Teradyne (TER) 10-Q 12 May 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Apr. 02, 2017	May 08, 2017
Document Information
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Apr. 2, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
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		198,950,727

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Apr. 02, 2017		Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 324,746		$ 307,884
Marketable securities	895,578		871,024
Accounts receivable, less allowance for doubtful accounts of $2,422 and $2,356 at April 2, 2017 and December 31, 2016, respectively	314,962		192,444
Inventories, net	203,278		135,958
Prepayments	106,987		108,454
Other current assets	8,602		8,039
Total current assets	1,854,153		1,623,803
Property, plant and equipment, net	253,548		253,821
Marketable securities	262,061		433,843
Deferred tax assets	127,918		107,405
Other assets	12,175		12,165
Retirement plans assets	7,517		7,712
Intangible assets, net	94,843		100,401
Goodwill	230,065		223,343
Total assets	2,842,280	[1]	2,762,493
Current liabilities:
Accounts payable	121,417		95,362
Accrued employees' compensation and withholdings	79,018		109,944
Deferred revenue and customer advances	78,794		84,478
Other accrued liabilities	67,651		51,382
Contingent consideration	21,711		1,050
Accrued income taxes	24,466		30,480
Total current liabilities	393,057		372,696
Retirement plans liabilities	110,069		106,938
Long-term deferred revenue and customer advances	25,983		23,463
Deferred tax liabilities	11,255		12,144
Long-term other accrued liabilities	9,921		28,642
Long-term contingent consideration	16,205		37,282
Long-term debt	355,937		352,669
Total liabilities	922,427		933,834
Commitments and contingencies (See Note P)
SHAREHOLDERS' EQUITY
Common stock, $0.125 par value, 1,000,000 shares authorized; 199,596 and 199,177 shares issued and outstanding at April 2, 2017 and December 31, 2016, respectively	24,950		24,897
Additional paid-in capital	1,605,502		1,593,684
Accumulated other comprehensive loss	(10,901)		(20,214)
Retained earnings	300,302		230,292
Total shareholders' equity	1,919,853		1,828,659
Total liabilities and shareholders' equity	$ 2,842,280		$ 2,762,493
[1]	Total business assets are directly attributable to each business. 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	Apr. 02, 2017	Dec. 31, 2016
Accounts receivable, less allowance for doubtful accounts	$ 2,422	$ 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	199,596,000	199,177,000
Common stock, shares outstanding	199,596,000	199,177,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Apr. 02, 2017	Apr. 03, 2016
Revenues:
Products		$ 373,204	$ 358,139
Services		83,709	72,855
Total revenues		456,913	430,994
Cost of revenues:
Cost of products		154,966	167,555
Cost of services		37,014	33,107
Total cost of revenues (exclusive of acquired intangible assets amortization shown separately below)		191,980	200,662
Gross profit		264,933	230,332
Operating expenses:
Engineering and development		76,182	73,464
Selling and administrative		84,906	79,174
Acquired intangible assets amortization		7,952	19,994
Restructuring and other		2,511	1,587
Total operating expenses		171,551	174,219
Income from operations		93,382	56,113
Non-operating (income) expense:
Interest income		(3,520)	(1,642)
Interest expense		5,402	710
Other (income) expense, net		(516)	(147)
Income before income taxes	[1],[2]	92,016	57,192
Income tax provision		6,795	7,206
Net income		$ 85,221	$ 49,986
Net income per common share:
Basic		$ 0.43	$ 0.24
Diluted		$ 0.42	$ 0.24
Weighted average common shares-basic		200,005	204,271
Weighted average common shares-diluted		201,936	205,732
Cash dividend declared per common share		$ 0.07	$ 0.06
[1]	Included in the income (loss) before income taxes for each of the segments are charges and credits related to inventory and other.
[2]	Interest income, interest expense, contingent consideration adjustments, pension and post retirement plans actuarial gains and other income (expense) are included in Corporate and Eliminations.

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Net income	$ 85,221	$ 49,986
Other comprehensive income, net of tax:
Foreign currency translation adjustments, net of tax of $0, $0, respectively	8,963	10,271
Available-for-sale marketable securities:
Unrealized gains on marketable securities arising during period, net of tax of $420, $1,253, respectively	513	3,071
Less: Reclassification adjustment for gains included in net income, net of tax of $(64), $11, respectively	(95)	(83)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Total	418	2,988
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), respectively	(68)	(80)
Other comprehensive income (loss)	9,313	13,179
Comprehensive income	$ 94,534	$ 63,165

CONDENSED CONSOLIDATED STATEME6

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Foreign currency translation adjustments, tax	$ 0	$ 0
Unrealized (losses) gains on marketable securities arising during period, tax	420	1,253
Reclassification adjustment for gains included in net income, tax	(64)	11
Amortization of net prior service (credit) cost included in net periodic pension and post-retirement expense/income, tax	$ (38)	$ (46)

CONDENSED CONSOLIDATED STATEME7

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Cash flows from operating activities:
Net income	$ 85,221	$ 49,986
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	16,143	16,192
Amortization	11,070	20,470
Stock-based compensation	8,945	7,925
Provision for excess and obsolete inventory	2,726	4,373
Deferred taxes	(3,477)	(5,496)
Contingent consideration adjustment	634	1,173
Retirement plans actuarial gains		(1,193)
Other	2	484
Changes in operating assets and liabilities:
Accounts receivable	(123,792)	(42,552)
Inventories	(62,152)	(702)
Prepayments and other assets	1,104	(1,148)
Accounts payable and other accrued expenses	(7,553)	1,346
Deferred revenue and customer advances	(3,333)	(13,836)
Retirement plans contributions	(947)	(1,250)
Income taxes	14,288	(52)
Net cash (used for) provided by operating activities	(61,121)	35,720
Cash flows from investing activities:
Purchases of property, plant and equipment	(22,066)	(20,334)
Purchases of available-for-sale marketable securities	(153,317)	(221,778)
Proceeds from sales of available-for-sale marketable securities	213,593	239,370
Proceeds from maturities of available-for-sale marketable securities	88,184	73,458
Net cash provided by investing activities	126,394	70,716
Cash flows from financing activities:
Issuance of common stock under stock purchase and stock option plans	15,084	9,140
Repurchase of common stock	(37,730)	(28,001)
Dividend payments	(14,021)	(12,253)
Payments related to net settlement of employee stock compensation awards	(12,289)	(8,972)
Payments of contingent consideration	(1,050)	(11,697)
Net cash used for financing activities	(50,006)	(51,783)
Effects of exchange rate changes on cash and cash equivalents	1,595
Increase in cash and cash equivalents	16,862	54,653
Cash and cash equivalents at beginning of period	307,884	264,705
Cash and cash equivalents at end of period	$ 324,746	$ 319,358

The Company

The Company	3 Months Ended
	Apr. 02, 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; • 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”); • industrial automation (“Industrial Automation”) products; and • wireless test (“Wireless Test”) systems.

Accounting Policies

Accounting Policies	3 Months Ended
	Apr. 02, 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, 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, paid-in 2016-09, ASU 2016-09 In addition, under ASU 2016-09, Upon adoption of ASU 2016-09, 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	3 Months Ended
	Apr. 02, 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.” one-step In October 2016, the FASB issued ASU 2016-16, “Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory ” pre-tax In February 2016, the FASB issued ASU 2016-02, “ Leases (Topic 842). ” “ Leases. ” of-use In January 2016, the FASB issued ASU 2016-01, “Financial Instruments—Overall (Subtopic 825-10): ” In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers (Topic 606),” 2015-14,

Inventories

Inventories	3 Months Ended
	Apr. 02, 2017
Inventories	D. INVENTORIES Inventories, net consisted of the following at April 2, 2017 and December 31, 2016: April 2, December 31, 2017 2016 (in thousands) Raw material $ 62,373 $ 58,530 Work-in-process 22,511 22,946 Finished goods 118,394 54,482 $ 203,278 $ 135,958 Inventory reserves for the periods ending April 2, 2017 and December 31, 2016 were $115.2 million and $116.0 million, respectively.

