Teradyne (TER) 10-K 1 Mar 17 2016 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2016	Feb. 24, 2017	Jul. 01, 2016
Document Information
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	FY
Trading Symbol	TER
Entity Registrant Name	TERADYNE, INC
Entity Central Index Key	97,210
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		200,302,178
Entity Public Float			$ 3,900,000,000

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents		$ 307,884	$ 264,705
Marketable securities		871,024	477,696
Accounts receivable, less allowance for doubtful accounts of $2,356 and $2,407 in 2016 and 2015, respectively		192,444	211,293
Inventories, net		135,958	153,588
Deferred tax assets			54,973
Prepayments		108,454	91,519
Other current assets		8,039	6,194
Total current assets		1,623,803	1,259,968
Property, plant and equipment, net		253,821	273,414
Marketable securities		433,843	265,928
Deferred tax assets		107,405	7,404
Other assets		12,165	13,080
Retirement plans assets		7,712	636
Intangible assets, net		100,401	239,831
Goodwill		223,343	488,413
Total assets	[1]	2,762,493	2,548,674
Current liabilities:
Accounts payable		95,362	92,358
Accrued employees' compensation and withholdings		109,944	113,994
Deferred revenue and customer advances		84,478	85,527
Other accrued liabilities		51,382	43,727
Contingent consideration		1,050	15,500
Accrued income taxes		30,480	21,751
Total current liabilities		372,696	372,857
Retirement plans liabilities		106,938	103,531
Long-term deferred revenue and customer advances		23,463	25,745
Deferred tax liabilities		12,144	26,663
Long-term other accrued liabilities		28,642	32,156
Long-term contingent consideration		37,282	21,936
Long-term debt		352,669
Total liabilities		933,834	582,888
Commitments and contingencies (Note K)
SHAREHOLDERS' EQUITY
Common stock, $0.125 par value, 1,000,000 shares authorized; 199,177 and 203,641 shares issued and outstanding at December 31, 2016 and 2015, respectively		24,897	25,455
Additional paid-in capital		1,593,684	1,480,647
Accumulated other comprehensive loss		(20,214)	(8,144)
Retained earnings		230,292	467,828
Total shareholders' equity		1,828,659	1,965,786
Total liabilities and shareholders' equity		$ 2,762,493	$ 2,548,674
[1]	Total business assets are directly attributable to each business. Corporate assets consist of cash and cash equivalents, marketable securities and certain other assets.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts receivable, less allowance for doubtful accounts	$ 2,356	$ 2,407
Common stock, par value	$ 0.125	$ 0.125
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	199,177,000	203,641,000
Common stock, shares outstanding	199,177,000	203,641,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2016		Oct. 02, 2016	[2],[3]	Jul. 03, 2016	[2],[4]	Apr. 03, 2016	[2],[5]	Dec. 31, 2015	[6],[7]	Oct. 04, 2015	[8]	Jul. 05, 2015	[9]	Apr. 05, 2015	Dec. 31, 2014	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Revenues:
Products	$ 303,667	[1],[2]	$ 334,610		$ 456,832		$ 358,139		$ 244,510		$ 386,488		$ 437,243		$ 272,325		$ 1,453,248		$ 1,340,566		$ 1,364,024
Services	76,322	[1],[2]	75,865		74,960		72,855		73,934		79,506		75,496		70,076		300,002		299,012		283,800
Total revenues	379,989	[1],[2]	410,475		531,792		430,994		318,444		465,994		512,739		342,401		1,753,250	[10]	1,639,578	[10]	1,647,824	[10]
Cost of revenues:
Cost of products	127,481	[1],[2]	148,266		215,795		167,555		120,322		170,963		181,491		118,996		659,097		591,772		640,787
Cost of services	33,502	[1],[2]	34,850		33,127		33,107		32,096		36,405		32,680		30,982		134,586		132,163		128,229
Total cost of revenues (exclusive of acquired intangible assets amortization shown separately below)	160,983	[1],[2]	183,116		248,922		200,662		152,418		207,368		214,171		149,978		793,683		723,935		769,016
Gross profit	219,006	[1],[2]	227,359		282,870		230,332		166,026		258,626		298,568		192,423		959,567		915,643		878,808
Operating expenses:
Engineering and development	70,052	[1],[2]	71,400		76,109		73,464		70,941		74,027		75,832		71,450		291,025		292,250		291,639
Selling and administrative	76,289	[1],[2]	78,794		81,425		79,174		79,718		77,481		77,073		72,041		315,682		306,313		319,713
Acquired intangible assets amortization	7,923	[1],[2]	8,487		16,244		19,994		19,911		20,053		15,258		13,808		52,648		69,031		70,771
Acquired intangible assets impairment					83,339												83,339		98,200
Goodwill impairment	0				254,946											$ 98,897	254,946		(254,946)		98,897
Restructuring and other	5,570	[1],[2]	12,177		2,608		1,587		5,204		261		(385)				21,942		5,080		1,365
Total operating expenses	159,834	[1],[2]	170,858		514,671		174,219		175,774		171,822		167,778		157,299		1,019,582		672,674		782,385
(Loss) income from operations	59,172	[1],[2]	56,501		(231,801)		56,113		(9,748)		86,804		130,790		35,124		(60,015)		242,969		96,423
Non-operating (income) expenses:
Interest income	(3,095)	[1],[2]	(2,892)		(1,666)		(1,642)		(2,017)		(1,708)		(1,674)		(1,816)		(9,296)		(7,214)		(6,259)
Interest expense	1,604	[1],[2]	633		691		710		762		508		444		162		3,637		1,876		6,934
Other (income) expense, net	1,779	[1],[2]	(921)		(9)		(147)		364		596		(116)		(5,660)		704		(4,817)		372
(Loss) income before income taxes	58,884	[1],[2]	59,681		(230,817)		57,192		(8,857)		87,408		132,136		42,438		(55,060)	[11],[12]	253,124	[11],[12]	95,376	[11],[12]
Income tax (benefit) provision	(7,461)	[1],[2]	(4,113)		(7,271)		7,206		(8,216)		15,955		29,257		9,651		(11,639)		46,647		14,104
Net (loss) income	$ 66,345	[1],[2]	$ 63,794		$ (223,546)		$ 49,986		$ (641)		$ 71,453		$ 102,879		$ 32,787		$ (43,421)		$ 206,477		$ 81,272
Net (loss) income per common share:
Basic	$ 0.33	[1],[2]	$ 0.32		$ (1.10)		$ 0.24		$ 0		$ 0.34		$ 0.48		$ 0.15		$ (0.21)		$ 0.98		$ 0.40
Diluted	0.33	[1],[2]	0.31		(1.10)		0.24		0		0.34		0.48		0.15		$ (0.21)		$ 0.97		$ 0.37
Weighted average common shares-basic																	202,578		211,544		202,908
Weighted average common shares-diluted																	202,578		213,321		222,550
Cash dividend declared per common share	$ 0.06	[1],[2]	$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.24		$ 0.24		$ 0.18
[1]	Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[2]	Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[3]	Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[4]	Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.
[5]	Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[6]	In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[7]	Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[8]	Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[9]	Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration.
[10]	Revenues attributable to a country are based on location of customer site.
[11]	Included in income (loss) before taxes are charges and credits related to restructuring and other, inventory charges, goodwill impairment charges and acquired intangible assets impairment charge.
[12]	Interest income, interest expense, other (income) expense, net, contingent consideration adjustments and pension and postretirement plans actuarial gains and losses are included in Corporate and Eliminations.

