Teradyne (TER) 10-Q 3 Aug 20 2020 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 28, 2020	Jul. 24, 2020
Cover [Abstract]
Amendment Flag	false
Document Type	10-Q
Document Fiscal Year Focus	2020
Entity Central Index Key	0000097210
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Document Period End Date	Jun. 28, 2020
Entity Registrant Name	TERADYNE, INC
Entity Filer Category	Large Accelerated Filer
Trading Symbol	TER
Document Quarterly Report	true
Document Transition Report	false
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Title of 12(b) Security	Common Stock
Security Exchange Name	NASDAQ
Entity File Number	001-06462
Entity Incorporation, State or Country Code	MA
Entity Tax Identification Number	04-2272148
Entity Address, Address Line One	600 Riverpark Drive
Entity Address, City or Town	North Reading
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01864
City Area Code	978
Local Phone Number	370-2700
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		166,032,335

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 725,431	$ 773,924
Marketable securities	229,791	137,303
Accounts receivable, less allowance for doubtful accounts of $1,829 and $1,736 at June 28, 2020 and December 31, 2019, respectively	694,521	362,368
Inventories, net	206,088	196,691
Prepayments and other current assets	238,176	188,598
Total current assets	2,094,007	1,658,884
Property, plant and equipment, net	353,595	320,216
Operating lease right-of-use assets, net	56,172	57,539
Marketable securities	106,968	104,490
Deferred tax assets	79,210	75,185
Retirement plans assets	17,817	18,457
Other assets	11,854	10,332
Acquired intangible assets, net	107,563	125,480
Goodwill	422,003	416,431
Total assets	3,249,189	2,787,014
Current liabilities:
Accounts payable	184,163	126,617
Accrued employees' compensation and withholdings	175,589	163,883
Deferred revenue and customer advances	124,224	104,876
Other accrued liabilities	119,732	70,871
Operating lease liabilities	20,000	19,476
Contingent consideration	16,789	9,106
Income taxes payable	89,216	44,200
Total current liabilities	729,713	539,029
Retirement plans liabilities	130,826	134,471
Long-term deferred revenue and customer advances	55,634	45,974
Long-term contingent consideration	32,948	30,599
Long-term other accrued liabilities	22,703	19,535
Deferred tax liabilities	11,997	14,070
Long-term operating lease liabilities	43,582	45,849
Long-term income taxes payable	74,930	82,642
Debt	402,305	394,687
Total liabilities	1,504,638	1,306,856
Commitments and contingencies (See Note Q)
SHAREHOLDERS' EQUITY
Common stock, $0.125 par value, 1,000,000 shares authorized: 165,806 and 166,410 shares issued and outstanding at June 28, 2020 and December 31, 2019, respectively	20,725	20,801
Additional paid-in capital	1,730,716	1,720,129
Accumulated other comprehensive loss	(8,500)	(18,854)
Retained earnings (accumulated deficit)	1,610	(241,918)
Total shareholders' equity	1,744,551	1,480,158
Total liabilities and shareholders' equity	$ 3,249,189	$ 2,787,014

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Accounts receivable, less allowance for doubtful accounts	$ 1,829	$ 1,736
Common stock, par value	$ 0.125	$ 0.125
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	165,806	166,410
Common stock, shares outstanding	165,806	166,410

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 28, 2020		Jun. 30, 2019		Jun. 28, 2020		Jun. 30, 2019
Revenues:
Total revenues	$ 838,661	[1]	$ 564,178	[1]	$ 1,543,016	[2]	$ 1,058,277	[2]
Cost of revenues:
Total cost of revenues (exclusive of acquired intangible assets amortization shown separately below)	367,188		240,260		665,993		446,724
Gross profit	471,473		323,918		877,023		611,553
Operating expenses:
Selling and administrative	113,259		108,811		224,647		210,824
Engineering and development	94,102		81,434		179,261		158,225
Acquired intangible assets amortization	8,941		10,083		18,832		20,717
Restructuring and other	37,222		(10,404)		29,616		(5,292)
Total operating expenses	253,524		189,924		452,356		384,474
Income from operations	217,949		133,994		424,667		227,079
Non-operating (income) expense:
Interest income	(1,368)		(4,384)		(4,119)		(9,373)
Interest expense	6,043		5,800		11,594		11,320
Other (income) expense, net	(4,017)		1,401		2,833		(24)
Income before income taxes	217,291		131,177		414,359		225,156
Income tax provision	28,383		33,780		49,261		18,621
Net income	$ 188,908		$ 97,397		$ 365,098		$ 206,535
Net income per common share:
Basic	$ 1.14		$ 0.57		$ 2.20		$ 1.20
Diluted	$ 1.05		$ 0.55		$ 2.02		$ 1.16
Weighted average common shares—basic	165,789		171,241		166,189		172,387
Weighted average common shares—diluted	180,257		178,590		180,497		177,781
Cash dividend declared per common share	$ 0.10		$ 0.09		$ 0.20		$ 0.18
Product [Member]
Revenues:
Total revenues	$ 734,630		$ 457,511		$ 1,345,536		$ 850,953
Cost of revenues:
Total cost of revenues (exclusive of acquired intangible assets amortization shown separately below)	322,732		193,299		582,728		358,667
Service [Member]
Revenues:
Total revenues	104,031		106,667		197,480		207,324
Cost of revenues:
Total cost of revenues (exclusive of acquired intangible assets amortization shown separately below)	$ 44,456		$ 46,961		$ 83,265		$ 88,057
[1]	Includes $2.5 million and $1.7 million in 2020 and 2019, respectively, for leases of Teradyne’s systems recognized outside Accounting Standards Codification (“ASC”) 606 “Revenue from Contracts with Customers.”
[2]	Includes $4.3 million and $3.4 million in 2020 and 2019, respectively, for leases of Teradyne’s systems recognized outside ASC 606 “Revenue from Contracts with Customers.”

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Net income	$ 188,908	$ 97,397	$ 365,098	$ 206,535
Other comprehensive income, net of tax:
Foreign currency translation adjustment, net of tax of $0, $0, $0, $0, respectively	15,805	5,642	7,026	983
Available-for-sale marketable securities:
Unrealized gains on debt securities arising during period, net of tax of $1,084, $678, $1,271, $1,256, respectively	3,793	2,537	4,830	4,637
Less: Reclassification adjustment for gains included in net income, net of tax of $(277), $(6), $(421), $(26), respectively	(983)	(27)	(1,499)	(97)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Total	2,810	2,510	3,331	4,540
Defined benefit retirement plans:
Amortization of prior service credit, net of tax of $0, $(11), $(1), $(21), respectively	(2)	(37)	(3)	(74)
Other comprehensive income	18,613	8,115	10,354	5,449
Comprehensive income	$ 207,521	$ 105,512	$ 375,452	$ 211,984

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Foreign currency translation adjustments, tax	$ 0	$ 0	$ 0	$ 0
Unrealized gains (losses) on marketable securities arising during period, net of tax	1,084	678	1,271	1,256
Reclassification adjustment for (gains) losses included in net income, net of tax	(277)	(6)	(421)	(26)
Amortization of prior service credit, net of tax	$ 0	$ (11)	$ (1)	$ (21)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit
Balance at Dec. 31, 2018	$ 1,522,354	$ 21,940	$ 1,671,645	$ (13,040)	$ (158,191)
Balance, Shares at Dec. 31, 2018		175,522
Net issuance of common stock under stock-based plans	643	$ 174	469
Net issuance of common stock under stock-based plans (in shares)		1,385
Stock-based compensation expense	16,097		16,097
Repurchase of common stock	$ (240,624)	$ (809)			(239,815)
Repurchase of common stock (in shares)	6,500	(6,471)
Cash dividends	$ (31,042)				(31,042)
Net income	206,535				206,535
Other comprehensive income	5,449			5,449
Balance at Jun. 30, 2019	1,479,412	$ 21,305	1,688,211	(7,591)	(222,513)
Balance, Shares at Jun. 30, 2019		170,436
Balance at Mar. 31, 2019	1,470,228	$ 21,544	1,679,997	(15,706)	(215,607)
Balance, Shares at Mar. 31, 2019		172,353
Net issuance of common stock under stock-based plans	692	$ 13	679
Net issuance of common stock under stock-based plans (in shares)		99
Stock-based compensation expense	7,535		7,535
Repurchase of common stock	(89,154)	$ (252)			(88,902)
Repurchase of common stock (in shares)		(2,016)
Cash dividends	(15,401)				(15,401)
Net income	97,397				97,397
Other comprehensive income	8,115			8,115
Balance at Jun. 30, 2019	1,479,412	$ 21,305	1,688,211	(7,591)	(222,513)
Balance, Shares at Jun. 30, 2019		170,436
Balance at Dec. 31, 2019	1,480,158	$ 20,801	1,720,129	(18,854)	(241,918)
Balance, Shares at Dec. 31, 2019		166,410
Net issuance of common stock under stock-based plans	(10,382)	$ 114	(10,496)
Net issuance of common stock under stock-based plans (in shares)		913
Stock-based compensation expense	21,083		21,083
Repurchase of common stock	$ (88,465)	$ (190)			(88,275)
Repurchase of common stock (in shares)	1,500	(1,517)
Cash dividends	$ (33,295)				(33,295)
Net income	365,098				365,098
Other comprehensive income	10,354			10,354
Balance at Jun. 28, 2020	1,744,551	$ 20,725	1,730,716	(8,500)	1,610
Balance, Shares at Jun. 28, 2020		165,806
Balance at Mar. 29, 2020	1,550,673	$ 20,742	1,721,367	(27,113)	(164,323)
Balance, Shares at Mar. 29, 2020		165,938
Net issuance of common stock under stock-based plans	(446)	$ 5	(451)
Net issuance of common stock under stock-based plans (in shares)		41
Stock-based compensation expense	9,800		9,800
Repurchase of common stock	(6,401)	$ (22)			(6,379)
Repurchase of common stock (in shares)		(173)
Cash dividends	(16,596)				(16,596)
Net income	188,908				188,908
Other comprehensive income	18,613			18,613
Balance at Jun. 28, 2020	$ 1,744,551	$ 20,725	$ 1,730,716	$ (8,500)	$ 1,610
Balance, Shares at Jun. 28, 2020		165,806

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Common Stock, Dividends, Per Share, Cash Paid	$ 0.10	$ 0.09	$ 0.10	$ 0.09

CONDENSED CONSOLIDATED STATEM_6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net income	$ 365,098	$ 206,535
Adjustments to reconcile net income from operations to net cash provided by operating activities:
Depreciation	38,305	33,882
Amortization	26,234	24,976
Stock-based compensation	21,367	18,109
Contingent consideration adjustment	19,239	(8,701)
Provision for excess and obsolete inventory	9,637	5,799
Deferred taxes	(7,163)	515
Gains on investments	(469)	(3,741)
Retirement plan actuarial (gains) losses	(99)	448
Other	523	429
Changes in operating assets and liabilities, net of businesses acquired:
Accounts receivable	(331,040)	(79,478)
Inventories	(3,728)	(2,447)
Prepayments and other assets	(49,479)	(17,067)
Accounts payable and other liabilities	113,578	(14,424)
Deferred revenue and customer advances	28,655	15,826
Retirement plans contributions	(2,501)	(2,414)
Income taxes	37,842	(14,973)
Net cash provided by operating activities	265,999	163,274
Cash flows from investing activities:
Purchases of property, plant and equipment	(84,014)	(58,956)
Purchases of marketable securities	(299,548)	(484,181)
Proceeds from maturities of marketable securities	182,984	233,193
Proceeds from sales of marketable securities	26,661	42,454
Proceeds from life insurance	546	273
Acquisition of businesses, net of cash acquired	149	(21,970)
Net cash used for investing activities	(173,222)	(289,187)
Cash flows from financing activities:
Issuance of common stock under stock purchase and stock option plans	12,757	15,089
Repurchase of common stock	(88,465)	(247,222)
Dividend payments	(33,266)	(31,019)
Payments related to net settlement of employee stock compensation awards	(22,519)	(14,446)
Payments of contingent consideration	(8,852)	(27,615)
Net cash used for financing activities	(140,345)	(305,213)
Effects of exchange rate changes on cash and cash equivalents	(925)	(519)
Decrease in cash and cash equivalents	(48,493)	(431,645)
Cash and cash equivalents at beginning of period	773,924	926,752
Cash and cash equivalents at end of period	725,431	495,107
Non-cash investing activities:
Capital expenditures incurred but not yet paid	$ 6,281	$ 4,068

The Company

The Company	6 Months Ended
	Jun. 28, 2020
The Company	A. THE COMPANY Teradyne, Inc. (“Teradyne”) is a leading global supplier of automation equipment for test and industrial applications. Teradyne designs, develops, manufactures and sells automatic test systems used to test semiconductors, wireless products, data storage and complex electronics systems in the consumer electronics, wireless, automotive, industrial, computing, communications, and aerospace and defense industries. Teradyne’s industrial automation products include collaborative robotic arms, autonomous mobile robots, and advanced robotic control software used by global manufacturing and light industrial customers to improve quality, increase manufacturing and material handling efficiency and decrease manufacturing • semiconductor test (“Semiconductor Test”) systems; • defense/aerospace (“Defense/Aerospace”) test instrumentation and systems, storage and system level test (“Storage Test”) systems, and circuit-board test and inspection (“Production Board Test”) systems (collectively these products represent “System Test”); • industrial automation (“Industrial Automation”) products; and • wireless test (“Wireless Test”) systems.

Accounting Policies

Accounting Policies	6 Months Ended
	Jun. 28, 2020
Accounting Policies	B. ACCOUNTING POLICIES Basis of Presentation The consolidated interim financial statements include the accounts of Teradyne and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated. These interim financial statements are unaudited and reflect all normal recurring adjustments that are, in the opinion of management, necessary for the fair statement of such interim financial statements. Certain prior year amounts were reclassified to conform to the current year presentation. The December 31, 2019 condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by United States of America generally accepted accounting principles (“U.S. GAAP”) for complete financial statements. The accompanying financial information should be read in conjunction with the consolidated financial statements and notes thereto contained in Teradyne’s Annual Report on Form 10-K, filed with the U.S. Securities and Exchange Commission (“SEC”) on March 2, 2020, for the year ended December 31, 2019. Preparation of Financial Statements and Use of Estimates The preparation of consolidated financial statements requires management to make estimates and judgments that affect the amounts reported in the financial statements. Due to the COVID-19 10-Q. Goodwill On January 26, 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-04, “Intangibles—Goodwill and Other (Topic 350): Simplifying the Accounting for Goodwill Impairment.” 2017-04 2017-04, one-step Credit Losses In June 2016, the FASB issued ASU 2016-13, 2016-13

Acquisitions

Acquisitions	6 Months Ended
	Jun. 28, 2020
Acquisitions	C. ACQUISITIONS AutoGuide LLC On November 13, 2019, Teradyne acquired 100% of the membership interests of AutoGuide, LLC (“AutoGuide”), a maker of high-payload autonomous mobile robots (“AMRs”), based in Chelmsford, MA, an emerging and fast growing segment of the global forklift market. The total purchase price was approximately $81.6 million, which included cash paid of approximately $57.6 million and $24.0 million in fair value of contingent consideration payable upon achievement of certain performance targets, extending potentially through 2022. At June 28, 2020, the maximum contingent consideration that could be paid is $106.9 million. The contingent consideration is payable upon achievement of certain thresholds and targets for revenue and earnings before interest and taxes for periods from January 1, 2019 to December 31, 2020, January 1, 2019 to December 31, 2021, and January 1, 2019 to December 31, 2022. The valuation of the contingent consideration is dependent on the following assumptions: forecasted revenues, revenue volatility, earnings before interest and taxes, and discount rate. These assumptions were estimated based on a review of the historical and projected results. The AutoGuide acquisition was accounted for as a bu s kg in manufacturing, warehouse and logistics applications. These products complement Mobile Industrial Robots Aps (“MiR”) lower payload products and expand the Industrial Automation segment, which is a key component of Teradyne’s growth strategy. The allocation of the total purchase price to AutoGuide’s net tangible assets and identifiable intangible assets was based on their estimated fair values as of the acquisition date. The excess of the purchase price over the identifiable intangible assets and net tangible assets in the amount of $41.2 million was allocated to goodwill, which is deductible for tax purposes. AutoGuide’s results have been included in Teradyne’s Industrial Automation segment from the date of acquisition. The following table represents the final allocation of the purchase price: Purchase Price Allocation (in thousands) Goodwill $ 41,223 Intangible assets 37,660 Tangible assets acquired and liabilities assumed: Other current assets 3,661 Non-current 1,227 Accounts payable and current liabilities (1,223 ) Long-term other liabilities (949 ) Total purchase price $ 81,599 Teradyne estimated the fair value of intangible assets using the income approach. Forecasted revenues is the key assumption for estimating the fair value. Acquired intangible assets are amortized on a straight-line basis over their estimated useful lives. Components of these intangible assets and their estimated useful lives at the acquisition date are as follows: Fair Value Estimated Useful Life (in thousands) (in years) Developed technology $ 24,590 6.0 Trademarks and tradenames 7,360 6.0 Customer relationships 5,450 7.0 Backlog 260 0.3 Total intangible assets $ 37,660 6.1 The following unaudited pro forma information gives effect to the acquisition of AutoGuide as if the acquisition occurred on January 1, 2018. The unaudited pro forma results are not necessarily indicative of what actually would have occurred had the acquisition been in effect for the periods presented: For the Three Months For the Six Months June 30, 2019 June 30, 2019 (in thousands) Revenue $ 565,978 $ 1,061,577 Net income 95,948 203,237 Net income per common share: Basic $ 0.56 $ 1.18 Diluted $ 0.54 $ 1.14 Lemsys SA On January 30, 2019, Teradyne acquired all of the issued and outstanding shares of Lemsys SA (“Lemsys”) for a total purchase price of approximately $9.1 million. Lemsys strengthens Teradyne’s position in the electrification trends of vehicles, solar and wind power, and industrial applications. The Lemsys acquisition was accounted for as a business combination and, accordingly, the results have been included in Teradyne’s Semiconductor Test segment from the date of acquisition. Teradyne’s final allocation of the purchase price was goodwill of $1.4 million, which is not deductible for tax purposes, acquired intangible assets of $4.6 million with an average estimated useful life of 5.2 years, and $3.1 million of net tangible assets. The acquisition was not material to Teradyne’s consolidated financial statements.