Financial Instruments

Financial Instruments	3 Months Ended
	Apr. 02, 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. 320-10 available-for-sale held-to-maturity available-for-sale 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 months ended April 2, 2017 and April 3, 2016. As defined in ASC 820-10, Fair Value Measurements and Disclosures, 820-10 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 Realized gains recorded in the three months ended April 2, 2017 and April 3, 2016 were $0.3 million and $0.2 million, respectively. Realized losses recorded in the three months ended April 2, 2017 and April 3, 2016 were $0.2 million and $0.2 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 months ended April 2, 2017 and April 3, 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 April 2, 2017 and December 31, 2016. April 2, 2017 Quoted Prices Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total (in thousands) Assets Cash $ 202,925 $ — $ — $ 202,925 Cash equivalents 115,578 6,243 — 121,821 Available-for-sale U.S. Treasury securities — 854,547 — 854,547 Commercial paper — 121,065 — 121,065 Corporate debt securities — 89,731 — 89,731 Certificates of deposit and time deposits — 50,578 — 50,578 U.S. government agency securities — 21,149 — 21,149 Equity and debt mutual funds 19,986 — — 19,986 Non-U.S. — 583 — 583 Total $ 338,489 $ 1,143,896 $ — $ 1,482,385 Derivative assets — 145 — 145 Total $ 338,489 $ 1,144,041 $ — $ 1,482,530 Liabilities Contingent consideration $ — $ — $ 37,916 $ 37,916 Derivative liabilities — 107 — 107 Total $ — $ 107 $ 37,916 $ 38,023 Reported as follows: (Level 1) (Level 2) (Level 3) Total (in thousands) Assets Cash and cash equivalents $ 318,503 $ 6,243 $ — $ 324,746 Marketable securities — 895,578 — 895,578 Long-term marketable securities 19,986 242,075 — 262,061 Prepayments — 145 — 145 $ 338,489 $ 1,144,041 $ — $ 1,482,530 Liabilities . Other current liabilities $ — $ 107 $ — $ 107 Contingent consideration — — 21,711 21,711 Long-term contingent consideration — — 16,205 16,205 $ — $ 107 $ 37,916 $ 38,023 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 — 900,038 — 900,038 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 — 42,014 — 42,014 Equity and debt mutual funds 18,171 — — 18,171 Non-U.S. — 728 — 728 Total $ 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 $ 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 $ — $ 131 $ 38,332 $ 38,463 Changes in the fair value of Level 3 contingent consideration for the three months ended April 2, 2017 and April 3, 2016 were as follows: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Balance at beginning of period $ 38,332 $ 37,436 Payments (a) (1,050 ) (15,000 ) Fair value adjustment (b) 634 1,173 Balance at end of period $ 37,916 $ 23,609 (a) In the three months ended April 2, 2017, Teradyne paid $1.1 million of the AIT contingent consideration. In the three months ended April 3, 2016 based on Universal Robots’ calendar year 2015 EBITDA results, Teradyne paid $15.0 million or 100% of the eligible EBITDA contingent consideration amount. (b) In the three months ended April 2, 2017 and April 3, 2016, the fair value of contingent consideration for the earn-out The following table provides quantitative information associated with the fair value measurement of Teradyne’s Level 3 financial instruments: Liability April 2, 2017 Fair Value Valuation Technique Unobservable Inputs Weighted Average (in thousands) Contingent consideration (Universal Robots) $ 21,711 Monte Carlo Simulation Revenues for the period July 1, 2015—December 31, 12.2 % Discount Rate 2.8 % $ 16,205 Monte Carlo Simulation Revenues for the period July 1, 2015—December 31, 12.2 % Discount Rate 2.8 % As of April 2, 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 April 2, 2017 and December 31, 2016 were as follows: April 2, 2017 December 31, 2016 Carrying Value Fair Value Carrying Value Fair Value (in thousands) Assets Cash and cash equivalents $ 324,746 $ 324,746 $ 307,884 $ 307,884 Marketable securities 1,157,639 1,157,639 1,304,867 1,304,867 Derivative assets 145 145 1 1 Liabilities Contingent consideration 37,916 37,916 38,332 38,332 Derivative liabilities 107 107 131 131 Convertible debt (1) 355,937 534,750 352,669 486,754 (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 April 2, 2017 Available-for-Sale Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) U.S. Treasury securities $ 856,714 $ 37 $ (2,204 ) $ 854,547 $ 846,287 Commercial paper 121,073 7 (15 ) 121,065 76,050 Corporate debt securities 89,164 1,151 (584 ) 89,731 56,678 Certificates of deposit and time deposits 50,541 37 — 50,578 — U.S. government agency securities 21,174 8 (33 ) 21,149 10,024 Equity and debt mutual funds 17,472 2,546 (32 ) 19,986 1,415 Non-U.S. 578 5 — 583 — $ 1,156,716 $ 3,791 $ (2,868 ) $ 1,157,639 $ 990,454 Reported as follows: Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Marketable securities $ 896,345 $ 56 $ (823 ) $ 895,578 $ 774,974 Long-term marketable securities 260,371 3,735 (2,045 ) 262,061 215,480 $ 1,156,716 $ 3,791 $ (2,868 ) $ 1,157,639 $ 990,454 December 31, 2016 Available-for-Sale Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) U.S. Treasury securities $ 901,975 $ 97 $ (2,034 ) $ 900,038 $ 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 42,026 7 (19 ) 42,014 13,461 Equity and debt mutual funds 16,505 1,724 (58 ) 18,171 1,661 Non-U.S. 745 6 (23 ) 728 137 $ 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 $ 1,304,711 $ 2,977 $ (2,821 ) $ 1,304,867 $ 732,979 As of April 2, 2017, the fair market value of investments with unrealized losses totaled $990.5 million. Of this value, $2.2 million had unrealized losses of $0.2 million for greater than one year and $988.3 million had unrealized losses of $2.6 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 April 2, 2017 and December 31, 2016, were temporary. The contractual maturities of investments held at April 2, 2017 were as follows: April 2, 2017 Cost Fair Market Value (in thousands) Due within one year $ 896,345 $ 895,578 Due after 1 year through 5 years 190,557 190,252 Due after 5 years through 10 years 12,270 11,812 Due after 10 years 40,072 40,011 Total $ 1,139,244 $ 1,137,653 Contractual maturities of investments held at April 2, 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 April 2, 2017 and December 31, 2016 was $89.2 million and $83.9 million, respectively. The fair value of the outstanding contracts was $0.0 million at April 2, 2017 and a loss of $0.1 million at December 31, 2016. For the three months ended April 2, 2017 and April 3, 2016, Teradyne recorded net realized losses related to foreign currency forward contracts hedging net monetary assets and liabilities of $1.0 million and $3.3 million, respectively. Gains and losses on foreign currency forward contracts and foreign currency remeasurement gains and losses on monetary assets and liabilities are included in other (income) expense, net. The following table summarizes the fair value of derivative instruments at April 2, 2017 and December 31, 2016: Balance Sheet Location April 2, 2017 December 31, 2016 (in thousands) Derivatives not designated as hedging instruments: Foreign exchange contracts assets Prepayments $ 145 $ 1 Foreign exchange contracts liabilities Other current liabilities (107 ) (131 ) Total derivatives $ 38 $ (130 ) The following table summarizes the effect of derivative instruments recognized in the statement of operations during the three months ended April 2, 2017 and April 3, 2016. Location of Losses For the Three Months Ended Recognized in April 2, April 3, Statements of Operations 2017 2016 (in thousands) Derivatives not designated as hedging instruments: Foreign exchange contracts Other (income) expense, net $ 1,011 $ 3,298 Total Derivatives $ 1,011 $ 3,298 The table does not reflect the corresponding gains and losses from the remeasurement of monetary assets and liabilities denominated in foreign currencies. For the three months ended April 2, 2017 and April 3, 2016, net gains from the remeasurement of monetary assets and liabilities denominated in foreign currencies were $1.5 million and $3.4 million, respectively.

Debt

Debt	3 Months Ended
	Apr. 02, 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. 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 the 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 Separately and concurrent with the pricing of the Notes, Teradyne entered into warrant transactions with the Option Counterparties (the “Warrant Transactions”) in which it sold net-share-settled The Note Hedge Transactions are expected to reduce the potential dilution to Teradyne’s common stock upon any conversion of the Notes. However, the Warrant Transactions could separately have a dilutive effect to the extent that the market value per share of Teradyne’s common stock exceeds the applicable strike price of the warrant. 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%. The Notes are classified as long-term debt in the balance sheet 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 April 2, 2017, unamortized debt issuance costs were $6.9 million. The notes are classified as long-term debt in the consolidated balance sheets at April 2, 2017 and December 31, 2016. The below tables represent the key components of Teradyne’s convertible senior notes: April 2, 2017 December 31, 2016 (in thousands) Debt Principal $ 460,000 $ 460,000 Unamortized discount 104,063 107,331 Net Carrying amount of convertible debt $ 355,937 $ 352,669 For the Three Months April 2, 2017 (in thousands) Contractual interest expense on the coupon $ 1,438 Amortization of the discount component and debt issue fees recognized as interest expense 3,268 Total interest expense on the convertible debt $ 4,706 As of April 2, 2017, the remaining unamortized discount was $104.1 million, which will be amortized over 6.8 years using the effective interest rate method. The carrying amount of the equity component was $100.8 million. As of April 2, 2017, the conversion rate was equal to the initial conversion price of approximately $31.84 per share and the if-converted 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 statement of operations. As of May 12, 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 May 12, 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	3 Months Ended
	Apr. 02, 2017
Prepayments	G. PREPAYMENTS Prepayments consist of the following and are included in prepayments on the balance sheet: April 2, December 31, 2017 2016 (in thousands) Contract manufacturer and supplier prepayments $ 83,398 $ 84,473 Prepaid maintenance and other services 7,210 7,676 Prepaid taxes 3,326 4,664 Other prepayments 13,053 11,641 Total prepayments $ 106,987 $ 108,454

Deferred Revenue and Customer A

Deferred Revenue and Customer Advances	3 Months Ended
	Apr. 02, 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: April 2, December 31, 2017 2016 (in thousands) Extended warranty $ 44,053 $ 46,753 Equipment maintenance and training 41,995 39,037 Customer advances, undelivered elements and other 18,729 22,151 Total deferred revenue and customer advances $ 104,777 $ 107,941

Product Warranty

Product Warranty	3 Months Ended
	Apr. 02, 2017
Product Warranty	I. PRODUCT WARRANTY Teradyne generally provides a one-year For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Balance at beginning of period $ 7,203 $ 6,925 Accruals for warranties issued during the period 3,021 3,490 Adjustments related to pre-existing (471 ) 243 Settlements made during the period (2,699 ) (3,162 ) Balance at end of period $ 7,054 $ 7,496 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 April 2, April 3, 2017 2016 (in thousands) Balance at beginning of period $ 46,753 $ 46,499 Deferral of new extended warranty revenue 6,125 6,827 Recognition of extended warranty deferred revenue (8,825 ) (7,211 ) Balance at end of period $ 44,053 $ 46,115