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net (loss) income	$ (43,421)	$ 206,477	$ 81,272
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustment, net of tax of $0, $0, $0	(13,162)	(8,759)
Unrealized gains (losses) on marketable securities:
Unrealized gains (losses) on marketable securities arising during period, net of tax of $923, $(1,667), $1,449, respectively	2,037	(3,075)	2,417
Less: Reclassification adjustment for gains included in net (loss) income, net of tax of $(255), $(390), $(645), respectively	(683)	(704)	(1,433)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax, Total	1,354	(3,779)	984
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 $(190), $(169), $(169), respectively	(321)	(295)	(295)
Prior service income arising during period, net of tax of $34, $0, $0, respectively	59
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	(262)	(295)	(295)
Other comprehensive (loss) income	(12,070)	(12,833)	689
Comprehensive (loss) income	$ (55,491)	$ 193,644	$ 81,961

CONSOLIDATED STATEMENTS OF COM6

CONSOLIDATED STATEMENTS OF COMPREHENSIVE (LOSS) INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Foreign currency translation adjustment, tax	$ 0	$ 0	$ 0
Unrealized gains (losses) on marketable securities arising during period, tax	923	(1,667)	1,449
Reclassification adjustment for gains included in net income,tax	(255)	(390)	(645)
Amortization of prior service (credit) cost included in net periodic pension and post-retirement expense/income, tax	(190)	(169)	(169)
Prior service credit, tax	$ 34	$ 0	$ 0

