Teradyne (TER) 10-Q9 Nov 172017 Q3 Quarterly reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Oct. 01, 2017	Nov. 03, 2017
Document Information
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Oct. 1, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	TER
Entity Registrant Name	TERADYNE, INC
Entity Central Index Key	97,210
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		196,157,730

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Oct. 01, 2017		Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 418,677		$ 307,884
Marketable securities	1,217,830		871,024
Accounts receivable, less allowance for doubtful accounts of $2,222 and $2,356 at October 1, 2017 and December 31, 2016, respectively	268,068		192,444
Inventories, net	125,183		135,958
Prepayments	105,309		108,454
Other current assets	5,021		8,039
Total current assets	2,140,088		1,623,803
Property, plant and equipment, net	259,080		253,821
Marketable securities	211,943		433,843
Deferred tax assets	120,228		107,405
Other assets	12,028		12,165
Retirement plans assets	10,954		7,712
Acquired intangible assets, net	85,729		100,401
Goodwill	249,277		223,343
Total assets	3,089,327	[1]	2,762,493
Current liabilities:
Accounts payable	79,429		95,362
Accrued employees' compensation and withholdings	113,634		109,944
Deferred revenue and customer advances	111,506		84,478
Other accrued liabilities	62,611		51,382
Contingent consideration	21,818		1,050
Accrued income taxes	42,377		30,480
Total current liabilities	431,375		372,696
Retirement plans liabilities	114,316		106,938
Long-term deferred revenue and customer advances	31,686		23,463
Deferred tax liabilities	10,543		12,144
Long-term other accrued liabilities	11,604		28,642
Long-term contingent consideration	17,311		37,282
Long-term debt	362,595		352,669
Total liabilities	979,430		933,834
Commitments and contingencies (See Note P)
SHAREHOLDERS' EQUITY
Common stock, $0.125 par value, 1,000,000 shares authorized; 196,711 and 199,177 shares issued and outstanding at October 1, 2017 and December 31, 2016, respectively	24,589		24,897
Additional paid-in capital	1,631,106		1,593,684
Accumulated other comprehensive income (loss)	16,001		(20,214)
Retained earnings	438,201		230,292
Total shareholders' equity	2,109,897		1,828,659
Total liabilities and shareholders' equity	$ 3,089,327		$ 2,762,493

[1]	Total assets are attributable to each segment. Corporate assets consist of cash and cash equivalents, marketable securities and certain other assets.

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Oct. 01, 2017	Dec. 31, 2016
Accounts receivable, less allowance for doubtful accounts	$ 2,222	$ 2,356
Common stock, par value	$ 0.125	$ 0.125
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	196,711,000	199,177,000
Common stock, shares outstanding	196,711,000	199,177,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Revenues:
Products		$ 412,854	$ 334,610	$ 1,396,413	$ 1,149,581
Services		90,524	75,865	260,778	223,680
Total revenues		503,378	410,475	1,657,191	1,373,261
Cost of revenues:
Cost of products		169,744	148,266	591,880	531,616
Cost of services		38,848	34,850	114,373	101,084
Total cost of revenues (exclusive of acquired intangible assets amortization shown separately below)		208,592	183,116	706,253	632,700
Gross profit		294,786	227,359	950,938	740,561
Operating expenses:
Selling and administrative		86,244	78,794	260,282	239,393
Engineering and development		77,190	71,400	235,101	220,973
Acquired intangible assets amortization		7,028	8,487	23,145	44,725
Restructuring and other		(4,407)	12,177	392	16,372
Goodwill impairment					254,946
Acquired intangible assets impairment					83,339
Total operating expenses		166,055	170,858	518,920	859,748
Income (loss) from operations		128,731	56,501	432,018	(119,187)
Non-operating (income) expense:
Interest income		(4,517)	(2,892)	(11,329)	(6,201)
Interest expense		5,372	633	16,283	2,034
Other (income) expense, net		439	(921)	735	(1,075)
Income (loss) before income taxes	[1],[2]	127,437	59,681	426,329	(113,945)
Income tax provision (benefit)		24,017	(4,113)	62,713	(4,178)
Net income (loss)		$ 103,420	$ 63,794	$ 363,616	$ (109,767)
Net income (loss) per common share:
Basic		$ 0.52	$ 0.32	$ 1.83	$ (0.54)
Diluted		$ 0.52	$ 0.31	$ 1.81	$ (0.54)
Weighted average common shares-basic		197,485	202,211	198,755	203,167
Weighted average common shares-diluted		200,775	203,929	201,413	203,167
Cash dividend declared per common share		$ 0.07	$ 0.06	$ 0.21	$ 0.18

[1]	Included in Corporate and Eliminations are: contingent consideration adjustments, pension and postretirement plans' actuarial gains (losses), impairment of fixed assets and expenses related to the Japan earthquake, property insurance recovery, interest income, interest expense and net foreign exchange gains (losses).
[2]	Included in income (loss) before income taxes are charges and credits related to restructuring and other, inventory charges, a goodwill impairment charge and an acquired intangible assets impairment charge.

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Net income (loss)	$ 103,420	$ 63,794	$ 363,616	$ (109,767)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	9,291	1,843	34,235	7,072
Available-for-sale marketable securities:
Unrealized gains (losses) on marketable securities arising during period, net of tax of $481, $51, $1,666, $2,405, respectively	950	(336)	2,448	5,110
Less: Reclassification adjustment for gains included in net income (loss), net of tax of $(67), $(150), $(173), $(152), respectively	(87)	(334)	(264)	(468)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Total	863	(670)	2,184	4,642
Defined benefit pension and post-retirement plans:
Amortization of prior service (credit) cost included in net periodic pension and post-retirement expense/income, net of tax of $(38), $(46), $(115), $(139) respectively	(68)	(81)	(204)	(244)
Prior service income arising during the period, net of tax of $0, $0, $0, $34, respectively				59
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(68)	(81)	(204)	(185)
Other comprehensive income	10,086	1,092	36,215	11,529
Comprehensive income (loss)	$ 113,506	$ 64,886	$ 399,831	$ (98,238)

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Unrealized gains (losses) on marketable securities arising during period, tax	$ 481	$ 51	$ 1,666	$ 2,405
Reclassification adjustment for gains included in net income, tax	(67)	(150)	(173)	(152)
Amortization of net prior service (credit) cost included in net periodic pension and post-retirement expense/income, tax	(38)	(46)	(115)	(139)
Prior service credit, tax	$ 0	$ 0	$ 0	$ 34

CONDENSED CONSOLIDATED STATEME7

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016
Cash flows from operating activities:
Net income (loss)	$ 363,616	$ (109,767)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	49,243	48,437
Amortization	32,313	46,275
Stock-based compensation	25,620	23,012
Provision for excess and obsolete inventory	7,154	15,148
Contingent consideration fair value adjustment	1,847	10,451
Deferred taxes	(679)	(42,568)
Retirement plans actuarial gains	(2,504)	(1,200)
Gain on insurance recovery	(4,309)
Tax benefit related to employee stock compensation awards		(3,399)
Goodwill impairment		254,946
Acquired intangible assets impairment		83,339
Other	429	151
Changes in operating assets and liabilities:
Accounts receivable	(75,623)	45,660
Inventories	23,770	48,601
Prepayments and other assets	7,362	(13,273)
Accounts payable and other accrued expenses	5,298	(39,584)
Deferred revenue and customer advances	34,535	53,380
Retirement plans contributions	(4,858)	(5,871)
Income taxes	15,808	4,227
Net cash provided by operating activities	479,022	417,965
Cash flows from investing activities:
Purchases of property, plant and equipment	(73,247)	(66,252)
Purchases of available-for-sale marketable securities	(1,036,523)	(875,837)
Proceeds from sales of available-for-sale marketable securities	443,169	466,744
Proceeds from maturities of available-for-sale marketable securities	473,255	202,162
Proceeds from property insurance	5,064	5,051
Net cash used for investing activities	(188,282)	(268,132)
Cash flows from financing activities:
Issuance of common stock under stock purchase and stock option plans	24,462	20,085
Repurchase of common stock	(151,821)	(85,092)
Dividend payments	(41,730)	(36,548)
Payments related to net settlement of employee stock compensation awards	(12,584)	(9,229)
Payments of contingent consideration	(1,050)	(11,697)
Tax benefit related to employee stock compensation awards		3,399
Net cash used for financing activities	(182,723)	(119,082)
Effects of exchange rate changes on cash and cash equivalents	2,776	2,481
Increase in cash and cash equivalents	110,793	33,232
Cash and cash equivalents at beginning of period	307,884	264,705
Cash and cash equivalents at end of period	$ 418,677	$ 297,937

The Company

The Company	9 Months Ended
The Company	Oct. 01, 2017
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 robots used by global manufacturing and light industrial customers to improve quality, increase manufacturing efficiency and decrease manufacturing costs. Teradyne’s automatic test equipment and industrial automation products and services include: • semiconductor test (“Semiconductor Test”) systems; • industrial automation (“Industrial Automation”) products • defense/aerospace (“Defense/Aerospace”) test instrumentation and systems, storage test (“Storage Test”) systems, and circuit-board test and inspection (“Production Board Test”) systems (collectively these products represent “System Test”); and • wireless test (“Wireless Test”) systems.

Accounting Policies

Accounting Policies	9 Months Ended
Accounting Policies	Oct. 01, 2017
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, 2016 condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America. 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 1, 2017, for the year ended December 31, 2016. 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. Actual results may differ significantly from these estimates. Stock-Based Compensation In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-09, “Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” Adoption of this ASU required recognition of a cumulative effect adjustment to retained earnings for any prior year excess tax benefits or tax deficiencies not previously recorded. The cumulative effect adjustment of $39 million was recorded as an increase to retained earnings and deferred tax assets. This ASU also required a change in how Teradyne recognizes the excess tax benefits or tax deficiencies related to stock-based compensation. Prior to adopting ASU 2016-09, these excess tax benefits or tax deficiencies were credited or charged to additional paid-in capital in Teradyne’s consolidated balance sheets. In accordance with ASU 2016-09, starting in the first quarter of 2017, these excess tax benefits or tax deficiencies are recognized as a discrete tax benefit or discrete tax expense to the current income tax provision in Teradyne’s consolidated statements of operations. ASU 2016-09 requires companies to adopt the amendment related to accounting for excess tax benefits or tax deficiencies on a prospective basis. For the three and nine months ended October 1, 2017, Teradyne recognized a discrete tax benefit of $0.0 and $6.0 million, respectively, related to net excess tax benefit. In addition, under ASU 2016-09, all excess tax benefits related to share-based payments are reported as cash flows from operating activities. Previously, excess tax benefits from share-based payments arrangements were reported as cash flows from financing activities. The classification amendment was applied prospectively. This ASU also clarifies that all cash payments made to taxing authorities on the employees’ behalf for withheld shares should be presented as financing activities on the statement of cash flows. Previously, Teradyne reported cash payments made to taxing authorities as operating activities on the statement of cash flows. This change was applied retrospectively. Upon adoption of ASU 2016-09, Teradyne made an accounting policy election to continue accounting for forfeitures by applying an estimated forfeiture rate. Contingencies and Litigation Teradyne may be subject to certain legal proceedings, lawsuits and other claims as discussed in Note P. Teradyne accrues for a loss contingency, including legal proceedings, lawsuits, pending claims and other legal matters, when the likelihood of a loss is probable and the amount of the loss can be reasonably estimated. When the reasonable estimate of the loss is within a range of amounts, and no amount in the range constitutes a better estimate than any other amount, Teradyne accrues the amount at the low end of the range. Teradyne adjusts the accruals from time to time as additional information is received, but the loss incurred may be significantly greater than or less than the amount accrued. Loss contingencies are disclosed when they are material and there is at least a reasonable possibility that a loss has been incurred. Attorney fees related to legal matters are expensed as incurred.

Recently Issued Accounting Pron

Recently Issued Accounting Pronouncements	9 Months Ended
Recently Issued Accounting Pronouncements	Oct. 01, 2017
Recently Issued Accounting Pronouncements	C. RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS On March 10, 2017, the FASB issued ASU 2017-07, “Compensation—Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost On January 26, 2017, the FASB issued ASU 2017-04, “Intangibles—Goodwill and Other (Topic 350): Simplifying the Accounting for Goodwill Impairment.” In October 2016, the FASB issued ASU 2016-16, “Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory ” In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842).” “Leases.” In January 2016, the FASB issued ASU 2016-01, “Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities ” In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” Teradyne has completed its preliminary assessment of the financial statement impact of the new standard and does not expect this ASU to have a material impact on its financial position or results of operations. This preliminary assessment is based on a review of the types and number of revenue arrangements currently in place including the review of individual customer contracts related to these revenue streams. The exact impact of the new standard will be dependent on facts and circumstances at adoption and could vary from quarter to quarter. Based on Teradyne’s preliminary assessment Teradyne does not expect any major changes to be made to existing accounting systems or internal controls. Teradyne will be required to record cumulative effect adjustments to retained earnings upon adopting the new standard in the first quarter of 2018.

Inventories

Inventories	9 Months Ended
Inventories	Oct. 01, 2017
Inventories	D. INVENTORIES Inventories, net consisted of the following at October 1, 2017 and December 31, 2016: October 1, December 31, (in thousands) Raw material $ 64,550 $ 58,530 Work-in-process 17,189 22,946 Finished goods 43,444 54,482 $ 125,183 $ 135,958 Inventory reserves for the periods ending October 1, 2017 and December 31, 2016 were $112.2 million and $116.0 million, respectively.