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Apr. 02, 2017
Stock-Based Compensation	J. 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 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 Non-GAAP non-cash non-recurring 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 three months ended April 2, 2017 and April 3, 2016, Teradyne granted 0.1 million and 0.1 million TSR PRSUs, respectively, 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 Three Months Ended April 2, April 3, 2017 2016 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 three months ended April 2, 2017 and April 3, 2016, Teradyne granted 0.1 million and 0.1 million, respectively of PBIT PRSUs with a grant date fair value of $27.72 and $18.71, respectively. During the three months ended April 2, 2017, Teradyne granted 0.8 million of service-based restricted stock unit awards to employees at a weighted average grant date fair value of $27.86 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 three months ended April 3, 2016, Teradyne granted 1.2 million of service-based restricted stock unit awards to employees at a weighted average grant date fair value of $18.83 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 Three Months Ended April 2, April 3, 2017 2016 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 (Loss) Income	3 Months Ended
	Apr. 02, 2017
Accumulated Other Comprehensive (Loss) Income	K. ACCUMULATED OTHER COMPREHENSIVE (LOSS) INCOME Changes in accumulated other comprehensive (loss) income, which is 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) Three Months Ended April 2, 2017 Balance at December 31, 2016, net of tax of $0, $209, $(778) $ (21,921 ) $ (60 ) $ 1,767 $ (20,214 ) Other comprehensive income before reclassifications, net of tax of $0, $420, $0 8,963 513 — 9,476 Amounts reclassified from accumulated other comprehensive income, net of tax of $0, $(64), $(38) — (95 ) (68 ) (163 ) Net current period other comprehensive income (loss), net of tax of $0, $356, $(38) 8,963 418 (68 ) 9,313 Balance at April 2, 2017, net of tax of $0, $565, $(816) $ (12,958 ) $ 358 $ 1,699 $ (10,901 ) Foreign Currency Translation Adjustments Unrealized Gains (Losses) on Marketable Securities Retirement Plans Prior Service Credit Total (in thousands) Three Months Ended April 3, 2016 Balance at December 31, 2015, net of tax of $0, $(459), $(622) $ (8,759 ) $ (1,414 ) $ 2,029 $ (8,144 ) Other comprehensive income before reclassifications, net of tax of $0, $1,253, $0 10,271 3,071 — 13,342 Amounts reclassified from accumulated other comprehensive income, net of tax of $0, $11, $(46) — (83 ) (80 ) (163 ) Net current period other comprehensive income (loss), net of tax of $0, $1,264, $(46) 10,271 2,988 (80 ) 13,179 Balance as April 3, 2016, net of tax of $0, $805, $(668) $ 1,512 $ 1,574 $ 1,949 $ 5,035 Reclassifications out of accumulated other comprehensive (loss) income to the statement of operations for the three months ended April 2, 2017 and April 3, 2016 were as follows: Details about Accumulated Other Comprehensive (Loss) Income Components For the Three Months Ended Affected Line Item in the Statements of Operations April 2, April 3, 2017 2016 (in thousands) Available-for-sale Unrealized gains, net of tax of $64, $(11) $ 95 $ 83 Interest income Defined benefit pension and postretirement plans: Amortization of prior service benefit, net of tax of $38, $46 68 80 (a) Total reclassifications, net of tax of $102, $35 $ 163 $ 163 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 Intangible Assets

Goodwill and Intangible Assets	3 Months Ended
	Apr. 02, 2017
Goodwill and Intangible Assets	L. GOODWILL AND INTANGIBLE ASSETS Goodwill Teradyne performs its annual goodwill impairment test as required under the provisions of ASC 350-10, “Intangibles—Goodwill and Other” The changes in the carrying amount of goodwill by reportable segments for the three months ended April 2, 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 6,722 — — — 6,722 Balance at April 2, 2017 Goodwill 211,573 158,699 361,819 260,540 992,631 Accumulated impairment losses — (148,183 ) (353,843 ) (260,540 ) (762,566 ) $ 211,573 $ 10,516 $ 7,976 $ — $ 230,065 Intangible Assets Teradyne reviews long-lived assets for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable or that the useful lives of these assets are no longer appropriate. Amortizable intangible assets consist of the following and are included in intangible assets, net on the balance sheet: April 2, 2017 Gross Carrying Amount Accumulated Amortization Cumulative Net Carrying Amount (in thousands) Developed technology $ 270,877 $ (211,065 ) $ (3,292 ) $ 56,520 Customer relationships 92,741 (79,114 ) (348 ) 13,279 Tradenames and trademarks 50,100 (24,331 ) (845 ) 24,924 Non-compete 320 (200 ) — 120 Customer backlog 170 (170 ) — — Total intangible assets $ 414,208 $ (314,880 ) $ (4,485 ) $ 94,843 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 320 (180 ) — 140 Customer backlog 170 (170 ) — — Total intangible assets $ 414,208 $ (306,868 ) $ (6,939 ) $ 100,401 Aggregate intangible asset amortization expense was $8.0 million and $20.0 million, respectively, for the three months ended April 2, 2017 and April 3, 2016. Estimated intangible asset amortization expense for each of the five succeeding fiscal years is as follows: Year Amortization Expense (in thousands) 2017 (remainder) 21,621 2018 27,475 2019 23,622 2020 10,325 2021 3,504 Thereafter 8,296

Net Income per Common Share

Net Income per Common Share	3 Months Ended
	Apr. 02, 2017
Net Income per Common Share	M. NET INCOME PER COMMON SHARE The following table sets forth the computation of basic and diluted net income per common share: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands, except per share amounts) Net income for basic and diluted net income per share $ 85,221 $ 49,986 Weighted average common shares-basic 200,005 204,271 Effect of dilutive potential common shares: Restricted stock units 1,533 965 Stock options 390 487 Employee stock purchase plan 8 9 Dilutive potential common shares 1,931 1,461 Weighted average common shares-diluted 201,936 205,732 Net income per common share-basic $ 0.43 $ 0.24 Net income per common share-diluted $ 0.42 $ 0.24 The computation of diluted net income per common share for the three months ended April 2, 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 April 3, 2016 excludes the effect of the potential exercise of stock options to purchase approximately 0.3 million shares because the effect would have been anti-dilutive.

Restructuring and Other

Restructuring and Other	3 Months Ended
	Apr. 02, 2017
Restructuring and Other	N. RESTRUCTURING AND OTHER During the three months ended April 2, 2017, Teradyne recorded $1.9 million of restructuring charges of which $1.3 million was for a lease impairment of a Wireless Test facility in Sunnyvale, CA and $0.6 million was for employee severance charges. The Sunnyvale, CA lease expires in 2020. The accrual for the future lease payments liability is reflected in other accrued liabilities and is expected to be paid over the term of the lease. During the three months ended April 2, 2017 and April 3, 2016, Teradyne recorded $0.6 million and $1.2 million, respectively, of other charges for the increase in the fair value of the Universal Robots contingent consideration liability. During the three months ended April 3, 2016, Teradyne recorded $0.4 million of employee severance charges.

Retirement Plans

Retirement Plans	3 Months Ended
	Apr. 02, 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. In the three months ended April 2, 2017, Teradyne contributed $0.6 million to the U.S. supplemental executive defined benefit pension plan and $0.2 million to certain qualified plans for non-U.S. For the three months ended April 2, 2017 and April 3, 2016, Teradyne’s net periodic pension cost (income) was comprised of the following: For the Three Months Ended April 2, 2017 April 3, 2016 United States Foreign United States Foreign (in thousands) Service cost $ 560 $ 185 $ 576 $ 207 Interest cost 3,312 163 3,414 206 Expected return on plan assets (3,000 ) (6 ) (3,443 ) (5 ) Amortization of prior service cost 18 — 24 — Net actuarial gain — — (1,193 ) — Settlement — — — (239 ) Total net periodic pension cost (income) $ 890 $ 342 $ (622 ) $ 169 Postretirement Benefit Plan In addition to receiving pension benefits, U.S. Teradyne employees 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 months ended April 2, 2017 and April 3, 2016, Teradyne’s net periodic postretirement income was comprised of the following: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Service cost $ 10 $ 10 Interest cost 50 56 Amortization of prior service benefit (124 ) (150 ) Total net periodic post-retirement benefit $ (64 ) $ (84 )

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Apr. 02, 2017
Commitments and Contingencies	P. COMMITMENTS AND CONTINGENCIES Purchase Commitments As of April 2, 2017, Teradyne had entered into purchase commitments for certain components and materials. The purchase commitments covered by the agreements aggregate to approximately $292.0 million, of which $281.7 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	3 Months Ended
	Apr. 02, 2017
Income Taxes	Q. INCOME TAXES The effective tax rate for the three months ended April 2, 2017 and April 3, 2016 was 7.4% and 12.6%, respectively. The decrease in the effective tax rate from the three months ended April 3, 2016 to the three months ended April 2, 2017 resulted from an increase in the discrete benefit from stock based compensation, a projected shift in the geographic distribution of income which decreased income subject to taxation in the U.S. relative to lower tax rate jurisdictions and a decrease in the discrete benefit from non-taxable The effective tax rates for the three months ended April 2, 2017 and April 3, 2016 differed from the expected federal statutory rate of 35% primarily because of the favorable effect of statutory rates applicable to income earned outside the United States. The tax rate for the three months ended April 2, 2017 and April 3, 2016 was 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 benefits recorded in the three months ended April 2, 2017 amounted to $7.0 million of which $5.5 million resulted from stock based compensation, $0.7 million related to U.S. research and development tax credits and $0.8 million from other discrete tax benefits. The $5.5 million of discrete benefit from stock based compensation included $5.2 million of excess tax benefits recognized pursuant to ASU No. 2016-09 “Improvements to Employee Share-Based Payment Accounting.” Discrete tax benefits recorded in the three months ended April 3, 2016 amounted to $2.5 million of which $1.2 million resulted from non-taxable 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 April 2, 2017, Teradyne believes that it will ultimately realize the deferred tax assets recorded on the condensed consolidated balance sheet. However, should Teradyne believe that it is more-likely-than-not As of April 2, 2017 and December 31, 2016, Teradyne had $40.7 million and $39.0 million, respectively, of reserves for uncertain tax positions. The $1.7 million net increase in reserves for uncertain tax positions is primarily composed of additions related to transfer pricing exposures and U.S. research and development tax credits. As of April 2, 2017, Teradyne estimates that it is reasonably possible that the balance of uncertain tax positions may decrease approximately $0.8 million in the next twelve months, as a result of a lapse of statutes of limitation. The estimated decrease is comprised primarily of reserves relating to U.S. research and development credits. Teradyne recognizes interest and penalties related to income tax matters in income tax expense. As of April 2, 2017 and December 31, 2016, $0.3 million and $0.4 million, respectively, of interest and penalties were accrued for uncertain tax positions. For the three months ended April 2, 2017, a benefit of $0.1 million was recorded for interest and penalties related to income tax items. For the three months ended April 3, 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 three months ended April 2, 2017 was $4.7 million, or $0.02 per diluted share. The tax savings due to the tax holiday for the three months ended April 3, 2016 was $2.6 million, or $0.01 per diluted share. The tax holiday is scheduled to expire on December 31, 2020.