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Balance, at Dec. 31, 2013	$ 1,985,094	$ 23,966	$ 1,390,896	$ 4,000	$ 566,232
Balance, Shares at Dec. 31, 2013		191,731
Issuance of stock to employees under benefit plans, net of shares withheld for payroll tax (in shares)		3,661
Issuance of stock to employees under benefit plans, net of shares withheld for payroll tax	9,273	$ 458	8,815
Proceeds from issuance of warrants		$ 2,653	(2,653)
Warrant settlement Shares		21,221
Stock-based compensation expense	39,868		39,868
Tax benefit related to stock options and restricted stock units	209		209
Cash dividends	(37,425)				(37,425)
Net income (loss)	81,272				81,272
Unrealized gains (losses) on marketable securities:
Unrealized (losses) gains on marketable securities arising during period, net of tax of $1,449, (1,667), 923, respectively	2,417			2,417
Less: Reclassification adjustment for gains included in net income, net of tax of $(645), $(390), (255), respectively	(1,433)			(1,433)
Amortization of prior service (credit) cost included in net periodic pension and post-retirement expense/income, net of tax $(169), $(169), $(190), respectively	(295)			(295)
Balance, at Dec. 31, 2014	2,078,980	$ 27,077	1,437,135	4,689	610,079
Balance, Shares at Dec. 31, 2014		216,613
Issuance of stock to employees under benefit plans, net of shares withheld for payroll tax (in shares)		2,649
Issuance of stock to employees under benefit plans, net of shares withheld for payroll tax	8,933	$ 331	8,602
Stock-based compensation expense	30,285		30,285
Repurchase of common stock	(299,949)	$ (1,953)			(297,996)
Repurchase of common stock (in shares)		(15,621)
Tax benefit related to stock options and restricted stock units	4,625		4,625
Cash dividends	(50,732)				(50,732)
Net income (loss)	206,477				206,477
Foreign currency translation adjustment	(8,759)			(8,759)
Unrealized gains (losses) on marketable securities:
Unrealized (losses) gains on marketable securities arising during period, net of tax of $1,449, (1,667), 923, respectively	(3,075)			(3,075)
Less: Reclassification adjustment for gains included in net income, net of tax of $(645), $(390), (255), respectively	(704)			(704)
Amortization of prior service (credit) cost included in net periodic pension and post-retirement expense/income, net of tax $(169), $(169), $(190), respectively	(295)			(295)
Balance, at Dec. 31, 2015	1,965,786	$ 25,455	1,480,647	(8,144)	467,828
Balance, Shares at Dec. 31, 2015		203,641
Issuance of stock to employees under benefit plans, net of shares withheld for payroll tax (in shares)		2,377
Issuance of stock to employees under benefit plans, net of shares withheld for payroll tax	10,665	$ 297	10,368
Equity component of convertible notes	100,836		100,836
Equity component of convertible notes issuance cost	(2,017)		(2,017)
Purchase of convertible notes hedges	(100,834)		(100,834)
Proceeds from issuance of warrants	67,852		67,852
Stock-based compensation expense	30,745		30,745
Repurchase of common stock	(146,331)	$ (855)			(145,476)
Repurchase of common stock (in shares)		(6,841)
Tax benefit related to stock options and restricted stock units	6,087		6,087
Cash dividends	(48,639)				(48,639)
Net income (loss)	(43,421)				(43,421)
Foreign currency translation adjustment	(13,162)			(13,162)
Unrealized gains (losses) on marketable securities:
Unrealized (losses) gains on marketable securities arising during period, net of tax of $1,449, (1,667), 923, respectively	2,037			2,037
Less: Reclassification adjustment for gains included in net income, net of tax of $(645), $(390), (255), respectively	(683)			(683)
Amortization of prior service (credit) cost included in net periodic pension and post-retirement expense/income, net of tax $(169), $(169), $(190), respectively	(321)			(321)
Prior service income arising during period, net of tax of $34	59			59
Balance, at Dec. 31, 2016	$ 1,828,659	$ 24,897	$ 1,593,684	$ (20,214)	$ 230,292
Balance, Shares at Dec. 31, 2016		199,177

CONSOLIDATED STATEMENTS OF SHA8

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Issuance of stock to employees under benefit plans, shares withheld for payroll tax	$ 9,808	$ 10,597	$ 12,018
Unrealized (losses) gains on marketable securities arising during period, tax	923	(1,667)	1,449
Reclassification adjustment for gains included in net income, tax	(255)	(390)	(645)
Amortization of prior service (credit) cost included in net periodic pension and post-retirement expense/income, tax	(190)	(169)	(169)
Prior service income arising during period, tax	$ 34	$ 0	$ 0