Revenue

Revenue	6 Months Ended
	Jun. 28, 2020
Revenue from Contract with Customer [Abstract]
Revenue	D. REVENUE Disaggregation of Revenue The following table provides information about disaggregated revenue by timing of revenue recognition, primary geographical market, and major product lines. Semiconductor Test Industrial Automation System on Memory System Test Universal Mobile AutoGuide Wireless Test Corporate and Other Total (in thousands) For the Three Months Ended June 28, 2020 (1) Timing of Revenue Recognition Point in Time $ 520,496 $ 80,032 $ 57,741 $ 41,804 $ 11,196 $ 3,408 $ 46,347 $ (253 ) $ 760,771 Over Time 54,077 4,542 14,065 1,747 76 545 2,838 — 77,890 Total $ 574,573 $ 84,574 $ 71,806 $ 43,551 $ 11,272 $ 3,953 $ 49,185 $ (253 ) $ 838,661 Geographical Market Asia Pacific $ 547,700 $ 82,492 $ 38,656 $ 14,279 $ 1,232 $ — $ 41,907 $ — $ 726,266 Americas 16,251 855 28,494 11,364 2,390 3,953 5,353 (253 ) 68,407 Europe, Middle East and Africa 10,622 1,227 4,656 17,908 7,650 — 1,925 — 43,988 Total $ 574,573 $ 84,574 $ 71,806 $ 43,551 $ 11,272 $ 3,953 $ 49,185 $ (253 ) $ 838,661 For the Three Months Ended June 30, 2019 (1) Timing of Revenue Recognition Point in Time $ 265,130 $ 53,984 $ 60,137 $ 62,015 $ 10,505 $ — $ 39,236 $ (89 ) $ 490,918 Over Time 51,483 4,301 13,270 2,206 — — 2,000 — 73,260 Total $ 316,613 $ 58,285 $ 73,407 $ 64,221 $ 10,505 $ — $ 41,236 $ (89 ) $ 564,178 Geographical Market Asia Pacific $ 285,981 $ 47,202 $ 38,191 $ 18,820 $ 2,681 $ — $ 34,642 $ — $ 427,517 Americas 15,601 8,783 29,911 17,980 2,783 — 5,926 (89 ) 80,895 Europe, Middle East and Africa 15,031 2,300 5,305 27,421 5,041 — 668 — 55,766 Total $ 316,613 $ 58,285 $ 73,407 $ 64,221 $ 10,505 $ — $ 41,236 $ (89 ) $ 564,178 For the Six Months Ended June 28, 2020 (2) Timing of Revenue Recognition Point in Time $ 868,542 $ 159,429 $ 158,453 $ 89,306 $ 20,293 $ 4,532 $ 87,403 $ (253 ) $ 1,387,705 Over Time 106,171 9,494 29,429 3,942 117 891 5,267 — 155,311 Total $ 974,713 $ 168,923 $ 187,882 $ 93,248 $ 20,410 $ 5,423 $ 92,670 $ (253 ) $ 1,543,016 Geographical Market Asia Pacific $ 910,433 $ 158,601 $ 118,674 $ 25,195 $ 2,825 $ — $ 79,711 $ — $ 1,295,439 Americas 33,637 7,751 56,784 26,108 5,855 5,423 10,041 (253 ) 145,346 Europe, Middle East and Africa 30,643 2,571 12,424 41,945 11,730 — 2,918 — 102,231 Total $ 974,713 $ 168,923 $ 187,882 $ 93,248 $ 20,410 $ 5,423 $ 92,670 $ (253 ) $ 1,543,016 For the Six Months Ended June 30, 2019 (2) Timing of Revenue Recognition Point in Time $ 503,952 $ 97,693 $ 105,373 $ 117,392 $ 19,613 $ — $ 66,691 $ (240 ) $ 910,474 Over Time 105,534 8,572 26,254 3,857 — — 3,586 — 147,803 Total $ 609,486 $ 106,265 $ 131,627 $ 121,249 $ 19,613 $ — $ 70,277 $ (240 ) $ 1,058,277 Geographical Market Asia Pacific $ 546,374 $ 85,988 $ 62,478 $ 33,437 $ 4,408 $ — $ 60,661 $ — $ 793,346 Americas 31,768 17,546 56,718 33,783 6,322 — 8,167 (240 ) 154,064 Europe, Middle East and Africa 31,344 2,731 12,431 54,029 8,883 — 1,449 — 110,867 Total $ 609,486 $ 106,265 $ 131,627 $ 121,249 $ 19,613 $ — $ 70,277 $ (240 ) $ 1,058,277 (1) Includes $2.5 million and $1.7 million in 2020 and 2019, respectively, for leases of Teradyne’s systems recognized outside Accounting Standards Codification (“ASC”) 606 “ Revenue from Contracts with Customers.” (2) Includes $4.3 million and $3.4 million in 2020 and 2019, respectively, for leases of Teradyne’s systems recognized outside ASC 606 “ Revenue from Contracts with Customers.” Contract Balances During the three and six months ended June 28, 2020, Teradyne recognized $21.1 million and $60.6 million, respectively, that was previously included within the deferred revenue and customer advances balances. During the three and six months ended June 30, 2019, Teradyne recognized $13.3 million and $33.4 million, respectively, that was previously included within the deferred revenue and customer advances balances. This revenue primarily relates to undelivered hardware, extended warranties, training, application support, and post contract support. Each of these represents a distinct performance obligation. Teradyne expects to recognize 69% of the remaining performance obligation in the next 12 months, 26% in 1-3 Accounts Receivable Teradyne sells certain trade accounts receivables on a non-recourse and $40.4 million for the three months ended June 28, 2020 and June 30, 2019, respectively and $96.8 million

Inventories

Inventories	6 Months Ended
	Jun. 28, 2020
Inventories	E. INVENTORIES Inventories, net consisted of the following at June 28, 2020 and December 31, 2019: June 28, December 31, (in thousands) Raw material $ 106,610 $ 118,595 Work-in-process 29,710 32,695 Finished goods 69,768 45,401 $ 206,088 $ 196,691 Inventory reserves at June 28, 2020 and December 31, 2019 were $107.4 million and $103.6 million, respectively.

Financial Instruments

Financial Instruments	6 Months Ended
	Jun. 28, 2020
Financial Instruments	F. FINANCIAL INSTRUMENTS Cash Equivalents Teradyne considers all highly liquid investments with maturities of three months or less at the date of acquisition to be cash equivalents. Marketable Securities Teradyne’s available-for-sale During the three and six months ended June 28, 2020 and June 30, 2019, there were no transfers in or out of Level 1, Level 2, or Level 3 financial instruments. Realized gains recorded in the three and six months ended June 28, 2020 were $1.6 million and $3.0 million, respectively. Realized losses recorded in the three and six months ended June 28, 2020 were $0.1 million and $0.2 million , respe ctively Unrealized gains . Unrealized losses on equity securities recorded in the six months ended June 28, 2020 were , respectively available-for-sale The cost of securities sold is based on the specific identification method. The following table sets forth by fair value hierarchy Teradyne’s financial assets and liabilities that were measured at fair value on a recurring basis as of June 28, 2020 and December 31, 2019. June 28, 2020 Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total (in thousands) Assets Cash $ 345,312 $ — $ — $ 345,312 Cash equivalents 326,347 53,772 — 380,119 Available-for-sale — U.S. Treasury securities — 165,305 — 165,305 Commercial paper — 63,844 — 63,844 Corporate debt securities — 63,218 — 63,218 Certificates of deposit and time deposits — 9,506 — 9,506 Debt mutual funds 6,876 — — 6,876 U.S. government agency securities — 4,425 — 4,425 Non-U.S. — 601 — 601 Equity securities: Mutual funds 22,984 — — 22,984 $ 701,519 $ 360,671 $ — $ 1,062,190 Derivative assets — 30 — 30 Total $ 701,519 $ 360,701 $ — $ 1,062,220 Liabilities Contingent consideration $ — $ — $ 49,737 $ 49,737 Derivative liabilities — 222 — 222 Total $ — $ 222 $ 49,737 $ 49,959 Reported as follows: (Level 1) (Level 2) (Level 3) Total (in thousands) Assets Cash and cash equivalents $ 671,659 $ 53,772 $ — $ 725,431 Marketable securities — 229,791 — 229,791 Long-term marketable securities 29,860 77,108 — 106,968 Prepayments and other current assets — 30 — 30 Total $ 701,519 $ 360,701 $ — $ 1,062,220 Liabilities . Other current liabilities $ — $ 222 $ — $ 222 Contingent consideration — — 16,789 16,789 Long-term contingent consideration — — 32,948 32,948 Total $ — $ 222 $ 49,737 $ 49,959 December 31, 2019 Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total (in thousands) Assets Cash $ 311,975 $ — $ — 311,975 Cash equivalents 410,285 51,664 — 461,949 Available-for-sale — Corporate debt securities — 97,307 — 97,307 Commercial paper — 54,149 — 54,149 U.S. Treasury securities — 42,382 — 42,382 U.S. government agency securities — 9,952 — 9,952 Debt mutual funds 6,888 — — 6,888 Certificates of deposit and time deposits — 4,751 — 4,751 Non-U.S. — 592 — 592 Equity securities: Equity mutual funds 25,772 — — 25,772 $ 754,920 $ 260,797 $ — $ 1,015,717 Derivative assets — 528 — 528 Total $ 754,920 $ 261,325 $ — $ 1,016,245 Liabilities Contingent consideration $ — $ — $ 39,705 $ 39,705 Derivative liabilities — 203 — 203 Total $ — $ 203 $ 39,705 $ 39,908 Reported as follows: (Level 1) (Level 2) (Level 3) Total (in thousands) Assets Cash and cash equivalents $ 722,260 $ 51,664 $ — $ 773,924 Marketable securities — 137,303 — 137,303 Long-term marketable securities 32,660 71,830 — 104,490 Prepayments and other current assets — 528 — 528 Total $ 754,920 $ 261,325 $ — $ 1,016,245 Liabilities Other accrued liabilities $ — $ 203 $ — $ 203 Contingent consideration — — 9,106 9,106 Long-term contingent consideration — — 30,599 30,599 Total $ — $ 203 $ 39,705 $ 39,908 Changes in the fair value of Level 3 contingent consideration for the three and six months ended June 28, 2020 and June 30, 2019 were as follows: For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, 2020 2019 2020 2019 (in thousands) Balance at beginning of period $ 20,472 $ 38,313 $ 39,705 $ 70,543 Foreign currency impact 6 206 (355 ) (405 ) Payments (a)(b) — — (8,852 ) (34,590 ) Fair value adjustment (c)(d) 29,259 (11,672 ) 19,239 (8,701 ) Balance at end of period $ 49,737 $ 26,847 $ 49,737 $ 26,847 (a) In the six months ended June 28, 2020, Teradyne paid $8.9 million of contingent consideration for the earn-out of (b) In the six months ended June 30, 2019, Teradyne paid $30.8 million and $3.8 million of contingent consideration for the earn-outs in connection with the acquisition of MiR and Universal Robots A/S (“Universal Robots”), respectively. (c) In the three and six months ended June 28, 2020, the fair value of contingent consideration for the earn-outs in connection with the acquisition of MiR decreased by $0.6 million and $3.6 million, respectively, due to lower forecasted results. In the three and six months ended June 28, 2020, the fair value of contingent consideration for the earn-outs in connection with the acquisition of AutoGuide increased by $29.9 million and $22.8 million, respectively , due to higher f or e sults (d) In the three and six months ended June 30, 2019, the fair value of contingent consideration for the earn-out The following table provides quantitative information associated with the fair value measurement of Teradyne’s Level 3 financial instruments: Liability June 28, 2020 Fair Valuation Technique Unobservable Inputs Weighted Average (in thousands) Contingent consideration (AutoGuide) $ 49,737 Monte Carlo Simulation Revenue volatility 15.5 % Discount Rate 1.8 % Contingent consideration (MiR) $ — Monte Carlo Simulation Revenue volatility 10.0 % Discount Rate 0.8 % As of June 28, 2020, the significant unobservable inputs used in the Monte Carlo simulation to fair value the AutoGuide and MiR contingent consideration include forecasted revenues, revenue volatility, earnings before interest and taxes, and discount rate. Increases or decreases in the inputs would result in a higher or lower fair value measurement. As of June 28, 2020, the maximum amount of contingent consideration that could be paid in connection with the acquisition of AutoGuide is $106.9 million. The earn-out As of June 28, 2020, the maximum amount of contingent consideration that could be paid in connection with the acquisition of MiR is $63.5 million. The remaining earn-out The carrying amounts and fair values of Teradyne’s financial instruments at June 28, 2020 and December 31, 2019 were as follows: June 28, 2020 December 31, 2019 Carrying Value Fair Value Carrying Value Fair Value (in thousands) Assets Cash and cash equivalents $ 725,431 $ 725,431 $ 773,924 $ 773,924 Marketable securities 336,759 336,759 241,793 241,793 Derivative assets 30 30 528 528 Liabilities Contingent consideration 49,737 49,737 39,705 39,705 Derivative liabilities 222 222 203 203 Convertible debt (1) 402,305 1,198,669 394,687 1,010,275 (1) The carrying value represents the bifurcated debt component only, while the fair value is based on quoted market prices for the convertible note, which includes the equity conversion features. The fair values of accounts receivable, net and accounts payable approximate the carrying value due to the short-term nature of these instruments. The following table summarizes the composition of available-for-sale June 28, 2020 Available-for-Sale Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) U.S. Treasury securities $ 163,586 $ 1,734 $ (15 ) $ 165,305 $ 18,709 Commercial paper 63,774 70 — 63,844 — Corporate debt securities 56,672 6,682 (136 ) 63,218 1,447 Certificates of deposit and time deposits 9,498 8 — 9,506 — Debt mutual funds 6,686 190 — 6,876 — U.S. government agency securities 4,353 72 — 4,425 — Non-U.S. 601 — — 601 — $ 305,170 $ 8,756 $ (151 ) $ 313,775 $ 20,156 Reported as follows: Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Marketable securities $ 229,471 $ 331 $ (11 ) $ 229,791 $ 17,366 Long-term marketable securities 75,699 8,425 (140 ) 83,984 2,790 $ 305,170 $ 8,756 $ (151 ) $ 313,775 $ 20,156 The following table summarizes the composition of available-for-sale December 31, 2019 Available-for-Sale Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Corporate debt securities $ 93,267 $ 4,081 $ (41 ) $ 97,307 $ 2,009 Commercial paper 54,124 26 (1 ) 54,149 1,391 U.S. Treasury securities 42,167 431 (216 ) 42,382 17,556 U.S. government agency securities 9,942 14 (4 ) 9,952 3,043 Debt mutual funds 6,753 135 — 6,888 — Certificates of deposit and time deposits 4,751 — — 4,751 — Non-U.S. 592 — — 592 — $ 211,596 $ 4,687 $ (262 ) $ 216,021 $ 23,999 Reported as follows: Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Marketable securities $ 137,144 $ 160 $ (1 ) $ 137,303 $ 2,922 Long-term marketable securities 74,452 4,527 (261 ) 78,718 21,077 $ 211,596 $ 4,687 $ (262 ) $ 216,021 $ 23,999 As of June 28, 2020 and December 31, 2019, the fair market value of investments with unrealized losses less than one year totaled $20.2 million and $23.6 million, respectively. Teradyne reviews its investments to identify and evaluate investments that have an indication of possible impairment. Based on this review, Teradyne determined that the unrealized losses related to these investments at June 28, 2020 and December 31, 2019 were not other than temporary. The contractual maturities of investments in available-for-sale June 28, 2020 Cost Fair Market Value (in thousands) Due within one year $ 229,471 $ 229,791 Due after 1 year through 5 years 21,054 21,587 Due after 5 years through 10 years 13,762 14,974 Due after 10 years 34,197 40,547 Total $ 298,484 $ 306,899 Contractual maturities of investments in available-for-sale d with a fair market value of $6.9 mi ll Derivatives Teradyne conducts business in a number of foreign countries, with certain transactions denominated in local currencies. The purpose of Teradyne’s foreign currency management is to minimize the effect of exchange rate fluctuations on certain foreign currency denominated monetary assets and liabilities. Teradyne does not use derivative financial instruments for trading or speculative purposes. To minimize the effect of exchange rate fluctuations associated with the remeasurement of monetary assets and liabilities denominated in foreign currencies, Teradyne enters into foreign currency forward contracts. The change in fair value of these derivatives is recorded directly in earnings, and is used to offset the change in value of monetary assets and liabilities denominated in foreign currencies. The notional amount of foreign currency forward contracts at June 28, 2020 and December 31, 2019 was $125.0 million and $144.9 million, respectively. Gains and losses on foreign currency forward contracts and foreign currency remeasurement gains and losses on monetary assets and liabilities are included in other (income) expense, net. The following table summarizes the fair value of derivative instruments as of June 28, 2020 and December 31, 2019: Balance Sheet Location June 28, December 31, (in thousands) Derivatives not designated as hedging instruments: Foreign exchange contracts Prepayments $ 30 $ 528 Foreign exchange contracts Other current liabilities (222 ) (203 ) Total derivatives $ (192 ) $ 325 The following table summarizes the effect of derivative instruments recognized in the statement of operations for the three and six months ended June 28, 2020 and June 30, 2019: Location of (Gains) Losses For the Three Months Ended For the Six Months Ended Recognized in June 28, June 30, June 28, June 30, Statement of Operations 2020 2019 2020 2019 (in thousands) Derivatives not designated as hedging instruments: Foreign exchange contracts Other (income) expense, net $470 $239 $4,481 $4,173 (1) The table does not reflect the corresponding gains and losses from the remeasurement of the monetary assets and liabilities denominated in foreign currencies. (2) For the three months ended June 28, 2020, net losses from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $0.4 million. For the six months ended June 28, 2020, net gains from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $1.6 million. (3) For the three months ended June 30, 2019, net losses from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $1.3 million. For the six months ended June 30, 2019, net gains from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $1.9 million. See Note G: “Debt” regarding derivatives related to the convertible senior notes.