Financial Instruments

Financial Instruments	9 Months Ended
Financial Instruments	Oct. 01, 2017
Financial Instruments	E. 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 accounts for its investments in debt and equity securities in accordance with the provisions of ASC 320-10, “ Investments—Debt and Equity Securities. On a quarterly basis, Teradyne reviews its investments to identify and evaluate those that have an indication of a potential other-than-temporary impairment. Factors considered in determining whether a loss is other-than-temporary include: • The length of time and the extent to which the market value has been less than cost; • The financial condition and near-term prospects of the issuer; and • The intent and ability to retain the investment in the issuer for a period of time sufficient to allow for any anticipated recovery in market value. Teradyne uses the market and income approach techniques to value its financial instruments and there were no changes in valuation techniques during the three and nine months ended October 1, 2017 and October 2, 2016. As defined in ASC 820-10, “ Fair Value Measurements and Disclosures, Level 1: Quoted prices in active markets for identical assets as of the reporting date; Level 2: Inputs other than Level 1, that are observable either directly or indirectly as of the reporting date. For example, a common approach for valuing fixed income securities is the use of matrix pricing. Matrix pricing is a mathematical technique used to value securities by relying on the securities’ relationship to other benchmark quoted prices, and is considered a Level 2 input; or Level 3: Unobservable inputs that are not supported by market data. Unobservable inputs are developed based on the best information available, which might include Teradyne’s own data. Teradyne’s available-for-sale debt and equity securities are classified as Level 1 and Level 2. Acquisition-related contingent consideration is classified as Level 3. Teradyne determines the fair value of acquisition-related contingent consideration using a Monte Carlo simulation model. Assumptions utilized in the model include forecasted revenues, revenue volatility and discount rate. The vast majority of Level 2 securities are fixed income securities priced by third party pricing vendors. These pricing vendors utilize the most recent observable market information in pricing these securities or, if specific prices are not available, use other observable inputs like market transactions involving identical or comparable securities. Realized gains recorded in the three and nine months ended October 1, 2017 were $0.2 million and $0.7 million, respectively. Realized losses recorded in the three and nine months ended October 1, 2017 were $0.0 million and $0.3 million, respectively. Realized gains in the three and nine months ended October 2, 2016 were $0.7 million and $1.2 million, respectively. Realized losses recorded in the three and nine months ended October 2, 2016 were $0.1 million and $0.4 million, respectively. Realized gains are included in interest income and realized losses are included in interest expense. Unrealized gains and losses are included in accumulated other comprehensive income (loss). The cost of securities sold is based on the specific identification method. During the three and nine months ended October 1, 2017 and October 2, 2016, there were no transfers in or out of Level 1, Level 2 or Level 3 financial instruments. 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 October 1, 2017 and December 31, 2016. October 1, 2017 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 $ 213,664 $ — $ — $ 213,664 Cash equivalents 166,803 38,210 — 205,013 Available-for-sale securities: U.S. Treasury securities — 942,250 — 942,250 Commercial paper — 194,948 — 194,948 Corporate debt securities — 118,487 — 118,487 Certificates of deposit and time deposits — 95,469 — 95,469 U.S. government agency securities — 55,938 — 55,938 Equity and debt mutual funds 22,104 — — 22,104 Non-U.S. government securities — 577 — 577 402,571 1,445,879 — 1,848,450 Derivative assets — 157 — 157 Total $ 402,571 $ 1,446,036 $ — $ 1,848,607 Liabilities Contingent consideration $ — $ — $ 39,129 $ 39,129 Derivative liabilities — 190 — 190 Total $ — $ 190 $ 39,129 $ 39,319 Reported as follows: (Level 1) (Level 2) (Level 3) Total (in thousands) Assets Cash and cash equivalents $ 380,467 $ 38,210 $ — $ 418,677 Marketable securities — 1,217,830 — 1,217,830 Long-term marketable securities 22,104 189,839 — 211,943 Prepayments — 157 — 157 Total $ 402,571 $ 1,446,036 $ — $ 1,848,607 Liabilities . Other current liabilities $ — $ 190 $ — $ 190 Contingent consideration — — 21,818 21,818 Long-term contingent consideration — — 17,311 17,311 Total $ — $ 190 $ 39,129 $ 39,319 December 31, 2016 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 $ 214,722 $ — $ — $ 214,722 Cash equivalents 37,458 55,704 — 93,162 Available for sale securities: U.S. Treasury securities — 902,800 — 902,800 Commercial paper — 161,630 — 161,630 Corporate debt securities — 100,153 — 100,153 Certificates of deposit and time deposits — 82,133 — 82,133 U.S. government agency securities — 39,252 — 39,252 Equity and debt mutual funds 18,171 — — 18,171 Non-U.S. government securities — 728 — 728 270,351 1,342,400 — 1,612,751 Derivative assets — 1 — 1 Total $ 270,351 $ 1,342,401 $ — $ 1,612,752 Liabilities Contingent consideration $ — $ — $ 38,332 $ 38,332 Derivative liabilities — 131 — 131 Total $ — $ 131 $ 38,332 $ 38,463 Reported as follows: (Level 1) (Level 2) (Level 3) Total (in thousands) Assets Cash and cash equivalents $ 252,180 $ 55,704 $ — $ 307,884 Marketable securities — 871,024 — 871,024 Long-term marketable securities 18,171 415,672 — 433,843 Prepayments — 1 — 1 Total $ 270,351 $ 1,342,401 $ — $ 1,612,752 Liabilities Other accrued liabilities $ — $ 131 $ — $ 131 Contingent consideration — — 1,050 1,050 Long-term contingent consideration — — 37,282 37,282 Total $ — $ 131 $ 38,332 $ 38,463 Changes in the fair value of Level 3 contingent consideration for the three and nine months ended October 1, 2017 and October 2, 2016 were as follows: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Balance at beginning of period $ 39,415 $ 24,914 $ 38,332 $ 37,436 Payments (a) — — (1,050 ) (15,000 ) Fair value adjustment (b)(c) (286 ) 7,973 1,847 10,451 Balance at end of period $ 39,129 $ 32,887 $ 39,129 $ 32,887 (a) In the nine months ended October 1, 2017, Teradyne paid $1.1 million of contingent consideration for the earn-out in connection with the acquisition of Avionics Interface Technology, LLC (“AIT”). In the nine months ended October 2, 2016, based on Universal Robots’ calendar year 2015 EBITDA results, Teradyne paid $15.0 million or 100% of the eligible EBITDA contingent consideration amount in connection with the acquisition of Universal Robots. (b) In the nine months ended October 1, 2017, the fair value of contingent consideration for the earn-out in connection with the acquisition of Universal Robots was increased by $1.8 million due to an increase in forecasted revenue. In the three and nine months ended October 2, 2016, the fair value of contingent consideration for the earn-out in connection with the acquisition of Universal Robots was increased by $8.0 million and $9.9 million, respectively, primarily due to an increase in forecasted revenue and a decrease in the discount rate. (c) In the nine months ended October 2, 2016, the fair value of contingent consideration for the earn-out in connection with the acquisition of AIT was increased by $0.6 million due to an increase in forecasted revenue. The following table provides quantitative information associated with the fair value measurement of Teradyne’s Level 3 financial instruments: Liability October 1, 2017 Fair Value Valuation Technique Unobservable Inputs Weighted Average (in thousands) Contingent consideration (Universal Robots) $21,818 Monte Carlo Simulation Revenue for the period July 1, 2015—December 31, 2017 volatility 11.5 % Discount rate 2.6 % $17,311 Monte Carlo Simulation Revenue for the period July 1, 2015—December 31, 2018 volatility 11.5 % Discount rate 2.6 % As of October 1, 2017, the significant unobservable inputs used in the Monte Carlo simulation to fair value the Universal Robots contingent consideration include forecasted revenue, revenue volatility and discount rate. Increases or decreases in the inputs would result in a higher or lower fair value measurement. The maximum payment for each of the two Universal Robots revenue earn-outs is $25.0 million. The carrying amounts and fair values of Teradyne’s financial instruments at October 1, 2017 and December 31, 2016 were as follows: October 1, 2017 December 31, 2016 Carrying Value Fair Value Carrying Value Fair Value (in thousands) Assets Cash and cash equivalents $ 418,677 $ 418,677 $ 307,884 $ 307,884 Marketable securities 1,429,773 1,429,773 1,304,867 1,304,867 Derivative assets 157 157 1 1 Liabilities Contingent consideration 39,129 39,129 38,332 38,332 Derivative liabilities 190 190 131 131 Convertible debt (1) 362,595 613,238 352,669 486,754 (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 tables summarize the composition of available-for-sale marketable securities at October 1, 2017 and December 31, 2016: October 1, 2017 Available-for-Sale Fair Market Value of Investments with Unrealized Losses Cost Unrealized Gain Unrealized (Loss) Fair Market Value (in thousands) U.S. Treasury securities $ 944,120 $ 64 $ (1,934 ) $ 942,250 $ 936,195 Commercial paper 194,985 11 (48 ) 194,948 140,562 Corporate debt securities 116,687 2,046 (246 ) 118,487 79,119 Certificates of deposit and time deposits 95,447 29 (7 ) 95,469 33,238 U.S. government agency securities 55,936 20 (18 ) 55,938 52,997 Equity and debt mutual funds 18,202 3,923 (21 ) 22,104 1,529 Non-U.S. government securities 570 7 — 577 — Total $ 1,425,947 $ 6,100 $ (2,274 ) $ 1,429,773 $ 1,243,640 Reported as follows: Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Marketable securities $ 1,218,752 $ 65 $ (987 ) $ 1,217,830 $ 1,088,881 Long-term marketable securities 207,195 6,035 (1,287 ) 211,943 154,759 Total $ 1,425,947 $ 6,100 $ (2,274 ) $ 1,429,773 $ 1,243,640 December 31, 2016 Available-for-Sale Fair Market Value of Investments with Unrealized Losses Cost Unrealized Gain Unrealized (Loss) Fair Market Value (in thousands) U.S. Treasury securities $ 904,737 $ 97 $ (2,034 ) $ 902,800 $ 572,284 Commercial paper 161,672 24 (66 ) 161,630 84,034 Corporate debt securities 99,708 1,065 (620 ) 100,153 53,642 Certificates of deposit and time deposits 82,080 54 (1 ) 82,133 7,760 U.S. government agency securities 39,264 7 (19 ) 39,252 13,461 Equity and debt mutual funds 16,505 1,724 (58 ) 18,171 1,661 Non-U.S. government securities 745 6 (23 ) 728 137 Total $ 1,304,711 $ 2,977 $ (2,821 ) $ 1,304,867 $ 732,979 Reported as follows: Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Marketable securities $ 871,321 $ 134 $ (431 ) $ 871,024 $ 423,128 Long-term marketable securities 433,390 2,843 (2,390 ) 433,843 309,851 Total $ 1,304,711 $ 2,977 $ (2,821 ) $ 1,304,867 $ 732,979 As of October 1, 2017, the fair market value of investments with unrealized losses totaled $1,243.6 million. Of this value, $113.3 million had unrealized losses of $0.9 million for greater than one year and $1,130.3 million had unrealized losses of $1.4 million for less than one year. As of December 31, 2016, the fair market value of investments with unrealized losses totaled $733.0 million. Of this value, $2.9 million had unrealized losses of $0.3 million for greater than one year and $730.1 million had unrealized losses of $2.5 million for less than one year. 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 October 1, 2017 and December 31, 2016 were temporary. The contractual maturities of investments held at October 1, 2017 were as follows: October 1, 2017 Cost Fair Market Value (in thousands) Due within one year $ 1,218,752 $ 1,217,830 Due after 1 year through 5 years 136,081 135,889 Due after 5 years through 10 years 14,129 13,818 Due after 10 years 38,783 40,132 Total $ 1,407,745 $ 1,407,669 Contractual maturities of investments held at October 1, 2017 exclude equity and debt mutual funds as they do not have contractual maturity dates. 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 October 1, 2017 and December 31, 2016 was $79.2 million and $83.9 million, respectively. The following table summarizes the fair value of derivative instruments at October 1, 2017 and December 31, 2016: Balance Sheet Location October 1, December 31, (in thousands) Derivatives not designated as hedging instruments: Foreign currency forward contracts assets Prepayments $ 157 $ 1 Foreign currency forward contracts liabilities Other current liabilities (190 ) (131 ) Total $ (33 ) $ (130 ) The following table summarizes the effect of derivative instruments recognized in the statement of operations during the three and nine months ended October 1, 2017 and October 2, 2016. Location of (Gains) Losses Recognized in Statement of Operations For the Three Months Ended For the Nine Months Ended October 1, 2017 October 2, 2016 October 1, 2017 October 2, 2016 (in thousands) Derivatives not designated as hedging instruments: Foreign currency forward contracts Other (income) expense, net $ (939 ) $ 941 $ (1,514 ) $ 11,140 Total $ (939 ) $ 941 $ (1,514 ) $ 11,140 (1) The table does not reflect the corresponding gains and losses from the remeasurement of monetary assets and liabilities denominated in foreign currencies. (2) For the three and nine months ended October 1, 2017, net losses from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $1.4 million and $2.3 million, respectively. (3) For the three and nine months ended October 2, 2016, net gains from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $1.9 million and $12.2 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.

Debt

Debt	9 Months Ended
Debt	Oct. 01, 2017
Debt	F. DEBT Convertible Senior Notes On December 12, 2016, Teradyne completed a private offering of $460.0 million convertible senior unsecured notes (the “Notes”). 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 semi-annually in arrears on June 15 and December 15 of each year, beginning on June 15, 2017. 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, 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. The conversion rate for the Notes will initially be 31.4102 shares per $1,000 principal amount, which is equivalent to an initial conversion price of approximately $31.84 per share of Teradyne’s common stock. The conversion rate is subject to adjustment under certain circumstances. 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 initial conversion price of the Notes of $31.84. The Note Hedge Transactions cover, subject to customary anti-dilution adjustments, approximately 14.4 million shares of Teradyne’s common stock. The convertible note hedge is considered indexed to Teradyne’s stock as the terms of the Note Hedge Transactions do not contain an exercise contingency and the settlement amount equals the difference between the fair value of a fixed number of Teradyne’s shares and a fixed strike price. Because the only variable that can affect the settlement amount is Teradyne’s stock price, which is an input to the fair value of a fixed-for-fixed option contract, the convertible note hedge is considered indexed to Teradyne’s 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 (or, at its election subject to certain conditions, cash-settled) warrants to the Option Counterparties. The Warrant Transactions cover, subject to customary anti-dilution adjustments, approximately 14.4 million shares of common stock. The strike price of the warrants will initially be $39.95 per share (subject to adjustment). The Warrant Transactions could have a dilutive effect to Teradyne’s common stock to the extent that the market price per share of Teradyne’s common stock, as measured under the terms of the Warrant Transactions, exceeds the applicable strike price of the warrants. 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. 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’s effective annual interest rate on the Notes is 5.0%. At October 1, 2017 and December 31, 2016, the Notes are classified as long-term debt in the balance sheets based on their December 15, 2023 maturity date. Debt issuance costs of approximately $7.2 million are being amortized to interest expense over the seven-year term of the Notes. As of October 1, 2017, unamortized debt issuance costs were $6.5 million. The below tables represent the key components of Teradyne’s convertible senior notes: October 1, 2017 December 31, 2016 (in thousands) Debt principal $ 460,000 $ 460,000 Unamortized discount 97,405 107,331 Net carrying amount of convertible debt $ 362,595 $ 352,669 For the Three Months For the Nine Months October 1, 2017 October 1, 2017 (in thousands) Contractual interest expense on the coupon $ 1,422 $ 4,297 Amortization of the discount component and debt issue fees recognized as interest expense 3,350 9,926 Total interest expense on the convertible debt $ 4,772 $ 14,223 As of October 1, 2017, the remaining unamortized discount was $97.4 million, which will be amortized over 6.3 years using the effective interest rate method. The carrying amount of the equity component was $100.8 million. As of October 1, 2017, the conversion rate was equal to the initial conversion price of approximately $31.84 per share and the if-converted value of the Notes was $538.7 million. Revolving Credit Facility On April 27, 2015, Teradyne entered into a Credit Agreement (the “Credit Agreement”) with Barclays Bank PLC, as administrative agent and collateral agent, and the lenders party thereto. The Credit Agreement provides for a five-year, senior secured revolving credit facility of up to $350 million (the “Credit Facility”). The Credit Agreement further provides that, subject to customary conditions, Teradyne may seek to obtain from existing or new lenders incremental commitments under the Credit Facility in an aggregate principal amount not to exceed $150 million. Proceeds from the Credit Facility may be used for general corporate purposes and working capital. Teradyne incurred $2.3 million in costs related to the revolving credit facility. These costs are being amortized over the five-year term of the revolving credit facility and are included in interest expense in the statements of operations. As of November 9, 2017, 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 0.00% to 1.00% per annum or LIBOR plus a margin ranging from 1.00% to 2.00% per annum, based on the Consolidated Leverage Ratio of Teradyne and its Restricted Subsidiaries. In addition, Teradyne will pay a commitment fee on the unused portion of the commitments under the Credit Facility ranging from 0.125% to 0.350% 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 and its Restricted Subsidiaries’ 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. As of November 9, 2017, Teradyne was in compliance with all covenants. 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.

Prepayments

Prepayments	9 Months Ended
Prepayments	Oct. 01, 2017
Prepayments	G. PREPAYMENTS Prepayments consist of the following and are included in prepayments on the balance sheet: October 1, December 31, (in thousands) Contract manufacturer prepayments $ 78,293 $ 84,473 Prepaid taxes 9,658 4,664 Prepaid maintenance and other services 6,685 7,676 Other prepayments 10,673 11,641 Total $ 105,309 $ 108,454

Deferred Revenue and Customer A

Deferred Revenue and Customer Advances	9 Months Ended
Deferred Revenue and Customer Advances	Oct. 01, 2017
Deferred Revenue and Customer Advances	H. 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: October 1, December 31, (in thousands) Extended warranty $ 26,492 $ 28,200 Customer advances, undelivered elements and other 58,577 32,938 Maintenance and training 58,123 46,803 Total $ 143,192 $ 107,941

Product Warranty

Product Warranty	9 Months Ended
Product Warranty	Oct. 01, 2017
Product Warranty	I. PRODUCT WARRANTY Teradyne generally provides a one-year warranty on its products, commencing upon installation, acceptance, delivery or shipment. A provision is recorded upon revenue recognition to cost of revenues for estimated warranty expense based on historical experience. Related costs are charged to the warranty accrual as incurred. The warranty balance below is included in other accrued liabilities on the balance sheet. For the Three Months Ended For the Nine Months Ended October 1, 2017 October 2, 2016 October 1, 2017 October 2, (in thousands) Balance at beginning of period $ 9,093 $ 8,784 $ 7,203 $ 6,925 Accruals for warranties issued during the period 2,734 3,248 11,049 11,626 Adjustments related to pre-existing warranties (35 ) (460 ) (499 ) (637 ) Settlements made during the period (3,055 ) (3,249 ) (9,016 ) (9,591 ) Balance at end of period $ 8,737 $ 8,323 $ 8,737 $ 8,323 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 extended warranty balance below is included in short and long-term deferred revenue and customer advances on the balance sheet. For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Balance at beginning of period $ 29,377 $ 30,422 $ 28,200 $ 30,024 Deferral of new extended warranty revenue 2,636 4,638 17,126 17,036 Recognition of extended warranty deferred revenue (5,521 ) (5,030 ) (18,834 ) (17,030 ) Balance at end of period $ 26,492 $ 30,030 $ 26,492 $ 30,030