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net (loss) income	$ (43,421)	$ 206,477	$ 81,272
Adjustments to reconcile net (loss) income from operations to net cash provided by operating activities:
Depreciation	64,782	68,181	73,390
Amortization	55,227	72,592	79,154
Stock-based compensation	30,750	30,451	40,307
Provision for excess and obsolete inventory	17,493	21,332	22,193
Goodwill impairment	254,946	(254,946)	98,897
Acquired intangible assets impairment	83,339	98,200
Deferred taxes	(62,936)	(7,124)	(19,928)
Tax benefit related to employee stock compensation awards	(6,198)	(4,715)	(535)
Impairment of fixed assets	4,179
Property insurance recovery	(5,363)
Gain from the sale of an equity investment		(5,406)
Non-cash charge for the sale of inventories revalued at the date of acquisition		1,567
Retirement plans actuarial (gains) losses	(3,203)	17,732	46,564
Contingent consideration adjustment	15,896	2,489	(630)
Other	(448)	(34)	2,874
Changes in operating assets and liabilities, net of businesses acquired:
Accounts receivable	18,325	(57,267)	8,060
Inventories	34,263	15,559	51,803
Prepayments and other assets	(18,882)	3,034	41,537
Accounts payable and other accrued expenses	(1,706)	48,213	(45,430)
Deferred revenue and customer advances	(3,634)	17,011	22,033
Retirement plan contributions	(6,044)	(12,095)	(33,916)
Income taxes	18,434	(5,156)	24,417
Net cash provided by operating activities	445,799	412,841	492,062
Cash flows from investing activities:
Purchases of property, plant and equipment	(85,272)	(89,878)	(168,982)
Purchases of available-for-sale marketable securities	(1,656,267)	(1,424,002)	(1,578,743)
Proceeds from maturities of available-for-sale marketable securities	243,232	360,264	570,358
Proceeds from sales of available-for-sale marketable securities	852,794	1,316,131	859,729
Proceeds from property insurance	5,051
Acquisition of businesses, net of cash acquired		(282,741)	(19,419)
Proceeds from life insurance		1,098	4,184
Proceeds from the sale of an equity investment		5,406
Net cash used for investing activities	(640,462)	(113,722)	(332,873)
Cash flows from financing activities:
Proceeds from issuance of convertible notes, net of issuance costs	450,800
Purchase of convertible note hedges	(100,834)
Proceeds from issuance of warrants	67,852
Issuance of common stock under stock option and stock purchase plans	20,473	19,530	21,291
Repurchase of common stock	(146,331)	(299,949)
Tax benefit related to employee stock compensation awards	6,198	4,715	535
Dividend payments	(48,619)	(50,713)	(37,425)
Payment of revolving credit facility costs		(2,253)
Payments of long-term debt			(190,972)
Payments of contingent consideration	(11,697)
Net cash provided by (used for) financing activities	237,842	(328,670)	(206,571)
Increase (decrease) in cash and cash equivalents	43,179	(29,551)	(47,382)
Cash and cash equivalents at beginning of year	264,705	294,256	341,638
Cash and cash equivalents at end of year	307,884	264,705	294,256
Cash paid for:
Interest	446	301	4,294
Income taxes	$ 40,424	$ 35,218	$ 25,893

The Company

The Company	12 Months Ended
	Dec. 31, 2016
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. On June 11, 2015, Teradyne acquired Universal Robots A/S (“Universal Robots”) for approximately $284 million of cash plus up to an additional $65 million of cash if certain performance targets are met extending through 2018. Universal Robots is the leading supplier of collaborative robots which are low-cost, easy-to-deploy simple-to-program

