Total	$ 75	$ 125
Debt Instrument, Quarterly Payments, Percentage of Loan					1.25%
Debt Instrument, Periodic Payment, Total	$ 2.5
Repayments of Long-term Debt, Total				$ 35

Note 5 - Debt - Carrying Amount

Note 5 - Debt - Carrying Amounts of Long-term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Unamortized debt issuance costs	$ (5,184)	$ (4,881)
Total debt	697,598	495,611
Less: Current maturities	10,060	6,250
Total long-term debt	687,538	489,361
Line of Credit [Member]
Debt, carrying amount
Unsecured Debt [Member]
Debt, carrying amount	157,500	122,500
Euro Senior Notes, Series A [Member]
Debt, carrying amount	135,335	139,623
Euro Senior Notes, Series B [Member]
Debt, carrying amount	109,887	113,369
US Senior Notes, Series A Due 2022 [Member]
Debt, carrying amount	25,000	25,000
US Senior Notes, Series B Due 2027 [Member]
Debt, carrying amount	100,000	100,000
US Senior Notes, Series A Due 2025 [Member]
Debt, carrying amount	50,000
US Senior Notes, Series B Due 2030 [Member]
Debt, carrying amount	125,000
Notes Payable, Other Payables [Member]
Debt, carrying amount	$ 60

Note 6 - Fair Value of Assets44

Note 6 - Fair Value of Assets and Liabilities (Details Textual) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Assets, Fair Value Disclosure	$ 0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	$ 0	$ 0

Note 6 - Fair Value of Assets45

Note 6 - Fair Value of Assets and Liabilities - Assets Measured at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Investments in equity securities	$ 15,328	$ 10,993
Mutual funds	9,950	7,962
Fair Value, Inputs, Level 1 [Member]
Investments in equity securities	15,328	10,993
Mutual funds	9,950	7,962
Fair Value, Inputs, Level 2 [Member]
Investments in equity securities
Mutual funds
Fair Value, Inputs, Level 3 [Member]
Investments in equity securities
Mutual funds

Note 6 - Fair Value of Assets46

Note 6 - Fair Value of Assets and Liabilities - Carrying Value and Estimated Fair Value of Senior Notes (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 30, 2017
Euro Senior Notes, Series A [Member] | Reported Value Measurement [Member]
Senior Notes, Fair Value	$ 135,335	$ 139,623
Euro Senior Notes, Series A [Member] | Estimate of Fair Value Measurement [Member]
Senior Notes, Fair Value	134,332	138,294
Euro Senior Notes, Series B [Member] | Reported Value Measurement [Member]
Senior Notes, Fair Value	109,887	113,369
Euro Senior Notes, Series B [Member] | Estimate of Fair Value Measurement [Member]
Senior Notes, Fair Value	107,963	111,579
US Senior Notes, Series A Due 2022 [Member] | Reported Value Measurement [Member]
Senior Notes, Fair Value	25,000	25,000
US Senior Notes, Series A Due 2022 [Member] | Estimate of Fair Value Measurement [Member]
Senior Notes, Fair Value	24,154	24,737
US Senior Notes, Series B Due 2027 [Member] | Reported Value Measurement [Member]
Senior Notes, Fair Value	100,000	100,000
US Senior Notes, Series B Due 2027 [Member] | Estimate of Fair Value Measurement [Member]
Senior Notes, Fair Value	95,711	99,992
US Senior Notes, Series A Due 2025 [Member] | Reported Value Measurement [Member]
Senior Notes, Fair Value	50,000
US Senior Notes, Series A Due 2025 [Member] | Estimate of Fair Value Measurement [Member]
Senior Notes, Fair Value	47,769
US Senior Notes, Series B Due 2030 [Member] | Reported Value Measurement [Member]
Senior Notes, Fair Value	125,000
US Senior Notes, Series B Due 2030 [Member] | Estimate of Fair Value Measurement [Member]
Senior Notes, Fair Value	$ 117,300