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
Stock-Based Compensation	Oct. 01, 2017
Stock-Based Compensation	. STOCK-BASED COMPENSATION Under Teradyne’s stock compensation plans, Teradyne grants stock options, restricted stock units and performance-based restricted stock units, and employees are eligible to purchase Teradyne’s common stock through its Employee Stock Purchase Plan (“ESPP”). 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. Time-based restricted stock unit awards granted to employees vest in equal annual installments over four years. Restricted stock unit awards granted to non-employee directors vest after a one year period, with 100% of the award vesting on the first anniversary of the grant date. Teradyne expenses the cost of the restricted stock unit awards subject to time-based vesting, which is determined to be the fair market value of the shares at the date of grant, ratably over the period during which the restrictions lapse. Commencing in January 2014, Teradyne granted performance-based restricted stock units (“PRSUs”) to its executive officers with a performance metric based on relative total shareholder return (“TSR”). For TSR grants issued in 2014 and 2015, Teradyne’s three-year TSR performance is measured against the Philadelphia Semiconductor Index. For TSR grants issued in 2016 and 2017, Teradyne’s three-year TSR performance is measured against the New York Stock Exchange (“NYSE”) Composite Index. The final number of TSR PRSUs that vest will vary based upon the level of performance achieved from 200% to 0% of the target shares. The TSR PRSUs will vest upon the three-year anniversary of the grant date. The TSR PRSUs are valued using a Monte Carlo simulation model. The number of units expected to be earned, based upon the achievement of the TSR market condition, is factored into the grant date Monte Carlo valuation. Compensation expense is recognized on a straight-line basis over the three-year service period. Compensation expense is recognized regardless of the eventual number of units that are earned based upon the market condition, provided the executive officer remains an employee at the end of the three-year period. Compensation expense is reversed if at any time during the three-year service period the executive officer is no longer an employee, subject to the retirement and termination eligibility provisions noted below. In January 2017 and 2016, Teradyne granted PRSUs to its executive officers with a performance metric based on three-year cumulative non-GAAP profit before interest and tax (“PBIT”) as a percent of Teradyne’s revenue. Non-GAAP PBIT is a financial measure equal to GAAP income from operations less restructuring and other, net; amortization of acquired intangible assets; acquisition and divestiture related charges or credits; pension actuarial gains and losses; non-cash convertible debt interest expense; and other non-recurring gains and charges. The final number of PBIT PRSUs that vest will vary based upon the level of performance achieved from 200% to 0% of the target shares. The PBIT PRSUs will vest upon the three-year anniversary of the grant date. Compensation expense is recognized on a straight-line basis over the three-year service period. Compensation expense is recognized based on the number of units that are earned based upon the three-year Teradyne PBIT as a percent of Teradyne’s revenue, provided the executive officer remains an employee at the end of the three-year period subject to the retirement and termination eligibility provisions noted below. Beginning with PRSUs granted in January 2014, if the 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 and at least ten years of service, then all or a portion of the recipient’s PRSUs (based on the actual performance percentage achieved on the determination date) will vest on the date the performance percentage is determined. Except as set forth in the preceding sentence, no PRSUs will vest if the executive officer is no longer an employee at the end of the three-year period. During the nine months ended October 1, 2017 and October 2, 2016, Teradyne granted 0.1 million TSR PRSUs with a grant date fair value of $35.66 and $20.29, respectively. The fair value was estimated using the Monte Carlo simulation model with the following assumptions: For the Nine Months Ended October 1, October 2, Risk-free interest rate 1.5 % 1.0 % Teradyne volatility-historical 26.6 % 27.0 % NYSE Composite Index volatility-historical 13.4 % 13.1 % Dividend yield 1.0 % 1.2 % Expected volatility was based on the historical volatility of Teradyne’s stock and the NYSE Composite Index for the 2017 and 2016 grant 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 $0.28 per share for 2017 grants and $0.24 per share for 2016 grants, divided by Teradyne’s stock price on the grant date of $28.56 for the 2017 grant and $19.43 for the 2016 grant. During the nine months ended October 1, 2017, Teradyne granted 0.1 million of PBIT PRSUs with a grant date fair value of $27.72. During the nine months ended October 1, 2017, Teradyne granted 0.8 million of service-based restricted stock unit awards to employees at a weighted average grant date fair value of $28.03, 0.1 million of service-based restricted stock unit awards to non-employee directors at a weighted average grant date fair value of $34.48, and 0.1 million of service-based stock options to executive officers at a weighted average grant date fair value of $7.13. During the nine months ended October 2, 2016, Teradyne granted 0.1 million PBIT PRSUs with a grant date fair value of $18.71. During the nine months ended October 2, 2016, Teradyne granted 1.2 million of service-based restricted stock unit awards to employees at a weighted average grant date fair value of $18.49, 0.1 million of service-based restricted stock unit awards to non-employee directors at a weighted average grant date fair value of $18.71 and 0.1 million of service-based stock options to executive officers at a weighted average grant date fair value of $5.30. Restricted stock unit awards granted to employees vest in equal annual installments over four years. Stock options vest in equal annual installments over four years and have a term of seven years from the date of grant. The fair value of stock options was estimated using the Black-Scholes option-pricing model with the following assumptions: For the Nine Months Ended October 1, October 2, Expected life (years) 5.0 5.0 Risk-free interest rate 2.0 % 1.4 % Volatility-historical 27.8 % 32.9 % Dividend yield 1.0 % 1.2 % 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 $0.28 per share for 2017 grants and $0.24 per share for 2016 grants, divided by Teradyne’s stock price on the grant date of $28.56 for the 2017 grant and $19.43 for the 2016 grant.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
Accumulated Other Comprehensive Income (Loss)	Oct. 01, 2017
Accumulated Other Comprehensive Income (Loss)	K. ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Changes in accumulated other comprehensive income (loss), 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) Nine Months Ended October 1, 2017 Balance at December 31, 2016, net of tax of $0, $209, $(778), respectively $ (21,921 ) $ (60 ) $ 1,767 $ (20,214 ) Other comprehensive income before reclassifications, net of tax of $0, $1,666, $0, respectively 34,235 2,448 — 36,683 Amounts reclassified from accumulated other comprehensive income, net of tax of $0, $(173), $(115), respectively — (264 ) (204 ) (468 ) Net current period other comprehensive income (loss), net of tax of $0, $1,493, $(115), respectively 34,235 2,184 (204 ) 36,215 Balance at October 1, 2017, net of tax of $0, $1,702, $(893), respectively $ 12,314 $ 2,124 $ 1,563 $ 16,001 Foreign Currency Translation Adjustments Unrealized Gains (Losses) on Marketable Securities Retirement Plans Prior Service Credit Total (in thousands) Nine Months Ended October 2, 2016 Balance at December 31, 2015, net of tax of $0, $(459), $(622), respectively $ (8,759 ) $ (1,414 ) $ 2,029 $ (8,144 ) Other comprehensive income before reclassifications, net of tax of $0, $2,405, $34, respectively 7,072 5,110 59 12,241 Amounts reclassified from accumulated other comprehensive income (loss), net of tax of $0, $(152), $(139), respectively — (468 ) (244 ) (712 ) Net current period other comprehensive income (loss), net of tax of $0, $2,253, $(105), respectively 7,072 4,642 (185 ) 11,529 Balance as October 2, 2016, net of tax of $0, $1,749, $(727), respectively $ (1,687 ) $ 3,228 $ 1,844 $ 3,385 Reclassifications out of accumulated other comprehensive (loss) income to the statement of operations for the three and nine months ended October 1, 2017 and October 2, 2016 were as follows: Details about Accumulated Other Comprehensive Income Components For the Three Months Ended For the Nine Months Ended Affected Line Item in the Statements of Operations October 1, October 2, October 1, October 2, (in thousands) Available-for-sale marketable securities: Unrealized gains, net of tax of $67, $150, $173, $152, respectively $ 87 $ 334 $ 264 $ 468 Interest income Defined benefit pension and postretirement plans: Amortization of prior service benefit, net of tax of $38, $46, $115, $139, respectively 68 81 204 244 (a) Total reclassifications, net of tax of $105, $196, $288, $291, respectively $ 155 $ 415 $ 468 $ 712 Net income (a) The amortization of prior service credit is included in the computation of net periodic pension cost and postretirement benefit; see Note O: “Retirement Plans.”

Goodwill and Acquired Intangibl

Goodwill and Acquired Intangible Assets	9 Months Ended
Goodwill and Acquired Intangible Assets	Oct. 01, 2017
Goodwill and Acquired Intangible Assets	L. 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” In the second quarter of 2016, the Wireless Test reporting unit (which is Teradyne’s Wireless Test operating and reportable segment) reduced headcount by 11% as a result of a sharp decline in projected demand attributable to an estimated smaller future wireless test market. The decrease in projected demand was due to lower forecasted buying from Teradyne’s largest Wireless Test segment customer (who had previously contributed between 51% and 73% of annual Wireless Test sales since the LitePoint acquisition in 2011) as a result of the customer’s numerous operational efficiencies; slower smartphone growth rates; and a slowdown of new wireless technology adoption. Teradyne considered the headcount reduction and sharp decline in projected demand to be a triggering event for an interim goodwill impairment test. Teradyne used the income and market approaches to determine the fair value of the Wireless Test reporting unit for step 1 of the goodwill impairment test. With respect to the income approach, Teradyne used the discounted cash flow method, which included seven year future cash flow projections and an estimated terminal value. The cash flow projections were prepared using Teradyne’s forecast, which was based upon underlying estimates of the total market size, and Teradyne’s market share in the wireless test market developed using Teradyne and independent third party data. The estimated terminal value was calculated using the Gordon Growth model. The market approach used a revenue multiple to develop an estimate of fair value. The revenue multiple was estimated using enterprise value as a ratio of next twelve months revenue for comparable companies. Teradyne equally weighted the income and market approaches to determine the fair value of the Wireless Test reporting unit. The carrying amount of the Wireless Test reporting unit exceeded its fair value; therefore, the second step of the goodwill impairment test was performed to calculate implied goodwill and to measure the amount of the impairment loss. Teradyne allocated the fair value of the Wireless Test reporting unit to all of its assets and liabilities (including unrecognized intangible assets). The net book value of raw materials inventory was estimated as an approximation of current replacement costs. The fair value of finished goods inventory was estimated at the present value of selling price less direct selling costs and profit on the selling effort. The selling price used in the inventory fair values was based upon the product gross margins included in Teradyne’s forecast. The fair value of the deferred revenue liability was estimated by assessing the costs required to service the obligation plus a reasonable profit margin. The fair value for personal property assets, which consisted of furniture and fixtures, machinery and equipment, computer equipment, software and leasehold improvements, was estimated using the replacement cost approach, which approximated carrying value. The fair value of intangible assets was estimated using the income approach and, in particular, developed technology and trademarks/trade names were valued using the relief-from-royalty method and customer relationships and customer backlog were valued using the discounted cash flow method. Royalty rates were estimated using rates applicable to wireless testing equipment and other similar technologies. Based upon this allocation, Teradyne determined that goodwill was valued at $8.0 million and recorded an impairment loss of $254.9 million in the second quarter of 2016. The changes in the carrying amount of goodwill by reportable segments for the nine months ended October 1, 2017, were as follows: Industrial Automation System Test Wireless Test Semiconductor Test Total (in thousands) Balance at December 31, 2016 Goodwill $ 204,851 $ 158,699 $ 361,819 $ 260,540 $ 985,909 Accumulated impairment losses — (148,183 ) (353,843 ) (260,540 ) (762,566 ) 204,851 10,516 7,976 — 223,343 Foreign currency translation adjustment 25,934 — — — 25,934 Balance at October 1, 2017 Goodwill 230,785 158,699 361,819 260,540 1,011,843 Accumulated impairment losses — (148,183 ) (353,843 ) (260,540 ) (762,566 ) $ 230,785 $ 10,516 $ 7,976 $ — $ 249,277 Acquired 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. As a result of the Wireless Test segment goodwill impairment review in the second quarter of 2016, Teradyne performed an impairment test of the Wireless Test segment’s intangible and long-lived assets. The impairment test is based on a comparison of the estimated undiscounted cash flows to the carrying value of the asset group. If undiscounted cash flows for the asset group are less than the carrying amount, the asset group is written down to its estimated fair value based on a discounted cash flow analysis. The cash flow estimates used to determine the impairment contain management’s best estimates using appropriate assumptions and projections at that time. The fair value of intangible assets was estimated using the income approach and, in particular, developed technology and trademarks/trade names were valued using the relief-from-royalty method and customer relationships were valued using the discounted cash flow method. Royalty rates were estimated using rates applicable to wireless testing equipment and other similar technologies. As a result of the analysis, Teradyne recorded an $83.3 million impairment charge in the second quarter of 2016 in acquired intangible assets impairment on the statements of operations. Amortizable acquired intangible assets consist of the following and are included in acquired intangible assets, net on the balance sheet: October 1, 2017 Gross Carrying Amount Accumulated Amortization Cumulative Net Carrying Amount (in thousands) Developed technology $ 270,877 $ (221,051 ) $ 1,057 $ 50,883 Customer relationships 92,741 (82,286 ) 111 10,566 Tradenames and trademarks 50,100 (26,171 ) 271 24,200 Non-compete agreement 320 (240 ) — 80 Total $ 414,038 $ (329,748 ) $ 1,439 $ 85,729 December 31, 2016 Gross Carrying Amount Accumulated Amortization Cumulative Net Carrying Amount (in thousands) Developed technology $ 270,877 $ (206,376 ) $ (5,093 ) $ 59,408 Customer relationships 92,741 (76,707 ) (538 ) 15,496 Tradenames and trademarks 50,100 (23,435 ) (1,308 ) 25,357 Non-compete agreement 320 (180 ) — 140 Total $ 414,038 $ (306,698 ) $ (6,939 ) $ 100,401 Aggregate acquired intangible assets amortization expense was $7.0 million and $23.1 million, respectively, for the three and nine months ended October 1, 2017 and $8.5 million and $44.7 million, respectively, for the three and nine months ended October 2, 2016. Estimated acquired intangible assets amortization expense for each of the five succeeding fiscal years is as follows: Year Amortization Expense (in thousands) 2017(remainder) 7,348 2018 29,268 2019 25,295 2020 11,134 2021 3,703 Thereafter 8,981

Net Income (Loss) per Common Sh

Net Income (Loss) per Common Share	9 Months Ended
Net Income (Loss) per Common Share	Oct. 01, 2017
Net Income (Loss) per Common Share	M. NET INCOME (LOSS) PER COMMON SHARE The following table sets forth the computation of basic and diluted net income (loss) per common share: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands, except per share amounts) Net income (loss) for basic and diluted net income (loss) per share $ 103,420 $ 63,794 $ 363,616 $ (109,767 ) Weighted average common shares-basic 197,485 202,211 198,755 203,167 Effect of dilutive potential common shares: Restricted stock units 1,832 1,282 1,663 — Incremental shares from assumed conversion of convertible note 1,144 — 632 — Stock options 306 421 337 — Employee stock purchase plan 8 15 26 — Dilutive potential common shares 3,290 1,718 2,658 — Weighted average common shares-diluted 200,775 203,929 201,413 203,167 Net income (loss) per common share-basic $ 0.52 $ 0.32 $ 1.83 $ (0.54 ) Net income (loss) per common share-diluted $ 0.52 $ 0.31 $ 1.81 $ (0.54 ) (1) Incremental shares from assumed conversion of the convertible notes for the three and nine months ended October 1, 2017 are calculated using the difference between the average Teradyne stock price for the period and the conversion price of $31.84, multiplied by the 14.4 million shares that would be issued upon conversion. The result of this calculation, representing the total intrinsic value of the convertible debt, is divided by the average Teradyne stock price for the period. The computation of diluted net income per common share for the three and nine months ended October 1, 2017 excludes the effect of the potential exercise of stock options to purchase approximately 0.1 million shares because the effect would have been anti-dilutive. The computation of diluted net income per common share for the three months ended October 2, 2016 excludes the effect of the potential exercise of stock options to purchase approximately 0.1 million shares because the effect would have been anti-dilutive. The computation of diluted net income per common share for the nine months ended October 2, 2016 excludes the effect of the potential exercise of all outstanding stock options and restricted stock units because Teradyne had a net loss and inclusion would be anti-dilutive.

Restructuring and Other

Restructuring and Other	9 Months Ended
Restructuring and Other	Oct. 01, 2017
Restructuring and Other	N. RESTRUCTURING AND OTHER During the three months ended October 1, 2017, Teradyne recorded $5.1 million of property insurance recovery related to the Japan earthquake, a $0.4 million credit related to a previously impaired lease termination of a Wireless Test facility in Sunnyvale, CA, and a $0.3 million credit for the decrease in the fair value of the Universal Robots contingent consideration liability, partially offset by $0.8 million of Japan earthquake related expenses and $0.6 million recorded for employee severance charges, primarily in Semiconductor Test. During the three months ended October 2, 2016, Teradyne recorded $8.0 million for the increase in the fair value of the Universal Robots contingent consideration liability and $4.2 million for employee severance charges, primarily in Semiconductor Test and Wireless Test. During the nine months ended October 1, 2017, Teradyne recorded $2.0 million for employee severance charges, primarily in Industrial Automation and Corporate, $1.8 million for the increase in the fair value of the Universal Robots contingent consideration liability, $0.9 million for a lease impairment of a Wireless Test facility in Sunnyvale, CA, which was terminated in September 2017, and $0.8 million of Japan earthquake related expenses, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake. During the nine months ended October 2, 2016, Teradyne recorded $10.5 million for the increase in the fair value of contingent consideration liability, of which $9.9 million was related to Universal Robots and $0.6 million was related to AIT, $5.9 million for employee severance charges, primarily in Semiconductor Test and Wireless Test, $4.2 million for an impairment of fixed assets, and $0.9 million for Japan earthquake related expenses, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.