Accounting Policies

Accounting Policies	12 Months Ended
	Dec. 31, 2016
Accounting Policies	B. ACCOUNTING POLICIES The consolidated financial statements include the accounts of Teradyne and its wholly-owned subsidiaries. All significant intercompany balances and transactions are eliminated. Certain prior years’ amounts were reclassified to conform to the current year presentation. Preparation of Financial Statements and Use of Estimates The preparation of consolidated financial statements requires management to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent liabilities. On an on-going Revenue Recognition Teradyne recognizes revenues, including revenues from distributors, when there is persuasive evidence of an arrangement, title and risk of loss have passed, delivery has occurred or the services have been rendered, the sales price is fixed or determinable and collection of the related receivable is reasonably assured. Title and risk of loss generally pass to Teradyne’s customers upon shipment or at delivery destination point. In circumstances where either title or risk of loss pass upon destination, acceptance or cash payment, Teradyne defers revenue recognition until such events occur except when title transfer is tied to cash payment outside the United States. Outside the United States, Teradyne recognizes revenue upon shipment or at delivery destination point, even if Teradyne retains a form of title to products delivered to customers, provided the sole purpose is to enable Teradyne to recover the products in the event of customer payment default and the arrangement does not prohibit the customer’s use or resale of the product in the ordinary course of business. Teradyne’s equipment has non-software For multiple element arrangements, Teradyne allocates revenue to all deliverables based on their relative selling prices. In such circumstances, a hierarchy is used to determine the selling price for allocating revenue to deliverables as follows: (i) vendor-specific objective evidence of selling price (“VSOE”), (ii) third-party evidence of selling price (“TPE”), and (iii) best estimate of the selling price (“BESP”). For a delivered item to be considered a separate unit the delivered item must have value to the customer on a standalone basis and the delivery or performance of the undelivered item must be considered probable and substantially in Teradyne’s control. Teradyne’s post-shipment obligations include installation, training services, one-year 605-20, Separately Priced Extended Warranty and Product Maintenance Contracts 605-25, Revenue Recognition Multiple-Element Arrangements. Teradyne’s products are generally subject to warranty and related costs of the warranty are provided for in cost of revenues when product revenue is recognized. Teradyne classifies shipping and handling costs in cost of revenue. Teradyne does not provide its customers with contractual rights of return for any of its products. As of December 31, 2016 and 2015, deferred revenue and customer advances consisted of the following and are included in the short and long-term deferred revenue and customer advances: 2016 2015 (in thousands) Extended warranty $ 46,753 $ 46,499 Equipment maintenance and training 39,037 30,616 Customer advances, undelivered elements and other 22,151 34,157 Total deferred revenue and customer advances $ 107,941 $ 111,272 Product Warranty Teradyne generally provides a one-year Amount (in thousands) Balance at December 31, 2013 $ 6,660 Accruals for warranties issued during the period 15,406 Accruals related to pre-existing (2,008 ) Settlements made during the period (11,116 ) Balance at December 31, 2014 8,942 Acquisition 409 Accruals for warranties issued during the period 11,539 Accruals related to pre-existing (3,159 ) Settlements made during the period (10,806 ) Balance at December 31, 2015 6,925 Accruals for warranties issued during the period 14,291 Accruals related to pre-existing (1,354 ) Settlements made during the period (12,659 ) Balance at December 31, 2016 $ 7,203 When Teradyne receives revenue for extended warranties, beyond one year, it is deferred and recognized on a straight-line basis over the contract period. Related costs are expensed as incurred. The balance below is included in short and long-term deferred revenue and customer advances: Amount (in thousands) Balance at December 31, 2013 $ 34,909 Deferral of new extended warranty revenue 29,519 Recognition of extended warranty deferred revenue (21,128 ) Balance at December 31, 2014 43,300 Acquisition 870 Deferral of new extended warranty revenue 28,549 Recognition of extended warranty deferred revenue (26,220 ) Balance at December 31, 2015 46,499 Deferral of new extended warranty revenue 27,182 Recognition of extended warranty deferred revenue (26,928 ) Balance at December 31, 2016 $ 46,753 Accounts Receivable and Allowance for Doubtful Accounts Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The volatility of the industries that Teradyne serves can cause certain of its customers to experience shortages of cash flows, which can impact their ability to make required payments. Teradyne maintains allowances for doubtful accounts for estimated losses resulting from the inability of its customers to make required payments. Estimated allowances for doubtful accounts are reviewed periodically taking into account the customer’s recent payment history, the customer’s current financial statements and other information regarding the customer’s credit worthiness. Account balances are written off against the allowance when it is determined the receivable will not be recovered. Inventories Inventories are stated at the lower of cost (first-in, first-out Investments 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 • 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. As defined in ASC 820-10, Fair Value Measurements and Disclosures, ASC 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 therefore is considered a Level 2 input. 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. In accordance with ASC 820-10, Prepayments Prepayments consist of the following and are included in prepayments on the balance sheet: 2016 2015 (in thousands) Contract manufacturer prepayments $ 77,017 $ 66,283 Prepaid maintenance and other services 7,676 8,481 Prepaid taxes 4,664 3,781 Other prepayments 19,097 12,974 Total prepayments $ 108,454 $ 91,519 Retirement and Postretirement Plans Teradyne recognizes net actuarial gains and losses and the change in the fair value of the plan assets in its operating results in the year in which they occur or upon any interim remeasurement of the plans. Teradyne calculates the expected return on plan assets using the fair value of the plan assets. Actuarial gains and losses are generally measured annually as of December 31 and, accordingly, recorded during the fourth quarter of each year or upon any interim remeasurement of the plans. Goodwill, Intangible and Long-Lived Assets Teradyne accounts for goodwill and intangible assets in accordance with ASC 350-10, Intangibles-Goodwill and Other. 