Debt

Debt	6 Months Ended
	Jun. 28, 2020
Debt	G. DEBT Convertible Senior Notes On December 12, 2016, Teradyne completed a private offering of $460.0 million aggregate principal amount of 1.25% convertible senior unsecured notes (the “Notes”) due December 15, 2023 and received net proceeds, after issuance costs, of approximately $450.8 million, $33.0 million of which was used to pay the net cost of the convertible note hedge transactions and $50.1 million of which was used to repurchase 2.0 million shares of Teradyne’s common stock under its existing stock repurchase program from purchasers of the Notes in privately negotiated transactions effected through one of the initial purchasers or its affiliates conducted concurrently with the pricing of the Note offering. The Notes will mature on December 15, 2023, unless earlier repurchased or converted. The Notes bear interest from December 12, 2016 at a rate of 1.25% per year payable semiannually in arrears on June 15 and December 15 of each year. The Notes will be convertible at the option of the noteholders at any time prior to the close of business on the business day immediately preceding September 15, 2023, only under the following circumstances: (1) during any calendar quarter beginning after March 31, 2017 (and only during such calendar quarter), if the closing sale price of Teradyne’s common stock, for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than 130% of the conversion price on each applicable trading day; (2) during the five business day period after any five consecutive trading day period (the “measurement period”) in which the trading price (as defined in the Indenture) per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the closing sale price of the Teradyne’s common stock and the conversion rate on each such trading day; and (3) upon the occurrence of specified corporate events. On or after September 15, 2023 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert their Notes at any time, regardless of the foregoing circumstances. Teradyne may satisfy its conversion obligation by paying or delivering cash, shares of its common stock or a combination of cash and shares of its common stock, at Teradyne’s election. As of June 28, 2020, the conversion price was approximately $31.59 per share of Teradyne’s common stock. The conversion rate is subject to adjustment under certain circumstances. As of August 3, 2020, nine holders exercised the option to convert eighteen thousand dollars’ worth of Notes. Concurrent with the offering of the Notes, Teradyne entered into convertible note hedge transactions (the “Note Hedge Transactions”) with the initial purchasers or their affiliates (the “Option Counterparties”). The Note Hedge Transactions cover, subject to customary anti-dilution adjustments, the number of shares of the common stock that underlie the Notes, with a strike price equal to the conversion price of the Notes of $31.59. The Note Hedge Transactions cover, subject to customary anti-dilution adjustments, approximately 14.6 million shares of Teradyne’s common stock. Separately and concurrent with the pricing of the Notes, Teradyne entered into warrant transactions with the Option Counterparties (the “Warrant Transactions”) in which it sold net-share-settled The Note Hedge Transactions are expected to reduce the potential dilution to Teradyne’s common stock upon any conversion of the Notes. However, the Warrant Transactions could separately have a dilutive effect to the extent that the market value per share of Teradyne’s common stock exceeds the applicable strike price of the warrant. The net cost of the Note Hedge Transactions, after being partially offset by the proceeds from the sale of the warrants, was approximately $33.0 million. In connection with establishing their initial hedge of these convertible note hedge and warrant transactions, the Option Counterparties have entered into various derivative transactions with respect to Teradyne’s common stock and/or purchased shares of Teradyne’s common stock or other securities, including the Notes, concurrent with, or shortly after, the pricing of the Notes. In addition, the Option Counterparties may modify their hedge positions by entering into or unwinding various derivative transactions with respect to Teradyne’s common stock or by selling Teradyne’s common stock or other securities, including the Notes, in secondary market transactions (and may do so during any observation period related to the conversion of the Notes). These activities could adversely affect the value of Teradyne’s common stock and the Notes. Teradyne considered the guidance of ASC 815-40, “Derivatives and Hedging—Contracts in Entity’s Own Equity,” fixed-for-fixed Teradyne assessed whether the convertible note hedge should be classified as equity under ASC 815-40. 815-40 Teradyne analyzed the Warrant Transactions under ASC 815-40, “Derivatives and Hedging—Contracts in Entity’s Own Equity,” paid-in The provisions of ASC 470-20, Debt with Conversion and Other Options, 470-20 seven-year The below tables represent the key components of Teradyne’s convertible senior notes: June 28, 2020 December 31, (in thousands) Debt Principal $ 459,987 $ 460,000 Unamortized discount 57,682 65,313 Net Carrying amount of convertible debt $ 402,305 $ 394,687 For the Three Months For the Six Months June 28, 2020 June 30, June 28, 2020 June 30, (in thousands) Contractual interest expense on the coupon $ 1,438 $ 1,438 $ 2,875 $ 2,875 Amortization of the discount component and debt issue fees recognized as interest expense 3,839 3,653 7,631 7,262 Total interest expense on the convertible debt $ 5,277 $ 5,091 $ 10,506 $ 10,137 As of June 28, 2020, the remaining unamortized discount was $57.7 million, which will be amortized over 3.5 years using the effective interest rate method. The carrying amount of the equity component was $100.8 million. As of June 28, 2020, the if-converted Revolving Credit Facility On May 1, 2020, Teradyne entered into a credit agreement (the “Credit Agreement”) with Truist Bank, as administrative agent and collateral agent, and the lenders party thereto. The Credit Agreement provides for a three-year Proceeds from the Credit Facility may be used for general corporate purposes and working capital. During the three months ended June 28, 2020, Teradyne incurred $3.5 million in costs related to the revolving credit facility. These costs are being amortized over the three-year As of August 3, 2020, Teradyne has not borrowed any funds under the Credit Facility. The interest rates applicable to loans under the Credit Facility are, at Teradyne’s option, equal to either a base rate plus a margin ranging from 0.50% to 1.25% per annum or LIBOR, a minimum of 0.75%, plus a margin ranging from 1.50% to 2.25% per annum, based on the consolidated leverage ratio of Teradyne. In addition, Teradyne will pay a commitment fee on the unused portion of the commitments under the Credit Facility ranging from 0.25% to 0.40% per annum, based on the then applicable consolidated leverage ratio. Teradyne is not required to repay any loans under the Credit Facility prior to maturity, subject to certain customary exceptions. Teradyne is permitted to prepay all or any portion of the loans under the Credit Facility prior to maturity without premium or penalty, other than customary LIBOR breakage costs. The Credit Agreement contains customary events of default, representations, warranties and affirmative and negative covenants that, among other things, limit Teradyne’s ability to sell assets, grant liens on assets, incur other secured indebtedness and make certain investments and restricted payments, all subject to exceptions set forth in the Credit Agreement. The Credit Agreement also requires Teradyne to satisfy two financial ratios measured as of the end of each fiscal quarter: a consolidated leverage ratio and an interest coverage ratio. The Credit Facility is guaranteed by certain of Teradyne’s domestic subsidiaries and collateralized by assets of Teradyne and such subsidiaries, including a pledge of 65% of the capital stock of certain foreign subsidiaries. As of August 3, 2020, Teradyne was in compliance with all covenants

Prepayments

Prepayments	6 Months Ended
	Jun. 28, 2020
Prepayments [Abstract]
Prepayments	H. PREPAYMENTS Prepayments consist of the following and are included in prepayments and other assets on the balance sheet: June 28, December 31, (in thousands) Contract manufacturer and supplier prepayments $ 191,029 $ 143,392 Prepaid maintenance and other services 10,316 8,046 Prepaid taxes 6,665 8,503 Other prepayments 14,171 16,753 Total prepayments $ 222,181 $ 176,694

Deferred Revenue and Customer A

Deferred Revenue and Customer Advances	6 Months Ended
	Jun. 28, 2020
Deferred Revenue and Customer Advances	I. DEFERRED REVENUE AND CUSTOMER ADVANCES Deferred revenue and customer advances consist of the following and are included in short and long-term deferred revenue and customer advances on the balance sheet: June 28, December 31, (in thousands) Maintenance, service and training $ 75,144 $ 63,815 Extended warranty 40,178 30,677 Customer advances, undelivered elements and other 64,536 56,358 Total deferred revenue and customer advances $ 179,858 $ 150,850

Product Warranty

Product Warranty	6 Months Ended
	Jun. 28, 2020
Product Warranty	J. PRODUCT WARRANTY Teradyne generally provides a one-year For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, (in thousands) Balance at beginning of period $ 10,971 $ 7,752 $ 8,996 $ 7,909 Accruals for warranties issued during the period 6,200 2,295 11,267 5,360 Accruals related to pre-existing 356 694 1,412 2,024 Settlements made during the period (4,511 ) (2,608 ) (8,659 ) (7,174 ) Acquisition — — — 14 Balance at end of period $ 13,016 $ 8,133 $ 13,016 $ 8,133 When Teradyne receives revenue for extended warranties, beyond one year, it is deferred and recognized on a straight-line basis over the contract period. Related costs are expensed as incurred. The balance below is included in short and long-term deferred revenue and customer advances. For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, (in thousands) Balance at beginning of period $ 33,503 $ 27,242 $ 30,677 $ 27,422 Deferral of new extended warranty revenue 11,450 5,476 19,050 11,296 Recognition of extended warranty deferred revenue (4,775 ) (4,002 ) (9,549 ) (10,002 ) Balance at end of period $ 40,178 $ 28,716 $ 40,178 $ 28,716

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 28, 2020
Stock-Based Compensation	K. STOCK-BASED COMPENSATION Under Teradyne’s stock compensation plans, Teradyne grants service-based restricted stock units, performance-based restricted stock units and stock options, and employees are eligible to purchase Teradyne’s common stock through its Employee Stock Purchase Plan (“ESPP”). Service-based restricted stock unit awards granted to employees vest in equal annual installments over four years. Restricted stock unit awards granted to non-employee one-year Performance-based restricted stock units (“PRSUs”) granted to Teradyne’s executive officers may have a performance metric based on relative total shareholder return (“TSR”). Teradyne’s three-year three-year PRSUs granted to Teradyne’s executive officers may also have a performance metric based on three-year cumulative non-GAAP Non-GAAP non-cash non-recurring If a PRSU recipient’s employment ends prior to the determination of the performance percentage due to (1) permanent disability or death or (2) retirement or termination other than for cause, after attaining both at least age sixty Stock options to purchase Teradyne’s common stock at 100% of the fair market value on the grant date vest in equal annual installments over four years from the grant date and have a maximum term of seven years. During the six months ended June 28, 2020 and June 30, 2019, Teradyne granted 0.4 million and 0.8 million of service-based restricted stock unit awards to employees at a weighted average grant date fair value of $70.52 and $36.84, respectively , non-employee During the six months ended June 28, 2020 and June 30, 2019, Teradyne granted 0.1 million of PBIT PRSUs with a grant date fair value of $70.94 and $36.88, respectively. During the six months ended June 28, 2020 and June 30, 2019, Teradyne granted 0.1 million of TSR PRSUs, with a grant date fair value of $89.93 and $51.51, respectively. The fair value was estimated using the Monte Carlo simulation model with the following assumptions: For the Six Months Ended June 28, June 30, Risk-free interest rate 1.5 % 2.6 % Teradyne volatility-historical 34.9 % 31.9 % NYSE Composite Index volatility-historical 11.4 % 11.9 % Dividend yield 0.6 % 1.0 % Expected volatility was based on the historical volatility of Teradyne’s stock and the NYSE Composite Index over the most recent three-year period. The risk-free interest rate was determined using the U.S. Treasury yield curve in effect at the time of grant. Dividend yield was based upon an estimated annual dividend amount of $0.40 per share divided by Teradyne’s stock price on the grant date of $72.10 for the 2020 grant and an estimated annual dividend amount of $0.36 per share divided by Teradyne’s stock price on the grant date of $36.75 for the 2019 grant. During the six months ended June 28, 2020 and June 30, 2019, Teradyne granted 0.1 million of service-based stock options to executive officers at a weighted average grant date fair value of $20.67 and $10.61, respectively. The fair value of stock options was estimated using the Black-Scholes option-pricing model with the following assumptions: For the Six Months Ended June 28, June 30, Expected life (years) 5.0 5.0 Risk-free interest rate 1.6 % 2.5 % Volatility-historical 31.6 % 30.1 % Dividend yield 0.6 % 1.0 % Teradyne determined the stock options’ expected life based upon historical exercise data for executive officers, the age of the executive officers and the terms of the stock option grant. Volatility was determined using historical volatility for a period equal to the expected life. The risk-free interest rate was determined using the U.S. Treasury yield curve in effect at the time of grant. Dividend yield was based upon an estimated annual dividend amount of $0.40 per share divided by Teradyne’s stock price on the grant date of $72.10 for the 2020 grant and an estimated annual dividend amount of $0.36 per share divided by Teradyne’s stock price on the grant date of $37.95 for the 2019 grant.

Accumulated Other Comprehensive

Accumulated Other Comprehensive (Loss) Income	6 Months Ended
	Jun. 28, 2020
Accumulated Other Comprehensive Income (Loss)	L. ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME Changes in accumulated other comprehensive (loss) income, which are presented net of tax, consist of the following: Foreign Currency Translation Adjustment Unrealized Gains (Losses) on Marketable Securities Retirement Plans Prior Service Credit Total (in thousands) Six Months Ended June 28, 2020 Balance at December 31, 2019, net of tax of $0, $946, $(1,124), respectively $ (23,514 ) $ 3,480 $ 1,180 $ (18,854 ) Other comprehensive income before reclassifications, net of tax of $0, $1,271, $0, respectively 7,026 4,830 — 11,856 Amounts reclassified from accumulated other comprehensive income, net of tax of $0, $(421), $(1), respectively — (1,499 ) (3 ) (1,502 ) Net current period other comprehensive income (loss), net of tax of $0, $850, $(1), respectively 7,026 3,331 (3 ) 10,354 Balance at June 28, 2020, net of tax of $0, $1,796, $(1,125), respectively $ (16,488 ) $ 6,811 $ 1,177 $ (8,500 ) Six Months Ended June 30, 2019 Balance at December 31, 2018, net of tax of $0, $(521), $(1,081), respectively $ (12,523 ) $ (1,845 ) $ 1,328 $ (13,040 ) Other comprehensive income before reclassifications, net of tax of $0, $1,256, $0, respectively 983 4,637 — 5,620 Amounts reclassified from accumulated other comprehensive income, net of tax of $0, $(26), $(21), respectively — (97 ) (74 ) (171 ) Net current period other comprehensive income (loss), net of tax of $0, $1,230, $(21), respectively 983 4,540 (74 ) 5,449 Balance as June 30, 2019, net of tax of $0, $709, $(1,102), respectively $ (11,540 ) $ 2,695 $ 1,254 $ (7,591 ) Reclassifications out of accumulated other comprehensive (loss) income to the statement of operations for the three and six months ended June 28, 2020 and June 30, 2019 were as follows: Details about Accumulated Other Comprehensive Income Components For the Three Months Ended For the Six Months Ended Affected Line Item in the Statements of Operations June 28, June 30, June 28, June 30, (in thousands) Available-for-sale Unrealized gains, net of tax of $277, $6, $421, $26, respectively $ 983 $ 27 $ 1,499 $ 97 Interest income Defined benefit retirement Amortization of prior service credit 2 37 3 74 (a) Total reclassifications, net of tax of $277, $17, $422, $47, respectively $ 985 $ 64 $ 1,502 $ 171 Net income (a) The amortization of prior service benefit is included in the computation of net periodic pension cost and postretirement benefit. See Note P: “Retirement Plans.”

Goodwill and Acquired Intangibl

Goodwill and Acquired Intangible Assets	6 Months Ended
	Jun. 28, 2020
Goodwill and Intangible Assets	M. GOODWILL AND ACQUIRED INTANGIBLE ASSETS Goodwill Teradyne performs its annual goodwill impairment test as required under the provisions of ASC 350-10, “Intangibles—Goodwill and Other” reporting The changes in the carrying amount of goodwill by reportable segments for the six months ended June 28, 2020, were as follows: Industrial Automation System Test Wireless Test Semiconductor Test Total (in thousands) Balance at December 31, 2019 Goodwill $ 396,483 $ 158,699 $ 361,819 $ 261,996 $ 1,178,997 Accumulated impairment losses — (148,183 ) (353,843 ) (260,540 ) (762,566 ) 396,483 10,516 7,976 1,456 416,431 AutoGuide acquisition (149 ) — — — (149 ) Foreign currency translation adjustment 5,671 — — 50 5,721 Balance at June 28, 2020 Goodwill 402,005 158,699 361,819 262,046 1,184,569 Accumulated impairment losses — (148,183 ) (353,843 ) (260,540 ) (762,566 ) $ 402,005 $ 10,516 $ 7,976 $ 1,506 $ 422,003 Intangible Assets Teradyne reviews long-lived assets for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable or that the useful lives of these assets are no longer appropriate. Amortizable intangible assets consist of the following and are included in intangible assets, net on the balance sheet: Gross Carrying Amount Accumulated Amortization Foreign Net Carrying Amount (in thousands) Balance at June 28, 2020 Developed technology $ 361,787 $ (292,394 ) $ (5,095 ) $ 64,298 Customer relationships 75,669 (61,730 ) (295 ) 13,644 Tradenames and trademarks 70,120 (39,457 ) (1,042 ) 29,621 Total intangible assets $ 507,576 $ (393,581 ) $ (6,432 ) $ 107,563 Balance at December 31, 2019 Developed technology $ 361,787 $ (279,000 ) $ (5,709 ) $ 77,078 Customer relationships 75,669 (59,077 ) (455 ) 16,137 Tradenames and trademarks 70,120 (36,671 ) (1,184 ) 32,265 Backlog 260 (260 ) — — Total intangible assets $ 507,836 $ (375,008 ) $ (7,348 ) $ 125,480 Aggregate intangible asset amortization expense was $8.9 million and $18.8 million, respectively, for the three and six months ended June 28, 2020 and $10.1 million and $20.7 million, respectively, for the three and six months ended June 30, 2019. Estimated intangible asset amortization expense for each of the five succeeding fiscal years is as follows: Year Amortization Expense (in thousands) 2020 (remainder) 11,721 2021 20,804 2022 19,911 2023 19,430 2024 19,123 Thereafter 16,574

Net Income Per Common Share

Net Income Per Common Share	6 Months Ended
	Jun. 28, 2020
Net Income per Common Share	N. NET INCOME PER COMMON SHARE The following table sets forth the computation of basic and diluted net income per common share: For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, 2020 2019 2020 2019 (in thousands, except per share amounts) Net income for basic and diluted net income per share $ 188,908 $ 97,397 $ 365,098 $ 206,535 Weighted average common shares-basic 165,789 171,241 166,189 172,387 Effect of dilutive potential common shares: Incremental shares from assumed conversion of convertible notes (1) 7,599 4,364 7,466 3,275 Convertible note hedge warrant shares (2) 5,824 1,778 5,658 889 Restricted stock units 913 1,002 1,038 1,012 Stock options 132 183 133 202 Employee stock purchase plan — 22 13 16 Dilutive potential common shares 14,468 7,349 14,308 5,394 Weighted average common shares-diluted 180,257 178,590 180,497 177,781 Net income per common share-basic $ 1.14 $ 0.57 $ 2.20 $ 1.20 Net income per common share-diluted $ 1.05 $ 0.55 $ 2.02 $ 1.16 (1) Incremental shares from assumed conversion of the convertible notes was calculated using the difference between the average Teradyne stock price for the period and the conversion price of $31.59, multiplied by 14.6 million shares. The result of this calculation, representing the total intrinsic value of the convertible debt, was divided by the average Teradyne stock price for the period. (2) Convertible notes hedge warrant shares were calculated using the difference between the average Teradyne stock price for the period and the warrant price of $39.64, multiplied by 14.6 million shares. The result of this calculation, representing the total intrinsic value of the warrant, was divided by the average Teradyne stock price for the period. The computation of diluted net income per common share for the three and six months ended June 28, 2020 excludes the effect of the potential vesting of 0.1 million and 0.2 million, respectively , The computation of diluted net income per common share for the three and six months ended June 30, 2019 excludes the effect of the potential vesting of 0.2 million and 0.4 million of stock options, respectively ,