Retirement Plans

Retirement Plans	9 Months Ended
Retirement Plans	Oct. 01, 2017
Retirement Plans	O. 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. subsidiaries. Benefits under these plans are based on employees’ years of service and compensation. Teradyne’s funding policy is to make contributions to these plans in accordance with local laws and to the extent that such contributions are tax deductible. The assets of the U.S. qualified pension plan consist primarily of fixed income and equity securities. In addition, Teradyne has unfunded qualified foreign plans as well as an unfunded supplemental executive defined benefit plan in the United States to provide retirement benefits in excess of levels allowed by the Employment Retirement Income Security Act (“ERISA”) and the Internal Revenue Code (“IRC”). In the nine months ended October 1, 2017, Teradyne contributed $1.9 million to the U.S. qualified pension plan, $1.9 million to the U.S. supplemental executive defined benefit pension plan and $0.6 million to certain qualified pension plans for non-U.S. subsidiaries. In the nine months ended October 2, 2016, Teradyne contributed $1.9 million to the U.S. qualified pension plan, $1.9 million to the U.S. supplemental executive defined benefit pension plan and $1.5 million to certain qualified pension plans for non-U.S. subsidiaries. For the three and nine months ended October 1, 2017 and October 2, 2016, Teradyne’s net periodic pension cost (income) was comprised of the following: For the Three Months Ended October 1, 2017 October 2, 2016 United States Foreign United States Foreign (in thousands) Service cost $ 560 $ 215 $ 575 $ 208 Interest cost 3,288 186 3,407 209 Expected return on plan assets (3,002 ) (6 ) (3,458 ) (6 ) Amortization of prior service cost 18 — 24 — Net actuarial loss — — — 662 Total $ 864 $ 395 $ 548 $ 1,073 For the Nine Months Ended October 1, 2017 October 2, 2016 United States Foreign United States Foreign (in thousands) Service cost $ 1,679 $ 606 $ 1,726 $ 614 Interest cost 9,863 527 10,222 614 Expected return on plan assets (9,006 ) (19 ) (10,373 ) (17 ) Amortization of prior service cost 53 — 72 — Net Actuarial (gain) loss (2,732 ) 243 (1,848 ) 662 Settlement — — — (184 ) Total $ (143 ) $ 1,357 $ (201 ) $ 1,689 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 nine months ended October 1, 2017 and October 2, 2016, Teradyne’s net periodic postretirement income was comprised of the following: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Service cost $ 8 $ 9 $ 25 $ 28 Interest cost 50 54 151 163 Amortization of prior service benefit (124 ) (151 ) (372 ) (455 ) Actuarial gain — — (15 ) (15 ) Total $ (66 ) $ (88 ) $ (211 ) $ (279 )

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Oct. 01, 2017
Commitments and Contingencies	P. COMMITMENTS AND CONTINGENCIES Purchase Commitments As of October 1, 2017, Teradyne had entered into purchase commitments for certain components and materials. The purchase commitments covered by the agreements aggregate to approximately $234.2 million, of which $226.3 million is for less than one year. Legal Claims Teradyne is subject to various legal proceedings and claims which have arisen in the ordinary course of business. In the opinion of management, the ultimate disposition of these matters will not have a material adverse effect on Teradyne’s results of operations, financial condition or cash flows.

Income Taxes

Income Taxes	9 Months Ended
Income Taxes	Oct. 01, 2017
Income Taxes	Q. INCOME TAXES The effective tax rate for the three months ended October 1, 2017 and October 2, 2016 was 18.8% and (6.9%), respectively. The effective tax rate for the nine months ended October 1, 2017 and October 2, 2016 was 14.7% and 3.7%, respectively. The increase in the effective tax rate from the three and nine months ended October 2, 2016 to the three and nine months ended October 1, 2017 is primarily attributable to a shift in the geographic distribution of income which increased income subject to taxation in the U.S. relative to lower tax rate jurisdictions, the effect of a U.S. non-deductible goodwill impairment charge and decreases in discrete tax benefits. The effective tax rates for the three and nine months ended October 1, 2017 differed from the expected federal statutory rate of 35% primarily because of the favorable effect of statutory rates applicable to income earned outside the U.S. The tax rates for the three and nine months ended October 1, 2017 were also reduced by the benefit from U.S. research and development tax credits, partially offset by additions to the uncertain tax positions for transfer pricing, both of which are included in the projected annual effective tax rate. Discrete tax items recorded in the three and nine months ended October 1, 2017 amounted to expense of $0.3 million and benefit of $6.1 million, respectively. The $0.3 million of discrete tax expense recorded in the three months ended October 1, 2017 was primarily composed of $0.8 million of expense related to non-taxable foreign exchange loss, $0.2 million of benefit from reductions in tax reserves and $0.2 million of benefit from stock based compensation. The $6.1 million of discrete tax benefit recorded in the nine months ended October 1, 2017 was primarily composed of $6.7 million of benefit from stock-based compensation, $1.0 million of expense related to actuarial gains, $0.7 million of benefit related to U.S. research and development tax credits, $0.5 million of benefit from reductions in tax reserves and $1.1 million of expense related to non-taxable foreign exchange loss. The effective tax rates for the three and nine months ended October 2, 2016 differed from the expected federal statutory rate of 35% as a result of a non-deductible goodwill impairment charge, which reduced the benefit of the U.S. loss before income taxes, and increases in uncertain tax positions for transfer pricing, offset by the effect of lower statutory rates applicable to income earned outside the U.S. and the benefit of U.S. research and development tax credits, all of which were included in the projected annual effective tax rate. Discrete tax benefits recorded in the three and nine months ended October 2, 2016 amounted to $6.4 million and $13.3 million respectively. The $6.4 million of discrete tax benefits recorded in the three months ended October 2, 2016 included $3.1 million from out-of-period adjustments, $1.6 million related to tax credit carryforwards, $0.7 million from non-taxable foreign exchange gains and $1.0 million of benefit from other discrete tax items. The $13.3 million of discrete tax benefits recorded in the nine months ended October 2, 2016 included $4.1 million from non-taxable foreign exchange gains, $3.1 million from out-of-period adjustments, $2.6 million of tax reserve releases resulting from the settlement of a U.S. tax audit, $1.6 million related to tax credit carryforwards, $0.9 million related to marketable securities and $1.0 million of benefit from other discrete tax items. During the three and nine months ended October 2, 2016, Teradyne recorded out-of-period adjustments of approximately $3.1 million to increase deferred tax assets and decrease income tax expense related to alternative minimum tax credits and capitalized inventory costs that should have been recognized previously. The out-of-period adjustments were not material to the relevant prior periods. 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 October 1, 2017, Teradyne believes that it will ultimately realize the deferred tax assets recorded on the condensed consolidated balance sheets. However, should Teradyne believe that it is more-likely-than-not that the deferred tax assets would not be realized, the tax provision would increase in the period in which Teradyne determined that the realizability was not likely. Teradyne considers the probability of future taxable income and historical profitability, among other factors, in assessing the realizability of the deferred tax assets. As of October 1, 2017 and December 31, 2016, Teradyne had $44.2 million and $39.0 million, respectively, of reserves for uncertain tax positions. The $5.2 million net increase in reserves for uncertain tax positions is primarily composed of additions related to transfer pricing exposures and tax credits. As of October 1, 2017, Teradyne estimates that there will be no material change in the balance of uncertain tax positions in the next twelve months. Teradyne recognizes interest and penalties related to income tax matters in income tax expense. As of October 1, 2017 and December 31, 2016, $0.4 million and $0.4 million, respectively, of interest and penalties were accrued for uncertain tax positions. For the nine months ended October 1, 2017, a benefit of $0.1 million was recorded for interest and penalties related to income tax items. For the nine months ended October 2, 2016, an expense of $0.3 million 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 nine months ended October 1, 2017 was $20.5 million, or $0.10 per diluted share. The tax savings due to the tax holiday for the nine months ended October 2, 2016 was $25.2 million, or $0.12 per diluted share. The tax holiday is scheduled to expire on December 31, 2020.

Segment Information

Segment Information	9 Months Ended
Segment Information	Oct. 01, 2017
Segment Information	R. SEGMENT INFORMATION Teradyne has four operating segments (Semiconductor Test, Industrial Automation, System Test and Wireless Test), which are its reportable segments. The Semiconductor Test segment includes operations related to the design, manufacturing and marketing of semiconductor test products and services. The Industrial Automation segment includes operations related to the design, manufacturing and marketing of collaborative robots. The System Test segment includes operations related to the design, manufacturing and marketing of products and services for defense/aerospace instrumentation test, storage test and circuit-board test. The Wireless Test segment includes operations related to the design, manufacturing and marketing of wireless test products and services. Each operating segment has a segment manager who is directly accountable to and maintains regular contact with Teradyne’s chief operating decision maker (Teradyne’s chief executive officer) to discuss operating activities, financial results, forecasts, and plans for the segment. 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 for the year ended December 31, 2016. Segment information for the three and nine months ended October 1, 2017 and October 2, 2016 is as follows: Semiconductor Test Industrial Automation System Test Wireless Test Corporate and Eliminations Consolidated (in thousands) Three Months Ended October 1, 2017 Revenues $ 396,881 $ 40,063 $ 35,569 $ 30,865 $ — $ 503,378 Income (loss) before income taxes (1)(2) 116,836 3,373 (3,344 ) 7,461 3,111 127,437 Total assets (3) 598,925 508,943 100,083 61,206 1,820,170 3,089,327 Three Months Ended October 2, 2016 Revenues $ 322,021 $ 23,505 $ 37,030 $ 27,919 $ — $ 410,475 Income (loss) before income taxes (1)(2) 67,710 (4,695 ) 1,550 1,049 (5,933 ) 59,681 Total assets (3) 522,529 340,030 90,713 65,953 1,346,462 2,365,687 Nine Months Ended October 1, 2017 Revenues $ 1,345,560 $ 115,672 $ 112,147 $ 83,812 $ — $ 1,657,191 Income (loss) before income taxes (1)(2) 426,081 (279 ) (11,795 ) 13,508 (1,186 ) 426,329 Total assets (3) 598,925 508,943 100,083 61,206 1,820,170 3,089,327 Nine Months Ended October 2, 2016 Revenues $ 1,097,608 $ 65,353 $ 139,640 $ 70,660 $ — $ 1,373,261 Income (loss) before income taxes (1)(2) 262,127 (16,364 ) 20,033 (375,596 ) (4,145 ) (113,945 ) Total assets (3) 522,529 340,030 90,713 65,953 1,346,462 2,365,687 (1) Included in Corporate and Eliminations are: contingent consideration adjustments, pension and postretirement plans’ actuarial gains (losses), impairment of fixed assets and expenses related to the Japan earthquake, property insurance recovery, interest income, interest expense and net foreign exchange gains (losses). (2) Included in income (loss) before income taxes are charges and credits related to restructuring and other, inventory charges, a goodwill impairment charge and an acquired intangible assets impairment charge. (3) Total assets are attributable to each segment. Corporate assets consist of cash and cash equivalents, marketable securities and certain other assets. Included in the Semiconductor Test segment are charges in the following line items in the statements of operations: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Cost of revenues—inventory charge $ 743 $ 2,351 $ 3,686 $ 8,270 Restructuring and other—employee severance 375 2,047 242 2,798 Included in the Industrial Automation segment are charges in the following line items in the statements of operations: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Cost of revenues—inventory charge $ 130 $ — $ 130 $ — Restructuring and other—employee severance 206 532 1,150 532 Included in the System Test segment are charges and credits in the following line items in the statements of operations: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Cost of revenues—inventory charge $ 251 $ 121 $ 1,609 $ 441 Restructuring and other—employee severance — (48 ) — (48 ) Included in the Wireless Test segment are charges and credits in the following line items in the statements of operations: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Cost of revenues—inventory charge $ 735 $ 561 $ 1,729 $ 6,437 Restructuring and other—lease impairment (393 ) — 900 — Goodwill impairment — — — 254,946 Acquired intangible assets impairment — — — 83,339 Restructuring and other—employee severance — 1,672 31 2,639 Included in Corporate and Eliminations are charges and credits in the following line items in the statements of operations: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Cost of revenues—pension actuarial losses (gains) $ — $ 364 $ (664 ) $ (250 ) Selling and administrative—pension actuarial losses (gains) — 192 (1,094 ) (441 ) Engineering and development—pension actuarial losses (gains) — 106 (746 ) (509 ) Restructuring and other—Universal Robots contingent consideration adjustment (286 ) 7,973 1,847 9,902 Restructuring and other—property insurance recovery (5,064 ) — (5,064 ) (5,051 ) Restructuring and other—expenses related to Japan earthquake and impairment of fixed assets 755 — 755 5,051 Restructuring and other—employee severance — — 530 — Restructuring and other—AIT contingent consideration adjustment — — — 550

Shareholders' Equity

Shareholders' Equity	9 Months Ended
Shareholders' Equity	Oct. 01, 2017
Shareholders' Equity	S. SHAREHOLDERS’ EQUITY Stock Repurchase Program In December 2016, the Board of Directors approved a $500 million share repurchase authorization which commenced on January 1, 2017. Teradyne intends to repurchase at least $200 million in 2017. During the nine months ended October 1, 2017, Teradyne repurchased 4.6 million shares of common stock at an average price of $32.66 per share, for a total price of $151.8 million. During the nine months ended October 2, 2016, Teradyne repurchased 4.3 million shares of common stock at an average price per share of $19.69, for a total price of $85.1 million. 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 2017, May 2017 and August 2017, Teradyne’s Board of Directors declared a quarterly cash dividend of $0.07 per share. Dividend payments for the three and nine months ended October 1, 2017 were $13.8 million and $41.7 million, respectively. In January 2016, May 2016 and August 2016, Teradyne’s Board of Directors declared a quarterly cash dividend of $0.06 per share. Dividend payments for the three and nine months ended October 2, 2016 were $12.1 million and $36.5 million, respectively. While Teradyne declared a quarterly cash dividend and authorized a share repurchase program, it may reduce or eliminate the cash dividend or 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)	9 Months Ended
Accounting Policies (Policies)	Oct. 01, 2017
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, 2016 condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America. 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,
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. Actual results may differ significantly from these estimates.
Stock-Based Compensation	Stock-Based Compensation In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-09, “Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” Adoption of this ASU required recognition of a cumulative effect adjustment to retained earnings for any prior year excess tax benefits or tax deficiencies not previously recorded. The cumulative effect adjustment of $39 million was recorded as an increase to retained earnings and deferred tax assets. This ASU also required a change in how Teradyne recognizes the excess tax benefits or tax deficiencies related to stock-based compensation. Prior to adopting ASU 2016-09, these excess tax benefits or tax deficiencies were credited or charged to additional paid-in capital in Teradyne’s consolidated balance sheets. In accordance with ASU 2016-09, starting in the first quarter of 2017, these excess tax benefits or tax deficiencies are recognized as a discrete tax benefit or discrete tax expense to the current income tax provision in Teradyne’s consolidated statements of operations. ASU 2016-09 requires companies to adopt the amendment related to accounting for excess tax benefits or tax deficiencies on a prospective basis. For the three and nine months ended October 1, 2017, Teradyne recognized a discrete tax benefit of $0.0 and $6.0 million, respectively, related to net excess tax benefit. In addition, under ASU 2016-09, all excess tax benefits related to share-based payments are reported as cash flows from operating activities. Previously, excess tax benefits from share-based payments arrangements were reported as cash flows from financing activities. The classification amendment was applied prospectively. This ASU also clarifies that all cash payments made to taxing authorities on the employees’ behalf for withheld shares should be presented as financing activities on the statement of cash flows. Previously, Teradyne reported cash payments made to taxing authorities as operating activities on the statement of cash flows. This change was applied retrospectively. Upon adoption of ASU 2016-09, Teradyne made an accounting policy election to continue accounting for forfeitures by applying an estimated forfeiture rate.
Contingencies and Litigation	Contingencies and Litigation Teradyne may be subject to certain legal proceedings, lawsuits and other claims as discussed in Note P. Teradyne accrues for a loss contingency, including legal proceedings, lawsuits, pending claims and other legal matters, when the likelihood of a loss is probable and the amount of the loss can be reasonably estimated. When the reasonable estimate of the loss is within a range of amounts, and no amount in the range constitutes a better estimate than any other amount, Teradyne accrues the amount at the low end of the range. Teradyne adjusts the accruals from time to time as additional information is received, but the loss incurred may be significantly greater than or less than the amount accrued. Loss contingencies are disclosed when they are material and there is at least a reasonable possibility that a loss has been incurred. Attorney fees related to legal matters are expensed as incurred.