Segment Information

Segment Information	3 Months Ended
	Apr. 02, 2017
Segment Information	R. SEGMENT INFORMATION Teradyne has four operating segments (Semiconductor Test, System Test, Industrial Automation 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 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 Industrial Automation segment includes operations related to the design, manufacturing and marketing of collaborative robots. 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 Segment information for the three months ended April 2, 2017 and April 3, 2016 is as follows: Semiconductor Test System Test Industrial Automation Wireless Test Corporate and Eliminations Consolidated (in thousands) Three Months Ended April 2, 2017 Revenues $ 355,528 $ 39,845 $ 36,272 $ 25,268 $ — $ 456,913 Income (loss) before income taxes (1)(2) 97,966 (2,759 ) (2,571 ) 1,532 (2,152 ) 92,016 Total assets (3) 740,334 106,754 331,016 61,356 1,602,820 2,842,280 Three Months Ended April 3, 2016 Revenues $ 340,264 $ 53,670 $ 16,746 $ 20,314 $ — $ 430,994 Income (loss) before income taxes (1)(2) 73,254 9,492 (7,168 ) (20,140 ) 1,754 57,192 Total assets (3) 664,555 90,695 350,589 408,466 1,034,669 2,548,974 (1) Interest income, interest expense, contingent consideration adjustments, pension and post retirement plans actuarial gains and other income (expense) are included in Corporate and Eliminations. (2) Included in the income (loss) before income taxes for each of the segments are charges and credits related to inventory and other. (3) Total business assets are directly attributable to each business. Corporate assets consist of cash and cash equivalents, marketable securities and certain other assets. Included in the Semiconductor Test segment are charges and credits in the following line items in the statements of operations: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Cost of revenues—inventory charge $ 1,319 $ 3,685 Restructuring and other (265 ) 414 Included in the System Test segment are charges in the following line item in the statements of operations: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Cost of revenues—inventory charge $ 885 $ — Included in the Industrial Automation segment are charges in the following line item in the statements of operations: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Restructuring and other $ 624 $ — Included in the Wireless Test segment are charges in the following line items in the statements of operations: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Restructuring and other—lease impairment $ 1,313 $ — Cost of revenues—inventory charge 522 605 Included in Corporate and Eliminations are charges in the following line items in the statements of operations: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Restructuring and other—Universal Robots contingent consideration adjustment $ 634 $ 1,173 Restructuring and other 205 —

Shareholders' Equity

Shareholders' Equity	3 Months Ended
	Apr. 02, 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 three months ended April 2, 2017, Teradyne repurchased 1.3 million shares of common stock for $37.7 million at an average price of $29.38 per share. During the three months ended April 3, 2016, Teradyne repurchased 1.5 million shares of common stock for $28.0 million at an average price of $18.81 per share. The total price includes commissions and is recorded as a reduction to retained earnings. Dividend Holders of Teradyne’s common stock are entitled to receive dividends when they are declared by Teradyne’s Board of Directors. In January 2017, Teradyne’s Board of Directors declared a quarterly cash dividend of $0.07 per share. Dividend payments for the three months ended April 2, 2017 were $14.0 million. In January 2016, Teradyne’s Board of Directors declared a quarterly cash dividend of $0.06 per share. Dividend payments for the three months ended April 3, 2016 were $12.3 million. 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)	3 Months Ended
	Apr. 02, 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, paid-in 2016-09, ASU 2016-09 In addition, under ASU 2016-09, Upon adoption of ASU 2016-09,
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)	3 Months Ended
	Apr. 02, 2017
Composition of Inventories, Net	Inventories, net consisted of the following at April 2, 2017 and December 31, 2016: April 2, December 31, 2017 2016 (in thousands) Raw material $ 62,373 $ 58,530 Work-in-process 22,511 22,946 Finished goods 118,394 54,482 $ 203,278 $ 135,958

Financial Instruments (Tables)

Financial Instruments (Tables)	3 Months Ended
	Apr. 02, 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 April 2, 2017 and December 31, 2016. April 2, 2017 Quoted Prices Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total (in thousands) Assets Cash $ 202,925 $ — $ — $ 202,925 Cash equivalents 115,578 6,243 — 121,821 Available-for-sale U.S. Treasury securities — 854,547 — 854,547 Commercial paper — 121,065 — 121,065 Corporate debt securities — 89,731 — 89,731 Certificates of deposit and time deposits — 50,578 — 50,578 U.S. government agency securities — 21,149 — 21,149 Equity and debt mutual funds 19,986 — — 19,986 Non-U.S. — 583 — 583 Total $ 338,489 $ 1,143,896 $ — $ 1,482,385 Derivative assets — 145 — 145 Total $ 338,489 $ 1,144,041 $ — $ 1,482,530 Liabilities Contingent consideration $ — $ — $ 37,916 $ 37,916 Derivative liabilities — 107 — 107 Total $ — $ 107 $ 37,916 $ 38,023 Reported as follows: (Level 1) (Level 2) (Level 3) Total (in thousands) Assets Cash and cash equivalents $ 318,503 $ 6,243 $ — $ 324,746 Marketable securities — 895,578 — 895,578 Long-term marketable securities 19,986 242,075 — 262,061 Prepayments — 145 — 145 $ 338,489 $ 1,144,041 $ — $ 1,482,530 Liabilities . Other current liabilities $ — $ 107 $ — $ 107 Contingent consideration — — 21,711 21,711 Long-term contingent consideration — — 16,205 16,205 $ — $ 107 $ 37,916 $ 38,023 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 — 900,038 — 900,038 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 — 42,014 — 42,014 Equity and debt mutual funds 18,171 — — 18,171 Non-U.S. — 728 — 728 Total $ 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 $ 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 $ — $ 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 months ended April 2, 2017 and April 3, 2016 were as follows: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Balance at beginning of period $ 38,332 $ 37,436 Payments (a) (1,050 ) (15,000 ) Fair value adjustment (b) 634 1,173 Balance at end of period $ 37,916 $ 23,609 (a) In the three months ended April 2, 2017, Teradyne paid $1.1 million of the AIT contingent consideration. In the three months ended April 3, 2016 based on Universal Robots’ calendar year 2015 EBITDA results, Teradyne paid $15.0 million or 100% of the eligible EBITDA contingent consideration amount. (b) In the three months ended April 2, 2017 and April 3, 2016, the fair value of contingent consideration for the earn-out
Quantitative Information Associated With Fair Value Measurement of Level 3 Financial Instrument	The following table provides quantitative information associated with the fair value measurement of Teradyne’s Level 3 financial instruments: Liability April 2, 2017 Fair Value Valuation Technique Unobservable Inputs Weighted Average (in thousands) Contingent consideration (Universal Robots) $ 21,711 Monte Carlo Simulation Revenues for the period July 1, 2015—December 31, 12.2 % Discount Rate 2.8 % $ 16,205 Monte Carlo Simulation Revenues for the period July 1, 2015—December 31, 12.2 % Discount Rate 2.8 %
Schedule of Carrying Amounts and Fair Values of Financial Instruments	The carrying amounts and fair values of Teradyne’s financial instruments at April 2, 2017 and December 31, 2016 were as follows: April 2, 2017 December 31, 2016 Carrying Value Fair Value Carrying Value Fair Value (in thousands) Assets Cash and cash equivalents $ 324,746 $ 324,746 $ 307,884 $ 307,884 Marketable securities 1,157,639 1,157,639 1,304,867 1,304,867 Derivative assets 145 145 1 1 Liabilities Contingent consideration 37,916 37,916 38,332 38,332 Derivative liabilities 107 107 131 131 Convertible debt (1) 355,937 534,750 352,669 486,754 (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 April 2, 2017 Available-for-Sale Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) U.S. Treasury securities $ 856,714 $ 37 $ (2,204 ) $ 854,547 $ 846,287 Commercial paper 121,073 7 (15 ) 121,065 76,050 Corporate debt securities 89,164 1,151 (584 ) 89,731 56,678 Certificates of deposit and time deposits 50,541 37 — 50,578 — U.S. government agency securities 21,174 8 (33 ) 21,149 10,024 Equity and debt mutual funds 17,472 2,546 (32 ) 19,986 1,415 Non-U.S. 578 5 — 583 — $ 1,156,716 $ 3,791 $ (2,868 ) $ 1,157,639 $ 990,454 Reported as follows: Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Marketable securities $ 896,345 $ 56 $ (823 ) $ 895,578 $ 774,974 Long-term marketable securities 260,371 3,735 (2,045 ) 262,061 215,480 $ 1,156,716 $ 3,791 $ (2,868 ) $ 1,157,639 $ 990,454 December 31, 2016 Available-for-Sale Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) U.S. Treasury securities $ 901,975 $ 97 $ (2,034 ) $ 900,038 $ 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 42,026 7 (19 ) 42,014 13,461 Equity and debt mutual funds 16,505 1,724 (58 ) 18,171 1,661 Non-U.S. 745 6 (23 ) 728 137 $ 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 $ 1,304,711 $ 2,977 $ (2,821 ) $ 1,304,867 $ 732,979
Contractual Maturities of Investments Held	The contractual maturities of investments held at April 2, 2017 were as follows: April 2, 2017 Cost Fair Market Value (in thousands) Due within one year $ 896,345 $ 895,578 Due after 1 year through 5 years 190,557 190,252 Due after 5 years through 10 years 12,270 11,812 Due after 10 years 40,072 40,011 Total $ 1,139,244 $ 1,137,653
Schedule of Derivative Instruments in Statement of Financial Position at Fair Value	The following table summarizes the fair value of derivative instruments at April 2, 2017 and December 31, 2016: Balance Sheet Location April 2, 2017 December 31, 2016 (in thousands) Derivatives not designated as hedging instruments: Foreign exchange contracts assets Prepayments $ 145 $ 1 Foreign exchange contracts liabilities Other current liabilities (107 ) (131 ) Total derivatives $ 38 $ (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 months ended April 2, 2017 and April 3, 2016. Location of Losses For the Three Months Ended Recognized in April 2, April 3, Statements of Operations 2017 2016 (in thousands) Derivatives not designated as hedging instruments: Foreign exchange contracts Other (income) expense, net $ 1,011 $ 3,298 Total Derivatives $ 1,011 $ 3,298