Restructuring and Other

Restructuring and Other	6 Months Ended
	Jun. 28, 2020
Restructuring and Related Activities [Abstract]
Restructuring and Other	O. RESTRUCTURING AND OTHER During the three months ended June 28, 2020, Teradyne recorded a $29.9 million charge for the increase in the fair value of the AutoGuide contingent consideration liability, a charge gain During the three months ended June 30, 2019, Teradyne recorded a $11.7 million gain During the six months ended June 28, 2020, Teradyne recorded a $22.8 million charge for the increase in the fair value of the AutoGuide contingent consideration liabilities, $4.5 million of acquisition related compensation and expenses, a charge a gain During the six months ended June 30, 2019, Teradyne recorded a $8.7 million gain ,

Retirement Plans

Retirement Plans	6 Months Ended
	Jun. 28, 2020
Retirement Plans	P. RETIREMENT PLANS ASC 715, “Compensation—Retirement Benefits” Defined Benefit Pension Plans Teradyne has defined benefit pension plans covering a portion of domestic employees and employees of certain non-U.S. In the six months ended June 28, 2020, Teradyne contributed $1.4 million to the U.S. supplemental executive defined benefit pension plan and $0.4 million to certain qualified pension plans for non-U.S. For the three and six months ended June , and June , , Teradyne’s net periodic pension cost was comprised of the following: For the Three Months Ended June 28, 2020 June 30, 2019 United States Foreign United States Foreign (in thousands) Service cost $ 433 $ 208 $ 399 $ 192 Interest cost 1,523 119 1,799 176 Expected return on plan assets (1,232 ) (15 ) (1,510 ) (7 ) Net actuarial loss 180 — 252 — Total net periodic pension cost $ 904 $ 312 $ 940 $ 361 For the Six Months Ended June 28, 2020 June 30, 2019 United States Foreign United States Foreign (in thousands) Service cost $ 866 $ 417 $ 804 $ 381 Interest cost 3,045 238 3,595 349 Expected return on plan assets (2,464 ) (31 ) (3,021 ) (14 ) Net actuarial loss 180 — 252 — Total net periodic pension cost $ 1,627 $ 624 $ 1,630 $ 716 Postretirement Benefit Plan In addition to receiving pension benefits, Teradyne employees in the United States who meet early retirement eligibility requirements as of their termination dates may participate in Teradyne’s Welfare Plan, which includes medical and dental benefits up to age 65. Death benefits provide a fixed sum to retirees’ survivors and are available to all retirees. Substantially all of Teradyne’s current U.S. employees could become eligible for these benefits, and the existing benefit obligation relates primarily to those employees. For the three and six months ended June 28, 2020 and June 30, 2019, Teradyne’s net periodic postretirement benefit cost was comprised of the following: For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, (in thousands) Service cost $ 17 $ 11 $ 28 $ 20 Interest cost 58 88 120 173 Amortization of prior service credit (2 ) (48 ) (4 ) (95 ) Net actuarial (gain) loss (279 ) 196 (279 ) 196 Total net periodic postretirement benefit (credit) cost $ (206 ) $ 247 $ (135 ) $ 294

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 28, 2020
Commitments and Contingencies	Q. COMMITMENTS AND CONTINGENCIES Purchase Commitments As of June 28, 2020, Teradyne had entered into purchase commitments for certain components and materials. The purchase commitments covered by the agreements aggregate to approximately $544.2 million, of which $534.3 million is for less than one year. Legal Claims Teradyne is subject to various legal proceedings and claims

Income Taxes

Income Taxes	6 Months Ended
	Jun. 28, 2020
Income Taxes	R. INCOME TAXES A reconciliation of the United States federal statutory corporate tax rate to Teradyne’s effective tax rate was as follows: For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, US statutory federal tax rate 21.0 % 21.0 % 21.0 % 21.0 % Discrete benefit related to release of reserves for uncertain tax positions 0.1 (0.3 ) 0.1 (11.5 ) Foreign taxes (4.6 ) (5.8 ) (5.1 ) (4.7 ) International provisions of the U.S. Tax Cuts and Jobs Act of 2017 (1.9 ) 1.9 (1.1 ) 0.8 Tax credits (1.4 ) (2.1 ) (1.6 ) (2.5 ) Discrete benefit related to equity compensation (0.1 ) (0.5 ) (2.0 ) (2.0 ) Discrete expense related to U.S. transition tax — 11.2 — 6.5 Other, net — 0.4 0.6 0.7 Effective tax rate 13.1 % 25.8 % 11.9 % 8.3 % On a quarterly basis, Teradyne evaluates the realizability of the deferred tax assets by jurisdiction and assesses the need for a valuation allowance. As of June 28, 2020, Teradyne believes that it will ultimately realize the deferred tax assets recorded on the condensed consolidated balance sheet. However, should Teradyne believe that it is more-likely-than-not As of June 28, 2020 and December 31, 2019, Teradyne had $21.4 million and $21.2 million, respectively, of reserves for uncertain tax positions. The $0.2 million net increase in reserves for uncertain tax positions is associated with U.S. research and development tax credits generated in the current year. As of June 28, 2020, Teradyne estimates that it is reasonably possible that the balance of unrecognized tax benefits may decrease by limitation. The estimated decrease relates to transfer pricing. Teradyne recognizes interest and penalties related to income tax matters in income tax expense. As of June 28, 2020 and December 31, 2019, $1.7 million and $1.4 million, respectively, of interest and penalties were accrued for uncertain tax positions. For the six months ended June 28, 2020 and June 30, 2019, expense of $0.3 million and $0.1 million, respectively, was recorded for interest and penalties related to income tax items. Teradyne qualifies for a tax holiday in Singapore by fulfilling the requirements of an agreement with the Singapore Economic Development Board under which certain headcount and spending requirements must be met. The tax savings due to the tax holiday for the six months ended June 28, 2020 was $13.6 million, or $0.08 per diluted share. The tax savings due to the tax holiday for the six months ended June 30, 2019 was $7.0 million, or $0.04 per diluted share. The tax holiday is scheduled to expire on December 31, 2020. Teradyne is currently in discussion with the Singapore Economic Development Board with respect to extension of the tax holiday for periods after December

Segment Information

Segment Information	6 Months Ended
	Jun. 28, 2020
Segment Reporting [Abstract]
Segment Information	S. SEGMENT INFORMATIO N Teradyne has four reportable segments (Semiconductor Test, System Test, Industrial Automation and Wireless Test). Each of the Semiconductor Test, System Test, and Wireless Test segments is also an individual operating segment. The Industrial Automation reportable segment consists of operating segments with discrete financial information, which have been combined into one reportable segment as they share similar economic characteristics, types of products, production processes and and system level , Teradyne evaluates performance based on several factors, of which the primary financial measure is business segment income (loss) before income taxes. The accounting policies of the business segments in effect are described in Note B: “Accounting Policies” in Teradyne’s Annual Report on Form 10-K Segment information for the three and six months ended June 28, 2020 and June 30, 2019 is as follows: Semiconductor Test System Test Industrial Automation Wireless Test Corporate and Other Consolidated (in thousands) Three Months Ended June 28, 2020 Revenues $ 659,147 $ 71,806 $ 58,776 $ 49,185 $ (253 ) $ 838,661 Income (loss) before income taxes (1)(2) 228,787 19,193 (11,403 ) 14,482 (33,768 ) 217,291 Total assets (3) 1,192,355 126,164 662,103 108,066 1,160,501 3,249,189 Three Months Ended June 30, 2019 Revenues $ 374,898 $ 73,407 $ 74,726 $ 41,236 $ (89 ) $ 564,178 Income before income taxes (1)(2) 91,355 23,535 (3,730 ) 10,930 9,087 131,177 Total assets (3) 745,073 123,460 601,676 93,232 1,108,073 2,671,514 Six Months Ended June 28, 2020 Revenues $ 1,143,636 $ 187,882 $ 119,081 $ 92,670 $ (253 ) $ 1,543,016 Income (loss) before income taxes (1)(2) 382,603 67,600 (26,738 ) 24,702 (33,808 ) 414,359 Total assets (3) 1,192,355 126,164 662,103 108,066 1,160,501 3,249,189 Six Months Ended June 30, 2019 Revenues $ 715,751 $ 131,627 $ 140,862 $ 70,277 $ (240 ) $ 1,058,277 Income (loss) before income taxes (1)(2) 174,404 38,875 (9,025 ) 14,558 6,344 225,156 Total assets (3) 745,073 123,460 601,676 93,232 1,108,073 2,671,514 (1) Included in Corporate and Other are: contingent consideration adjustments, severance charges, interest income, interest expense, net foreign exchange gains (losses), pension and postretirement plans actuarial (gains) losses, intercompany eliminations and acquisition related charges. (2) Included in income (loss) before taxes are charges and credits related to restructuring and other, and inventory charges. (3) Total assets are attributable to each segment. Corporate assets consist of cash and cash equivalents, marketable securities and certain other assets. Included in each segment are charges and credits in the following line items in the statements of operations: For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, (in thousands) (in thousands) Semiconductor Test: Contract termination settlement charge $ 4,000 $ — $ 4,000 $ — Cost of revenues—inventory charge 3,799 2,278 6,825 3,452 Restructuring and other—employee severance — — — 924 Wireless Test: Cost of revenues—inventory charge 1,582 829 2,155 1,168 Industrial Automation: Restructuring and other—acquisition related expenses and compensation — — 790 1,695 System Test: Cost of revenues—inventory charge — — — 763 Corporate and Other: Restructuring and other—AutoGuide contingent consideration adjustment 29,927 — 22,785 — Restructuring and other—acquisition related expenses and compensation 2,974 — 3,715 — Restructuring and other – other 750 — 750 — Restructuring and other—MiR contingent consideration adjustment (668 ) (11,671 ) (3,546 ) (8,668 )

Shareholders' Equity

Shareholders' Equity	6 Months Ended
	Jun. 28, 2020
Equity [Abstract]
Shareholders' Equity	T. SHAREHOLDERS’ EQUITY Stock Repurchase Program In January 2020, Teradyne’s Board of Directors authorized a new stock repurchase program for up to $1.0 billion of common stock. Effective April 1, 2020, Teradyne suspended its share repurchase program. During the six months ended June 28, 2020, Teradyne repurchased 1.5 million shares of common stock for $88.5 million at an average price of $58.33 per share. During the six months ended June 30, 2019, Teradyne repurchased 6.5 million shares of common stock for $247.2 million at an average price of $38.20 per share. The total price includes commissions and is recorded as a reduction to retained earnings. Dividend Holders of Teradyne’s common stock are entitled to receive dividends when they are declared by Teradyne’s Board of Directors. In January 2020 and May 2020, Teradyne’s Board of Directors declared a quarterly cash dividend of $0.10 per share. Dividend payments for the three and six months ended June 28, 2020 were $16.6 million and $33.3 million, respectively. In January 2019 and May 2019, Teradyne’s Board of Directors declared a quarterly cash dividend of $0.09 per share. Dividend payments for the three and six months ended June 30, 2019 were $15.4 million and $31.0 million, respectively. While Teradyne declared a quarterly cash dividend and has suspended its share repurchase program, it may reduce or eliminate the cash dividend and may implement a new share repurchase program in the future. Future cash dividends and stock repurchases are subject to the discretion of Teradyne’s Board of Directors, which will consider, among other things, Teradyne’s earnings, capital requirements and financial condition.

Accounting Policies (Policies)

Accounting Policies (Policies)	6 Months Ended
	Jun. 28, 2020
Basis of Presentation	Basis of Presentation The consolidated interim financial statements include the accounts of Teradyne and its wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated. These interim financial statements are unaudited and reflect all normal recurring adjustments that are, in the opinion of management, necessary for the fair statement of such interim financial statements. Certain prior year amounts were reclassified to conform to the current year presentation. The December 31, 2019 condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by United States of America generally accepted accounting principles (“U.S. GAAP”) for complete financial statements. The accompanying financial information should be read in conjunction with the consolidated financial statements and notes thereto contained in Teradyne’s Annual Report on Form 10-K, filed with the U.S. Securities and Exchange Commission (“SEC”) on March 2, 2020, for the year ended December 31, 2019.
Preparation of Financial Statements and Use of Estimates	Preparation of Financial Statements and Use of Estimates The preparation of consolidated financial statements requires management to make estimates and judgments that affect the amounts reported in the financial statements. Due to the COVID-19 10-Q.
Goodwill	Goodwill On January 26, 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-04, “Intangibles—Goodwill and Other (Topic 350): Simplifying the Accounting for Goodwill Impairment.” 2017-04 2017-04, one-step
Credit Losses	Credit Losses In June 2016, the FASB issued ASU 2016-13, 2016-13

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Jun. 28, 2020
Final Allocation of Purchase Price	The following table represents the final allocation of the purchase price: Purchase Price Allocation (in thousands) Goodwill $ 41,223 Intangible assets 37,660 Tangible assets acquired and liabilities assumed: Other current assets 3,661 Non-current 1,227 Accounts payable and current liabilities (1,223 ) Long-term other liabilities (949 ) Total purchase price $ 81,599
Components of Intangible Assets and Their Estimated Useful Lives at Acquisition Date	Components of these intangible assets and their estimated useful lives at the acquisition date are as follows: Fair Value Estimated Useful Life (in thousands) (in years) Developed technology $ 24,590 6.0 Trademarks and tradenames 7,360 6.0 Customer relationships 5,450 7.0 Backlog 260 0.3 Total intangible assets $ 37,660 6.1
Pro Forma Results Under Acquisitions	The unaudited pro forma results are not necessarily indicative of what actually would have occurred had the acquisition been in effect for the periods presented: For the Three Months For the Six Months June 30, 2019 June 30, 2019 (in thousands) Revenue $ 565,978 $ 1,061,577 Net income 95,948 203,237 Net income per common share: Basic $ 0.56 $ 1.18 Diluted $ 0.54 $ 1.14

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 28, 2020
Revenue from Contract with Customer [Abstract]
Disaggregated Revenue by Primary Geographical Market, Major Product Line and Timing of Revenue Recognition	The following table provides information about disaggregated revenue by timing of revenue recognition, primary geographical market, and major product lines. Semiconductor Test Industrial Automation System on Memory System Test Universal Mobile AutoGuide Wireless Test Corporate and Other Total (in thousands) For the Three Months Ended June 28, 2020 (1) Timing of Revenue Recognition Point in Time $ 520,496 $ 80,032 $ 57,741 $ 41,804 $ 11,196 $ 3,408 $ 46,347 $ (253 ) $ 760,771 Over Time 54,077 4,542 14,065 1,747 76 545 2,838 — 77,890 Total $ 574,573 $ 84,574 $ 71,806 $ 43,551 $ 11,272 $ 3,953 $ 49,185 $ (253 ) $ 838,661 Geographical Market Asia Pacific $ 547,700 $ 82,492 $ 38,656 $ 14,279 $ 1,232 $ — $ 41,907 $ — $ 726,266 Americas 16,251 855 28,494 11,364 2,390 3,953 5,353 (253 ) 68,407 Europe, Middle East and Africa 10,622 1,227 4,656 17,908 7,650 — 1,925 — 43,988 Total $ 574,573 $ 84,574 $ 71,806 $ 43,551 $ 11,272 $ 3,953 $ 49,185 $ (253 ) $ 838,661 For the Three Months Ended June 30, 2019 (1) Timing of Revenue Recognition Point in Time $ 265,130 $ 53,984 $ 60,137 $ 62,015 $ 10,505 $ — $ 39,236 $ (89 ) $ 490,918 Over Time 51,483 4,301 13,270 2,206 — — 2,000 — 73,260 Total $ 316,613 $ 58,285 $ 73,407 $ 64,221 $ 10,505 $ — $ 41,236 $ (89 ) $ 564,178 Geographical Market Asia Pacific $ 285,981 $ 47,202 $ 38,191 $ 18,820 $ 2,681 $ — $ 34,642 $ — $ 427,517 Americas 15,601 8,783 29,911 17,980 2,783 — 5,926 (89 ) 80,895 Europe, Middle East and Africa 15,031 2,300 5,305 27,421 5,041 — 668 — 55,766 Total $ 316,613 $ 58,285 $ 73,407 $ 64,221 $ 10,505 $ — $ 41,236 $ (89 ) $ 564,178 For the Six Months Ended June 28, 2020 (2) Timing of Revenue Recognition Point in Time $ 868,542 $ 159,429 $ 158,453 $ 89,306 $ 20,293 $ 4,532 $ 87,403 $ (253 ) $ 1,387,705 Over Time 106,171 9,494 29,429 3,942 117 891 5,267 — 155,311 Total $ 974,713 $ 168,923 $ 187,882 $ 93,248 $ 20,410 $ 5,423 $ 92,670 $ (253 ) $ 1,543,016 Geographical Market Asia Pacific $ 910,433 $ 158,601 $ 118,674 $ 25,195 $ 2,825 $ — $ 79,711 $ — $ 1,295,439 Americas 33,637 7,751 56,784 26,108 5,855 5,423 10,041 (253 ) 145,346 Europe, Middle East and Africa 30,643 2,571 12,424 41,945 11,730 — 2,918 — 102,231 Total $ 974,713 $ 168,923 $ 187,882 $ 93,248 $ 20,410 $ 5,423 $ 92,670 $ (253 ) $ 1,543,016 For the Six Months Ended June 30, 2019 (2) Timing of Revenue Recognition Point in Time $ 503,952 $ 97,693 $ 105,373 $ 117,392 $ 19,613 $ — $ 66,691 $ (240 ) $ 910,474 Over Time 105,534 8,572 26,254 3,857 — — 3,586 — 147,803 Total $ 609,486 $ 106,265 $ 131,627 $ 121,249 $ 19,613 $ — $ 70,277 $ (240 ) $ 1,058,277 Geographical Market Asia Pacific $ 546,374 $ 85,988 $ 62,478 $ 33,437 $ 4,408 $ — $ 60,661 $ — $ 793,346 Americas 31,768 17,546 56,718 33,783 6,322 — 8,167 (240 ) 154,064 Europe, Middle East and Africa 31,344 2,731 12,431 54,029 8,883 — 1,449 — 110,867 Total $ 609,486 $ 106,265 $ 131,627 $ 121,249 $ 19,613 $ — $ 70,277 $ (240 ) $ 1,058,277 (1) Includes $2.5 million and $1.7 million in 2020 and 2019, respectively, for leases of Teradyne’s systems recognized outside Accounting Standards Codification (“ASC”) 606 “ Revenue from Contracts with Customers.” (2) Includes $4.3 million and $3.4 million in 2020 and 2019, respectively, for leases of Teradyne’s systems recognized outside ASC 606 “ Revenue from Contracts with Customers.”