350-10, more-likely-than-not two-step more-likely-than-not two-step In accordance with ASC 360-10, Impairment or Disposal of Long-Lived Assets, Property, Plant and Equipment Property, plant and equipment are stated at cost and depreciated over the estimated useful lives of the assets. Leasehold improvements and major renewals are capitalized and included in property, plant and equipment accounts while expenditures for maintenance and repairs and minor renewals are charged to expense. When assets are retired, the assets and related accumulated depreciation are removed from the accounts and any resulting gain or loss is reflected in the consolidated statements of operations. Teradyne provides for depreciation of its assets principally on the straight-line method with the cost of the assets being charged to expense over their useful lives as follows: Buildings 40 years Building improvements 5 to 10 years Leasehold improvements Lesser of lease term or 10 years Furniture and fixtures 10 years Test systems manufactured internally 6 years Machinery and equipment 3 to 5 years Software 3 to 5 years Test systems manufactured internally are used by Teradyne for customer evaluations and manufacturing and support of its customers. Teradyne depreciates the test systems manufactured internally over a six-year Engineering and Development Costs Teradyne’s products are highly technical in nature and require a large and continuing engineering and development effort. Software development costs incurred prior to the establishment of technological feasibility are charged to expense. Software development costs incurred subsequent to the establishment of technological feasibility are capitalized until the product is available for release to customers. To date, the period between achieving technological feasibility and general availability of the product has been short and software development costs eligible for capitalization have not been material. Engineering and development costs are expensed as incurred and consist primarily of salaries, contractor fees, including non-recurring Stock Compensation Plans and Employee Stock Purchase Plan Stock-based compensation expense is based on the grant-date fair value estimated in accordance with the provisions of ASC 718-10, Compensation-Stock Compensation 718-10, Under its stock compensation plans, Teradyne has granted 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”). Income Taxes Deferred tax assets and liabilities are determined based on differences between financial reporting and tax basis of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The measurement of deferred tax assets is reduced by a valuation allowance if it is more likely than not that some or all of the deferred tax assets will not be realized. Teradyne performed the required assessment of positive and negative evidence regarding the realization of the net deferred tax assets in accordance with ASC 740, “Accounting for Income Taxes.” tax-planning non-U.S. non-equity with-and-without Advertising Costs Teradyne expenses all advertising costs as incurred. Advertising costs were $6.4 million, $3.3 million and $1.9 million in 2016, 2015 and 2014, respectively. Translation of Non-U.S. The functional currency for all subsidiaries is the U.S. dollar, except for the Industrial Automation segment for which the local currency is its functional currency. All foreign currency denominated monetary assets and liabilities are remeasured on a monthly basis into the functional currency using exchange rates in effect at the end of the period. All foreign currency denominated non-monetary Net foreign exchange gains and losses resulting from remeasurement are included in other (income) expense, net. For the years ended December 31, 2016 and 2015, gains from the remeasurement of the monetary assets and liabilities denominated in foreign currencies were $8.0 million and $2.5 million, respectively. For the year ended December 31, 2014, losses from the remeasurement of the monetary assets and liabilities denominated in foreign currencies were $0.9 million. These amounts do not reflect the corresponding gains (losses) from foreign exchange contracts. See Note G: “Financial Instruments” regarding foreign exchange contracts. Net Income (Loss) per Common Share Basic net (loss) income per common share is calculated by dividing net (loss) income by the weighted average number of common shares outstanding during the period. Except where the result would be antidilutive, diluted net (loss) income per common share is calculated by dividing net (loss) income by the sum of the weighted average number of common shares plus common stock equivalents, if applicable. For the year ended December 31, 2014, dilutive potential common shares included incremental shares from the assumed conversion of the convertible notes and the convertible notes hedge warrant shares. Incremental shares from the assumed conversion of the convertible notes were calculated using the difference between the average Teradyne stock price for the period and the conversion price of $5.48, multiplied by 34.7 million shares. The result of this calculation, representing the total intrinsic value of the convertible debt, was divided by the average Teradyne stock price for the period. Convertible notes hedge warrant shares were calculated using the difference between the average Teradyne stock price for the period and the warrant price of $7.67, multiplied by 34.7 million shares. The result of this calculation, representing the total intrinsic value of the warrant, was divided by the average Teradyne stock price for the period. Teradyne’s call option for 34.7 million shares at an exercise price of $5.48 was not used in the GAAP earnings per share calculation as its effect was anti-dilutive. In 2014, Teradyne settled its conversion spread (i.e., the intrinsic value of the embedded option feature contained in the convertible debt) in shares. Teradyne accounted for its conversion spread using the treasury stock method. Teradyne determined that it had the ability and intent to settle the principal amount of the convertible debt in cash; accordingly, the principal amount was excluded from the determination of diluted earnings per share. With respect to its convertible debt issued in 2016, Teradyne has determined that it has the ability and intent to settle the principal of the convertible debt in cash; accordingly, the principal amount is excluded from the determination of diluted earnings per share. As a result, Teradyne is accounting for the conversion spread using the treasury stock method. Comprehensive Income (Loss) Comprehensive income (loss) includes net income, unrealized pension and postretirement prior service costs and benefits, unrealized gains and losses on investments in debt and equity marketable securities and foreign currency translation adjustment.