Debt (Tables)

Debt (Tables)	3 Months Ended
	Apr. 02, 2017
Components of Convertible Senior Notes	The below tables represent the key components of Teradyne’s convertible senior notes: April 2, 2017 December 31, 2016 (in thousands) Debt Principal $ 460,000 $ 460,000 Unamortized discount 104,063 107,331 Net Carrying amount of convertible debt $ 355,937 $ 352,669 For the Three Months April 2, 2017 (in thousands) Contractual interest expense on the coupon $ 1,438 Amortization of the discount component and debt issue fees recognized as interest expense 3,268 Total interest expense on the convertible debt $ 4,706

Prepayments (Tables)

Prepayments (Tables)	3 Months Ended
	Apr. 02, 2017
Schedule of Prepayments	Prepayments consist of the following and are included in prepayments on the balance sheet: April 2, December 31, 2017 2016 (in thousands) Contract manufacturer and supplier prepayments $ 83,398 $ 84,473 Prepaid maintenance and other services 7,210 7,676 Prepaid taxes 3,326 4,664 Other prepayments 13,053 11,641 Total prepayments $ 106,987 $ 108,454

Deferred Revenue and Customer32

Deferred Revenue and Customer Advances (Tables)	3 Months Ended
	Apr. 02, 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: April 2, December 31, 2017 2016 (in thousands) Extended warranty $ 44,053 $ 46,753 Equipment maintenance and training 41,995 39,037 Customer advances, undelivered elements and other 18,729 22,151 Total deferred revenue and customer advances $ 104,777 $ 107,941

Product Warranty (Tables)

Product Warranty (Tables)	3 Months Ended
	Apr. 02, 2017
Other Accrued Liabilities	The warranty balance below is included in other accrued liabilities on the balance sheet. For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Balance at beginning of period $ 7,203 $ 6,925 Accruals for warranties issued during the period 3,021 3,490 Adjustments related to pre-existing (471 ) 243 Settlements made during the period (2,699 ) (3,162 ) Balance at end of period $ 7,054 $ 7,496
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 April 2, April 3, 2017 2016 (in thousands) Balance at beginning of period $ 46,753 $ 46,499 Deferral of new extended warranty revenue 6,125 6,827 Recognition of extended warranty deferred revenue (8,825 ) (7,211 ) Balance at end of period $ 44,053 $ 46,115

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Apr. 02, 2017
Schedule of Estimated Fair Value of TSR Performance-Based Restricted Stock Unit Awards Assumptions	The fair value was estimated using the Monte Carlo simulation model with the following assumptions: For the Three Months Ended April 2, April 3, 2017 2016 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 %
Stock Options
Fair Value of Stock Options Using Assumptions	The fair value of stock options was estimated using the Black-Scholes option-pricing model with the following assumptions: For the Three Months Ended April 2, April 3, 2017 2016 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 %

Accumulated Other Comprehensi35

Accumulated Other Comprehensive (Loss) Income (Tables)	3 Months Ended
	Apr. 02, 2017
Changes in Accumulated Other Comprehensive (Loss) Income	Changes in accumulated other comprehensive (loss) income, which is 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) Three Months Ended April 2, 2017 Balance at December 31, 2016, net of tax of $0, $209, $(778) $ (21,921 ) $ (60 ) $ 1,767 $ (20,214 ) Other comprehensive income before reclassifications, net of tax of $0, $420, $0 8,963 513 — 9,476 Amounts reclassified from accumulated other comprehensive income, net of tax of $0, $(64), $(38) — (95 ) (68 ) (163 ) Net current period other comprehensive income (loss), net of tax of $0, $356, $(38) 8,963 418 (68 ) 9,313 Balance at April 2, 2017, net of tax of $0, $565, $(816) $ (12,958 ) $ 358 $ 1,699 $ (10,901 ) Foreign Currency Translation Adjustments Unrealized Gains (Losses) on Marketable Securities Retirement Plans Prior Service Credit Total (in thousands) Three Months Ended April 3, 2016 Balance at December 31, 2015, net of tax of $0, $(459), $(622) $ (8,759 ) $ (1,414 ) $ 2,029 $ (8,144 ) Other comprehensive income before reclassifications, net of tax of $0, $1,253, $0 10,271 3,071 — 13,342 Amounts reclassified from accumulated other comprehensive income, net of tax of $0, $11, $(46) — (83 ) (80 ) (163 ) Net current period other comprehensive income (loss), net of tax of $0, $1,264, $(46) 10,271 2,988 (80 ) 13,179 Balance as April 3, 2016, net of tax of $0, $805, $(668) $ 1,512 $ 1,574 $ 1,949 $ 5,035
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 months ended April 2, 2017 and April 3, 2016 were as follows: Details about Accumulated Other Comprehensive (Loss) Income Components For the Three Months Ended Affected Line Item in the Statements of Operations April 2, April 3, 2017 2016 (in thousands) Available-for-sale Unrealized gains, net of tax of $64, $(11) $ 95 $ 83 Interest income Defined benefit pension and postretirement plans: Amortization of prior service benefit, net of tax of $38, $46 68 80 (a) Total reclassifications, net of tax of $102, $35 $ 163 $ 163 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 Intangible Assets

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Apr. 02, 2017
Changes in Carrying Amount of Goodwill by Segment	The changes in the carrying amount of goodwill by reportable segments for the three months ended April 2, 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 6,722 — — — 6,722 Balance at April 2, 2017 Goodwill 211,573 158,699 361,819 260,540 992,631 Accumulated impairment losses — (148,183 ) (353,843 ) (260,540 ) (762,566 ) $ 211,573 $ 10,516 $ 7,976 $ — $ 230,065
Schedule of Estimated Intangible Asset Amortization Expense	Estimated intangible asset amortization expense for each of the five succeeding fiscal years is as follows: Year Amortization Expense (in thousands) 2017 (remainder) 21,621 2018 27,475 2019 23,622 2020 10,325 2021 3,504 Thereafter 8,296
Wireless Test
Schedule of Amortizable Intangible Assets	Amortizable intangible assets consist of the following and are included in intangible assets, net on the balance sheet: April 2, 2017 Gross Carrying Amount Accumulated Amortization Cumulative Net Carrying Amount (in thousands) Developed technology $ 270,877 $ (211,065 ) $ (3,292 ) $ 56,520 Customer relationships 92,741 (79,114 ) (348 ) 13,279 Tradenames and trademarks 50,100 (24,331 ) (845 ) 24,924 Non-compete 320 (200 ) — 120 Customer backlog 170 (170 ) — — Total intangible assets $ 414,208 $ (314,880 ) $ (4,485 ) $ 94,843 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 320 (180 ) — 140 Customer backlog 170 (170 ) — — Total intangible assets $ 414,208 $ (306,868 ) $ (6,939 ) $ 100,401

Net Income per Common Share (Ta

Net Income per Common Share (Tables)	3 Months Ended
	Apr. 02, 2017
Computation of Basic and Diluted Net Income Per Common Share	The following table sets forth the computation of basic and diluted net income per common share: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands, except per share amounts) Net income for basic and diluted net income per share $ 85,221 $ 49,986 Weighted average common shares-basic 200,005 204,271 Effect of dilutive potential common shares: Restricted stock units 1,533 965 Stock options 390 487 Employee stock purchase plan 8 9 Dilutive potential common shares 1,931 1,461 Weighted average common shares-diluted 201,936 205,732 Net income per common share-basic $ 0.43 $ 0.24 Net income per common share-diluted $ 0.42 $ 0.24

Retirement Plans (Tables)

Retirement Plans (Tables)	3 Months Ended
	Apr. 02, 2017
Defined Benefit Pension Plans
Net Periodic Pension and Postretirement Cost (Income)	For the three months ended April 2, 2017 and April 3, 2016, Teradyne’s net periodic pension cost (income) was comprised of the following: For the Three Months Ended April 2, 2017 April 3, 2016 United States Foreign United States Foreign (in thousands) Service cost $ 560 $ 185 $ 576 $ 207 Interest cost 3,312 163 3,414 206 Expected return on plan assets (3,000 ) (6 ) (3,443 ) (5 ) Amortization of prior service cost 18 — 24 — Net actuarial gain — — (1,193 ) — Settlement — — — (239 ) Total net periodic pension cost (income) $ 890 $ 342 $ (622 ) $ 169
Postretirement Benefit Plans
Net Periodic Pension and Postretirement Cost (Income)	For the three months ended April 2, 2017 and April 3, 2016, Teradyne’s net periodic postretirement income was comprised of the following: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Service cost $ 10 $ 10 Interest cost 50 56 Amortization of prior service benefit (124 ) (150 ) Total net periodic post-retirement benefit $ (64 ) $ (84 )