Inventories (Tables)

Inventories (Tables)	9 Months Ended
Inventories (Tables)	Oct. 01, 2017
Composition of Inventories, Net	Inventories, net consisted of the following at October 1, 2017 and December 31, 2016: October 1, December 31, (in thousands) Raw material $ 64,550 $ 58,530 Work-in-process 17,189 22,946 Finished goods 43,444 54,482 $ 125,183 $ 135,958

Financial Instruments (Tables)

Financial Instruments (Tables)	9 Months Ended
Financial Instruments (Tables)	Oct. 01, 2017
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 October 1, 2017 and December 31, 2016. October 1, 2017 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 $ 213,664 $ — $ — $ 213,664 Cash equivalents 166,803 38,210 — 205,013 Available-for-sale securities: U.S. Treasury securities — 942,250 — 942,250 Commercial paper — 194,948 — 194,948 Corporate debt securities — 118,487 — 118,487 Certificates of deposit and time deposits — 95,469 — 95,469 U.S. government agency securities — 55,938 — 55,938 Equity and debt mutual funds 22,104 — — 22,104 Non-U.S. government securities — 577 — 577 402,571 1,445,879 — 1,848,450 Derivative assets — 157 — 157 Total $ 402,571 $ 1,446,036 $ — $ 1,848,607 Liabilities Contingent consideration $ — $ — $ 39,129 $ 39,129 Derivative liabilities — 190 — 190 Total $ — $ 190 $ 39,129 $ 39,319 Reported as follows: (Level 1) (Level 2) (Level 3) Total (in thousands) Assets Cash and cash equivalents $ 380,467 $ 38,210 $ — $ 418,677 Marketable securities — 1,217,830 — 1,217,830 Long-term marketable securities 22,104 189,839 — 211,943 Prepayments — 157 — 157 Total $ 402,571 $ 1,446,036 $ — $ 1,848,607 Liabilities . Other current liabilities $ — $ 190 $ — $ 190 Contingent consideration — — 21,818 21,818 Long-term contingent consideration — — 17,311 17,311 Total $ — $ 190 $ 39,129 $ 39,319 December 31, 2016 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 $ 214,722 $ — $ — $ 214,722 Cash equivalents 37,458 55,704 — 93,162 Available for sale securities: U.S. Treasury securities — 902,800 — 902,800 Commercial paper — 161,630 — 161,630 Corporate debt securities — 100,153 — 100,153 Certificates of deposit and time deposits — 82,133 — 82,133 U.S. government agency securities — 39,252 — 39,252 Equity and debt mutual funds 18,171 — — 18,171 Non-U.S. government securities — 728 — 728 270,351 1,342,400 — 1,612,751 Derivative assets — 1 — 1 Total $ 270,351 $ 1,342,401 $ — $ 1,612,752 Liabilities Contingent consideration $ — $ — $ 38,332 $ 38,332 Derivative liabilities — 131 — 131 Total $ — $ 131 $ 38,332 $ 38,463 Reported as follows: (Level 1) (Level 2) (Level 3) Total (in thousands) Assets Cash and cash equivalents $ 252,180 $ 55,704 $ — $ 307,884 Marketable securities — 871,024 — 871,024 Long-term marketable securities 18,171 415,672 — 433,843 Prepayments — 1 — 1 Total $ 270,351 $ 1,342,401 $ — $ 1,612,752 Liabilities Other accrued liabilities $ — $ 131 $ — $ 131 Contingent consideration — — 1,050 1,050 Long-term contingent consideration — — 37,282 37,282 Total $ — $ 131 $ 38,332 $ 38,463
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 nine months ended October 1, 2017 and October 2, 2016 were as follows: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Balance at beginning of period $ 39,415 $ 24,914 $ 38,332 $ 37,436 Payments (a) — — (1,050 ) (15,000 ) Fair value adjustment (b)(c) (286 ) 7,973 1,847 10,451 Balance at end of period $ 39,129 $ 32,887 $ 39,129 $ 32,887 (a) In the nine months ended October 1, 2017, Teradyne paid $1.1 million of contingent consideration for the earn-out in connection with the acquisition of Avionics Interface Technology, LLC (“AIT”). In the nine months ended October 2, 2016, based on Universal Robots’ calendar year 2015 EBITDA results, Teradyne paid $15.0 million or 100% of the eligible EBITDA contingent consideration amount in connection with the acquisition of Universal Robots. (b) In the nine months ended October 1, 2017, the fair value of contingent consideration for the earn-out in connection with the acquisition of Universal Robots was increased by $1.8 million due to an increase in forecasted revenue. In the three and nine months ended October 2, 2016, the fair value of contingent consideration for the earn-out in connection with the acquisition of Universal Robots was increased by $8.0 million and $9.9 million, respectively, primarily due to an increase in forecasted revenue and a decrease in the discount rate. (c) In the nine months ended October 2, 2016, the fair value of contingent consideration for the earn-out in connection with the acquisition of AIT was increased by $0.6 million due to an increase in forecasted revenue.
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 October 1, 2017 Fair Value Valuation Technique Unobservable Inputs Weighted Average (in thousands) Contingent consideration (Universal Robots) $21,818 Monte Carlo Simulation Revenue for the period July 1, 2015—December 31, 2017 volatility 11.5 % Discount rate 2.6 % $17,311 Monte Carlo Simulation Revenue for the period July 1, 2015—December 31, 2018 volatility 11.5 % Discount rate 2.6 %
Schedule of Carrying Amounts and Fair Values of Financial Instruments	The carrying amounts and fair values of Teradyne’s financial instruments at October 1, 2017 and December 31, 2016 were as follows: October 1, 2017 December 31, 2016 Carrying Value Fair Value Carrying Value Fair Value (in thousands) Assets Cash and cash equivalents $ 418,677 $ 418,677 $ 307,884 $ 307,884 Marketable securities 1,429,773 1,429,773 1,304,867 1,304,867 Derivative assets 157 157 1 1 Liabilities Contingent consideration 39,129 39,129 38,332 38,332 Derivative liabilities 190 190 131 131 Convertible debt (1) 362,595 613,238 352,669 486,754 (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 tables summarize the composition of available-for-sale marketable securities at October 1, 2017 and December 31, 2016: October 1, 2017 Available-for-Sale Fair Market Value of Investments with Unrealized Losses Cost Unrealized Gain Unrealized (Loss) Fair Market Value (in thousands) U.S. Treasury securities $ 944,120 $ 64 $ (1,934 ) $ 942,250 $ 936,195 Commercial paper 194,985 11 (48 ) 194,948 140,562 Corporate debt securities 116,687 2,046 (246 ) 118,487 79,119 Certificates of deposit and time deposits 95,447 29 (7 ) 95,469 33,238 U.S. government agency securities 55,936 20 (18 ) 55,938 52,997 Equity and debt mutual funds 18,202 3,923 (21 ) 22,104 1,529 Non-U.S. government securities 570 7 — 577 — Total $ 1,425,947 $ 6,100 $ (2,274 ) $ 1,429,773 $ 1,243,640 Reported as follows: Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Marketable securities $ 1,218,752 $ 65 $ (987 ) $ 1,217,830 $ 1,088,881 Long-term marketable securities 207,195 6,035 (1,287 ) 211,943 154,759 Total $ 1,425,947 $ 6,100 $ (2,274 ) $ 1,429,773 $ 1,243,640 December 31, 2016 Available-for-Sale Fair Market Value of Investments with Unrealized Losses Cost Unrealized Gain Unrealized (Loss) Fair Market Value (in thousands) U.S. Treasury securities $ 904,737 $ 97 $ (2,034 ) $ 902,800 $ 572,284 Commercial paper 161,672 24 (66 ) 161,630 84,034 Corporate debt securities 99,708 1,065 (620 ) 100,153 53,642 Certificates of deposit and time deposits 82,080 54 (1 ) 82,133 7,760 U.S. government agency securities 39,264 7 (19 ) 39,252 13,461 Equity and debt mutual funds 16,505 1,724 (58 ) 18,171 1,661 Non-U.S. government securities 745 6 (23 ) 728 137 Total $ 1,304,711 $ 2,977 $ (2,821 ) $ 1,304,867 $ 732,979 Reported as follows: Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Marketable securities $ 871,321 $ 134 $ (431 ) $ 871,024 $ 423,128 Long-term marketable securities 433,390 2,843 (2,390 ) 433,843 309,851 Total $ 1,304,711 $ 2,977 $ (2,821 ) $ 1,304,867 $ 732,979
Contractual Maturities of Investments Held	The contractual maturities of investments held at October 1, 2017 were as follows: October 1, 2017 Cost Fair Market Value (in thousands) Due within one year $ 1,218,752 $ 1,217,830 Due after 1 year through 5 years 136,081 135,889 Due after 5 years through 10 years 14,129 13,818 Due after 10 years 38,783 40,132 Total $ 1,407,745 $ 1,407,669
Schedule of Derivative Instruments in Statement of Financial Position at Fair Value	The following table summarizes the fair value of derivative instruments at October 1, 2017 and December 31, 2016: Balance Sheet Location October 1, December 31, (in thousands) Derivatives not designated as hedging instruments: Foreign currency forward contracts assets Prepayments $ 157 $ 1 Foreign currency forward contracts liabilities Other current liabilities (190 ) (131 ) Total $ (33 ) $ (130 )
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 during the three and nine months ended October 1, 2017 and October 2, 2016. Location of (Gains) Losses Recognized in Statement of Operations For the Three Months Ended For the Nine Months Ended October 1, 2017 October 2, 2016 October 1, 2017 October 2, 2016 (in thousands) Derivatives not designated as hedging instruments: Foreign currency forward contracts Other (income) expense, net $ (939 ) $ 941 $ (1,514 ) $ 11,140 Total $ (939 ) $ 941 $ (1,514 ) $ 11,140 (1) The table does not reflect the corresponding gains and losses from the remeasurement of monetary assets and liabilities denominated in foreign currencies. (2) For the three and nine months ended October 1, 2017, net losses from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $1.4 million and $2.3 million, respectively. (3) For the three and nine months ended October 2, 2016, net gains from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $1.9 million and $12.2 million, respectively.

Debt (Tables)

Debt (Tables)	9 Months Ended
Debt (Tables)	Oct. 01, 2017
Components of Convertible Senior Notes	The below tables represent the key components of Teradyne’s convertible senior notes: October 1, 2017 December 31, 2016 (in thousands) Debt principal $ 460,000 $ 460,000 Unamortized discount 97,405 107,331 Net carrying amount of convertible debt $ 362,595 $ 352,669 For the Three Months For the Nine Months October 1, 2017 October 1, 2017 (in thousands) Contractual interest expense on the coupon $ 1,422 $ 4,297 Amortization of the discount component and debt issue fees recognized as interest expense 3,350 9,926 Total interest expense on the convertible debt $ 4,772 $ 14,223

Prepayments (Tables)

Prepayments (Tables)	9 Months Ended
Prepayments (Tables)	Oct. 01, 2017
Schedule of Prepayments	Prepayments consist of the following and are included in prepayments on the balance sheet: October 1, December 31, (in thousands) Contract manufacturer prepayments $ 78,293 $ 84,473 Prepaid taxes 9,658 4,664 Prepaid maintenance and other services 6,685 7,676 Other prepayments 10,673 11,641 Total $ 105,309 $ 108,454

Deferred Revenue and Customer32

Deferred Revenue and Customer Advances (Tables)	9 Months Ended
Deferred Revenue and Customer Advances (Tables)	Oct. 01, 2017
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: October 1, December 31, (in thousands) Extended warranty $ 26,492 $ 28,200 Customer advances, undelivered elements and other 58,577 32,938 Maintenance and training 58,123 46,803 Total $ 143,192 $ 107,941

Product Warranty (Tables)

Product Warranty (Tables)	9 Months Ended
Product Warranty (Tables)	Oct. 01, 2017
Other Accrued Liabilities	The warranty balance below is included in other accrued liabilities on the balance sheet. For the Three Months Ended For the Nine Months Ended October 1, 2017 October 2, 2016 October 1, 2017 October 2, (in thousands) Balance at beginning of period $ 9,093 $ 8,784 $ 7,203 $ 6,925 Accruals for warranties issued during the period 2,734 3,248 11,049 11,626 Adjustments related to pre-existing warranties (35 ) (460 ) (499 ) (637 ) Settlements made during the period (3,055 ) (3,249 ) (9,016 ) (9,591 ) Balance at end of period $ 8,737 $ 8,323 $ 8,737 $ 8,323
Extended Product Warranty of Short and Long-Term Deferred Revenue and Customer Advances	The extended warranty balance below is included in short and long-term deferred revenue and customer advances on the balance sheet. For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Balance at beginning of period $ 29,377 $ 30,422 $ 28,200 $ 30,024 Deferral of new extended warranty revenue 2,636 4,638 17,126 17,036 Recognition of extended warranty deferred revenue (5,521 ) (5,030 ) (18,834 ) (17,030 ) Balance at end of period $ 26,492 $ 30,030 $ 26,492 $ 30,030

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
Stock-Based Compensation (Tables)	Oct. 01, 2017
Schedule of Estimated Fair Value of TSR Performance-Based Restricted Stock Unit Awards Assumptions	The fair value of stock options was estimated using the Black-Scholes option-pricing model with the following assumptions: For the Nine Months Ended October 1, October 2, Expected life (years) 5.0 5.0 Risk-free interest rate 2.0 % 1.4 % Volatility-historical 27.8 % 32.9 % Dividend yield 1.0 % 1.2 %
Stock Options
Fair Value of Stock Options Using Assumptions	The fair value was estimated using the Monte Carlo simulation model with the following assumptions: For the Nine Months Ended October 1, October 2, Risk-free interest rate 1.5 % 1.0 % Teradyne volatility-historical 26.6 % 27.0 % NYSE Composite Index volatility-historical 13.4 % 13.1 % Dividend yield 1.0 % 1.2 %

Accumulated Other Comprehensi35

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
Accumulated Other Comprehensive Income (Loss) (Tables)	Oct. 01, 2017
Changes in Accumulated Other Comprehensive (Loss) Income	Changes in accumulated other comprehensive income (loss), 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) Nine Months Ended October 1, 2017 Balance at December 31, 2016, net of tax of $0, $209, $(778), respectively $ (21,921 ) $ (60 ) $ 1,767 $ (20,214 ) Other comprehensive income before reclassifications, net of tax of $0, $1,666, $0, respectively 34,235 2,448 — 36,683 Amounts reclassified from accumulated other comprehensive income, net of tax of $0, $(173), $(115), respectively — (264 ) (204 ) (468 ) Net current period other comprehensive income (loss), net of tax of $0, $1,493, $(115), respectively 34,235 2,184 (204 ) 36,215 Balance at October 1, 2017, net of tax of $0, $1,702, $(893), respectively $ 12,314 $ 2,124 $ 1,563 $ 16,001 Foreign Currency Translation Adjustments Unrealized Gains (Losses) on Marketable Securities Retirement Plans Prior Service Credit Total (in thousands) Nine Months Ended October 2, 2016 Balance at December 31, 2015, net of tax of $0, $(459), $(622), respectively $ (8,759 ) $ (1,414 ) $ 2,029 $ (8,144 ) Other comprehensive income before reclassifications, net of tax of $0, $2,405, $34, respectively 7,072 5,110 59 12,241 Amounts reclassified from accumulated other comprehensive income (loss), net of tax of $0, $(152), $(139), respectively — (468 ) (244 ) (712 ) Net current period other comprehensive income (loss), net of tax of $0, $2,253, $(105), respectively 7,072 4,642 (185 ) 11,529 Balance as October 2, 2016, net of tax of $0, $1,749, $(727), respectively $ (1,687 ) $ 3,228 $ 1,844 $ 3,385
Reclassifications Out of Accumulated Other Comprehensive (Loss) Income to Statements of Operations	Reclassifications out of accumulated other comprehensive (loss) income to the statement of operations for the three and nine months ended October 1, 2017 and October 2, 2016 were as follows: Details about Accumulated Other Comprehensive Income Components For the Three Months Ended For the Nine Months Ended Affected Line Item in the Statements of Operations October 1, October 2, October 1, October 2, (in thousands) Available-for-sale marketable securities: Unrealized gains, net of tax of $67, $150, $173, $152, respectively $ 87 $ 334 $ 264 $ 468 Interest income Defined benefit pension and postretirement plans: Amortization of prior service benefit, net of tax of $38, $46, $115, $139, respectively 68 81 204 244 (a) Total reclassifications, net of tax of $105, $196, $288, $291, respectively $ 155 $ 415 $ 468 $ 712 Net income (a) The amortization of prior service credit is included in the computation of net periodic pension cost and postretirement benefit; see Note O: “Retirement Plans.”