Recently Issued Accounting Pron

Recently Issued Accounting Pronouncements	12 Months Ended
	Dec. 31, 2016
Recently Issued Accounting Pronouncements	C. RECENTLY ISSUED ACCOUNTING PRONOUNCEMENTS On January 26, 2017, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2017-04, “Intangibles—Goodwill and Other (Topic 350): Simplifying the Accounting for Goodwill Impairment.” one-step On October 24, 2016, the FASB issued ASU 2016-16, “Accounting for Income Taxes: Intra-Entity Asset Transfers of Assets Other than Inventory ” pre-tax On March 31, 2016, the FASB issued ASU 2016-09, “Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” paid-in In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842).” “Leases.” right-of-use In January 2016, the FASB issued ASU 2016-01, “Financial Instruments—Overall (Subtopic 825-10): ” In November 2015, the FASB issued ASU 2015-17, “Income Taxes (Topic 740): Balance Sheet Classification of Deferred Taxes ” 2015-17 In April, 2015, the FASB issued ASU 2015-03, Simplifying the Presentation of Debt Issuance Costs, 2015-03 line-of-credit 2015-15, Interest—Imputation of Interest (Subtopic 835-30) line-of-credit line-of-credit line-of-credit In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40). 2014-15 In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606), 2015-14,

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2016
Acquisitions	D. ACQUISITIONS Business Universal Robots On June 11, 2015, Teradyne acquired all of the outstanding equity of Universal Robots A/S (“Universal Robots”) located in Odense, Denmark. Universal Robots is the leading supplier of collaborative robots which are low-cost, easy-to-deploy simple-to-program The Universal Robots acquisition was accounted for as a business combination and, accordingly, the results have been included in Teradyne’s consolidated results of operations from the date of acquisition. The allocation of the total purchase price to Universal Robots’ net tangible liabilities and identifiable intangible assets was based on their estimated fair values as of the acquisition date. The excess of the purchase price over the identifiable intangible assets and net tangible liabilities in the amount of $221.1 million was allocated to goodwill, which is not deductible for tax purposes. The following table represents the final allocation of the purchase price: Purchase Price Allocation (in thousands) Goodwill $ 221,128 Intangible assets 121,590 Tangible assets acquired and liabilities assumed: Current assets 10,853 Non-current 3,415 Accounts payable and current liabilities (11,976 ) Long-term deferred tax liabilities (26,653 ) Long-term other liabilities (2,920 ) Total purchase price $ 315,437 Teradyne estimated the fair value of intangible assets using the income and cost approaches. Acquired intangible assets are amortized on a straight-line basis over their estimated useful lives. Components of these intangible assets and their estimated useful lives at the acquisition date are as follows: Fair Value Estimated Useful (in thousands) (in years) Developed technology $ 89,240 4.9 Trademarks and tradenames 22,920 10.0 Customer relationships 9,430 2.0 Total intangible assets $ 121,590 5.6 For the period from June 12, 2015 to December 31, 2015, Universal Robots contributed $41.9 million of revenues and had a $7.6 million loss before income taxes. The following unaudited pro forma information gives effect to the acquisition of Universal Robots as if the acquisition occurred on January 1, 2014. The unaudited pro forma results are not necessarily indicative of what actually would have occurred had the acquisition been in effect for the periods presented: For the Years Ended December 31, December 31, (in thousands, except per Revenue $ 1,657,626 $ 1,686,689 Net income $ 199,784 $ 61,078 Net income per common share: Basic $ 0.94 $ 0.30 Diluted $ 0.94 $ 0.27 Pro forma results for the year ended December 31, 2015 were adjusted to exclude $1.6 million of non-recurring Pro forma results for the year ended December 31, 2014 were adjusted to include $1.6 million of non-recurring Avionics Interface Technologies, LLC. On October 31, 2014, Teradyne acquired all of the assets and liabilities of Avionics Interface Technologies, LLC (“AIT”) located in Omaha, Nebraska and Dayton, Ohio. AIT is a supplier of equipment for testing state-of-the-art The total purchase price of $21.2 million consisted of $19.4 million of cash paid to acquire AIT’s assets and liabilities and $1.8 million in fair value of contingent consideration payable upon the achievement of certain revenue and gross margin targets in 2015 and 2016. The total amount of contingent consideration paid was $1.1 million, which was paid in January 2017. The valuation of the contingent consideration utilized the following assumptions: (1) probability of meeting each target; (2) expected timing of meeting each target; and (3) discount rate reflecting the risk associated with the expected payments. The probabilities and timing for each target were estimated based on a review of the historical and projected results. A discount rate of 4.7 percent was selected based on the cost of debt for the business. A significant portion of the risk in achieving the contingent consideration was captured in the probabilities assigned to meeting each target. The AIT acquisition was accounted for as a business combination and, accordingly, the results have been included in Teradyne’s consolidated results of operations from the date of acquisition. The allocation of the total purchase price of AIT’s net tangible and identifiable intangible assets was based on their estimated fair values as of the acquisition date. The excess of the purchase price over the identifiable intangible and net tangible assets in the amount of $10.5 million was allocated to goodwill, which is deductible for tax purposes. The following represents the final allocation of the purchase price: Purchase Price Allocation (in thousands) Goodwill $ 10,516 Intangible assets 9,080 Tangible assets acquired and liabilities assumed: Current assets 2,452 Non-current 359 Accounts payable and current liabilities (1,164 ) Total purchase price $ 21,243 Teradyne estimated the fair value of intangible assets using the income approach. Acquired intangible assets are amortized on a straight-line basis over their estimated useful lives. Components of these intangible assets and their estimated useful lives at the acquisition date are as follows: Fair Value Estimated Useful (in thousands) (in years) Customer relationships $ 5,630 5.0 Developed technology 2,580 4.8 Trademarks and tradenames 380 5.0 Non-compete 320 4.0 Customer order backlog 170 0.3 Total intangible assets $ 9,080 4.8 For the period from October 31, 2014 to December 31, 2014, AIT contributed $0.6 million of revenues and had a $0.8 million loss before income taxes. The following unaudited pro forma information gives effect to the acquisition of AIT as if the acquisition occurred on January 1, 2013. The unaudited pro forma results are not necessarily indicative of what actually would have occurred had the acquisition been in effect for the periods presented: For the Year Ended December 31, 2014 (in thousands, except per share amounts) Revenues $ 1,655,038 Net income $ 82,169 Income per common share: Basic $ 0.40 Diluted $ 0.37

Inventories

Inventories	12 Months Ended
	Dec. 31, 2016
Inventories	E. INVENTORIES Inventories, net consisted of the following at December 31, 2016 and 2015: 2016 2015 (in thousands) Raw material $ 58,530 $ 73,117 Work-in-process 22,946 32,825 Finished goods 54,482 47,646 $ 135,958 $ 153,588 Inventory reserves for the years ended December 31, 2016 and 2015 were $116.0 million and $119.4 million, respectively.