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Apr. 02, 2017
Segment Information	Segment information for the three months ended April 2, 2017 and April 3, 2016 is as follows: Semiconductor Test System Test Industrial Automation Wireless Test Corporate and Eliminations Consolidated (in thousands) Three Months Ended April 2, 2017 Revenues $ 355,528 $ 39,845 $ 36,272 $ 25,268 $ — $ 456,913 Income (loss) before income taxes (1)(2) 97,966 (2,759 ) (2,571 ) 1,532 (2,152 ) 92,016 Total assets (3) 740,334 106,754 331,016 61,356 1,602,820 2,842,280 Three Months Ended April 3, 2016 Revenues $ 340,264 $ 53,670 $ 16,746 $ 20,314 $ — $ 430,994 Income (loss) before income taxes (1)(2) 73,254 9,492 (7,168 ) (20,140 ) 1,754 57,192 Total assets (3) 664,555 90,695 350,589 408,466 1,034,669 2,548,974 (1) Interest income, interest expense, contingent consideration adjustments, pension and post retirement plans actuarial gains and other income (expense) are included in Corporate and Eliminations. (2) Included in the income (loss) before income taxes for each of the segments are charges and credits related to inventory and other. (3) Total business assets are directly attributable to each business. 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 in the following line items in the statements of operations: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Restructuring and other—lease impairment $ 1,313 $ — Cost of revenues—inventory charge 522 605
Semiconductor Test
Schedule of Segment Reporting Information by Segment Charges	Included in the Semiconductor Test segment are charges and credits in the following line items in the statements of operations: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Cost of revenues—inventory charge $ 1,319 $ 3,685 Restructuring and other (265 ) 414
System Test
Schedule of Segment Reporting Information by Segment Charges	Included in the System Test segment are charges in the following line item in the statements of operations: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Cost of revenues—inventory charge $ 885 $ —
Industrial Automation
Schedule of Segment Reporting Information by Segment Charges	Included in the Industrial Automation segment are charges in the following line item in the statements of operations: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Restructuring and other $ 624 $ —
Corporate And Eliminations
Schedule of Segment Reporting Information by Segment Charges	Included in Corporate and Eliminations are charges in the following line items in the statements of operations: For the Three Months Ended April 2, April 3, 2017 2016 (in thousands) Restructuring and other—Universal Robots contingent consideration adjustment $ 634 $ 1,173 Restructuring and other 205 —

Accounting Policies - Additiona

Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
New Accounting Pronouncements or Change in Accounting Principle
Income tax provision (benefit)	$ 6,795	$ 7,206
ASU 2016-09
New Accounting Pronouncements or Change in Accounting Principle
Cumulative effect adjustment to increase retained earnings and deferred tax assets	39,000
Income tax provision (benefit)	$ (5,200)

Composition of Inventories, Net

Composition of Inventories, Net (Detail) - USD ($) $ in Thousands	Apr. 02, 2017	Dec. 31, 2016
Inventory [Line Items]
Raw material	$ 62,373	$ 58,530
Work-in-process	22,511	22,946
Finished goods	118,394	54,482
Inventories, net	$ 203,278	$ 135,958

Inventories - Additional Inform

Inventories - Additional Information (Detail) - USD ($) $ in Millions	Apr. 02, 2017	Dec. 31, 2016
Inventory [Line Items]
Inventory reserves	$ 115.2	$ 116

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Apr. 02, 2017	Apr. 03, 2016	Apr. 02, 2017	Dec. 31, 2016
Financial Instruments and Fair Value [Line Items]
Available-for-sale securities, realized loss	$ 200,000	$ 200,000
Available-for-sale securities, realized gain	300,000	200,000
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	990,454,000		$ 990,454,000	$ 732,979,000
Fair market value of investments with unrealized losses greater than one year	2,200,000		2,200,000	2,900,000
Aggregate loss of investments with unrealized losses greater than one year			200,000	300,000
Fair market value of investments with unrealized losses less than one year	988,300,000		988,300,000	730,100,000
Aggregate loss of investments with unrealized losses less than one year			2,600,000	2,500,000
Gains (losses) on foreign currency transactions	1,500,000	3,400,000
Realized (losses) gains on foreign currency contracts	(1,000,000)	$ (3,300,000)
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	89,200,000		$ 89,200,000	83,900,000
Gains (losses) on foreign currency transactions	$ 0			$ (100,000)

Schedule of Fair Value of Finan

Schedule of Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Apr. 02, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	$ 1,157,639	$ 1,304,867
U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	854,547	900,038
Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	89,731	100,153
Certificates of Deposit and Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	50,578	82,133
Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	121,065	161,630
U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	21,149	42,014
Equity And Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	19,986	18,171
Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	583	728
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	1,482,385	1,612,751
Derivative assets	145	1
Total	1,482,530	1,612,752
Contingent consideration	37,916	38,332
Derivative liabilities	107	131
Total	38,023	38,463
Fair Value, Measurements, Recurring | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	202,925	214,722
Fair Value, Measurements, Recurring | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	121,821	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	854,547	900,038
Fair Value, Measurements, Recurring | Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	89,731	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	50,578	82,133
Fair Value, Measurements, Recurring | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	121,065	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	21,149	42,014
Fair Value, Measurements, Recurring | Equity And Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	19,986	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	583	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	338,489	270,351
Total	338,489	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	202,925	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	115,578	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	19,986	18,171
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	1,143,896	1,342,400
Derivative assets	145	1
Total	1,144,041	1,342,401
Derivative liabilities	107	131
Total	107	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	6,243	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	854,547	900,038
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	89,731	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	50,578	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	121,065	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	21,149	42,014
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	583	728
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent consideration	37,916	38,332
Total	$ 37,916	$ 38,332

Schedule of Reported Financial

Schedule of Reported Financial Assets and Liabilities (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Apr. 02, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	$ 1,482,530	$ 1,612,752
Liabilities	38,023	38,463
Other Current Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	107
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	324,746	307,884
Marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	895,578	871,024
Long-term marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	262,061	433,843
Prepayments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	145	1
Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	21,711	1,050
Long Term Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	16,205	37,282
Quoted Prices in Active Markets for Identical Instruments (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	338,489	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	318,503	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	19,986	18,171
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	1,144,041	1,342,401
Liabilities	107	131
Significant Other Observable Inputs (Level 2) | Other Current Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	107
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	6,243	55,704
Significant Other Observable Inputs (Level 2) | Marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	895,578	871,024
Significant Other Observable Inputs (Level 2) | Long-term marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	242,075	415,672
Significant Other Observable Inputs (Level 2) | Prepayments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	145	1
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	37,916	38,332
Significant Unobservable Inputs (Level 3) | Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	21,711	1,050
Significant Unobservable Inputs (Level 3) | Long Term Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	$ 16,205	$ 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
		Apr. 02, 2017	Apr. 03, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period		$ 38,332	$ 37,436
Payments	[1]	(1,050)	(15,000)
Fair value adjustment	[2]	634	1,173
Ending Balance		$ 37,916	$ 23,609
[1]	In the three months ended April 2, 2017, Teradyne paid $1.1 million of the AIT contingent consideration. In the three months ended April 3, 2016 based on Universal Robots' calendar year 2015 EBITDA results, Teradyne paid $15.0 million or 100% of the eligible EBITDA contingent consideration amount.
[2]	In the three months ended April 2, 2017 and April 3, 2016, the fair value of contingent consideration for the earn-out in connection with the acquisition of Universal Robots was increased by $0.6 million and $1.2 million, respectively, primarily due to a decrease in the discount rate.

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
	Apr. 02, 2017	Apr. 03, 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	634	1,173
Universal Robots
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payments of contingent consideration	1,100	$ 15,000
EBITDA contingent consideration amount, percentage		100.00%
Increase(decrease)in contingent consideration	$ 600	$ 1,200

Quantitative Information Associ

Quantitative Information Associated With Fair Value Measurement of Level 3 Financial Instrument (Detail) - Monte Carlo Simulation $ in Thousands	3 Months Ended
	Apr. 02, 2017USD ($)
Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Contingent consideration	$ 16,205
Significant Unobservable Inputs (Level 3) | Universal Robots
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Contingent consideration	$ 21,711
Revenues for the period July 1, 2015-December 31, 2017 | Universal Robots
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Target achievement, volatility	12.20%
Discount Rate	2.80%
Revenues for the period July 1, 2015-December 31, 2018 | Universal Robots
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Target achievement, volatility	12.20%
Discount Rate	2.80%

Schedule of Carrying Amounts an

Schedule of Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands		Apr. 02, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Marketable securities		$ 1,157,639	$ 1,304,867
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and cash equivalents		324,746	307,884
Marketable securities		1,157,639	1,304,867
Derivative assets		145	1
Contingent consideration		37,916	38,332
Derivative liabilities		107	131
Convertible debt	[1]	534,750	486,754
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and cash equivalents		324,746	307,884
Marketable securities		1,157,639	1,304,867
Derivative assets		145	1
Contingent consideration		37,916	38,332
Derivative liabilities		107	131
Convertible debt	[1]	$ 355,937	$ 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	Apr. 02, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	$ 1,156,716	$ 1,304,711
Available-for-sale marketable securities, Unrealized Gain	3,791	2,977
Available-for-sale marketable securities, Unrealized (Loss)	(2,868)	(2,821)
Available-for-sale marketable securities, Fair Market Value	1,157,639	1,304,867
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	990,454	732,979
U.S. Treasury Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	856,714	901,975
Available-for-sale marketable securities, Unrealized Gain	37	97
Available-for-sale marketable securities, Unrealized (Loss)	(2,204)	(2,034)
Available-for-sale marketable securities, Fair Market Value	854,547	900,038
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	846,287	572,284
Corporate Debt Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	89,164	99,708
Available-for-sale marketable securities, Unrealized Gain	1,151	1,065
Available-for-sale marketable securities, Unrealized (Loss)	(584)	(620)
Available-for-sale marketable securities, Fair Market Value	89,731	100,153
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	56,678	53,642
U.S. Government Agency Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	21,174	42,026
Available-for-sale marketable securities, Unrealized Gain	8	7
Available-for-sale marketable securities, Unrealized (Loss)	(33)	(19)
Available-for-sale marketable securities, Fair Market Value	21,149	42,014
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	10,024	13,461
Certificates of Deposit and Time Deposits
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	50,541	82,080
Available-for-sale marketable securities, Unrealized Gain	37	54
Available-for-sale marketable securities, Unrealized (Loss)		(1)
Available-for-sale marketable securities, Fair Market Value	50,578	82,133
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses		7,760
Commercial Paper
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	121,073	161,672
Available-for-sale marketable securities, Unrealized Gain	7	24
Available-for-sale marketable securities, Unrealized (Loss)	(15)	(66)
Available-for-sale marketable securities, Fair Market Value	121,065	161,630
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	76,050	84,034
Equity And Debt Mutual Funds
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	17,472	16,505
Available-for-sale marketable securities, Unrealized Gain	2,546	1,724
Available-for-sale marketable securities, Unrealized (Loss)	(32)	(58)
Available-for-sale marketable securities, Fair Market Value	19,986	18,171
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	1,415	1,661
Non-U.S. Government Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	578	745
Available-for-sale marketable securities, Unrealized Gain	5	6
Available-for-sale marketable securities, Unrealized (Loss)		(23)
Available-for-sale marketable securities, Fair Market Value	$ 583	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	Apr. 02, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	$ 1,156,716	$ 1,304,711
Available-for-sale marketable securities, Unrealized Gain	3,791	2,977
Available-for-sale marketable securities, Unrealized (Loss)	(2,868)	(2,821)
Available-for-sale marketable securities, Fair Market Value	1,157,639	1,304,867
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	990,454	732,979
Marketable securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	896,345	871,321
Available-for-sale marketable securities, Unrealized Gain	56	134
Available-for-sale marketable securities, Unrealized (Loss)	(823)	(431)
Available-for-sale marketable securities, Fair Market Value	895,578	871,024
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	774,974	423,128
Long-term marketable securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	260,371	433,390
Available-for-sale marketable securities, Unrealized Gain	3,735	2,843
Available-for-sale marketable securities, Unrealized (Loss)	(2,045)	(2,390)
Available-for-sale marketable securities, Fair Market Value	262,061	433,843
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	$ 215,480	$ 309,851