Inventories (Tables)

Inventories (Tables)	6 Months Ended
	Jun. 28, 2020
Composition of Inventories, Net	Inventories, net consisted of the following at June 28, 2020 and December 31, 2019: June 28, December 31, (in thousands) Raw material $ 106,610 $ 118,595 Work-in-process 29,710 32,695 Finished goods 69,768 45,401 $ 206,088 $ 196,691

Financial Instruments (Tables)

Financial Instruments (Tables)	6 Months Ended
	Jun. 28, 2020
Schedule of Fair Value of Financial Assets and Liabilities Measured on Recurring Basis	The following table sets forth by fair value hierarchy Teradyne’s financial assets and liabilities that were measured at fair value on a recurring basis as of June 28, 2020 and December 31, 2019. June 28, 2020 Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total (in thousands) Assets Cash $ 345,312 $ — $ — $ 345,312 Cash equivalents 326,347 53,772 — 380,119 Available-for-sale — U.S. Treasury securities — 165,305 — 165,305 Commercial paper — 63,844 — 63,844 Corporate debt securities — 63,218 — 63,218 Certificates of deposit and time deposits — 9,506 — 9,506 Debt mutual funds 6,876 — — 6,876 U.S. government agency securities — 4,425 — 4,425 Non-U.S. — 601 — 601 Equity securities: Mutual funds 22,984 — — 22,984 $ 701,519 $ 360,671 $ — $ 1,062,190 Derivative assets — 30 — 30 Total $ 701,519 $ 360,701 $ — $ 1,062,220 Liabilities Contingent consideration $ — $ — $ 49,737 $ 49,737 Derivative liabilities — 222 — 222 Total $ — $ 222 $ 49,737 $ 49,959 Reported as follows: (Level 1) (Level 2) (Level 3) Total (in thousands) Assets Cash and cash equivalents $ 671,659 $ 53,772 $ — $ 725,431 Marketable securities — 229,791 — 229,791 Long-term marketable securities 29,860 77,108 — 106,968 Prepayments and other current assets — 30 — 30 Total $ 701,519 $ 360,701 $ — $ 1,062,220 Liabilities . Other current liabilities $ — $ 222 $ — $ 222 Contingent consideration — — 16,789 16,789 Long-term contingent consideration — — 32,948 32,948 Total $ — $ 222 $ 49,737 $ 49,959 December 31, 2019 Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total (in thousands) Assets Cash $ 311,975 $ — $ — 311,975 Cash equivalents 410,285 51,664 — 461,949 Available-for-sale — Corporate debt securities — 97,307 — 97,307 Commercial paper — 54,149 — 54,149 U.S. Treasury securities — 42,382 — 42,382 U.S. government agency securities — 9,952 — 9,952 Debt mutual funds 6,888 — — 6,888 Certificates of deposit and time deposits — 4,751 — 4,751 Non-U.S. — 592 — 592 Equity securities: Equity mutual funds 25,772 — — 25,772 $ 754,920 $ 260,797 $ — $ 1,015,717 Derivative assets — 528 — 528 Total $ 754,920 $ 261,325 $ — $ 1,016,245 Liabilities Contingent consideration $ — $ — $ 39,705 $ 39,705 Derivative liabilities — 203 — 203 Total $ — $ 203 $ 39,705 $ 39,908 Reported as follows: (Level 1) (Level 2) (Level 3) Total (in thousands) Assets Cash and cash equivalents $ 722,260 $ 51,664 $ — $ 773,924 Marketable securities — 137,303 — 137,303 Long-term marketable securities 32,660 71,830 — 104,490 Prepayments and other current assets — 528 — 528 Total $ 754,920 $ 261,325 $ — $ 1,016,245 Liabilities Other accrued liabilities $ — $ 203 $ — $ 203 Contingent consideration — — 9,106 9,106 Long-term contingent consideration — — 30,599 30,599 Total $ — $ 203 $ 39,705 $ 39,908
Schedule of Changes in Fair Value of Level 3 Contingent Consideration	Changes in the fair value of Level 3 contingent consideration for the three and six months ended June 28, 2020 and June 30, 2019 were as follows: For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, 2020 2019 2020 2019 (in thousands) Balance at beginning of period $ 20,472 $ 38,313 $ 39,705 $ 70,543 Foreign currency impact 6 206 (355 ) (405 ) Payments (a)(b) — — (8,852 ) (34,590 ) Fair value adjustment (c)(d) 29,259 (11,672 ) 19,239 (8,701 ) Balance at end of period $ 49,737 $ 26,847 $ 49,737 $ 26,847 (a) In the six months ended June 28, 2020, Teradyne paid $8.9 million of contingent consideration for the earn-out of (b) In the six months ended June 30, 2019, Teradyne paid $30.8 million and $3.8 million of contingent consideration for the earn-outs in connection with the acquisition of MiR and Universal Robots A/S (“Universal Robots”), respectively. (c) In the three and six months ended June 28, 2020, the fair value of contingent consideration for the earn-outs in connection with the acquisition of MiR decreased by $0.6 million and $3.6 million, respectively, due to lower forecasted results. In the three and six months ended June 28, 2020, the fair value of contingent consideration for the earn-outs in connection with the acquisition of AutoGuide increased by $29.9 million and $22.8 million, respectively , due to higher f or e sults (d) In the three and six months ended June 30, 2019, the fair value of contingent consideration for the earn-out
Quantitative Information Associated With Fair Value Measurement of Level 3 Financial Instrument	The following table provides quantitative information associated with the fair value measurement of Teradyne’s Level 3 financial instruments: Liability June 28, 2020 Fair Valuation Technique Unobservable Inputs Weighted Average (in thousands) Contingent consideration (AutoGuide) $ 49,737 Monte Carlo Simulation Revenue volatility 15.5 % Discount Rate 1.8 % Contingent consideration (MiR) $ — Monte Carlo Simulation Revenue volatility 10.0 % Discount Rate 0.8 %
Schedule of Carrying Amounts and Fair Values of Financial Instruments	The carrying amounts and fair values of Teradyne’s financial instruments at June 28, 2020 and December 31, 2019 were as follows: June 28, 2020 December 31, 2019 Carrying Value Fair Value Carrying Value Fair Value (in thousands) Assets Cash and cash equivalents $ 725,431 $ 725,431 $ 773,924 $ 773,924 Marketable securities 336,759 336,759 241,793 241,793 Derivative assets 30 30 528 528 Liabilities Contingent consideration 49,737 49,737 39,705 39,705 Derivative liabilities 222 222 203 203 Convertible debt (1) 402,305 1,198,669 394,687 1,010,275 (1) The carrying value represents the bifurcated debt component only, while the fair value is based on quoted market prices for the convertible note, which includes the equity conversion features.
Schedule of Available-for-Sale Marketable Securities	The following table summarizes the composition of available-for-sale June 28, 2020 Available-for-Sale Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) U.S. Treasury securities $ 163,586 $ 1,734 $ (15 ) $ 165,305 $ 18,709 Commercial paper 63,774 70 — 63,844 — Corporate debt securities 56,672 6,682 (136 ) 63,218 1,447 Certificates of deposit and time deposits 9,498 8 — 9,506 — Debt mutual funds 6,686 190 — 6,876 — U.S. government agency securities 4,353 72 — 4,425 — Non-U.S. 601 — — 601 — $ 305,170 $ 8,756 $ (151 ) $ 313,775 $ 20,156 Reported as follows: Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Marketable securities $ 229,471 $ 331 $ (11 ) $ 229,791 $ 17,366 Long-term marketable securities 75,699 8,425 (140 ) 83,984 2,790 $ 305,170 $ 8,756 $ (151 ) $ 313,775 $ 20,156 The following table summarizes the composition of available-for-sale December 31, 2019 Available-for-Sale Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Corporate debt securities $ 93,267 $ 4,081 $ (41 ) $ 97,307 $ 2,009 Commercial paper 54,124 26 (1 ) 54,149 1,391 U.S. Treasury securities 42,167 431 (216 ) 42,382 17,556 U.S. government agency securities 9,942 14 (4 ) 9,952 3,043 Debt mutual funds 6,753 135 — 6,888 — Certificates of deposit and time deposits 4,751 — — 4,751 — Non-U.S. 592 — — 592 — $ 211,596 $ 4,687 $ (262 ) $ 216,021 $ 23,999 Reported as follows: Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Marketable securities $ 137,144 $ 160 $ (1 ) $ 137,303 $ 2,922 Long-term marketable securities 74,452 4,527 (261 ) 78,718 21,077 $ 211,596 $ 4,687 $ (262 ) $ 216,021 $ 23,999
Contractual Maturities of Investments Held	The contractual maturities of investments in available-for-sale June 28, 2020 Cost Fair Market Value (in thousands) Due within one year $ 229,471 $ 229,791 Due after 1 year through 5 years 21,054 21,587 Due after 5 years through 10 years 13,762 14,974 Due after 10 years 34,197 40,547 Total $ 298,484 $ 306,899
Schedule of Derivative Instruments in Statement of Financial Position at Fair Value	The following table summarizes the fair value of derivative instruments as of June 28, 2020 and December 31, 2019: Balance Sheet Location June 28, December 31, (in thousands) Derivatives not designated as hedging instruments: Foreign exchange contracts Prepayments $ 30 $ 528 Foreign exchange contracts Other current liabilities (222 ) (203 ) Total derivatives $ (192 ) $ 325
Schedule of Effect of Derivative Instruments on Statement of Operations Recognized	The following table summarizes the effect of derivative instruments recognized in the statement of operations for the three and six months ended June 28, 2020 and June 30, 2019: Location of (Gains) Losses For the Three Months Ended For the Six Months Ended Recognized in June 28, June 30, June 28, June 30, Statement of Operations 2020 2019 2020 2019 (in thousands) Derivatives not designated as hedging instruments: Foreign exchange contracts Other (income) expense, net $470 $239 $4,481 $4,173 (1) The table does not reflect the corresponding gains and losses from the remeasurement of the monetary assets and liabilities denominated in foreign currencies. (2) For the three months ended June 28, 2020, net losses from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $0.4 million. For the six months ended June 28, 2020, net gains from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $1.6 million. (3) For the three months ended June 30, 2019, net losses from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $1.3 million. For the six months ended June 30, 2019, net gains from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $1.9 million. See Note G: “Debt” regarding derivatives related to the convertible senior notes.

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 28, 2020
Components of Convertible Senior Notes	The below tables represent the key components of Teradyne’s convertible senior notes: June 28, 2020 December 31, (in thousands) Debt Principal $ 459,987 $ 460,000 Unamortized discount 57,682 65,313 Net Carrying amount of convertible debt $ 402,305 $ 394,687 For the Three Months For the Six Months June 28, 2020 June 30, June 28, 2020 June 30, (in thousands) Contractual interest expense on the coupon $ 1,438 $ 1,438 $ 2,875 $ 2,875 Amortization of the discount component and debt issue fees recognized as interest expense 3,839 3,653 7,631 7,262 Total interest expense on the convertible debt $ 5,277 $ 5,091 $ 10,506 $ 10,137

Prepayments (Tables)

Prepayments (Tables)	6 Months Ended
	Jun. 28, 2020
Prepayments [Abstract]
Schedule of Prepayments and other assets	Prepayments consist of the following and are included in prepayments and other assets on the balance sheet: June 28, December 31, (in thousands) Contract manufacturer and supplier prepayments $ 191,029 $ 143,392 Prepaid maintenance and other services 10,316 8,046 Prepaid taxes 6,665 8,503 Other prepayments 14,171 16,753 Total prepayments $ 222,181 $ 176,694

Deferred Revenue and Customer_2

Deferred Revenue and Customer Advances (Tables)	6 Months Ended
	Jun. 28, 2020
Revenue Recognition and Deferred Revenue [Abstract]
Deferred Revenue and Customer Advances	Deferred revenue and customer advances consist of the following and are included in short and long-term deferred revenue and customer advances on the balance sheet: June 28, December 31, (in thousands) Maintenance, service and training $ 75,144 $ 63,815 Extended warranty 40,178 30,677 Customer advances, undelivered elements and other 64,536 56,358 Total deferred revenue and customer advances $ 179,858 $ 150,850

Product Warranty (Tables)

Product Warranty (Tables)	6 Months Ended
	Jun. 28, 2020
Other Accrued Liabilities	Related costs are charged to the warranty accrual as incurred. The balance below is included in other accrued liabilities. For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, (in thousands) Balance at beginning of period $ 10,971 $ 7,752 $ 8,996 $ 7,909 Accruals for warranties issued during the period 6,200 2,295 11,267 5,360 Accruals related to pre-existing 356 694 1,412 2,024 Settlements made during the period (4,511 ) (2,608 ) (8,659 ) (7,174 ) Acquisition — — — 14 Balance at end of period $ 13,016 $ 8,133 $ 13,016 $ 8,133
Extended Product Warranty of Short and Long-Term Deferred Revenue and Customer Advances	The balance below is included in short and long-term deferred revenue and customer advances. For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, (in thousands) Balance at beginning of period $ 33,503 $ 27,242 $ 30,677 $ 27,422 Deferral of new extended warranty revenue 11,450 5,476 19,050 11,296 Recognition of extended warranty deferred revenue (4,775 ) (4,002 ) (9,549 ) (10,002 ) Balance at end of period $ 40,178 $ 28,716 $ 40,178 $ 28,716

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 28, 2020
Schedule of Estimated Fair Value of TSR Performance-Based Restricted Stock Unit Awards Assumptions	The fair value was estimated using the Monte Carlo simulation model with the following assumptions: For the Six Months Ended June 28, June 30, Risk-free interest rate 1.5 % 2.6 % Teradyne volatility-historical 34.9 % 31.9 % NYSE Composite Index volatility-historical 11.4 % 11.9 % Dividend yield 0.6 % 1.0 %
Fair Value of Stock Options Using Assumptions	The fair value of stock options was estimated using the Black-Scholes option-pricing model with the following assumptions: For the Six Months Ended June 28, June 30, Expected life (years) 5.0 5.0 Risk-free interest rate 1.6 % 2.5 % Volatility-historical 31.6 % 30.1 % Dividend yield 0.6 % 1.0 %

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive (Loss) Income (Tables)	6 Months Ended
	Jun. 28, 2020
Changes in Accumulated Other Comprehensive (Loss) Income	Changes in accumulated other comprehensive (loss) income, which are presented net of tax, consist of the following: Foreign Currency Translation Adjustment Unrealized Gains (Losses) on Marketable Securities Retirement Plans Prior Service Credit Total (in thousands) Six Months Ended June 28, 2020 Balance at December 31, 2019, net of tax of $0, $946, $(1,124), respectively $ (23,514 ) $ 3,480 $ 1,180 $ (18,854 ) Other comprehensive income before reclassifications, net of tax of $0, $1,271, $0, respectively 7,026 4,830 — 11,856 Amounts reclassified from accumulated other comprehensive income, net of tax of $0, $(421), $(1), respectively — (1,499 ) (3 ) (1,502 ) Net current period other comprehensive income (loss), net of tax of $0, $850, $(1), respectively 7,026 3,331 (3 ) 10,354 Balance at June 28, 2020, net of tax of $0, $1,796, $(1,125), respectively $ (16,488 ) $ 6,811 $ 1,177 $ (8,500 ) Six Months Ended June 30, 2019 Balance at December 31, 2018, net of tax of $0, $(521), $(1,081), respectively $ (12,523 ) $ (1,845 ) $ 1,328 $ (13,040 ) Other comprehensive income before reclassifications, net of tax of $0, $1,256, $0, respectively 983 4,637 — 5,620 Amounts reclassified from accumulated other comprehensive income, net of tax of $0, $(26), $(21), respectively — (97 ) (74 ) (171 ) Net current period other comprehensive income (loss), net of tax of $0, $1,230, $(21), respectively 983 4,540 (74 ) 5,449 Balance as June 30, 2019, net of tax of $0, $709, $(1,102), respectively $ (11,540 ) $ 2,695 $ 1,254 $ (7,591 )
Reclassifications Out of Accumulated Other Comprehensive Income to Statements of Operations	Reclassifications out of accumulated other comprehensive (loss) income to the statement of operations for the three and six months ended June 28, 2020 and June 30, 2019 were as follows: Details about Accumulated Other Comprehensive Income Components For the Three Months Ended For the Six Months Ended Affected Line Item in the Statements of Operations June 28, June 30, June 28, June 30, (in thousands) Available-for-sale Unrealized gains, net of tax of $277, $6, $421, $26, respectively $ 983 $ 27 $ 1,499 $ 97 Interest income Defined benefit retirement Amortization of prior service credit 2 37 3 74 (a) Total reclassifications, net of tax of $277, $17, $422, $47, respectively $ 985 $ 64 $ 1,502 $ 171 Net income (a) The amortization of prior service benefit is included in the computation of net periodic pension cost and postretirement benefit. See Note P: “Retirement Plans.”

Goodwill and Acquired Intangi_2

Goodwill and Acquired Intangible Assets (Tables)	6 Months Ended
	Jun. 28, 2020
Changes in Carrying Amount of Goodwill by Segment	The changes in the carrying amount of goodwill by reportable segments for the six months ended June 28, 2020, were as follows: Industrial Automation System Test Wireless Test Semiconductor Test Total (in thousands) Balance at December 31, 2019 Goodwill $ 396,483 $ 158,699 $ 361,819 $ 261,996 $ 1,178,997 Accumulated impairment losses — (148,183 ) (353,843 ) (260,540 ) (762,566 ) 396,483 10,516 7,976 1,456 416,431 AutoGuide acquisition (149 ) — — — (149 ) Foreign currency translation adjustment 5,671 — — 50 5,721 Balance at June 28, 2020 Goodwill 402,005 158,699 361,819 262,046 1,184,569 Accumulated impairment losses — (148,183 ) (353,843 ) (260,540 ) (762,566 ) $ 402,005 $ 10,516 $ 7,976 $ 1,506 $ 422,003
Schedule of Estimated Intangible Assets Amortization Expense	Estimated intangible asset amortization expense for each of the five succeeding fiscal years is as follows: Year Amortization Expense (in thousands) 2020 (remainder) 11,721 2021 20,804 2022 19,911 2023 19,430 2024 19,123 Thereafter 16,574
Wireless Test
Schedule of Amortizable Intangible Assets	Amortizable intangible assets consist of the following and are included in intangible assets, net on the balance sheet: Gross Carrying Amount Accumulated Amortization Foreign Net Carrying Amount (in thousands) Balance at June 28, 2020 Developed technology $ 361,787 $ (292,394 ) $ (5,095 ) $ 64,298 Customer relationships 75,669 (61,730 ) (295 ) 13,644 Tradenames and trademarks 70,120 (39,457 ) (1,042 ) 29,621 Total intangible assets $ 507,576 $ (393,581 ) $ (6,432 ) $ 107,563 Balance at December 31, 2019 Developed technology $ 361,787 $ (279,000 ) $ (5,709 ) $ 77,078 Customer relationships 75,669 (59,077 ) (455 ) 16,137 Tradenames and trademarks 70,120 (36,671 ) (1,184 ) 32,265 Backlog 260 (260 ) — — Total intangible assets $ 507,836 $ (375,008 ) $ (7,348 ) $ 125,480

Net Income Per Common Share (Ta

Net Income Per Common Share (Tables)	6 Months Ended
	Jun. 28, 2020
Computation of Basic and Diluted Net Income (Loss) Per Common Share	The following table sets forth the computation of basic and diluted net income per common share: For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, 2020 2019 2020 2019 (in thousands, except per share amounts) Net income for basic and diluted net income per share $ 188,908 $ 97,397 $ 365,098 $ 206,535 Weighted average common shares-basic 165,789 171,241 166,189 172,387 Effect of dilutive potential common shares: Incremental shares from assumed conversion of convertible notes (1) 7,599 4,364 7,466 3,275 Convertible note hedge warrant shares (2) 5,824 1,778 5,658 889 Restricted stock units 913 1,002 1,038 1,012 Stock options 132 183 133 202 Employee stock purchase plan — 22 13 16 Dilutive potential common shares 14,468 7,349 14,308 5,394 Weighted average common shares-diluted 180,257 178,590 180,497 177,781 Net income per common share-basic $ 1.14 $ 0.57 $ 2.20 $ 1.20 Net income per common share-diluted $ 1.05 $ 0.55 $ 2.02 $ 1.16 (1) Incremental shares from assumed conversion of the convertible notes was calculated using the difference between the average Teradyne stock price for the period and the conversion price of $31.59, multiplied by 14.6 million shares. The result of this calculation, representing the total intrinsic value of the convertible debt, was divided by the average Teradyne stock price for the period. (2) Convertible notes hedge warrant shares were calculated using the difference between the average Teradyne stock price for the period and the warrant price of $39.64, multiplied by 14.6 million shares. The result of this calculation, representing the total intrinsic value of the warrant, was divided by the average Teradyne stock price for the period.