Goodwill and Acquired Intangi36

Goodwill and Acquired Intangible Assets (Tables)	9 Months Ended
Goodwill and Acquired Intangible Assets (Tables)	Oct. 01, 2017
Changes in Carrying Amount of Goodwill by Segment	The changes in the carrying amount of goodwill by reportable segments for the nine months ended October 1, 2017, were as follows: Industrial Automation System Test Wireless Test Semiconductor Test Total (in thousands) Balance at December 31, 2016 Goodwill $ 204,851 $ 158,699 $ 361,819 $ 260,540 $ 985,909 Accumulated impairment losses — (148,183 ) (353,843 ) (260,540 ) (762,566 ) 204,851 10,516 7,976 — 223,343 Foreign currency translation adjustment 25,934 — — — 25,934 Balance at October 1, 2017 Goodwill 230,785 158,699 361,819 260,540 1,011,843 Accumulated impairment losses — (148,183 ) (353,843 ) (260,540 ) (762,566 ) $ 230,785 $ 10,516 $ 7,976 $ — $ 249,277
Schedule of Estimated Acquired Intangible Asset Amortization Expense	Estimated acquired intangible assets amortization expense for each of the five succeeding fiscal years is as follows: Year Amortization Expense (in thousands) 2017(remainder) 7,348 2018 29,268 2019 25,295 2020 11,134 2021 3,703 Thereafter 8,981
Wireless Test
Schedule of Amortizable Acquired Intangible Assets	Amortizable acquired intangible assets consist of the following and are included in acquired intangible assets, net on the balance sheet: October 1, 2017 Gross Carrying Amount Accumulated Amortization Cumulative Net Carrying Amount (in thousands) Developed technology $ 270,877 $ (221,051 ) $ 1,057 $ 50,883 Customer relationships 92,741 (82,286 ) 111 10,566 Tradenames and trademarks 50,100 (26,171 ) 271 24,200 Non-compete agreement 320 (240 ) — 80 Total $ 414,038 $ (329,748 ) $ 1,439 $ 85,729 December 31, 2016 Gross Carrying Amount Accumulated Amortization Cumulative Net Carrying Amount (in thousands) Developed technology $ 270,877 $ (206,376 ) $ (5,093 ) $ 59,408 Customer relationships 92,741 (76,707 ) (538 ) 15,496 Tradenames and trademarks 50,100 (23,435 ) (1,308 ) 25,357 Non-compete agreement 320 (180 ) — 140 Total $ 414,038 $ (306,698 ) $ (6,939 ) $ 100,401

Net Income (Loss) per Common 37

Net Income (Loss) per Common Share (Tables)	9 Months Ended
Net Income (Loss) per Common Share (Tables)	Oct. 01, 2017
Computation of Basic and Diluted Net Income (loss) Per Common Share	The following table sets forth the computation of basic and diluted net income (loss) per common share: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands, except per share amounts) Net income (loss) for basic and diluted net income (loss) per share $ 103,420 $ 63,794 $ 363,616 $ (109,767 ) Weighted average common shares-basic 197,485 202,211 198,755 203,167 Effect of dilutive potential common shares: Restricted stock units 1,832 1,282 1,663 — Incremental shares from assumed conversion of convertible note 1,144 — 632 — Stock options 306 421 337 — Employee stock purchase plan 8 15 26 — Dilutive potential common shares 3,290 1,718 2,658 — Weighted average common shares-diluted 200,775 203,929 201,413 203,167 Net income (loss) per common share-basic $ 0.52 $ 0.32 $ 1.83 $ (0.54 ) Net income (loss) per common share-diluted $ 0.52 $ 0.31 $ 1.81 $ (0.54 ) (1) Incremental shares from assumed conversion of the convertible notes for the three and nine months ended October 1, 2017 are calculated using the difference between the average Teradyne stock price for the period and the conversion price of $31.84, multiplied by the 14.4 million shares that would be issued upon conversion. The result of this calculation, representing the total intrinsic value of the convertible debt, is divided by the average Teradyne stock price for the period.

Retirement Plans (Tables)

Retirement Plans (Tables)	9 Months Ended
Retirement Plans (Tables)	Oct. 01, 2017
Defined Benefit Pension Plans
Net Periodic Pension and Postretirement Cost (Income)	For the three and nine months ended October 1, 2017 and October 2, 2016, Teradyne’s net periodic pension cost (income) was comprised of the following: For the Three Months Ended October 1, 2017 October 2, 2016 United States Foreign United States Foreign (in thousands) Service cost $ 560 $ 215 $ 575 $ 208 Interest cost 3,288 186 3,407 209 Expected return on plan assets (3,002 ) (6 ) (3,458 ) (6 ) Amortization of prior service cost 18 — 24 — Net actuarial loss — — — 662 Total $ 864 $ 395 $ 548 $ 1,073 For the Nine Months Ended October 1, 2017 October 2, 2016 United States Foreign United States Foreign (in thousands) Service cost $ 1,679 $ 606 $ 1,726 $ 614 Interest cost 9,863 527 10,222 614 Expected return on plan assets (9,006 ) (19 ) (10,373 ) (17 ) Amortization of prior service cost 53 — 72 — Net Actuarial (gain) loss (2,732 ) 243 (1,848 ) 662 Settlement — — — (184 ) Total $ (143 ) $ 1,357 $ (201 ) $ 1,689
Postretirement Benefit Plans
Net Periodic Pension and Postretirement Cost (Income)	For the three and nine months ended October 1, 2017 and October 2, 2016, Teradyne’s net periodic postretirement income was comprised of the following: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Service cost $ 8 $ 9 $ 25 $ 28 Interest cost 50 54 151 163 Amortization of prior service benefit (124 ) (151 ) (372 ) (455 ) Actuarial gain — — (15 ) (15 ) Total $ (66 ) $ (88 ) $ (211 ) $ (279 )

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
Segment Information (Tables)	Oct. 01, 2017
Segment Information	Segment information for the three and nine months ended October 1, 2017 and October 2, 2016 is as follows: Semiconductor Test Industrial Automation System Test Wireless Test Corporate and Eliminations Consolidated (in thousands) Three Months Ended October 1, 2017 Revenues $ 396,881 $ 40,063 $ 35,569 $ 30,865 $ — $ 503,378 Income (loss) before income taxes (1)(2) 116,836 3,373 (3,344 ) 7,461 3,111 127,437 Total assets (3) 598,925 508,943 100,083 61,206 1,820,170 3,089,327 Three Months Ended October 2, 2016 Revenues $ 322,021 $ 23,505 $ 37,030 $ 27,919 $ — $ 410,475 Income (loss) before income taxes (1)(2) 67,710 (4,695 ) 1,550 1,049 (5,933 ) 59,681 Total assets (3) 522,529 340,030 90,713 65,953 1,346,462 2,365,687 Nine Months Ended October 1, 2017 Revenues $ 1,345,560 $ 115,672 $ 112,147 $ 83,812 $ — $ 1,657,191 Income (loss) before income taxes (1)(2) 426,081 (279 ) (11,795 ) 13,508 (1,186 ) 426,329 Total assets (3) 598,925 508,943 100,083 61,206 1,820,170 3,089,327 Nine Months Ended October 2, 2016 Revenues $ 1,097,608 $ 65,353 $ 139,640 $ 70,660 $ — $ 1,373,261 Income (loss) before income taxes (1)(2) 262,127 (16,364 ) 20,033 (375,596 ) (4,145 ) (113,945 ) Total assets (3) 522,529 340,030 90,713 65,953 1,346,462 2,365,687 (1) Included in Corporate and Eliminations are: contingent consideration adjustments, pension and postretirement plans’ actuarial gains (losses), impairment of fixed assets and expenses related to the Japan earthquake, property insurance recovery, interest income, interest expense and net foreign exchange gains (losses). (2) Included in income (loss) before income taxes are charges and credits related to restructuring and other, inventory charges, a goodwill impairment charge and an acquired intangible assets impairment charge. (3) Total assets are attributable to each segment. Corporate assets consist of cash and cash equivalents, marketable securities and certain other assets.
Wireless Test
Schedule of Segment Reporting Information by Segment Charges	Included in the Wireless Test segment are charges and credits in the following line items in the statements of operations: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Cost of revenues—inventory charge $ 735 $ 561 $ 1,729 $ 6,437 Restructuring and other—lease impairment (393 ) — 900 — Goodwill impairment — — — 254,946 Acquired intangible assets impairment — — — 83,339 Restructuring and other—employee severance — 1,672 31 2,639
Semiconductor Test
Schedule of Segment Reporting Information by Segment Charges	Included in the Semiconductor Test segment are charges in the following line items in the statements of operations: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Cost of revenues—inventory charge $ 743 $ 2,351 $ 3,686 $ 8,270 Restructuring and other—employee severance 375 2,047 242 2,798
Industrial Automation
Schedule of Segment Reporting Information by Segment Charges	Included in the Industrial Automation segment are charges in the following line items in the statements of operations: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Cost of revenues—inventory charge $ 130 $ — $ 130 $ — Restructuring and other—employee severance 206 532 1,150 532
System Test
Schedule of Segment Reporting Information by Segment Charges	Included in the System Test segment are charges and credits in the following line items in the statements of operations: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Cost of revenues—inventory charge $ 251 $ 121 $ 1,609 $ 441 Restructuring and other—employee severance — (48 ) — (48 )
Corporate And Eliminations
Schedule of Segment Reporting Information by Segment Charges	Included in Corporate and Eliminations are charges and credits in the following line items in the statements of operations: For the Three Months Ended For the Nine Months Ended October 1, October 2, October 1, October 2, (in thousands) Cost of revenues—pension actuarial losses (gains) $ — $ 364 $ (664 ) $ (250 ) Selling and administrative—pension actuarial losses (gains) — 192 (1,094 ) (441 ) Engineering and development—pension actuarial losses (gains) — 106 (746 ) (509 ) Restructuring and other—Universal Robots contingent consideration adjustment (286 ) 7,973 1,847 9,902 Restructuring and other—property insurance recovery (5,064 ) — (5,064 ) (5,051 ) Restructuring and other—expenses related to Japan earthquake and impairment of fixed assets 755 — 755 5,051 Restructuring and other—employee severance — — 530 — Restructuring and other—AIT contingent consideration adjustment — — — 550

Accounting Policies - Additiona

Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
New Accounting Pronouncements or Change in Accounting Principle
Income tax provision (benefit)	$ 24,017	$ (4,113)	$ 62,713	$ (4,178)
ASU 2016-09
New Accounting Pronouncements or Change in Accounting Principle
Cumulative effect adjustment to increase retained earnings and deferred tax assets	39,000		39,000
Income tax provision (benefit)	$ 0		$ (6,000)

Composition of Inventories, Net

Composition of Inventories, Net (Detail) - USD ($) $ in Thousands	Oct. 01, 2017	Dec. 31, 2016
Inventory [Line Items]
Raw material	$ 64,550	$ 58,530
Work-in-process	17,189	22,946
Finished goods	43,444	54,482
Inventories, net	$ 125,183	$ 135,958

Inventories - Additional Inform

Inventories - Additional Information (Detail) - USD ($) $ in Millions	Oct. 01, 2017	Dec. 31, 2016
Inventory [Line Items]
Inventory reserves	$ 112.2	$ 116

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016	Dec. 31, 2016
Financial Instruments and Fair Value [Line Items]
Available-for-sale securities, realized loss	$ 0	$ 100,000	$ 300,000	$ 400,000
Available-for-sale securities, realized gain	200,000	$ 700,000	700,000	$ 1,200,000
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	1,243,640,000		1,243,640,000		$ 732,979,000
Fair market value of investments with unrealized losses greater than one year	113,300,000		113,300,000		2,900,000
Aggregate loss of investments with unrealized losses greater than one year			900,000		300,000
Fair market value of investments with unrealized losses less than one year	1,130,300,000		1,130,300,000		730,100,000
Aggregate loss of investments with unrealized losses less than one year			1,400,000		2,500,000
Universal Robots
Financial Instruments and Fair Value [Line Items]
Maximum payment per earn-out			25,000,000
Foreign Exchange Contracts
Financial Instruments and Fair Value [Line Items]
Notional amount of foreign currency forward contracts	$ 79,200,000		$ 79,200,000		$ 83,900,000

Schedule of Fair Value of Finan

Schedule of Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Oct. 01, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	$ 1,429,773	$ 1,304,867
U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	942,250	902,800
Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	118,487	100,153
Certificates of Deposit and Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	95,469	82,133
Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	194,948	161,630
U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	55,938	39,252
Equity And Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	22,104	18,171
Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	577	728
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	1,848,450	1,612,751
Derivative assets	157	1
Total	1,848,607	1,612,752
Contingent consideration	39,129	38,332
Derivative liabilities	190	131
Total	39,319	38,463
Fair Value, Measurements, Recurring \| Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	213,664	214,722
Fair Value, Measurements, Recurring \| Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	205,013	93,162
Fair Value, Measurements, Recurring \| U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	942,250	902,800
Fair Value, Measurements, Recurring \| Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	118,487	100,153
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	95,469	82,133
Fair Value, Measurements, Recurring \| Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	194,948	161,630
Fair Value, Measurements, Recurring \| U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	55,938	39,252
Fair Value, Measurements, Recurring \| Equity And Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	22,104	18,171
Fair Value, Measurements, Recurring \| Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	577	728
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	402,571	270,351
Total	402,571	270,351
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	213,664	214,722
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	166,803	37,458
Quoted Prices in Active Markets for Identical Instruments (Level 1) \| Fair Value, Measurements, Recurring \| Equity And Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	22,104	18,171
Significant Other Observable Inputs (Level 2) \| Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	1,445,879	1,342,400
Derivative assets	157	1
Total	1,446,036	1,342,401
Derivative liabilities	190	131
Total	190	131
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	38,210	55,704
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	942,250	902,800
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	118,487	100,153
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	95,469	82,133
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	194,948	161,630
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	55,938	39,252
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	577	728
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent consideration	39,129	38,332
Total	$ 39,129	$ 38,332

Schedule of Reported Financial

Schedule of Reported Financial Assets and Liabilities (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Oct. 01, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	$ 1,848,607	$ 1,612,752
Liabilities	39,319	38,463
Other Current Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	190
Other Accrued Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities		131
Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	418,677	307,884
Marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	1,217,830	871,024
Long-term marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	211,943	433,843
Prepayments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	157	1
Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	21,818	1,050
Long Term Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	17,311	37,282
Quoted Prices in Active Markets for Identical Instruments (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	402,571	270,351
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	380,467	252,180
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	22,104	18,171
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	1,446,036	1,342,401
Liabilities	190	131
Significant Other Observable Inputs (Level 2) \| Other Current Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	190
Significant Other Observable Inputs (Level 2) \| Other Accrued Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities		131
Significant Other Observable Inputs (Level 2) \| Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	38,210	55,704
Significant Other Observable Inputs (Level 2) \| Marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	1,217,830	871,024
Significant Other Observable Inputs (Level 2) \| Long-term marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	189,839	415,672
Significant Other Observable Inputs (Level 2) \| Prepayments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	157	1
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	39,129	38,332
Significant Unobservable Inputs (Level 3) \| Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	21,818	1,050
Significant Unobservable Inputs (Level 3) \| Long Term Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	$ 17,311	$ 37,282

Schedule of Changes in Fair Val

Schedule of Changes in Fair Value of Level 3 Contingent Consideration (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period		$ 39,415	$ 24,914	$ 38,332	$ 37,436
Payments	[1]			(1,050)	(15,000)
Fair value adjustment	[2],[3]	(286)	7,973	1,847	10,451
Ending Balance		$ 39,129	$ 32,887	$ 39,129	$ 32,887

[1]	In the nine months ended October 1, 2017, Teradyne paid $1.1 million of contingent consideration for the earn-out in connection with the acquisition of Avionics Interface Technology, LLC ("AIT"). In the nine months ended October 2, 2016, based on Universal Robots' calendar year 2015 EBITA results, Teradyne paid $15.0 million or 100% of the eligible EBITA contingent consideration amount in connection with the acquisition of Universal Robots.
[2]	In the nine months ended October 1, 2017, the fair value of contingent consideration for the earn-out in connection with the acquisition of Universal Robots was increased by $1.8 million due to an increase in forecasted revenue. In the three and nine months ended October 2, 2016, the fair value of contingent consideration for the earn-out in connection with the acquisition of Universal Robots was increased by $8.0 million and $9.9 million, respectively, primarily due to an increase in forecasted revenue and a decrease in the discount rate.
[3]	In the nine months ended October 2, 2016, the fair value of contingent consideration for the earn-out in connection with the acquisition of AIT was increased by $0.6 million due to an increase in forecasted revenue.