Note 7 - Benefit Plans (Details

Note 7 - Benefit Plans (Details Textual) $ in Millions	Jun. 30, 2018USD ($)
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 2.3

Note 7 - Benefit Plans - Benefi

Note 7 - Benefit Plans - Benefit Plan Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Service cost	$ 533	$ 408	$ 1,066	$ 816
Interest cost	501	360	1,002	720
Expected return on plan assets	(540)	(476)	(1,080)	(952)
Amortization of prior service (credit)	74	84	148	168
Net periodic benefit cost	$ 568	$ 376	$ 1,136	$ 752

Note 8 - Shareholders' Equity49

Note 8 - Shareholders' Equity (Details Textual) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Dec. 30, 2017
Accumulated Other Comprehensive Income (Loss), Pension and Other Post-retirement Benefit Plans, Liability Adjustment Tax	$ 0.4	$ 1.4
Accounting Standards Update 2016-01 [Member]
Cumulative Effect on Retained Earnings, Net of Tax, Total	$ 9.8
IXYS Corporation [Member]
Stock Issued During Period, Shares, Acquisitions	2,092,491

Note 8 - Shareholders' Equity -

Note 8 - Shareholders' Equity - Changes in Shareholders' Equity (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Balance				$ 927,556
Net income		$ 42,326	$ 48,638	78,354	$ 87,530
Other comprehensive income (loss)				(16,221)
Stock-based compensation				15,883
Withheld shares on restricted share units for withholding taxes				(7,042)
Stock options exercised				17,654
Issuance of common stock(a)	[1]			472,301
Cash dividends paid ($0.37 per share)				(18,458)
Non-controlling interest				(7)
Balance		1,470,020		1,470,020
Parent [Member]
Balance				927,419
Net income				78,354
Other comprehensive income (loss)				(16,221)
Stock-based compensation				15,883
Withheld shares on restricted share units for withholding taxes				(7,042)
Stock options exercised				17,654
Issuance of common stock(a)	[1]			472,301
Cash dividends paid ($0.37 per share)				(18,458)
Non-controlling interest
Balance		1,469,890		1,469,890
Noncontrolling Interest [Member]
Balance				137
Net income
Other comprehensive income (loss)
Stock-based compensation
Withheld shares on restricted share units for withholding taxes
Stock options exercised
Issuance of common stock(a)	[1]
Cash dividends paid ($0.37 per share)
Non-controlling interest				(7)
Balance		$ 130		$ 130
[1]	The issuance of common stock (2,092,491 shares) during the six months ended June 30, 2018 relates to the acquisition of IXYS. See Note 2, Acquisitions for further discussion.

Note 8 - Shareholders' Equity51

Note 8 - Shareholders' Equity - Changes in Shareholders' Equity (Details) (Parentheticals)	6 Months Ended
	Jun. 30, 2018$ / shares
Cash dividends paid, per share (in dollars per share)	$ 0.37
Parent [Member]
Cash dividends paid, per share (in dollars per share)
Noncontrolling Interest [Member]
Cash dividends paid, per share (in dollars per share)

Note 8 - Shareholders' Equity52

Note 8 - Shareholders' Equity - Components of Accumulated Other Comprehensive Income (Loss) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2018USD ($)
Balance	$ 927,556
Activity in the period	(16,221)
Balance	1,470,020
Accumulated Defined Benefit Plans Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Balance	(10,836)	[1]
Cumulative effect adjustment (b)		[1],[2]
Activity in the period	763	[1]
Balance	(10,073)	[1]
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member]
Balance	9,795
Cumulative effect adjustment (b)	(9,795)	[1],[2]
Activity in the period
Balance
Accumulated Foreign Currency Adjustment Including Portion Attributable to Noncontrolling Interest [Member]
Balance	(62,627)
Cumulative effect adjustment (b)		[1],[2]
Activity in the period	(16,984)
Balance	(79,611)
AOCI Including Portion Attributable to Noncontrolling Interest [Member]
Balance	(63,668)
Cumulative effect adjustment (b)	(9,795)	[1],[2]
Activity in the period	(16,221)
Balance	$ (89,684)
[1]	The balances at June 30, 2018 and December 30, 2017 are net of taxes of $0.2 million and $1.4 million, respectively.
[2]	The Company adopted ASU 2016-01 on December 31, 2017 on a modified retrospective basis, recognizing the cumulative effect as a $9.8 million increase to retained earnings. See Note 1, Summary of Significant Accounting Policies and Other Information, for further discussion.