Contractual Maturities of Inves

Contractual Maturities of Investments Held (Detail) $ in Thousands	Apr. 02, 2017USD ($)
Schedule of Available-for-sale Securities
Due within one year, cost	$ 896,345
Due after 1 year through 5 years, cost	190,557
Due after 5 years through 10 years, cost	12,270
Due after 10 years, cost	40,072
Total, cost	1,139,244
Due within one year, fair market value	895,578
Due after 1 year through 5 years, fair market value	190,252
Due after 5 years through 10 years, fair market value	11,812
Due after 10 years, fair market value	40,011
Total, fair market value	$ 1,137,653

Schedule of Derivative Instrume

Schedule of Derivative Instruments in Statement of Financial Position at Fair Value (Detail) - USD ($) $ in Thousands	Apr. 02, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative assets (liabilities), net	$ 38	$ (130)
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Prepayments
Derivatives, Fair Value [Line Items]
Derivative assets	145	1
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	$ (107)	$ (131)

Schedule of Effect of Derivativ

Schedule of Effect of Derivative Instruments in Statement of Operations Recognized (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Losses on derivatives recognized in statements of operations	$ 1,011	$ 3,298
Other (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Losses on derivatives recognized in statements of operations	$ 1,011	$ 3,298

Debt - Additional Information (

Debt - Additional Information (Detail) $ / shares in Units, shares in Millions	Apr. 02, 2017USD ($)$ / shares	Apr. 27, 2015USD ($)	Apr. 02, 2017USD ($)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	$ 460,000,000
Senior notes maturity date	Dec. 15, 2023
Trading days measurement period | d			20
Consecutive trading days measurement period			30 days
Percentage of conversion price			130.00%
Debt instrument conversion ratio			0.314102
Initial debt conversion price | $ / shares	$ 31.84		$ 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%		5.00%
Financing cost	$ 6,900,000		$ 6,900,000		$ 7,200,000
Debt issuance costs, amortization period			7 years
Unamortized discount	104,100,000		$ 104,100,000
Debt Instrument, convertible, remaining discount amortization period			6 years 9 months 18 days
Debt instrument, convertible, carrying amount of equity component	100,800,000		$ 100,800,000
Value of notes converted			$ 449,300,000
Conversion option two
Debt Instrument
Trading days measurement period | d			5
Consecutive trading days measurement period			5 days
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		$ 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	Apr. 02, 2017	Dec. 31, 2016	Dec. 12, 2016
Debt Instrument
Net Carrying amount of convertible debt	$ 355,937	$ 352,669
1.25% Convertible Senior Unsecured Notes Due December 15, 2023
Debt Instrument
Debt Principal	460,000	460,000	$ 460,000
Unamortized discount	104,063	107,331
Net Carrying amount of convertible debt	$ 355,937	$ 352,669

Interest Expense on Convertible

Interest Expense on Convertible Senior Notes (Detail) $ in Thousands	3 Months Ended
	Apr. 02, 2017USD ($)
Debt Instrument
Contractual interest expense on the coupon	$ 1,438
Amortization of the discount component and debt issue fees recognized as interest expense	3,268
Total interest expense on the convertible debt	$ 4,706

Schedule of Prepayments (Detail

Schedule of Prepayments (Detail) - USD ($) $ in Thousands	Apr. 02, 2017	Dec. 31, 2016
Prepaid And Other Current Assets [Line Items]
Contract manufacturer and supplier prepayments	$ 83,398	$ 84,473
Prepaid maintenance and other services	7,210	7,676
Prepaid taxes	3,326	4,664
Other prepayments	13,053	11,641
Total prepayments	$ 106,987	$ 108,454

Deferred Revenue and Customer59

Deferred Revenue and Customer Advances (Detail) - USD ($) $ in Thousands	Apr. 02, 2017	Dec. 31, 2016	Apr. 03, 2016	Dec. 31, 2015
Deferred Revenue Arrangement
Extended warranty	$ 44,053	$ 46,753	$ 46,115	$ 46,499
Equipment maintenance and training	41,995	39,037
Customer advances, undelivered elements and other	18,729	22,151
Total deferred revenue and customer advances	$ 104,777	$ 107,941

Warranty Accrual Included in Ot

Warranty Accrual Included in Other Accrued Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Product Warranty Liability [Line Items]
Balance at beginning of period	$ 7,203	$ 6,925
Accruals for warranties issued during the period	3,021	3,490
Adjustments related to pre-existing warranties	(471)	243
Settlements made during the period	(2,699)	(3,162)
Balance at end of period	$ 7,054	$ 7,496

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
	Apr. 02, 2017	Apr. 03, 2016
Product Warranty Liability [Line Items]
Balance at beginning of period	$ 46,753	$ 46,499
Deferral of new extended warranty revenue	6,125	6,827
Recognition of extended warranty deferred revenue	(8,825)	(7,211)
Balance at end of period	$ 44,053	$ 46,115

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - $ / shares shares in Millions	1 Months Ended		3 Months Ended
	Jan. 31, 2016	Jan. 31, 2014	Apr. 02, 2017	Apr. 03, 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			$ 27.86	$ 18.83
Service-Based Restricted Stock Units | Director
Share-based Compensation Arrangement by Share-based Payment Award
Restricted stock unit awards granted				0.1
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 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	3 Months Ended
	Apr. 02, 2017	Apr. 03, 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 Va64

Schedule of Estimated Fair Value of Stock Options Grant Using Black Scholes Option Pricing Model (Detail) - Stock Options	3 Months Ended
	Apr. 02, 2017	Apr. 03, 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 (Loss) Income (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 1,828,659
Other comprehensive income before reclassifications, net of tax	9,476	$ 13,342
Amounts reclassified from accumulated other comprehensive income, net of tax	(163)	(163)
Other comprehensive income (loss)	9,313	13,179
Ending balance	1,919,853
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	8,963	10,271
Other comprehensive income (loss)	8,963	10,271
Ending balance	(12,958)	1,512
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	513	3,071
Amounts reclassified from accumulated other comprehensive income, net of tax	(95)	(83)
Other comprehensive income (loss)	418	2,988
Ending balance	358	1,574
Amortization of prior service credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	1,767	2,029
Amounts reclassified from accumulated other comprehensive income, net of tax	(68)	(80)
Other comprehensive income (loss)	(68)	(80)
Ending balance	1,699	1,949
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	(163)	(163)
Ending balance	$ (10,901)	$ 5,035

Changes in Accumulated Other 66

Changes in Accumulated Other Comprehensive (Loss) Income (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income, tax	$ (102)	$ (35)
Foreign currency translation adjustments, tax	0	0	$ 0	$ 0
Unrealized gains on marketable securities, tax	565	805	209	(459)
Retirement plans prior service benefit, tax	(816)	(668)	$ (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	420	1,253
Amounts reclassified from accumulated other comprehensive income, tax	(64)	11
Other comprehensive income (loss), tax	356	1,264
Amortization of prior service credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive (loss) income before reclassifications, tax	0	0
Amounts reclassified from accumulated other comprehensive income, tax	(38)	(46)
Other comprehensive income (loss), tax	$ (38)	$ (46)

Reclassifications Out of Accumu

Reclassifications Out of Accumulated Other Comprehensive (Loss) Income to Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income	$ (3,520)	$ (1,642)
Reclassifications, net of tax	163	163
Unrealized Gains (Losses) on Marketable Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax	95	83
Amortization of prior service credit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax	68	80
Accumulated Other Comprehensive Income (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax	163	163
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	$ 95	$ 83

Reclassifications Out of Accu68

Reclassifications Out of Accumulated Other Comprehensive (Loss) Income to Statements of Operations (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	$ 102	$ 35
Unrealized Gains (Losses) on Marketable Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	64	(11)
Amortization of prior service credit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	$ 38	$ 46

Changes in Carrying Amount of G

Changes in Carrying Amount of Goodwill by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Dec. 31, 2016
Goodwill [Line Items]
Foreign currency translation adjustment	$ 6,722
Goodwill	992,631	$ 985,909
Accumulated impairment losses	(762,566)	(762,566)
Goodwill	230,065	223,343
Wireless Test
Goodwill [Line Items]
Goodwill	361,819	361,819
Accumulated impairment losses	(353,843)	(353,843)
Goodwill	7,976	7,976
Industrial Automation
Goodwill [Line Items]
Foreign currency translation adjustment	6,722
Goodwill	211,573	204,851
Goodwill	211,573	204,851
System Test
Goodwill [Line Items]
Goodwill	158,699	158,699
Accumulated impairment losses	(148,183)	(148,183)
Goodwill	10,516	10,516
Semiconductor Test
Goodwill [Line Items]
Goodwill	260,540	260,540
Accumulated impairment losses	$ (260,540)	$ (260,540)