Schedule of Changes in Fair V47

Schedule of Changes in Fair Value of Level 3 Contingent Consideration (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payments of contingent consideration			$ 1,050	$ 11,697
Increase(decrease)in contingent consideration			1,847	10,451
Universal Robots
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payments of contingent consideration				$ 15,000
EBITDA contingent consideration amount, percentage		100.00%		100.00%
Increase(decrease)in contingent consideration	$ (300)	$ 8,000	1,800	$ 9,900
Avionics Interface Technologies, LLC
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payments of contingent consideration			$ 1,100
Increase(decrease)in contingent consideration				$ 600

Quantitative Information Associ

Quantitative Information Associated With Fair Value Measurement of Level 3 Financial Instrument (Detail) - Monte Carlo Simulation $ in Thousands	9 Months Ended
	Oct. 01, 2017USD ($)
Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Contingent consideration	$ 17,311
Significant Unobservable Inputs (Level 3) \| Universal Robots
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Contingent consideration	$ 21,818
Revenue for the period July 1, 2015-December 31, 2017 \| Universal Robots
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Target achievement, volatility	11.50%
Discount Rate	2.60%
Revenue for the period July 1, 2015-December 31, 2018 \| Universal Robots
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Target achievement, volatility	11.50%
Discount Rate	2.60%

Schedule of Carrying Amounts an

Schedule of Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands		Oct. 01, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Marketable securities		$ 1,429,773	$ 1,304,867
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and cash equivalents		418,677	307,884
Marketable securities		1,429,773	1,304,867
Derivative assets		157	1
Contingent consideration		39,129	38,332
Derivative liabilities		190	131
Convertible debt	[1]	613,238	486,754
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and cash equivalents		418,677	307,884
Marketable securities		1,429,773	1,304,867
Derivative assets		157	1
Contingent consideration		39,129	38,332
Derivative liabilities		190	131
Convertible debt	[1]	$ 362,595	$ 352,669

[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

Schedule of Available for Sale Marketable Securities (Detail) - USD ($) $ in Thousands	Oct. 01, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	$ 1,425,947	$ 1,304,711
Available-for-sale marketable securities, Unrealized Gain	6,100	2,977
Available-for-sale marketable securities, Unrealized (Loss)	(2,274)	(2,821)
Available-for-sale marketable securities, Fair Market Value	1,429,773	1,304,867
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	1,243,640	732,979
U.S. Treasury Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	944,120	904,737
Available-for-sale marketable securities, Unrealized Gain	64	97
Available-for-sale marketable securities, Unrealized (Loss)	(1,934)	(2,034)
Available-for-sale marketable securities, Fair Market Value	942,250	902,800
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	936,195	572,284
Corporate Debt Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	116,687	99,708
Available-for-sale marketable securities, Unrealized Gain	2,046	1,065
Available-for-sale marketable securities, Unrealized (Loss)	(246)	(620)
Available-for-sale marketable securities, Fair Market Value	118,487	100,153
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	79,119	53,642
U.S. Government Agency Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	55,936	39,264
Available-for-sale marketable securities, Unrealized Gain	20	7
Available-for-sale marketable securities, Unrealized (Loss)	(18)	(19)
Available-for-sale marketable securities, Fair Market Value	55,938	39,252
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	52,997	13,461
Certificates of Deposit and Time Deposits
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	95,447	82,080
Available-for-sale marketable securities, Unrealized Gain	29	54
Available-for-sale marketable securities, Unrealized (Loss)	(7)	(1)
Available-for-sale marketable securities, Fair Market Value	95,469	82,133
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	33,238	7,760
Commercial Paper
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	194,985	161,672
Available-for-sale marketable securities, Unrealized Gain	11	24
Available-for-sale marketable securities, Unrealized (Loss)	(48)	(66)
Available-for-sale marketable securities, Fair Market Value	194,948	161,630
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	140,562	84,034
Equity And Debt Mutual Funds
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	18,202	16,505
Available-for-sale marketable securities, Unrealized Gain	3,923	1,724
Available-for-sale marketable securities, Unrealized (Loss)	(21)	(58)
Available-for-sale marketable securities, Fair Market Value	22,104	18,171
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	1,529	1,661
Non-U.S. Government Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	570	745
Available-for-sale marketable securities, Unrealized Gain	7	6
Available-for-sale marketable securities, Unrealized (Loss)		(23)
Available-for-sale marketable securities, Fair Market Value	$ 577	728
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses		$ 137

Schedule of Reported Available

Schedule of Reported Available for Sale Marketable Securities (Detail) - USD ($) $ in Thousands	Oct. 01, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	$ 1,425,947	$ 1,304,711
Available-for-sale marketable securities, Unrealized Gain	6,100	2,977
Available-for-sale marketable securities, Unrealized (Loss)	(2,274)	(2,821)
Available-for-sale marketable securities, Fair Market Value	1,429,773	1,304,867
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	1,243,640	732,979
Marketable securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	1,218,752	871,321
Available-for-sale marketable securities, Unrealized Gain	65	134
Available-for-sale marketable securities, Unrealized (Loss)	(987)	(431)
Available-for-sale marketable securities, Fair Market Value	1,217,830	871,024
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	1,088,881	423,128
Long-term marketable securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	207,195	433,390
Available-for-sale marketable securities, Unrealized Gain	6,035	2,843
Available-for-sale marketable securities, Unrealized (Loss)	(1,287)	(2,390)
Available-for-sale marketable securities, Fair Market Value	211,943	433,843
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	$ 154,759	$ 309,851

Contractual Maturities of Inves

Contractual Maturities of Investments Held (Detail) $ in Thousands	Oct. 01, 2017USD ($)
Schedule of Available-for-sale Securities
Due within one year, cost	$ 1,218,752
Due after 1 year through 5 years, cost	136,081
Due after 5 years through 10 years, cost	14,129
Due after 10 years, cost	38,783
Total, cost	1,407,745
Due within one year, fair market value	1,217,830
Due after 1 year through 5 years, fair market value	135,889
Due after 5 years through 10 years, fair market value	13,818
Due after 10 years, fair market value	40,132
Total, fair market value	$ 1,407,669

Schedule of Derivative Instrume

Schedule of Derivative Instruments in Statement of Financial Position at Fair Value (Detail) - USD ($) $ in Thousands	Oct. 01, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative assets (liabilities), net	$ (33)	$ (130)
Not Designated as Hedging Instrument \| Foreign currency forward contracts \| Prepayments
Derivatives, Fair Value [Line Items]
Derivative assets	157	1
Not Designated as Hedging Instrument \| Foreign currency forward contracts \| Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	$ (190)	$ (131)

Schedule of Effect of Derivativ

Schedule of Effect of Derivative Instruments in Statement of Operations Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Derivative Instruments, Gain (Loss) [Line Items]
(Gains) losses on derivatives recognized in statements of operations	$ (939)	$ 941	$ (1,514)	$ 11,140
Other (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
(Gains) losses on derivatives recognized in statements of operations	$ (939)	$ 941	$ (1,514)	$ 11,140

Schedule of Effect of Derivat55

Schedule of Effect of Derivative Instruments in Statement of Operations Recognized (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Gains (losses) on foreign currency transactions	$ (1.4)	$ 1.9	$ (2.3)	$ 12.2

Debt - Additional Information (

Debt - Additional Information (Detail) $ / shares in Units, shares in Millions	Apr. 27, 2015USD ($)	Oct. 01, 2017USD ($)d$ / sharesshares	Dec. 31, 2016USD ($)	Dec. 12, 2016USD ($)
Debt Instrument
Term of loan, years	5 years
Pledge percentage of capital stock	65.00%
1.25% Convertible Senior Unsecured Notes Due December 15, 2023
Debt Instrument
Debt instrument, interest rate, stated percentage				1.25%
Aggregate principal amount		$ 460,000,000	$ 460,000,000	$ 460,000,000
Senior notes maturity date		Dec. 15, 2023
Trading days measurement period \| d		20
Consecutive trading days measurement period \| d		30
Percentage of conversion price		130.00%
Debt instrument conversion ratio		0.314102
Initial debt conversion price \| $ / shares		$ 31.84
Shares that would be issued upon conversion \| shares		14.4
Strike price per share of warrant \| $ / shares		$ 39.95
Debt instrument, effective annual interest rate		5.00%
Financing cost		$ 6,500,000		$ 7,200,000
Debt issuance costs, amortization period		7 years
Unamortized discount		$ 97,400,000
Debt Instrument, convertible, remaining discount amortization period		6 years 3 months 19 days
Debt instrument, convertible, carrying amount of equity component		$ 100,800,000
Value of notes converted		$ 538,700,000
Conversion option two
Debt Instrument
Trading days measurement period \| d		5
Consecutive trading days measurement period \| d		5
Percentage of closing sale price of common stock and conversion rate product		98.00%
Maximum
Debt Instrument
Aggregate principal amount	$ 150,000,000
Commitment fee percentage of unused portion of credit facility	0.35%
Minimum
Debt Instrument
Commitment fee percentage of unused portion of credit facility	0.125%
Base Rate \| Maximum
Debt Instrument
Debt instrument, basis spread on variable rate	1.00%
Base Rate \| Minimum
Debt Instrument
Debt instrument, basis spread on variable rate	0.00%
London Interbank Offered Rate (LIBOR) \| Maximum
Debt Instrument
Debt instrument, basis spread on variable rate	2.00%
London Interbank Offered Rate (LIBOR) \| Minimum
Debt Instrument
Debt instrument, basis spread on variable rate	1.00%
Revolving Credit Facility
Debt Instrument
Financing cost		$ 2,300,000
Financing cost, amortization term		5 years
Revolving Credit Facility \| Maximum
Debt Instrument
Credit facility, borrowing capacity	$ 350,000,000

Components of Convertible Senio

Components of Convertible Senior Notes (Detail) - USD ($) $ in Thousands	Oct. 01, 2017	Dec. 31, 2016	Dec. 12, 2016
Debt Instrument
Net carrying amount of convertible debt	$ 362,595	$ 352,669
1.25% Convertible Senior Unsecured Notes Due December 15, 2023
Debt Instrument
Debt principal	460,000	460,000	$ 460,000
Unamortized discount	97,405	107,331
Net carrying amount of convertible debt	$ 362,595	$ 352,669

Interest Expense on Convertible

Interest Expense on Convertible Senior Notes (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Oct. 01, 2017	Oct. 01, 2017
Debt Instrument
Contractual interest expense on the coupon	$ 1,422	$ 4,297
Amortization of the discount component and debt issue fees recognized as interest expense	3,350	9,926
Total interest expense on the convertible debt	$ 4,772	$ 14,223

Schedule of Prepayments (Detail

Schedule of Prepayments (Detail) - USD ($) $ in Thousands	Oct. 01, 2017	Dec. 31, 2016
Prepaid And Other Current Assets [Line Items]
Contract manufacturer prepayments	$ 78,293	$ 84,473
Prepaid taxes	9,658	4,664
Prepaid maintenance and other services	6,685	7,676
Other prepayments	10,673	11,641
Total	$ 105,309	$ 108,454

Deferred Revenue and Customer60

Deferred Revenue and Customer Advances (Detail) - USD ($) $ in Thousands	Oct. 01, 2017	Jul. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Dec. 31, 2015
Deferred Revenue Arrangement
Extended warranty	$ 26,492	$ 29,377	$ 28,200	$ 30,030	$ 30,422	$ 30,024
Customer advances, undelivered elements and other	58,577		32,938
Maintenance and training	58,123		46,803
Total	$ 143,192		$ 107,941

Warranty Accrual Included in Ot

Warranty Accrual Included in Other Accrued Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Product Warranty Liability [Line Items]
Balance at beginning of period	$ 9,093	$ 8,784	$ 7,203	$ 6,925
Accruals for warranties issued during the period	2,734	3,248	11,049	11,626
Adjustments related to pre-existing warranties	(35)	(460)	(499)	(637)
Settlements made during the period	(3,055)	(3,249)	(9,016)	(9,591)
Balance at end of period	$ 8,737	$ 8,323	$ 8,737	$ 8,323

Extended Product Warranty Inclu

Extended Product Warranty Included in Short and Long-Term Deferred Revenue and Customer Advances (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Product Warranty Liability [Line Items]
Balance at beginning of period	$ 29,377	$ 30,422	$ 28,200	$ 30,024
Deferral of new extended warranty revenue	2,636	4,638	17,126	17,036
Recognition of extended warranty deferred revenue	(5,521)	(5,030)	(18,834)	(17,030)
Balance at end of period	$ 26,492	$ 30,030	$ 26,492	$ 30,030

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - $ / shares shares in Millions	1 Months Ended		9 Months Ended
	Jan. 31, 2016	Jan. 31, 2014	Oct. 01, 2017	Oct. 02, 2016
Share-based Compensation Arrangement by Share-based Payment Award
Stock options term			7 years
Service-Based Restricted Stock Units \| Employees
Share-based Compensation Arrangement by Share-based Payment Award
Restricted stock unit awards granted			0.8	1.2
Weighted average grant date fair value of restricted stock units granted			$ 28.03	$ 18.49
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			$ 7.13	$ 5.30
Restricted stock unit awards granted				0.1
Service-Based Restricted Stock Units \| Non Employee Directors And Certain Employees
Share-based Compensation Arrangement by Share-based Payment Award
Restricted stock unit awards granted			0.1	0.1
Weighted average grant date fair value of restricted stock units granted			$ 34.48	$ 18.71
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
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
Percentage of awards vesting on the first anniversary of grant date			100.00%
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of common stock price paid			100.00%
Period of stock granted to employees and executive officers vest in equal annual installments			4 years
Stock options term			7 years
TSR Performance-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Total shareholder return performance measurement period	3 years
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	0.1
Weighted average grant date fair value of restricted stock units granted			$ 35.66	$ 20.29
Estimated annual dividend amount per share			0.28	0.24
Stock price			$ 28.56	$ 19.43
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	200.00%
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	0.00%
PBIT Performance-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Total shareholder return performance measurement period	3 years
Restricted stock unit awards granted			0.1	0.1
Weighted average grant date fair value of restricted stock units granted			$ 27.72	$ 18.71
PBIT 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	200.00%
PBIT 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	0.00%

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	9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016
Share-based Compensation Arrangement by Share-based Payment Award
Risk-free interest rate	1.50%	1.00%
Expected historical volatility	26.60%	27.00%
Dividend yield	1.00%	1.20%
New York Stock Exchange Composite Index
Share-based Compensation Arrangement by Share-based Payment Award
Expected historical volatility	13.40%	13.10%

Schedule of Estimated Fair Va65

Schedule of Estimated Fair Value of Stock Options Grant Using Black Scholes Option Pricing Model (Detail) - Stock Options	9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016
Share-based Compensation Arrangement by Share-based Payment Award
Expected life (years)	5 years	5 years
Risk-free interest rate	2.00%	1.40%
Volatility-historical	27.80%	32.90%
Dividend yield	1.00%	1.20%

Changes in Accumulated Other Co

Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			$ 1,828,659
Other comprehensive income before reclassifications, net of tax			36,683	$ 12,241
Amounts reclassified from accumulated other comprehensive income, net of tax			(468)	(712)
Other comprehensive income	$ 10,086	$ 1,092	36,215	11,529
Ending balance	2,109,897		2,109,897
Foreign currency translation reclassification adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(21,921)	(8,759)
Other comprehensive income before reclassifications, net of tax			34,235	7,072
Other comprehensive income			34,235	7,072
Ending balance	12,314	(1,687)	12,314	(1,687)
Unrealized Gains (Losses) on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(60)	(1,414)
Other comprehensive income before reclassifications, net of tax			2,448	5,110
Amounts reclassified from accumulated other comprehensive income, net of tax			(264)	(468)
Other comprehensive income			2,184	4,642
Ending balance	2,124	3,228	2,124	3,228
Amortization of prior service credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			1,767	2,029
Other comprehensive income before reclassifications, net of tax				59
Amounts reclassified from accumulated other comprehensive income, net of tax	(68)	(81)	(204)	(244)
Other comprehensive income			(204)	(185)
Ending balance	1,563	1,844	1,563	1,844
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(20,214)	(8,144)
Amounts reclassified from accumulated other comprehensive income, net of tax	(155)	(415)	(468)	(712)
Ending balance	$ 16,001	$ 3,385	$ 16,001	$ 3,385

Changes in Accumulated Other 67

Changes in Accumulated Other Comprehensive Income (Loss) (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income, tax	$ (105)	$ (196)	$ (288)	$ (291)
Foreign currency translation adjustments, tax	0	0	0	0	$ 0	$ 0
Unrealized gains on marketable securities, tax	1,702	1,749	1,702	1,749	209	(459)
Retirement plans prior service benefit, tax	(893)	(727)	(893)	(727)	$ (778)	$ (622)
Foreign currency translation reclassification adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive (loss) income before reclassifications, tax			0	0
Amounts reclassified from accumulated other comprehensive income, tax			0	0
Other comprehensive income (loss), tax			0	0
Unrealized Gains (Losses) on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive (loss) income before reclassifications, tax			1,666	2,405
Amounts reclassified from accumulated other comprehensive income, tax	(67)	(150)	(173)	(152)
Other comprehensive income (loss), tax			1,493	2,253
Amortization of prior service credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive (loss) income before reclassifications, tax			0	34
Amounts reclassified from accumulated other comprehensive income, tax	$ (38)	$ (46)	(115)	(139)
Other comprehensive income (loss), tax			$ (115)	$ (105)