Note 9 - Income Taxes (Details

Note 9 - Income Taxes (Details Textual) - USD ($) $ in Millions	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2018	Dec. 30, 2017	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, Percent, Total	19.10%		15.20%	19.20%	16.50%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent							35.00%
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability		$ 47
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability, Toll Charge		49
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability, Other Than Toll Charge		$ (2)
Deferred Tax Liabilities, Undistributed Foreign Earnings								$ 12
Foreign Tax Authority [Member]
Deferred Tax Liabilities, Undistributed Foreign Earnings								11.8
Domestic Tax Authority [Member]
Deferred Tax Liabilities, Undistributed Foreign Earnings								$ 0.2
Other Long-term Liabilities [Member]
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability, Toll Charge, Noncurrent	$ 38.5
Accrued Income Taxes [Member]
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability, Toll Charge, Current	$ 3.4
IXYS Corporation [Member]
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability, Toll Charge				$ 10
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent						21.00%

Note 10 - Earnings Per Share (D

Note 10 - Earnings Per Share (Details Textual) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	47,849	46,100	23,659	21,896

Note 10 - Earnings Per Share -

Note 10 - Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Net income	$ 42,326	$ 48,638	$ 78,354	$ 87,530
Basic (in shares)	25,004	22,822	24,671	22,785
Effect of dilutive securities (in shares)	397	201	415	220
Diluted (in shares)	25,401	23,023	25,086	23,005
Earnings Per Share:
Basic earnings per share (in dollars per share)	$ 1.69	$ 2.13	$ 3.18	$ 3.84
Diluted earnings per share (in dollars per share)	$ 1.67	$ 2.11	$ 3.12	$ 3.80

Note 11 - Related Party Trans56

Note 11 - Related Party Transactions (Details Textual) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2018USD ($)
Powersem [Member]
Revenue from Related Parties	$ 0.3	$ 0.4
Related Party Transaction, Purchases from Related Party	1	2.1
Accounts Receivable, Related Parties	0.1	0.1
Accounts Payable, Related Parties	0.3	0.3
EB Tech [Member]
Related Party Transaction, Amounts of Transaction	0.1	0.2
ATEC [Member]
Accounts Payable, Related Parties	0.7	0.7
Related Party Transaction, Amounts of Transaction	$ 2.8	$ 5.2
Powersem [Member]
Equity Method Investment, Ownership Percentage	45.00%	45.00%
EB Tech [Member]
Equity Method Investment, Ownership Percentage	20.00%	20.00%
ATEC [Member]
Equity Method Investment, Ownership Percentage	24.00%	24.00%

Note 12 - Segment Information57

Note 12 - Segment Information (Details Textual) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)	Jul. 01, 2017USD ($)	Jun. 30, 2018USD ($)	Jul. 01, 2017USD ($)
Number of Operating Segments			3
Asset Impairment Charges, Total			$ 1,125
Other Segments [Member] | Operating Income (Loss) [Member]
Business Combination, Acquisition Related Costs	$ 24,400	$ 300	63,200	$ 1,800
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Inventory	19,000		36,900
Business Combination, Acquisition Related Costs and Integration Costs, Legal, Accounting and Other Expenses	2,300		14,100
Business Combination, Backlog Amortization Costs	3,100		5,600
Business Combination, Share-based Compensation			4,500
Business Combination, Other Expenses			2,100
Restructuring Charges, Total	3,200		3,900
Asset Impairment Charges, Total	$ 1,100
Other Asset Impairment Charges			$ 1,100