Retirement Plans (Tables)

Retirement Plans (Tables)	6 Months Ended
	Jun. 28, 2020
Defined Benefit Pension Plans
Net Periodic Pension and Postretirement Benefit Costs	For the Three Months Ended June 28, 2020 June 30, 2019 United States Foreign United States Foreign (in thousands) Service cost $ 433 $ 208 $ 399 $ 192 Interest cost 1,523 119 1,799 176 Expected return on plan assets (1,232 ) (15 ) (1,510 ) (7 ) Net actuarial loss 180 — 252 — Total net periodic pension cost $ 904 $ 312 $ 940 $ 361 For the Six Months Ended June 28, 2020 June 30, 2019 United States Foreign United States Foreign (in thousands) Service cost $ 866 $ 417 $ 804 $ 381 Interest cost 3,045 238 3,595 349 Expected return on plan assets (2,464 ) (31 ) (3,021 ) (14 ) Net actuarial loss 180 — 252 — Total net periodic pension cost $ 1,627 $ 624 $ 1,630 $ 716
Postretirement Benefit Plans
Net Periodic Pension and Postretirement Benefit Costs	For the three and six months ended June 28, 2020 and June 30, 2019, Teradyne’s net periodic postretirement benefit cost was comprised of the following: For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, (in thousands) Service cost $ 17 $ 11 $ 28 $ 20 Interest cost 58 88 120 173 Amortization of prior service credit (2 ) (48 ) (4 ) (95 ) Net actuarial (gain) loss (279 ) 196 (279 ) 196 Total net periodic postretirement benefit (credit) cost $ (206 ) $ 247 $ (135 ) $ 294

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 28, 2020
Reconciliation of Effective Tax Rate	A reconciliation of the United States federal statutory corporate tax rate to Teradyne’s effective tax rate was as follows: For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, US statutory federal tax rate 21.0 % 21.0 % 21.0 % 21.0 % Discrete benefit related to release of reserves for uncertain tax positions 0.1 (0.3 ) 0.1 (11.5 ) Foreign taxes (4.6 ) (5.8 ) (5.1 ) (4.7 ) International provisions of the U.S. Tax Cuts and Jobs Act of 2017 (1.9 ) 1.9 (1.1 ) 0.8 Tax credits (1.4 ) (2.1 ) (1.6 ) (2.5 ) Discrete benefit related to equity compensation (0.1 ) (0.5 ) (2.0 ) (2.0 ) Discrete expense related to U.S. transition tax — 11.2 — 6.5 Other, net — 0.4 0.6 0.7 Effective tax rate 13.1 % 25.8 % 11.9 % 8.3 %

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 28, 2020
Segment Information	Segment information for the three and six months ended June 28, 2020 and June 30, 2019 is as follows: Semiconductor Test System Test Industrial Automation Wireless Test Corporate and Other Consolidated (in thousands) Three Months Ended June 28, 2020 Revenues $ 659,147 $ 71,806 $ 58,776 $ 49,185 $ (253 ) $ 838,661 Income (loss) before income taxes (1)(2) 228,787 19,193 (11,403 ) 14,482 (33,768 ) 217,291 Total assets (3) 1,192,355 126,164 662,103 108,066 1,160,501 3,249,189 Three Months Ended June 30, 2019 Revenues $ 374,898 $ 73,407 $ 74,726 $ 41,236 $ (89 ) $ 564,178 Income before income taxes (1)(2) 91,355 23,535 (3,730 ) 10,930 9,087 131,177 Total assets (3) 745,073 123,460 601,676 93,232 1,108,073 2,671,514 Six Months Ended June 28, 2020 Revenues $ 1,143,636 $ 187,882 $ 119,081 $ 92,670 $ (253 ) $ 1,543,016 Income (loss) before income taxes (1)(2) 382,603 67,600 (26,738 ) 24,702 (33,808 ) 414,359 Total assets (3) 1,192,355 126,164 662,103 108,066 1,160,501 3,249,189 Six Months Ended June 30, 2019 Revenues $ 715,751 $ 131,627 $ 140,862 $ 70,277 $ (240 ) $ 1,058,277 Income (loss) before income taxes (1)(2) 174,404 38,875 (9,025 ) 14,558 6,344 225,156 Total assets (3) 745,073 123,460 601,676 93,232 1,108,073 2,671,514 (1) Included in Corporate and Other are: contingent consideration adjustments, severance charges, interest income, interest expense, net foreign exchange gains (losses), pension and postretirement plans actuarial (gains) losses, intercompany eliminations and acquisition related charges. (2) Included in income (loss) before taxes are charges and credits related to restructuring and other, and inventory charges. (3) Total assets are attributable to each segment. Corporate assets consist of cash and cash equivalents, marketable securities and certain other assets.
Schedule of Segment Reporting Information by Segment Charges	Included in each segment are charges and credits in the following line items in the statements of operations: For the Three Months Ended For the Six Months Ended June 28, June 30, June 28, June 30, (in thousands) (in thousands) Semiconductor Test: Contract termination settlement charge $ 4,000 $ — $ 4,000 $ — Cost of revenues—inventory charge 3,799 2,278 6,825 3,452 Restructuring and other—employee severance — — — 924 Wireless Test: Cost of revenues—inventory charge 1,582 829 2,155 1,168 Industrial Automation: Restructuring and other—acquisition related expenses and compensation — — 790 1,695 System Test: Cost of revenues—inventory charge — — — 763 Corporate and Other: Restructuring and other—AutoGuide contingent consideration adjustment 29,927 — 22,785 — Restructuring and other—acquisition related expenses and compensation 2,974 — 3,715 — Restructuring and other – other 750 — 750 — Restructuring and other—MiR contingent consideration adjustment (668 ) (11,671 ) (3,546 ) (8,668 )

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail)	Nov. 13, 2019USD ($)	Apr. 25, 2018USD ($)	Jan. 30, 2019USD ($)	Jun. 28, 2020USD ($)	Jan. 31, 2019USD ($)
Mobile Industrial Robots (MiR)
Business Acquisition [Line Items]
Total preliminary purchase price		$ 81,599,000
Arrangement range of outcomes value high				$ 63,500,000
Goodwill, not deductible for tax purposes		$ 41,200,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		6 years 1 month 6 days
Lemsys [Member]
Business Acquisition [Line Items]
Total preliminary purchase price					$ 1,400,000
Total preliminary purchase price			$ 9,100,000
Acquired value of intangible assets					4,600,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life			5 years 2 months 12 days
Net tangible assets					$ 3,100,000
Autoguide LLC [Member]
Business Acquisition [Line Items]
Arrangement range of outcomes value high				$ 106,900,000
Autoguide LLC [Member] | Industrial Automation [Member]
Business Acquisition [Line Items]
Total preliminary purchase price	$ 81,600,000
Cash paid to acquire outstanding common and preferred stock	57,600,000
Contingent consideration	$ 24,000,000
Quantity of material to be transported				4,500
Business acquisition percentage of equity	100.00%

Final Allocation of Purchase Pr

Final Allocation of Purchase Price (Detail) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019	Apr. 25, 2018
Business Acquisition [Line Items]
Goodwill	$ 422,003	$ 416,431
Mobile Industrial Robots (MiR)
Business Acquisition [Line Items]
Goodwill			$ 41,223
Intangible assets			37,660
Other current assets			3,661
Non-current assets			1,227
Accounts payable and current liabilities			(1,223)
Long-term other liabilities			(949)
Total purchase price			$ 81,599

Components of Intangible Assets

Components of Intangible Assets and Their Estimated Useful Lives at Acquisition Date (Detail) - Mobile Industrial Robots (MiR) $ in Thousands	Apr. 25, 2018USD ($)
Business Acquisition [Line Items]
Total intangible assets, fair value	$ 37,660
Total intangible assets, estimated useful life, years	6 years 1 month 6 days
Developed technology
Business Acquisition [Line Items]
Total intangible assets, fair value	$ 24,590
Total intangible assets, estimated useful life, years	6 years
Trademarks and tradenames
Business Acquisition [Line Items]
Total intangible assets, fair value	$ 7,360
Total intangible assets, estimated useful life, years	6 years
Customer Relationships
Business Acquisition [Line Items]
Total intangible assets, fair value	$ 5,450
Total intangible assets, estimated useful life, years	7 years
Customer backlog
Business Acquisition [Line Items]
Total intangible assets, fair value	$ 260
Total intangible assets, estimated useful life, years	3 months 18 days

Pro Forma Results Under Acquisi

Pro Forma Results Under Acquisition (Detail) - Mobile Industrial Robots (MiR) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Business Acquisition [Line Items]
Revenue	$ 565,978	$ 1,061,577
Net income	$ 95,948	$ 203,237
Net income per common share, basic	$ 0.56	$ 1.18
Net income per common share, diluted	$ 0.54	$ 1.14

Revenue - Additional Informatio

Revenue - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Deferred Revenue And Customer Advances	$ 21.1	$ 13.3	$ 60.6	$ 33.4
Deferred Revenue and Trade Accounts Receivable	$ 50	$ 40.4	$ 96.8	$ 82.1
Short-term Contract with Customer [Member]
Revenue, Remaining Performance Obligation, Percentage	69.00%		69.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction Period			12 months
Long-term Contract with Customer [Member]
Revenue, Remaining Performance Obligation, Percentage	26.00%		26.00%
Long-term Contract with Customer [Member] | Maximum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction Period			3 years
Long-term Contract with Customer [Member] | Minimum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction Period			1 year

Disaggregated Revenue by Primar

Disaggregated Revenue by Primary Geographical Market, Major Product Line and Timing of Revenue Recognition (Detail) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 28, 2020		Jun. 30, 2019		Jun. 28, 2020		Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Total	$ 838,661	[1]	$ 564,178	[1]	$ 1,543,016	[2]	$ 1,058,277	[2]
Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	659,147		374,898		1,143,636		715,751
System Test
Disaggregation of Revenue [Line Items]
Total	71,806	[1]	73,407	[1]	187,882	[2]	131,627	[2]
Industrial Automation
Disaggregation of Revenue [Line Items]
Total	58,776		74,726		119,081		140,862
Wireless Test
Disaggregation of Revenue [Line Items]
Total	49,185	[1]	41,236	[1]	92,670	[2]	70,277	[2]
Corporate and Other
Disaggregation of Revenue [Line Items]
Total	(253)	[1]	(89)	[1]	(253)	[2]	(240)	[2]
Point in Time
Disaggregation of Revenue [Line Items]
Total	760,771	[1]	490,918	[1]	1,387,705	[2]	910,474	[2]
Point in Time | System Test
Disaggregation of Revenue [Line Items]
Total	57,741	[1]	60,137	[1]	158,453	[2]	105,373	[2]
Point in Time | Wireless Test
Disaggregation of Revenue [Line Items]
Total	46,347	[1]	39,236	[1]	87,403	[2]	66,691	[2]
Point in Time | Corporate and Other
Disaggregation of Revenue [Line Items]
Total	(253)	[1]	(89)	[1]	(253)	[2]	(240)	[2]
Over Time
Disaggregation of Revenue [Line Items]
Total	77,890	[1]	73,260	[1]	155,311	[2]	147,803	[2]
Over Time | System Test
Disaggregation of Revenue [Line Items]
Total	14,065	[1]	13,270	[1]	29,429	[2]	26,254	[2]
Over Time | Wireless Test
Disaggregation of Revenue [Line Items]
Total	2,838	[1]	2,000	[1]	5,267	[2]	3,586	[2]
Over Time | Corporate and Other
Disaggregation of Revenue [Line Items]
Total		[1]				[2]
Americas
Disaggregation of Revenue [Line Items]
Total	68,407	[1]	80,895	[1]	145,346	[2]	154,064	[2]
Americas | System Test
Disaggregation of Revenue [Line Items]
Total	28,494	[1]	29,911	[1]	56,784	[2]	56,718	[2]
Americas | Wireless Test
Disaggregation of Revenue [Line Items]
Total	5,353	[1]	5,926	[1]	10,041	[2]	8,167	[2]
Americas | Corporate and Other
Disaggregation of Revenue [Line Items]
Total	(253)	[1]	(89)	[1]	(253)	[2]	(240)	[2]
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Total	43,988	[1]	55,766	[1]	102,231	[2]	110,867	[2]
Europe, Middle East and Africa | System Test
Disaggregation of Revenue [Line Items]
Total	4,656	[1]	5,305	[1]	12,424	[2]	12,431	[2]
Europe, Middle East and Africa | Wireless Test
Disaggregation of Revenue [Line Items]
Total	1,925	[1]	668	[1]	2,918	[2]	1,449	[2]
Europe, Middle East and Africa | Corporate and Other
Disaggregation of Revenue [Line Items]
Total		[1]				[2]
Asia Pacific
Disaggregation of Revenue [Line Items]
Total	726,266	[1]	427,517	[1]	1,295,439	[2]	793,346	[2]
Asia Pacific | System Test
Disaggregation of Revenue [Line Items]
Total	38,656	[1]	38,191	[1]	118,674	[2]	62,478	[2]
Asia Pacific | Wireless Test
Disaggregation of Revenue [Line Items]
Total	41,907	[1]	34,642	[1]	79,711	[2]	60,661	[2]
Asia Pacific | Corporate and Other
Disaggregation of Revenue [Line Items]
Total		[1]				[2]
SOC | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	574,573	[1]	316,613	[1]	974,713	[2]	609,486	[2]
SOC | Point in Time | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	520,496	[1]	265,130	[1]	868,542	[2]	503,952	[2]
SOC | Over Time | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	54,077	[1]	51,483	[1]	106,171	[2]	105,534	[2]
SOC | Americas | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	16,251	[1]	15,601	[1]	33,637	[2]	31,768	[2]
SOC | Europe, Middle East and Africa | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	10,622	[1]	15,031	[1]	30,643	[2]	31,344	[2]
SOC | Asia Pacific | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	547,700	[1]	285,981	[1]	910,433	[2]	546,374	[2]
Memory | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	84,574	[1]	58,285	[1]	168,923	[2]	106,265	[2]
Memory | Point in Time | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	80,032	[1]	53,984	[1]	159,429	[2]	97,693	[2]
Memory | Over Time | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	4,542	[1]	4,301	[1]	9,494	[2]	8,572	[2]
Memory | Americas | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	855	[1]	8,783	[1]	7,751	[2]	17,546	[2]
Memory | Europe, Middle East and Africa | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	1,227	[1]	2,300	[1]	2,571	[2]	2,731	[2]
Memory | Asia Pacific | Semiconductor Test
Disaggregation of Revenue [Line Items]
Total	82,492	[1]	47,202	[1]	158,601	[2]	85,988	[2]
Universal Robots (UR) | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	43,551	[1]	64,221	[1]	93,248	[2]	121,249	[2]
Universal Robots (UR) | Point in Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	41,804	[1]	62,015	[1]	89,306	[2]	117,392	[2]
Universal Robots (UR) | Over Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	1,747	[1]	2,206	[1]	3,942	[2]	3,857	[2]
Universal Robots (UR) | Americas | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	11,364	[1]	17,980	[1]	26,108	[2]	33,783	[2]
Universal Robots (UR) | Europe, Middle East and Africa | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	17,908	[1]	27,421	[1]	41,945	[2]	54,029	[2]
Universal Robots (UR) | Asia Pacific | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	14,279	[1]	18,820	[1]	25,195	[2]	33,437	[2]
MiR | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	11,272	[1]	10,505	[1]	20,410	[2]	19,613	[2]
MiR | Point in Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	11,196	[1]	10,505	[1]	20,293	[2]	19,613	[2]
MiR | Over Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	76	[1]			117	[2]
MiR | Americas | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	2,390	[1]	2,783	[1]	5,855	[2]	6,322	[2]
MiR | Europe, Middle East and Africa | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	7,650	[1]	5,041	[1]	11,730	[2]	8,883	[2]
MiR | Asia Pacific | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	1,232	[1]	$ 2,681	[1]	2,825	[2]	$ 4,408	[2]
Autoguide LLC [Member] | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	3,953	[1]			5,423	[2]
Autoguide LLC [Member] | Point in Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	3,408	[1]			4,532	[2]
Autoguide LLC [Member] | Over Time | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	545	[1]			891	[2]
Autoguide LLC [Member] | Americas | Industrial Automation
Disaggregation of Revenue [Line Items]
Total	3,953	[1]			5,423	[2]
Autoguide LLC [Member] | Europe, Middle East and Africa | Industrial Automation
Disaggregation of Revenue [Line Items]
Total		[1]				[2]
Autoguide LLC [Member] | Asia Pacific | Industrial Automation
Disaggregation of Revenue [Line Items]
Total		[1]				[2]
[1]	Includes $2.5 million and $1.7 million in 2020 and 2019, respectively, for leases of Teradyne’s systems recognized outside Accounting Standards Codification (“ASC”) 606 “Revenue from Contracts with Customers.”
[2]	Includes $4.3 million and $3.4 million in 2020 and 2019, respectively, for leases of Teradyne’s systems recognized outside ASC 606 “Revenue from Contracts with Customers.”