Schedule of Amortizable Intangi

Schedule of Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 02, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 414,208	$ 414,208
Accumulated Amortization	(314,880)	(306,868)
Cumulative Foreign Currency Translation Adjustment	(4,485)	(6,939)
Net Carrying Amount	94,843	100,401
Developed technology
Finite-Lived Intangible Assets
Gross Carrying Amount	270,877	270,877
Accumulated Amortization	(211,065)	(206,376)
Cumulative Foreign Currency Translation Adjustment	(3,292)	(5,093)
Net Carrying Amount	56,520	59,408
Customer Relationships
Finite-Lived Intangible Assets
Gross Carrying Amount	92,741	92,741
Accumulated Amortization	(79,114)	(76,707)
Cumulative Foreign Currency Translation Adjustment	(348)	(538)
Net Carrying Amount	13,279	15,496
Trademarks and tradenames
Finite-Lived Intangible Assets
Gross Carrying Amount	50,100	50,100
Accumulated Amortization	(24,331)	(23,435)
Cumulative Foreign Currency Translation Adjustment	(845)	(1,308)
Net Carrying Amount	24,924	25,357
Non-compete Agreements
Finite-Lived Intangible Assets
Gross Carrying Amount	320	320
Accumulated Amortization	(200)	(180)
Net Carrying Amount	120	140
Customer backlog
Finite-Lived Intangible Assets
Gross Carrying Amount	170	170
Accumulated Amortization	$ (170)	$ (170)

Goodwill and Intangible Asset71

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Goodwill and Intangible Assets Disclosure [Line Items]
Acquired intangible assets amortization	$ 7,952	$ 19,994

Schedule of Estimated Intangibl

Schedule of Estimated Intangible Asset Amortization Expense (Detail) $ in Thousands	Apr. 02, 2017USD ($)
Finite-Lived Intangible Assets
2017 (remainder)	$ 21,621
2,018	27,475
2,019	23,622
2,020	10,325
2,021	3,504
Thereafter	$ 8,296

Computation of Basic and Dilute

Computation of Basic and Diluted Net Income Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Net Income Loss Per Common Share
Net income for basic and diluted net income per share	$ 85,221	$ 49,986
Weighted average common shares-basic	200,005	204,271
Employee stock purchase plan	8	9
Dilutive potential common shares	1,931	1,461
Weighted average common shares-diluted	201,936	205,732
Net income per common share-basic	$ 0.43	$ 0.24
Net income per common share-diluted	$ 0.42	$ 0.24
Restricted Stock Units
Net Income Loss Per Common Share
Incremental shares attributable to share based payment arrangements	1,533	965
Stock Options
Net Income Loss Per Common Share
Incremental shares attributable to share based payment arrangements	390	487

Net Income per Common Share - A

Net Income per Common Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Net Income Loss Per Common Share
Exercise of stock options	0.1	0.3

Restructuring and Other - Addit

Restructuring and Other - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Restructuring Cost and Reserve
Restructuring charges	$ 1,900
Lease expiration year	2,020
Contingent consideration adjustment	$ 634	$ 1,173
Wireless Test
Restructuring Cost and Reserve
Lease impairment	1,300
Universal Robots
Restructuring Cost and Reserve
Contingent consideration adjustment	600	1,200
Semiconductor Test and Wireless Test
Restructuring Cost and Reserve
Severance benefit and charges	$ 600
Semiconductor Test
Restructuring Cost and Reserve
Severance benefit and charges		$ 400

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail) $ in Millions	3 Months Ended
	Apr. 02, 2017USD ($)
U.S. Supplemental Executive Defined Benefit Pension Plan
Defined Benefit Plan Disclosure
Contribution to defined benefit pension plans	$ 0.6
Non-United States Subsidiaries
Defined Benefit Plan Disclosure
Contribution to defined benefit pension plans	$ 0.2

Schedule of Net Periodic Pensio

Schedule of Net Periodic Pension and Postretirement Cost (Income) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2017	Apr. 03, 2016
Defined Benefit Plan Disclosure
Net actuarial gain		$ (1,193)
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Service cost	$ 560	576
Interest cost	3,312	3,414
Expected return on plan assets	(3,000)	(3,443)
Amortization of prior service cost	18	24
Net actuarial gain		(1,193)
Total net periodic pension cost (income)	890	(622)
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Service cost	185	207
Interest cost	163	206
Expected return on plan assets	(6)	(5)
Settlement		(239)
Total net periodic pension cost (income)	342	169
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Service cost	10	10
Interest cost	50	56
Amortization of prior service benefit	(124)	(150)
Total net periodic pension cost (income)	$ (64)	$ (84)

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	Apr. 02, 2017USD ($)
Purchase Commitment, Excluding Long-term Commitment
Aggregate purchase commitments	$ 292
Purchase commitments less than one year	$ 281.7

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Apr. 02, 2017	Apr. 02, 2017	Apr. 03, 2016	Dec. 31, 2016
Income Taxes [Line Items]
Effective tax rate		7.40%	12.60%
U.S. statutory federal tax rate		35.00%	35.00%
Discrete tax benefits		$ 7	$ 2.5
Discrete tax benefits, stock based compensation		5.5
Discrete tax benefits, U.S. research and development tax credits		0.7
Discrete tax benefits, other		0.8	0.4
Discrete tax benefits, non-taxable foreign exchange gains			1.2
Discrete tax benefits, marketable securities			0.9
Uncertain tax positions	$ 40.7	40.7		$ 39
Net Increase in uncertain tax positions		1.7
Decrease in uncertain tax position resulting from expiration of statutes of limitations	0.8
Accrued interest and penalties	$ 0.3	0.3		$ 0.4
Interest and penalties related to income tax, expense (benefit)		(0.1)	0.3
Tax savings due to the tax holiday		$ 4.7	$ 2.6
Tax savings due to the tax holiday, per share		$ 0.02	$ 0.01
Tax holiday expiration date		December 31, 2020
ASU 2016-09
Income Taxes [Line Items]
Discrete tax benefits, stock based compensation		$ 5.2

Segment Information - Additiona

Segment Information - Additional Information (Detail)	3 Months Ended
	Apr. 02, 2017Segment
Segment Reporting Information [Line Items]
Operating segments	4

Schedule of Segment Information

Schedule of Segment Information (Detail) - USD ($) $ in Thousands		3 Months Ended
		Apr. 02, 2017		Apr. 03, 2016		Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues		$ 456,913		$ 430,994
Income (loss) before income taxes	[1],[2]	92,016		57,192
Total assets		2,842,280	[3]	2,548,974	[3]	$ 2,762,493
Semiconductor Test
Segment Reporting Information [Line Items]
Revenues		355,528		340,264
Income (loss) before income taxes	[1],[2]	97,966		73,254
Total assets	[3]	740,334		664,555
System Test
Segment Reporting Information [Line Items]
Revenues		39,845		53,670
Income (loss) before income taxes	[1],[2]	(2,759)		9,492
Total assets	[3]	106,754		90,695
Wireless Test
Segment Reporting Information [Line Items]
Revenues		25,268		20,314
Income (loss) before income taxes	[1],[2]	1,532		(20,140)
Total assets	[3]	61,356		408,466
Industrial Automation
Segment Reporting Information [Line Items]
Revenues		36,272		16,746
Income (loss) before income taxes	[1],[2]	(2,571)		(7,168)
Total assets	[3]	331,016		350,589
Corporate And Eliminations
Segment Reporting Information [Line Items]
Income (loss) before income taxes	[1],[2]	(2,152)		1,754
Total assets	[3]	$ 1,602,820		$ 1,034,669
[1]	Included in the income (loss) before income taxes for each of the segments are charges and credits related to inventory and other.
[2]	Interest income, interest expense, contingent consideration adjustments, pension and post retirement plans actuarial gains and other income (expense) are included in Corporate and Eliminations.
[3]	Total business assets are directly attributable to each business. 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
	Apr. 02, 2017	Apr. 03, 2016
Segment Reporting Information [Line Items]
Restructuring and other	$ 2,511	$ 1,587
Contingent consideration adjustment	634	1,173
Universal Robots
Segment Reporting Information [Line Items]
Contingent consideration adjustment	600	1,200
Semiconductor Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	1,319	3,685
Restructuring and other	(265)	414
Corporate And Eliminations
Segment Reporting Information [Line Items]
Restructuring and other	205
Corporate And Eliminations | Universal Robots | Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment	634	1,173
Industrial Automation
Segment Reporting Information [Line Items]
Restructuring and other	624
Wireless Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	522	$ 605
Restructuring and other	$ 1,313

Schedule of Segment Reporting83

Schedule of Segment Reporting Information by Segment Charges and Credit (Detail) $ in Thousands	3 Months Ended
	Apr. 02, 2017USD ($)
System Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	$ 885

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended		12 Months Ended
	Apr. 02, 2017	Apr. 03, 2016	Dec. 31, 2017	Jan. 31, 2017	Dec. 31, 2016	Jan. 31, 2016
Stockholders Equity Note Disclosure [Line Items]
Stock repurchase program, authorized amount					$ 500,000,000
Repurchase of stock, value		$ 28,000,000
Cumulative repurchases, shares	1.3
Cumulative repurchases, value	$ 37,700,000
Common stock average price	$ 29.38	$ 18.81
Repurchase of stock, shares		1.5
Dividends payable, amount per share				$ 0.07		$ 0.06
Dividend payment	$ 14,021,000	$ 12,253,000
Minimum | Scenario, Forecast
Stockholders Equity Note Disclosure [Line Items]
Repurchase of stock, value			$ 200,000,000