Note 12 - Segment Information -

Note 12 - Segment Information - Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Revenue		$ 459,183	$ 313,355	$ 876,996	$ 598,797
Depreciation and amortization		26,190	15,617	49,802	30,690
Operating income		59,622	60,270	97,193	109,123
Interest expense		5,782	3,281	11,205	6,401
Foreign exchange loss (gain)		3,200	(558)	(7,354)	(2,115)
Other expense (income), net		(1,678)	190	(3,621)	52
Income before income taxes		52,318	57,357	96,963	104,785
Electronics [Member]
Revenue		299,357	169,387	563,768	323,154
Depreciation and amortization		15,651	8,707	29,329	17,095
Operating income		67,311	42,967	121,275	78,173
Automotive [Member]
Revenue		127,172	116,457	253,302	224,297
Depreciation and amortization		5,969	5,580	11,939	10,950
Operating income		15,711	15,713	34,102	30,778
Industrial [Member]
Revenue		32,654	27,511	59,926	51,346
Depreciation and amortization		1,467	1,330	2,927	2,645
Operating income		5,279	1,905	9,988	2,012
Other Segments [Member]
Depreciation and amortization		3,103		5,607
Operating income	[1]	$ (28,679)	$ (315)	$ (68,172)	$ (1,840)
[1]	Included in "Other" Operating income (loss) for the 2018 second quarter is $24.4 million ($63.2 million year-to-date) of charges primarily related to IXYS acquisition and include $19.0 million ($36.9 million year-to-date) of purchase accounting inventory charges, $2.3 million ($14.1 million year-to-date) in acquisition-related and integration costs primarily related to legal, accounting and other expenses associated with the acquisition of IXYS, $3.1 million ($5.6 million year-to-date) in backlog amortization costs, stock compensation expense recognized immediately upon close for converted IXYS options related to prior services periods $4.5 million year-to-date and other charges of $2.1 million year-to-date. In addition, there were $3.2 million ($3.9 million year-to-date) of severance and other restructuring charges and $1.1 million of impairment charges ($1.1 million year-to-date) associated with the closure of the Radio Pulse and Custom businesses, respectively.

Note 12 - Segment Information59

Note 12 - Segment Information - Revenues and Long-lived Assets by Geographical Area (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017	Dec. 30, 2017
Net sales		$ 459,183	$ 313,355	$ 876,996	$ 598,797
Long-lived assets		338,755		338,755		$ 250,577
Additions to long-lived assets				40,315	28,878
UNITED STATES
Net sales		137,236	100,648	261,112	187,306
Long-lived assets		59,097		59,097		23,490
Additions to long-lived assets				4,234	1,149
CHINA
Net sales	[1]	127,776	86,891	234,284	165,111
Long-lived assets		92,832		92,832		86,866
Additions to long-lived assets	[2]			14,711	10,200
MEXICO
Long-lived assets		66,063		66,063		62,510
Additions to long-lived assets				8,874	10,925
GERMANY
Long-lived assets		35,013		35,013		1,082
Additions to long-lived assets				5,182
Other Countries [Member]
Net sales	[3]	194,171	$ 125,816	381,600	246,380
Long-lived assets		54,269		54,269		45,500
Additions to long-lived assets				3,073	5,259
PHILIPPINES
Long-lived assets		$ 31,481		31,481		$ 31,129
Additions to long-lived assets				$ 4,241	$ 1,345
[1]	Includes mainland China, Taiwan, and Hong Kong.
[2]	Includes mainland China, Taiwan, and Hong Kong.
[3]	Each country included in Other countries are less than 10% of net sales.