Disaggregated Revenue by Prim_2

Disaggregated Revenue by Primary Geographical Market, Major Product Line and Timing of Revenue Recognition (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Accounting Policies [Abstract]
Revenue on leases	$ 2.5	$ 1.7	$ 4.3	$ 3.4

Composition of Inventories, Net

Composition of Inventories, Net (Detail) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Raw material	$ 106,610	$ 118,595
Work-in-process	29,710	32,695
Finished goods	69,768	45,401
Inventories, net	$ 206,088	$ 196,691

Inventories - Additional Inform

Inventories - Additional Information (Detail) - USD ($) $ in Millions	Jun. 28, 2020	Dec. 31, 2019
Inventory [Line Items]
Inventory reserves	$ 107.4	$ 103.6

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019	Dec. 31, 2019
Financial Instruments and Fair Value [Line Items]
Available-for-sale securities, realized gain	$ 1,600,000	$ 100,000	$ 3,000,000	$ 200,000
Available-for-sale securities, realized loss	100,000		200,000	100,000
Fair market value of investments with unrealized losses less than one year	20,200,000		20,200,000		$ 23,600,000
Unrealized Gain (loss) on contracts	400,000	1,300,000	1,600,000	1,900,000
Equity securities unrealized gain loss		$ 900,000		$ 3,700,000
Equity securities unrealized (gains) loss	3,700,000		6,000,000
Debt Mutual Funds
Financial Instruments and Fair Value [Line Items]
Available for sale securities with out contractual maturity date	6,900		6,900
Mobile Industrial Robots (MiR)
Financial Instruments and Fair Value [Line Items]
Maximum amount of contingent consideration paid for acquisition	63,500,000		63,500,000
Autoguide LLC [Member]
Financial Instruments and Fair Value [Line Items]
Maximum amount of contingent consideration paid for acquisition	$ 106,900,000		106,900,000
Foreign Exchange Contracts
Financial Instruments and Fair Value [Line Items]
Unrealized Gain (loss) on contracts			$ 125,000,000		$ 144,900,000

Schedule of Fair Value of Finan

Schedule of Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	$ 313,775	$ 216,021
U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	165,305	42,382
Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	63,844	54,149
Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	63,218	97,307
Certificates of Deposit and Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	9,506	4,751
U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	4,425	9,952
Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	6,876	6,888
Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	601	592
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	1,062,190	1,015,717
Derivative assets	30	528
Total	1,062,220	1,016,245
Contingent consideration	49,737	39,705
Derivative liabilities	222	203
Total	49,959	39,908
Fair Value, Measurements, Recurring | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	345,312	311,975
Fair Value, Measurements, Recurring | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	380,119	461,949
Fair Value, Measurements, Recurring | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	165,305	42,382
Fair Value, Measurements, Recurring | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	63,844	54,149
Fair Value, Measurements, Recurring | Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	63,218	97,307
Fair Value, Measurements, Recurring | Certificates of Deposit and Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	9,506	4,751
Fair Value, Measurements, Recurring | U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	4,425	9,952
Fair Value, Measurements, Recurring | Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	6,876	6,888
Fair Value, Measurements, Recurring | Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	601	592
Fair Value, Measurements, Recurring | Equity Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale equity securities	22,984	25,772
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	701,519	754,920
Total	701,519	754,920
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Fair Value, Measurements, Recurring | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	345,312	311,975
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Fair Value, Measurements, Recurring | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	326,347	410,285
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Fair Value, Measurements, Recurring | Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	6,876	6,888
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Fair Value, Measurements, Recurring | Equity Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale equity securities	22,984	25,772
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	360,671	260,797
Derivative assets	30	528
Total	360,701	261,325
Derivative liabilities	222	203
Total	222	203
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	53,772	51,664
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	165,305	42,382
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	63,844	54,149
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	63,218	97,307
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Certificates of Deposit and Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	9,506	4,751
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	4,425	9,952
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	601	592
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent consideration	49,737	39,705
Total	$ 49,737	$ 39,705

Schedule of Reported Financial

Schedule of Reported Financial Assets and Liabilities (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	$ 1,062,220	$ 1,016,245
Liabilities	49,959	39,908
Other Current Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	222	203
Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	725,431	773,924
Marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	229,791	137,303
Long-term marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	106,968	104,490
Prepayments and other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	30	528
Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	16,789	9,106
Long Term Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	32,948	30,599
Quoted Prices in Active Markets for Identical Instruments (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	701,519	754,920
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	671,659	722,260
Quoted Prices in Active Markets for Identical Instruments (Level 1) | Long-term marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	29,860	32,660
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	360,701	261,325
Liabilities	222	203
Significant Other Observable Inputs (Level 2) | Other Current Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	222	203
Significant Other Observable Inputs (Level 2) | Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	53,772	51,664
Significant Other Observable Inputs (Level 2) | Marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	229,791	137,303
Significant Other Observable Inputs (Level 2) | Long-term marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	77,108	71,830
Significant Other Observable Inputs (Level 2) | Prepayments and other current assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	30	528
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	49,737	39,705
Significant Unobservable Inputs (Level 3) | Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	16,789	9,106
Significant Unobservable Inputs (Level 3) | Long Term Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	$ 32,948	$ 30,599

Schedule of Changes in Fair Val

Schedule of Changes in Fair Value of Level 3 Contingent Consideration (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 20,472	$ 38,313	$ 39,705	$ 70,543
Foreign currency impact	6	206	(355)	(405)
Payments	0	0	(8,852)	(34,590)
Fair value adjustment	29,259	(11,672)	19,239	(8,701)
Balance at end of period	$ 49,737	$ 26,847	$ 49,737	$ 26,847

Schedule of Changes in Fair V_2

Schedule of Changes in Fair Value of Level 3 Contingent Consideration (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payments of contingent consideration			$ 8,852	$ 27,615
Increase (decrease) in contingent consideration			19,239	(8,701)
Universal Robots (UR)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payments of contingent consideration				30,800
Increase (decrease) in contingent consideration				3,800
Avionics Interface Technologies, LLC
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payments of contingent consideration			8,900
MiR
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payments of contingent consideration	$ 600	$ 11,700
Increase (decrease) in contingent consideration			3,600	$ 8,700
Autoguide LLC [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payments of contingent consideration	$ 29,900
Increase (decrease) in contingent consideration			$ 22,800

Quantitative Information Associ

Quantitative Information Associated With Fair Value Measurement of Level 3 Financial Instrument (Detail) - Monte Carlo Simulation $ in Thousands	6 Months Ended
	Jun. 28, 2020USD ($)
Mobile Industrial Robots (MiR)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Target achievement, volatility	10.00%
Discount rate	0.80%
Autoguide LLC [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Target achievement, volatility	15.50%
Discount rate	1.80%
Significant Unobservable Inputs (Level 3) | Mobile Industrial Robots (MiR)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	$ 0
Significant Unobservable Inputs (Level 3) | Autoguide LLC [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	$ 49,737

Schedule of Carrying Amounts an

Schedule of Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Marketable securities	$ 313,775	$ 216,021
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and cash equivalents	725,431	773,924
Marketable securities	336,759	241,793
Derivative assets	30	528
Contingent consideration	49,737	39,705
Derivative liabilities	222	203
Convertible debt	402,305	394,687
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and cash equivalents	725,431	773,924
Marketable securities	336,759	241,793
Derivative assets	30	528
Contingent consideration	49,737	39,705
Derivative liabilities	222	203
Convertible debt	$ 1,198,669	$ 1,010,275

Schedule of Available for Sale

Schedule of Available for Sale Marketable Securities (Detail) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	$ 305,170	$ 211,596
Available-for-sale marketable securities, Unrealized Gain	8,756	4,687
Available-for-sale marketable securities, Unrealized (Loss)	(151)	(262)
Available-for-sale marketable securities, Fair Market Value	313,775	216,021
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	20,156	23,999
U.S. Treasury Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	163,586	42,167
Available-for-sale marketable securities, Unrealized Gain	1,734	431
Available-for-sale marketable securities, Unrealized (Loss)	(15)	(216)
Available-for-sale marketable securities, Fair Market Value	165,305	42,382
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	18,709	17,556
Commercial Paper
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	63,774	54,124
Available-for-sale marketable securities, Unrealized Gain	70	26
Available-for-sale marketable securities, Unrealized (Loss)	0	(1)
Available-for-sale marketable securities, Fair Market Value	63,844	54,149
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	0	1,391
Corporate Debt Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	56,672	93,267
Available-for-sale marketable securities, Unrealized Gain	6,682	4,081
Available-for-sale marketable securities, Unrealized (Loss)	(136)	(41)
Available-for-sale marketable securities, Fair Market Value	63,218	97,307
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	1,447	2,009
Certificates of Deposit and Time Deposits
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	9,498	4,751
Available-for-sale marketable securities, Unrealized Gain	8
Available-for-sale marketable securities, Fair Market Value	9,506	4,751
U.S. Government Agency Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	4,353	9,942
Available-for-sale marketable securities, Unrealized Gain	72	14
Available-for-sale marketable securities, Unrealized (Loss)	0	(4)
Available-for-sale marketable securities, Fair Market Value	4,425	9,952
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	0	3,043
Debt Mutual Funds
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	6,686	6,753
Available-for-sale marketable securities, Unrealized Gain	190	135
Available-for-sale marketable securities, Fair Market Value	6,876	6,888
Non-U.S. Government Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	601	592
Available-for-sale marketable securities, Fair Market Value	$ 601	$ 592

Schedule of Reported Available

Schedule of Reported Available for Sale Marketable Securities (Detail) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	$ 305,170	$ 211,596
Available-for-sale marketable securities, Unrealized Gain	8,756	4,687
Available-for-sale marketable securities, Unrealized (Loss)	(151)	(262)
Available-for-sale marketable securities, Fair Market Value	313,775	216,021
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	20,156	23,999
Marketable securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	229,471	137,144
Available-for-sale marketable securities, Unrealized Gain	331	160
Available-for-sale marketable securities, Unrealized (Loss)	(11)	(1)
Available-for-sale marketable securities, Fair Market Value	229,791	137,303
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	17,366	2,922
Long-term marketable securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	75,699	74,452
Available-for-sale marketable securities, Unrealized Gain	8,425	4,527
Available-for-sale marketable securities, Unrealized (Loss)	(140)	(261)
Available-for-sale marketable securities, Fair Market Value	83,984	78,718
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	$ 2,790	$ 21,077

Contractual Maturities of Inves

Contractual Maturities of Investments in Debt Securities Held (Detail) $ in Thousands	Jun. 28, 2020USD ($)
Schedule of Available-for-sale Securities
Due within one year, cost	$ 229,471
Due after 1 year through 5 years, cost	21,054
Due after 5 years through 10 years, cost	13,762
Due after 10 years, cost	34,197
Total, cost	298,484
Due within one year, fair market value	229,791
Due after 1 year through 5 years, fair market value	21,587
Due after 5 years through 10 years, fair market value	14,974
Due after 10 years, fair maket value	40,547
Total, fair market value	$ 306,899

Schedule of Derivative Instrume

Schedule of Derivative Instruments in Statement of Financial Position at Fair Value (Detail) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative assets (liabilities), net	$ (192)	$ 325
Not Designated as Hedging Instrument | Foreign currency forward contracts | Prepayments
Derivatives, Fair Value [Line Items]
Derivative assets	30	528
Not Designated as Hedging Instrument | Foreign currency forward contracts | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	$ (222)	$ (203)

Schedule of Effect of Derivativ

Schedule of Effect of Derivative Instruments in Statement of Operations Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Other (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Losses on derivatives recognized in statements of operations	$ 470	$ 239	$ 4,481	$ 4,173

Schedule of Effect of Derivat_2

Schedule of Effect of Derivative Instruments in Statement of Operations Recognized (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on foreign currency transactions	$ 0.4	$ 1.3	$ 1.6	$ 1.9

Debt - Additional Information (

Debt - Additional Information (Detail) $ / shares in Units, $ in Thousands, shares in Millions	Jun. 28, 2020USD ($)$ / shares	May 01, 2020USD ($)	Dec. 12, 2016USD ($)Customershares	Jun. 28, 2020USD ($)$ / sharesshares	Jun. 30, 2019USD ($)shares	Jun. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Debt Instrument
Repurchase of common stock				$ 88,465	$ 247,222
Repurchase of stock, shares | shares				1.5	6.5
Term of loan, years		3 years
Line of Credit Facility, Maximum Borrowing Capacity		$ 400,000
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases		$ 150,000
Line of Credit Facility, Interest Rate Description		The interest rates applicable to loans under the Credit Facility are, at Teradyne’s option, equal to either a base rate plus a margin ranging from 0.50% to 1.25% per annum or LIBOR, a minimum of 0.75%, plus a margin ranging from 1.50% to 2.25% per annum, based on the consolidated leverage ratio of Teradyne. In addition, Teradyne will pay a commitment fee on the unused portion of the commitments under the Credit Facility ranging from 0.25% to 0.40% per annum, based on the then applicable consolidated leverage ratio.
Collateral Pledged [Member]
Debt Instrument
Line of Credit Facility, Interest Rate Description		65
1.25% Convertible Senior Unsecured Notes Due December 15, 2023
Debt Instrument
Aggregate principal amount	$ 459,987		$ 460,000	$ 459,987			$ 460,000
Debt instrument, interest rate, stated percentage			1.25%
Debt instrument, net proceeds after issuance costs	$ 31,590		$ 450,800
Payment for net cost of convertible note hedges net of warrant proceeds			33,000	$ 33,000
Repurchase of common stock			$ 50,100
Repurchase of stock, shares | shares			2
Senior notes maturity date			Dec. 15, 2023
Debt instrument, frequency of periodic payment			payable semiannually in arrears on June 15 and December 15 of each year
Debt instrument, conversion option expiration date			Sep. 15, 2023
Debt instrument conversion price | $ / shares	$ 31.59			$ 31.59
Shares that would be issued upon conversion | shares				14.6
Strike price per share of warrant | $ / shares				$ 39.64
Debt instrument, convertible, carrying amount of equity component	$ 100,800			$ 100,800
Debt instrument, effective annual interest rate	5.00%			5.00%
Financing cost	$ 7,200			$ 7,200		$ 3,800
Debt issuance costs, amortization period				7 years
Unamortized discount	57,700			$ 57,700
Debt Instrument, convertible, remaining discount amortization period				3 years 6 months
Value of notes converted				$ 1,192,000
Debt Instrument, Face Amount	459,987		$ 460,000	459,987			$ 460,000
1.25% Convertible Senior Unsecured Notes Due December 15, 2023 | Conversion option one
Debt Instrument
Trading days measurement period | Customer			20
Consecutive trading days measurement period | Customer			30
Percentage of conversion price			130.00%
1.25% Convertible Senior Unsecured Notes Due December 15, 2023 | Conversion option two
Debt Instrument
Aggregate principal amount			$ 1,000
Trading days measurement period | Customer			5
Consecutive trading days measurement period | Customer			5
Percentage of closing sale price of common stock and conversion rate product			98.00%
Debt Instrument, Face Amount			$ 1,000
Revolving Credit Facility
Debt Instrument
Revolving credit facility costs incurred	$ 3,500			$ 3,500
Term of revolving credit facility	3 years			3 years

Components of Convertible Senio

Components of Convertible Senior Notes (Detail) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019	Dec. 12, 2016
Debt Instrument
Net carrying amount of convertible debt	$ 402,305	$ 394,687
1.25% Convertible Senior Unsecured Notes Due December 15, 2023
Debt Instrument
Debt principal	459,987	460,000	$ 460,000
Unamortized discount	57,682	65,313
Net carrying amount of convertible debt	$ 402,305	$ 394,687

Interest Expense on Convertible

Interest Expense on Convertible Senior Notes (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Debt Instrument
Contractual interest expense on the coupon	$ 1,438	$ 1,438	$ 2,875	$ 2,875
Amortization of the discount component and debt issue fees recognized as interest expense	3,839	3,653	7,631	7,262
Total interest expense on the convertible debt	$ 5,277	$ 5,091	$ 10,506	$ 10,137

Schedule of Prepayments and Oth

Schedule of Prepayments and Other Assets (Detail) - USD ($) $ in Thousands	Jun. 28, 2020	Dec. 31, 2019
Prepaid And Other Current Assets [Line Items]
Contract manufacturer and supplier prepayments	$ 191,029	$ 143,392
Prepaid maintenance and other services	10,316	8,046
Prepaid taxes	6,665	8,503
Other prepayments	14,171	16,753
Total prepayments	$ 222,181	$ 176,694

Deferred Revenue and Customer_3

Deferred Revenue and Customer Advances (Detail) - USD ($) $ in Thousands	Jun. 28, 2020	Mar. 29, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Deferred Revenue Arrangement
Maintenance, service and training	$ 75,144		$ 63,815
Extended warranty	40,178	$ 33,503	30,677	$ 28,716	$ 27,242	$ 27,422
Customer advances, undelivered performance obligations and other	64,536		56,358
Total deferred revenue and customer advances	$ 179,858		$ 150,850

Warranty Accrual Included in Ot

Warranty Accrual Included in Other Accrued Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Product Warranty Liability [Line Items]
Balance at beginning of period	$ 10,971	$ 7,752	$ 8,996	$ 7,909
Accruals for warranties issued during the period	6,200	2,295	11,267	5,360
Accruals related to pre-existing warranties	356	694	1,412	2,024
Settlements made during the period	(4,511)	(2,608)	(8,659)	(7,174)
Acquisition			0	14
Balance at end of period	$ 13,016	$ 8,133	$ 13,016	$ 8,133

Extended Product Warranty of Sh

Extended Product Warranty of Short and Long-Term Deferred Revenue and Customer Advances (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Product Warranty Liability [Line Items]
Balance at beginning of period	$ 33,503	$ 27,242	$ 30,677	$ 27,422
Deferral of new extended warranty revenue	11,450	5,476	19,050	11,296
Recognition of extended warranty deferred revenue	(4,775)	(4,002)	(9,549)	(10,002)
Balance at end of period	$ 40,178	$ 28,716	$ 40,178	$ 28,716