Reclassifications Out of Accumu

Reclassifications Out of Accumulated Other Comprehensive (Loss) Income to Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income	$ (4,517)	$ (2,892)	$ (11,329)	$ (6,201)
Reclassifications, net of tax			468	712
Unrealized Gains (Losses) on Marketable Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax			264	468
Amortization of prior service credit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax	68	81	204	244
Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax	155	415	468	712
Reclassification out of Accumulated Other Comprehensive Income \| Unrealized Gains (Losses) on Marketable Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income	$ 87	$ 334	$ 264	$ 468

Reclassifications Out of Accu69

Reclassifications Out of Accumulated Other Comprehensive (Loss) Income to Statements of Operations (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	$ 105	$ 196	$ 288	$ 291
Unrealized Gains (Losses) on Marketable Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	67	150	173	152
Amortization of prior service credit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	$ 38	$ 46	$ 115	$ 139

Goodwill and Acquired Intangi70

Goodwill and Acquired Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Jul. 03, 2016	Oct. 01, 2017	Oct. 02, 2016	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Line Items]
Goodwill impairment					$ 254,946
Goodwill	$ 249,277			$ 249,277		$ 223,343
Intangible assets impairment					83,339
Acquired intangible assets amortization	7,028	$ 8,487		23,145	44,725
Wireless Test
Goodwill and Intangible Assets Disclosure [Line Items]
Employee reduction, percentage			11.00%
Goodwill impairment			$ 254,946		254,946
Goodwill	$ 7,976		8,000	$ 7,976		$ 7,976
Intangible assets impairment			$ 83,300		$ 83,339
Wireless Test \| Sales Revenue, Segment \| Customer Concentration Risk \| Minimum
Goodwill and Intangible Assets Disclosure [Line Items]
Concentration risk, percentage			51.00%
Wireless Test \| Sales Revenue, Segment \| Customer Concentration Risk \| Maximum
Goodwill and Intangible Assets Disclosure [Line Items]
Concentration risk, percentage			73.00%

Changes in Carrying Amount of G

Changes in Carrying Amount of Goodwill by Segment (Detail) - USD ($) $ in Thousands	9 Months Ended
	Oct. 01, 2017	Dec. 31, 2016	Jul. 03, 2016
Goodwill [Line Items]
Foreign currency translation adjustment	$ 25,934
Goodwill	1,011,843	$ 985,909
Accumulated impairment losses	(762,566)	(762,566)
Goodwill	249,277	223,343
Industrial Automation
Goodwill [Line Items]
Foreign currency translation adjustment	25,934
Goodwill	230,785	204,851
Goodwill	230,785	204,851
System Test
Goodwill [Line Items]
Goodwill	158,699	158,699
Accumulated impairment losses	(148,183)	(148,183)
Goodwill	10,516	10,516
Wireless Test
Goodwill [Line Items]
Goodwill	361,819	361,819
Accumulated impairment losses	(353,843)	(353,843)
Goodwill	7,976	7,976	$ 8,000
Semiconductor Test
Goodwill [Line Items]
Goodwill	260,540	260,540
Accumulated impairment losses	$ (260,540)	$ (260,540)

Schedule of Acquired Amortizabl

Schedule of Acquired Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Oct. 01, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 414,038	$ 414,038
Accumulated Amortization	(329,748)	(306,698)
Cumulative Foreign Currency Translation Adjustment	1,439	(6,939)
Net Carrying Amount	85,729	100,401
Developed technology
Finite-Lived Intangible Assets
Gross Carrying Amount	270,877	270,877
Accumulated Amortization	(221,051)	(206,376)
Cumulative Foreign Currency Translation Adjustment	1,057	(5,093)
Net Carrying Amount	50,883	59,408
Customer Relationships
Finite-Lived Intangible Assets
Gross Carrying Amount	92,741	92,741
Accumulated Amortization	(82,286)	(76,707)
Cumulative Foreign Currency Translation Adjustment	111	(538)
Net Carrying Amount	10,566	15,496
Trademarks and tradenames
Finite-Lived Intangible Assets
Gross Carrying Amount	50,100	50,100
Accumulated Amortization	(26,171)	(23,435)
Cumulative Foreign Currency Translation Adjustment	271	(1,308)
Net Carrying Amount	24,200	25,357
Non-compete Agreements
Finite-Lived Intangible Assets
Gross Carrying Amount	320	320
Accumulated Amortization	(240)	(180)
Net Carrying Amount	$ 80	$ 140

Schedule of Estimated Acquired

Schedule of Estimated Acquired Intangible Asset Amortization Expense (Detail) $ in Thousands	Oct. 01, 2017USD ($)
Finite-Lived Intangible Assets
2017 (remainder)	$ 7,348
2,018	29,268
2,019	25,295
2,020	11,134
2,021	3,703
Thereafter	$ 8,981

Computation of Basic and Dilute

Computation of Basic and Diluted Net Income (loss) Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Net Income Loss Per Common Share
Net income (loss) for basic and diluted net income (loss) per share		$ 103,420	$ 63,794	$ 363,616	$ (109,767)
Weighted average common shares-basic		197,485	202,211	198,755	203,167
Incremental shares from assumed conversion of convertible note	[1]	1,144		632
Employee stock purchase plan		8	15	26
Dilutive potential common shares		3,290	1,718	2,658
Weighted average common shares-diluted		200,775	203,929	201,413	203,167
Net income (loss) per common share-basic		$ 0.52	$ 0.32	$ 1.83	$ (0.54)
Net income (loss) per common share-diluted		$ 0.52	$ 0.31	$ 1.81	$ (0.54)
Restricted Stock Units
Net Income Loss Per Common Share
Incremental shares attributable to share based payment arrangements		1,832	1,282	1,663
Stock Options
Net Income Loss Per Common Share
Incremental shares attributable to share based payment arrangements		306	421	337

[1]	Incremental shares from assumed conversion of the convertible notes for the three and nine months ended October 1, 2017 are calculated using the difference between the average Teradyne stock price for the period and the conversion price of $31.84, multiplied by the 14.4 million shares that would be issued upon conversion. The result of this calculation, representing the total intrinsic value of the convertible debt, is divided by the average Teradyne stock price for the period.

Computation of Basic and Dilu75

Computation of Basic and Diluted Net Income (loss) Per Common Share (Parenthetical) (Detail) - Convertible Notes shares in Millions	3 Months Ended	9 Months Ended
	Oct. 01, 2017$ / sharesshares	Oct. 01, 2017$ / sharesshares
Net Income Loss Per Common Share
Initial debt conversion price \| $ / shares	$ 31.84	$ 31.84
Shares that would be issued upon conversion \| shares	14.4	14.4

Net Income (loss) per Common 76

Net Income (loss) per Common Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017
Net Income Loss Per Common Share
Exercise of stock options	0.1	0.1	0.1

Restructuring and Other - Addit

Restructuring and Other - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Restructuring Cost and Reserve
Contingent consideration adjustment			$ 1,847	$ 10,451
Lease termination period			2017-09
Property, Plant and Equipment
Restructuring Cost and Reserve
Impairment of fixed assets and other expenses				4,200
Semiconductor Test and Wireless Test
Restructuring Cost and Reserve
Severance benefit and charges	$ 600	$ 4,200		5,900
Industrial Automation
Restructuring Cost and Reserve
Severance benefit and charges			$ 2,000
Earthquake Related Expenses
Restructuring Cost and Reserve
Impairment of fixed assets and other expenses	800		800
Wireless Test
Restructuring Cost and Reserve
Lease termination	400
Lease impairment			900
Impairment of fixed assets and expenses related to the Japan earthquake
Restructuring Cost and Reserve
Property insurance, recovery	5,100		5,100	5,100
Impairment of fixed assets and expenses related to the Japan earthquake \| Earthquake Related Expenses
Restructuring Cost and Reserve
Impairment of fixed assets and other expenses				900
Universal Robots
Restructuring Cost and Reserve
Contingent consideration adjustment	$ (300)	$ 8,000	$ 1,800	9,900
Avionics Interface Technologies, LLC
Restructuring Cost and Reserve
Contingent consideration adjustment				$ 600

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016
U.S. Supplemental Executive Defined Benefit Pension Plan
Defined Benefit Plan Disclosure
Contribution to defined benefit pension plans	$ 1.9	$ 1.9
Non-United States Subsidiaries
Defined Benefit Plan Disclosure
Contribution to defined benefit pension plans	0.6	1.5
U.S. Qualified Pension Plan
Defined Benefit Plan Disclosure
Contribution to defined benefit pension plans	$ 1.9	$ 1.9

Schedule of Net Periodic Pensio

Schedule of Net Periodic Pension and Postretirement Cost (Income) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Defined Benefit Plan Disclosure
Net Actuarial (gain) loss			$ (2,504)	$ (1,200)
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Service cost	$ 560	$ 575	1,679	1,726
Interest cost	3,288	3,407	9,863	10,222
Expected return on plan assets	(3,002)	(3,458)	(9,006)	(10,373)
Amortization of prior service cost	18	24	53	72
Net Actuarial (gain) loss			(2,732)	(1,848)
Total	864	548	(143)	(201)
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Service cost	215	208	606	614
Interest cost	186	209	527	614
Expected return on plan assets	(6)	(6)	(19)	(17)
Net Actuarial (gain) loss		662	243	662
Settlement				(184)
Total	395	1,073	1,357	1,689
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Service cost	8	9	25	28
Interest cost	50	54	151	163
Amortization of prior service benefit	(124)	(151)	(372)	(455)
Actuarial gain			(15)	(15)
Total	$ (66)	$ (88)	$ (211)	$ (279)

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Thousands	Oct. 01, 2017USD ($)
Purchase Commitment, Excluding Long-term Commitment
Aggregate purchase commitments	$ 234,200
Purchase commitments less than one year	$ 226,300

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 03, 2016	Oct. 02, 2016	Dec. 31, 2016
Income Taxes [Line Items]
Effective tax rate	18.80%	6.90%	14.70%	3.70%
U.S. statutory federal tax rate	35.00%	35.00%	35.00%		35.00%
Discrete tax expense (benefits)	$ 0.3	$ (6.4)	$ (6.1)		$ (13.3)
Gains (loss) on non-taxable foreign exchange	0.8	(0.7)	1.1		(4.1)
Discrete tax expense (benefits) from reductions in tax reserves	0.2		0.5
Discrete tax benefits, stock based compensation	0.2		6.7
Discrete tax expense, actuarial gains			1
Discrete tax benefits, U.S. research and development tax credits			0.7
Out-of-period adjustments		3.1			3.1
Discrete tax benefits related to tax credit carryforwards		1.6			1.6
Discrete tax benefits, Other		$ 1			1
Tax reserve releases resulting from the settlement of a U.S. tax audit					2.6
Discrete tax benefits, marketable securities					0.9
Uncertain tax positions	44.2		44.2			$ 39
Net Increase in uncertain tax positions			5.2
Accrued interest and penalties	$ 0.4		0.4			$ 0.4
Interest and penalties related to income tax, expense (benefit)			0.1		0.3
Tax savings due to the tax holiday			$ 20.5		$ 25.2
Tax savings due to the tax holiday, per share			$ 0.10		$ 0.12
Tax holiday expiration date			December 31, 2020

Segment Information - Additiona

Segment Information - Additional Information (Detail)	9 Months Ended
Segment Information - Additional Information (Detail)	Oct. 01, 2017Segment
Segment Reporting Information [Line Items]
Operating segments	4

Schedule of Segment Information

Schedule of Segment Information (Detail) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
		Oct. 01, 2017		Oct. 02, 2016		Oct. 01, 2017		Oct. 02, 2016		Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues		$ 503,378		$ 410,475		$ 1,657,191		$ 1,373,261
Income (loss) before income taxes	[1],[2]	127,437		59,681		426,329		(113,945)
Total assets		3,089,327	[3]	2,365,687	[3]	3,089,327	[3]	2,365,687	[3]	$ 2,762,493
Semiconductor Test
Segment Reporting Information [Line Items]
Revenues		396,881		322,021		1,345,560		1,097,608
Income (loss) before income taxes	[1],[2]	116,836		67,710		426,081		262,127
Total assets	[3]	598,925		522,529		598,925		522,529
Industrial Automation
Segment Reporting Information [Line Items]
Revenues		40,063		23,505		115,672		65,353
Income (loss) before income taxes	[1],[2]	3,373		(4,695)		(279)		(16,364)
Total assets	[3]	508,943		340,030		508,943		340,030
System Test
Segment Reporting Information [Line Items]
Revenues		35,569		37,030		112,147		139,640
Income (loss) before income taxes	[1],[2]	(3,344)		1,550		(11,795)		20,033
Total assets	[3]	100,083		90,713		100,083		90,713
Wireless Test
Segment Reporting Information [Line Items]
Revenues		30,865		27,919		83,812		70,660
Income (loss) before income taxes	[1],[2]	7,461		1,049		13,508		(375,596)
Total assets	[3]	61,206		65,953		61,206		65,953
Corporate And Eliminations
Segment Reporting Information [Line Items]
Income (loss) before income taxes	[1],[2]	3,111		(5,933)		(1,186)		(4,145)
Total assets	[3]	$ 1,820,170		$ 1,346,462		$ 1,820,170		$ 1,346,462

[1]	Included in Corporate and Eliminations are: contingent consideration adjustments, pension and postretirement plans' actuarial gains (losses), impairment of fixed assets and expenses related to the Japan earthquake, property insurance recovery, interest income, interest expense and net foreign exchange gains (losses).
[2]	Included in income (loss) before income taxes are charges and credits related to restructuring and other, inventory charges, a goodwill impairment charge and an acquired intangible assets impairment charge.
[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 I

Schedule of Segment Reporting Information by Segment Charges (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Jul. 03, 2016	Oct. 01, 2017	Oct. 02, 2016
Segment Reporting Information [Line Items]
Goodwill impairment					$ 254,946
Acquired intangible assets impairment					83,339
Restructuring and other-employee severance	$ (4,407)	$ 12,177		$ 392	16,372
Contingent consideration adjustment				1,847	10,451
Property insurance recovery				4,309
Universal Robots
Segment Reporting Information [Line Items]
Contingent consideration adjustment	(300)	8,000		1,800	9,900
Avionics Interface Technologies, LLC
Segment Reporting Information [Line Items]
Contingent consideration adjustment					600
Semiconductor Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	743	2,351		3,686	8,270
Restructuring and other-employee severance	375	2,047		242	2,798
Wireless Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	735	561		1,729	6,437
Restructuring and other-lease impairment	(393)			900
Goodwill impairment			$ 254,946		254,946
Acquired intangible assets impairment			$ 83,300		83,339
Restructuring and other-employee severance		1,672		31	2,639
Corporate And Eliminations
Segment Reporting Information [Line Items]
Restructuring and other-employee severance				530
Property insurance recovery	(5,064)			(5,064)	(5,051)
Corporate And Eliminations \| Cost of revenues
Segment Reporting Information [Line Items]
Pension actuarial losses (gains)		364		(664)	(250)
Corporate And Eliminations \| Selling and administrative
Segment Reporting Information [Line Items]
Pension actuarial losses (gains)		192		(1,094)	(441)
Corporate And Eliminations \| Engineering and development
Segment Reporting Information [Line Items]
Pension actuarial losses (gains)		106		(746)	(509)
Corporate And Eliminations \| Universal Robots \| Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment	(286)	7,973		1,847	9,902
Corporate And Eliminations \| Impairment of fixed assets and expenses related to the Japan earthquake
Segment Reporting Information [Line Items]
Building impairment and other expenses	755			755	5,051
Corporate And Eliminations \| Avionics Interface Technologies, LLC
Segment Reporting Information [Line Items]
Contingent consideration adjustment					550
Industrial Automation
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	130			130
Restructuring and other-employee severance	$ 206	$ 532		$ 1,150	$ 532

Schedule of Segment Reporting85

Schedule of Segment Reporting Information by Segment Charges and Credit (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Segment Reporting Information [Line Items]
Restructuring and other-employee severance	$ (4,407)	$ 12,177	$ 392	$ 16,372
System Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	$ 251	121	$ 1,609	441
Restructuring and other-employee severance		$ (48)		$ (48)

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016	Dec. 31, 2017	Aug. 31, 2017	May 31, 2017	Jan. 31, 2017	Dec. 31, 2016	Aug. 31, 2016	May 31, 2016	Jan. 31, 2016
Stockholders Equity Note Disclosure [Line Items]
Stock repurchase program, authorized amount									$ 500,000,000
Repurchase of stock, value				$ 85,100,000
Cumulative repurchases, shares	4.6		4.6
Cumulative repurchases, value	$ 151,800,000		$ 151,800,000
Common stock average price			$ 32.66	$ 19.69
Repurchase of stock, shares				4.3
Dividends payable, amount per share						$ 0.07	$ 0.07	$ 0.07		$ 0.06	$ 0.06	$ 0.06
Dividend payment	$ 13,800,000	$ 12,100,000	$ 41,730,000	$ 36,548,000
Minimum \| Scenario, Forecast
Stockholders Equity Note Disclosure [Line Items]
Repurchase of stock, value					$ 200,000,000