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - $ / shares shares in Millions	6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award
Stock price	$ 72.10	$ 37.95
Stock Options | Measurement Input, Expected Dividend Payment [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Estimated annual dividend amount per share	$ 0.40	$ 72.10
Restricted Stock Units | Employees
Share-based Compensation Arrangement by Share-based Payment Award
Period of stock granted to employees and executive officers vest in equal annual installments	4 years
Percentage of awards vesting on the first anniversary of grant date	100.00%
Restricted Stock Units | Director
Share-based Compensation Arrangement by Share-based Payment Award
Period of stock granted to employees and executive officers vest in equal annual installments	1 year
TSR Performance-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Total shareholder return performance measurement period	3 years	3 years
Share-based compensation arrangement by share-based payment award, description	capped at four times the grant date value for grants prior to 2019
Minimum age of retirement to be eligible for PRSUs	60 years
Minimum years of service for retirement to be eligible for PRSUs	10 years
Restricted stock unit awards granted	0.1
Weighted average grant date fair value of restricted stock units granted	$ 89.93	$ 51.51
Stock price	0.36	$ 36.75
TSR Performance-Based Restricted Stock Units | Measurement Input, Expected Dividend Payment [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Estimated annual dividend amount per share	$ 0.40
TSR Performance-Based Restricted Stock Units | Share-based Compensation Award, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of vesting of target shares upon performance achieved	0.00%	0.00%
TSR Performance-Based Restricted Stock Units | Share-based Compensation Award, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of vesting of target shares upon performance achieved	200.00%	200.00%
TSR Performance-Based Restricted Stock Units | Non Employees
Share-based Compensation Arrangement by Share-based Payment Award
Restricted stock unit awards granted	0.1
Weighted average grant date fair value of restricted stock units granted	$ 64.99	$ 48.03
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of common stock price paid	100.00%
PBIT Performance-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Restricted stock unit awards granted	0.1
Weighted average grant date fair value of restricted stock units granted	$ 70.94	$ 36.88
Service-Based Restricted Stock Units | Employees
Share-based Compensation Arrangement by Share-based Payment Award
Restricted stock unit awards granted	0.4	0.8
Weighted average grant date fair value of restricted stock units granted	$ 70.52	$ 36.84
Service-Based Restricted Stock Units | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award
Restricted stock unit awards granted		0.1
Weighted average grant date fair value of restricted stock units granted	$ 20.67	$ 10.61

Schedule of Estimated Fair Valu

Schedule of Estimated Fair Value of TSR Performance-Based Restricted Stock Unit Awards Assumptions (Detail) - TSR Performance-Based Restricted Stock Units	6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award
Risk-free interest rate	1.50%	2.60%
Expected historical volatility	34.90%	31.90%
Dividend yield	0.60%	1.00%
New York Stock Exchange Composite Index
Share-based Compensation Arrangement by Share-based Payment Award
Expected historical volatility	11.40%	11.90%

Schedule of Estimated Fair Va_2

Schedule of Estimated Fair Value of Stock Options Grant Using Black Scholes Option Pricing Model (Detail) - Stock Options	6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award
Expected life (years)	5 years	5 years
Risk-free interest rate	1.60%	2.50%
Volatility-historical	31.60%	30.10%
Dividend yield	0.60%	1.00%

Changes in Accumulated Other Co

Changes in Accumulated Other Comprehensive (Loss) Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 1,550,673	$ 1,470,228	$ 1,480,158	$ 1,522,354
Other comprehensive income	18,613	8,115	10,354	5,449
Balance	1,744,551	1,479,412	1,744,551	1,479,412
Foreign Currency Translation Reclassification Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(23,514)	(12,523)
Other comprehensive loss before reclassifications, net of tax			7,026	983
Amounts reclassified from accumulated other comprehensive income (loss), net of tax			0	0
Other comprehensive income			7,026	983
Balance	(16,488)	(11,540)	(16,488)	(11,540)
Unrealized Gains (Losses) on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			3,480	(1,845)
Other comprehensive loss before reclassifications, net of tax			4,830	4,637
Amounts reclassified from accumulated other comprehensive income (loss), net of tax			(1,499)	(97)
Other comprehensive income			3,331	4,540
Balance	6,811	2,695	6,811	2,695
Amortization of Prior Service Credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			1,180	1,328
Other comprehensive loss before reclassifications, net of tax			0	0
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(2)	(37)	(3)	(74)
Other comprehensive income			(3)	(74)
Balance	1,177	1,254	1,177	1,254
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(27,113)	(15,706)	(18,854)	(13,040)
Other comprehensive loss before reclassifications, net of tax			11,856	5,620
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(985)	(64)	(1,502)	(171)
Other comprehensive income	18,613	8,115	10,354	5,449
Balance	$ (8,500)	$ (7,591)	$ (8,500)	$ (7,591)

Changes in Accumulated Other _2

Changes in Accumulated Other Comprehensive (Loss) Income (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss), tax	$ (277)	$ (17)	$ (422)	$ (47)
Foreign currency translation adjustments, tax	0	0	0	0	$ 0
Unrealized (losses) gains on marketable securities, tax	1,796	709	1,796	709	946	$ (521)
Retirement plans prior service benefit, tax	(1,125)	(1,102)	(1,125)	(1,102)	$ (1,124)	$ (1,081)
Foreign Currency Translation Reclassification Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications, tax			0	0
Amounts reclassified from accumulated other comprehensive income (loss), tax			0	0
Other comprehensive income (loss), tax			0	0
Unrealized (Losses) Gains on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications, tax			1,271	1,256
Amounts reclassified from accumulated other comprehensive income (loss), tax	(277)	(6)	(421)	(26)
Other comprehensive income (loss), tax			850	1,230
Amortization of Prior Service Credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss) before reclassifications, tax			0	0
Amounts reclassified from accumulated other comprehensive income (loss), tax	$ 0	$ (11)	(1)	(21)
Other comprehensive income (loss), tax			$ (1)	$ (21)

Reclassifications Out of Accumu

Reclassifications Out of Accumulated Other Comprehensive Income to Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income (expense)	$ 983	$ 27	$ 1,499	$ 97
Amortization of Prior Service Credit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax	2	37	3	74
Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax	$ 985	$ 64	$ 1,502	$ 171

Reclassifications Out of Accu_2

Reclassifications Out of Accumulated Other Comprehensive Income to Statements of Operations (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	$ 277	$ 17	$ 422	$ 47
Unrealized (Losses) Gains on Marketable Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	277	6	421	26
Amortization of Prior Service Credit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	$ 0	$ 11	$ 1	$ 21

Goodwill and Acquired Intangi_3

Goodwill and Acquired Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Line Items]
Acquired intangible assets amortization	$ 8,941	$ 10,083	$ 18,832	$ 20,717

Changes in Carrying Amount of G

Changes in Carrying Amount of Goodwill by Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Jun. 28, 2020
Goodwill [Line Items]
Foreign currency translation adjustment	$ 5,721
Goodwill	1,178,997	$ 1,184,569
Accumulated impairment losses	(762,566)	(762,566)
Goodwill	416,431	422,003
Autoguide LLC
Goodwill [Line Items]
Goodwill acquisition	(149)
Industrial Automation
Goodwill [Line Items]
Foreign currency translation adjustment	5,671
Goodwill	396,483	402,005
Goodwill	396,483	402,005
Industrial Automation | Autoguide LLC
Goodwill [Line Items]
Goodwill acquisition	(149)
Wireless Test
Goodwill [Line Items]
Goodwill	361,819	361,819
Accumulated impairment losses	(353,843)	(353,843)
Goodwill	7,976	7,976
Semiconductor Test
Goodwill [Line Items]
Foreign currency translation adjustment	50
Goodwill	261,996	262,046
Accumulated impairment losses	(260,540)	(260,540)
Goodwill	1,456	1,506
System Test
Goodwill [Line Items]
Goodwill	158,699	158,699
Accumulated impairment losses	(148,183)	(148,183)
Goodwill	$ 10,516	$ 10,516

Schedule of Amortizable Intangi

Schedule of Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 28, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 507,576	$ 507,836
Accumulated Amortization	(393,581)	(375,008)
Foreign Currency Translation Adjustment	(6,432)	(7,348)
Net Carrying Amount	107,563	125,480
Developed technology
Finite-Lived Intangible Assets
Gross Carrying Amount	361,787	361,787
Accumulated Amortization	(292,394)	(279,000)
Foreign Currency Translation Adjustment	(5,095)	(5,709)
Net Carrying Amount	64,298	77,078
Customer Relationships
Finite-Lived Intangible Assets
Gross Carrying Amount	75,669	75,669
Accumulated Amortization	(61,730)	(59,077)
Foreign Currency Translation Adjustment	(295)	(455)
Net Carrying Amount	13,644	16,137
Trademarks and tradenames
Finite-Lived Intangible Assets
Gross Carrying Amount	70,120	70,120
Accumulated Amortization	(39,457)	(36,671)
Foreign Currency Translation Adjustment	(1,042)	(1,184)
Net Carrying Amount	$ 29,621	32,265
Backlog
Finite-Lived Intangible Assets
Gross Carrying Amount		260
Accumulated Amortization		$ (260)

Schedule of Estimated Intangibl

Schedule of Estimated Intangible Asset Amortization Expense (Detail) $ in Thousands	Jun. 28, 2020USD ($)
Finite-Lived Intangible Assets
2020 (remainder)	$ 11,721
2021	20,804
2022	19,911
2023	19,430
2024	19,123
Thereafter	$ 16,574

Computation of Basic and Dilute

Computation of Basic and Diluted Net Income Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Net Income Loss Per Common Share
Net income for basic and diluted net income per share		$ 188,908	$ 97,397	$ 365,098	$ 206,535
Weighted average common shares-basic		165,789	171,241	166,189	172,387
Incremental shares from assumed conversion of convertible notes	[1]	7,599	4,364	7,466	3,275
Convertible note hedge warrant shares	[2]	5,824	1,778	5,658	889
Employee stock purchase plan		0	22	13	16
Dilutive potential common shares		14,468	7,349	14,308	5,394
Weighted average common shares-diluted		180,257	178,590	180,497	177,781
Net income per common share-basic		$ 1.14	$ 0.57	$ 2.20	$ 1.20
Net income per common share-diluted		$ 1.05	$ 0.55	$ 2.02	$ 1.16
Restricted Stock Units
Net Income Loss Per Common Share
Incremental shares attributable to share based payment arrangements		913	1,002	1,038	1,012
Stock Options
Net Income Loss Per Common Share
Incremental shares attributable to share based payment arrangements		132	183	133	202
[1]	Incremental shares from assumed conversion of the convertible notes was calculated using the difference between the average Teradyne stock price for the period and the conversion price of $31.59, multiplied by 14.6 million shares. The result of this calculation, representing the total intrinsic value of the convertible debt, was divided by the average Teradyne stock price for the period.
[2]	Convertible notes hedge warrant shares were calculated using the difference between the average Teradyne stock price for the period and the warrant price of $39.64, multiplied by 14.6 million shares. The result of this calculation, representing the total intrinsic value of the warrant, was divided by the average Teradyne stock price for the period.

Computation of Basic and Dilu_2

Computation of Basic and Diluted Net Income Per Common Share (Parenthetical) (Detail) shares in Millions	3 Months Ended
	Jun. 28, 2020$ / sharesshares
Convertible Notes
Net Income Loss Per Common Share
Initial debt conversion price | $ / shares	$ 31.59
Shares that would be issued upon conversion | shares	14.6
Convertible Notes Hedge Warrant
Net Income Loss Per Common Share
Initial debt conversion price | $ / shares	$ 39.64
Shares that would be issued upon conversion | shares	14.6

Net Income Per Common Share - A

Net Income Per Common Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Net Income Loss Per Common Share
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0.1	0.2	0.2	0.4

Restructuring and Other - Addit

Restructuring and Other - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Restructuring Cost and Reserve
Contingent consideration adjustment			$ 19,239	$ (8,701)
Semiconductor Test
Restructuring Cost and Reserve
Contingent consideration adjustment		$ (11,700)		(8,700)
Severance benefit and charges	$ 800	800	800	1,800
Acquisition related costs	3,100		4,500
Impairment charges fixed assets	4,000	500		1,600
Contract termination settlement fee	4,000	$ 0	4,000	0
Restructuring and other			1,100
Universal Robots (UR)
Restructuring Cost and Reserve
Contingent consideration adjustment				$ 3,800
TER Corporate And Eliminations | Universal Robots (UR)
Restructuring Cost and Reserve
Contingent consideration adjustment	29,900		22,800
TER Corporate And Eliminations | Mobile Industrial Robots (MiR)
Restructuring Cost and Reserve
Contingent consideration adjustment	$ (600)		$ (3,600)

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 28, 2020USD ($)
United States Plans
Defined Benefit Plan Disclosure
Contribution to defined benefit pension plans	$ 1.4
U.S. Supplemental Executive Defined Benefit Pension Plan
Defined Benefit Plan Disclosure
Contribution to defined benefit pension plans	$ 0.4

Schedule of Net Periodic Pensio

Schedule of Net Periodic Pension and Postretirement (income) Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Defined Benefit Plan Disclosure
Net actuarial (gain) loss			$ (99)	$ 448
UNITED STATES
Defined Benefit Plan Disclosure
Service cost	$ 433	$ 399	866	804
Interest cost	1,523	1,799	3,045	3,595
Expected return on plan assets	(1,232)	(1,510)	(2,464)	(3,021)
Net actuarial (gain) loss	180	252	180	252
Total net periodic pension (credit) cost	904	940	1,627	1,630
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Service cost	208	192	417	381
Interest cost	119	176	238	349
Expected return on plan assets	(15)	(7)	(31)	(14)
Total net periodic pension (credit) cost	312	361	624	716
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Service cost	17	11	28	20
Interest cost	58	88	120	173
Amortization of prior service cost	(2)	(48)	(4)	(95)
Net actuarial (gain) loss	(279)	196	(279)	196
Total net periodic pension (credit) cost	$ (206)	$ 247	$ (135)	$ 294

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	Jun. 28, 2020USD ($)
Purchase Commitment, Excluding Long-term Commitment
Aggregate purchase commitments	$ 544.2
Purchase commitments less than one year	$ 534.3

Schedule of Reconciliation of E

Schedule of Reconciliation of Effective Tax Rate (Detail)	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Income Tax Disclosure [Line Items]
US statutory federal tax rate	21.00%	21.00%	21.00%	21.00%
Foreign taxes	(4.60%)	(5.80%)	(5.10%)	(4.70%)
Discrete benefit related to release of reserves for uncertain tax positions	0.10%	(0.30%)	0.10%	(11.50%)
International provisions of the U.S. Tax Cuts and Jobs Act of 2017	(1.90%)	1.90%	(1.10%)	0.80%
Tax credits	(1.40%)	(2.10%)	(1.60%)	(2.50%)
Discrete benefit related to equity compensation	(0.10%)	(0.50%)	(2.00%)	(2.00%)
Discrete expense related to U.S. transition tax	0.00%	11.20%	0.00%	6.50%
Other, net	0.00%	0.40%	0.60%	0.70%
Effective tax rate	13.10%	25.80%	11.90%	8.30%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Dec. 31, 2019
Income Taxes [Line Items]
Tax savings due to the tax holiday	$ 13.6	$ 7
Tax savings due to the tax holiday, per share	$ 0.08	$ 0.04
Reduction in un recognized tax benefits	$ 1.1
Accrued interest and penalties	1.7		$ 1.4
Interest and penalties related to income tax, expense (benefit)	0.3	$ 0.1
Uncertain tax positions	21.4		$ 21.2
Net increase in reserves for uncertain tax positions	$ 0.2

Segment Information - Additiona

Segment Information - Additional Information (Detail)	6 Months Ended
	Jun. 28, 2020Segments
Segment Reporting Information [Line Items]
Number of Operating Segments	4

Schedule of Segment Information

Schedule of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 28, 2020		Jun. 30, 2019		Jun. 28, 2020		Jun. 30, 2019		Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenues	$ 838,661	[1]	$ 564,178	[1]	$ 1,543,016	[2]	$ 1,058,277	[2]
Income (loss) before income taxes	217,291		131,177		414,359		225,156
Total assets	3,249,189		2,671,514		3,249,189		2,671,514		$ 2,787,014
Semiconductor Test
Segment Reporting Information [Line Items]
Revenues	659,147		374,898		1,143,636		715,751
Income (loss) before income taxes	228,787		91,355		382,603		174,404
Total assets	1,192,355		745,073		1,192,355		745,073
System Test
Segment Reporting Information [Line Items]
Revenues	71,806	[1]	73,407	[1]	187,882	[2]	131,627	[2]
Income (loss) before income taxes	19,193		23,535		67,600		38,875
Total assets	126,164		123,460		126,164		123,460
Industrial Automation
Segment Reporting Information [Line Items]
Revenues	58,776		74,726		119,081		140,862
Income (loss) before income taxes	(11,403)		(3,730)		(26,738)		(9,025)
Total assets	662,103		601,676		662,103		601,676
Wireless Test
Segment Reporting Information [Line Items]
Revenues	49,185	[1]	41,236	[1]	92,670	[2]	70,277	[2]
Income (loss) before income taxes	14,482		10,930		24,702		14,558
Total assets	108,066		93,232		108,066		93,232
Corporate And Others [Member]
Segment Reporting Information [Line Items]
Revenues	(253)		(89)		(253)		(240)
Income (loss) before income taxes	(33,768)		9,087		(33,808)		6,344
Total assets	$ 1,160,501		$ 1,108,073		$ 1,160,501		$ 1,108,073
[1]	Includes $2.5 million and $1.7 million in 2020 and 2019, respectively, for leases of Teradyne’s systems recognized outside Accounting Standards Codification (“ASC”) 606 “Revenue from Contracts with Customers.”
[2]	Includes $4.3 million and $3.4 million in 2020 and 2019, respectively, for leases of Teradyne’s systems recognized outside ASC 606 “Revenue from Contracts with Customers.”

Schedule of Segment Reporting I

Schedule of Segment Reporting Information by Segment Charges (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Restructuring and other-employee severance	$ 37,222	$ (10,404)	$ 29,616	$ (5,292)
Contingent consideration adjustment			19,239	(8,701)
Universal Robots (UR)
Segment Reporting Information [Line Items]
Contingent consideration adjustment				3,800
Semiconductor Test
Segment Reporting Information [Line Items]
Restructuring and other			1,100
Cost of revenues-inventory charge	3,799	2,278	6,825	3,452
Restructuring and other-employee severance	0	0	0	924
Contingent consideration adjustment		(11,700)		(8,700)
Contract termination settlement charge	4,000	0	4,000	0
System Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	0	0	0	763
Industrial Automation
Segment Reporting Information [Line Items]
Restructuring and other	0	0	790	1,695
Wireless Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	1,582	829	2,155	1,168
Corporate And Eliminations | Restructuring and other
Segment Reporting Information [Line Items]
Restructuring and other	750	0	750	0
Corporate And Eliminations | Universal Robots (UR) | Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment	2,974	0	3,715	0
Corporate And Eliminations | Mobile Industrial Robots (MiR) | Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment	(668)	(11,671)	(3,546)	(8,668)
Corporate And Eliminations | AutoGuide [Member] | Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment	$ 29,927	$ 0	$ 22,785	$ 0

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019	May 31, 2020	Jan. 31, 2020	May 31, 2019	Jan. 31, 2019
Cumulative repurchases, shares			1.5	6.5
Common stock average price			$ 58.33	$ 38.20
Dividends Payable, Amount Per Share					$ 0.10	$ 0.10	$ 0.09	$ 0.09
Dividend payment	$ 16,600	$ 15,400	$ 33,266	$ 31,019
Share Repurchase Program [Member]
Cumulative repurchases, value			88,500	$ 247,200
Maximum [Member]
Stock repurchase program, authorized amount	$ 1,000,000		$ 1,000,000