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2016
Property, Plant and Equipment	F. PROPERTY, PLANT AND EQUIPMENT Property, plant and equipment, net consisted of the following at December 31, 2016 and 2015: 2016 2015 (in thousands) Land $ 16,561 $ 16,561 Buildings 98,031 108,797 Machinery and equipment 601,835 595,445 Furniture and fixtures, and software 82,897 82,612 Leasehold improvements 46,612 43,328 Construction in progress 3,032 2,630 848,968 849,373 Less: accumulated depreciation 595,147 575,959 $ 253,821 $ 273,414 Depreciation of property, plant and equipment for the years ended December 31, 2016, 2015 and 2014 was $64.8 million, $68.2 million and $73.4 million, respectively. As of December 31, 2016 and 2015, the gross book value included in machinery and equipment for internally manufactured test systems being leased by customers was $19.4 million and $20.4 million, respectively. As of December 31, 2016 and 2015, the accumulated depreciation on these test systems was $10.5 million and $8.5 million, respectively.

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2016
Financial Instruments	G. FINANCIAL INSTRUMENTS Cash Equivalents Teradyne considers all highly liquid investments with maturities of three months or less at the date of acquisition to be cash equivalents. Marketable Securities Teradyne’s available-for-sale Realized gains recorded in 2016, 2015 and 2014 were $1.6 million, $1.7 million and $2.4 million, respectively. Realized losses recorded in 2016 and 2015 were $0.5 million and $0.4 million, respectively. There were no realized losses recorded in 2014. 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 years ended December 31, 2016 and 2015, 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 December 31, 2016 and 2015: 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 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 current liabilities $ — $ 131 $ — $ 131 Contingent consideration — — 1,050 1,050 Long-term contingent consideration — — 37,282 37,282 $ — $ 131 $ 38,332 $ 38,463 December 31, 2015 Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total (in thousands) Assets Cash $ 213,336 $ — $ — $ 213,336 Cash equivalents 49,241 2,128 — 51,369 Available-for-sale U.S. Treasury securities — 419,958 — 419,958 Corporate debt securities — 161,634 — 161,634 U.S. government agency securities — 83,952 — 83,952 Certificates of deposit and time deposits — 43,394 — 43,394 Commercial paper — 20,308 — 20,308 Equity and debt mutual funds 13,954 — — 13,954 Non-U.S. — 424 — 424 Total $ 276,531 $ 731,798 $ — $ 1,008,329 Derivative assets — 109 — 109 Total $ 276,531 $ 731,907 $ — $ 1,008,438 Liabilities Contingent consideration $ — $ — $ 37,436 $ 37,436 Derivative liabilities — 146 — 146 Total $ — $ 146 $ 37,436 $ 37,582 Reported as follows: (Level 1) (Level 2) (Level 3) Total (in thousands) Assets Cash and cash equivalents $ 262,577 $ 2,128 $ — $ 264,705 Marketable securities — 477,696 — 477,696 Long-term marketable securities 13,954 251,974 — 265,928 Prepayments — 109 — 109 $ 276,531 $ 731,907 $ — $ 1,008,438 Liabilities Other current liabilities $ — $ 146 $ — $ 146 Contingent consideration — — 15,500 15,500 Long-term contingent consideration — — 21,936 21,936 $ — $ 146 $ 37,436 $ 37,582 Changes in the fair value of Level 3 contingent consideration for the years ended December 31, 2016 and 2015 were as follows: Contingent Consideration (in thousands) Balance at December 31, 2014 $ 3,350 Acquisition of Universal Robots 31,597 Fair value adjustment of Universal Robots (1) 5,339 Fair value adjustment of AIT (2) (1,250 ) Fair value adjustment of ZTEC (3) (1,600 ) Balance at December 31, 2015 37,436 Payments (4) (15,000 ) Fair value adjustment of AIT (5) 550 Fair value adjustment of Universal Robots (5) 15,346 Balance at December 31, 2016 $ 38,332 (1) During the year ended December 31, 2015, the fair value of contingent consideration for the earn-out (2) During the year ended December 31, 2015, the fair value of contingent consideration for the earn-out (3) During the year ended December 31, 2015, the fair value measurement of the contingent consideration for the earn-out earn-out earn-out (4) During the year ended December 31, 2016, based on Universal Robots’ calendar year 2015 EBITDA results, Teradyne paid $15 million or 100% of the eligible EBITDA contingent consideration amount. (5) During the year ended December 31, 2016, the fair value of contingent consideration for the earn-out earn-out The following table provides quantitative information associated with the fair value measurement of Teradyne’s Level 3 financial instrument: Liability December 31, 2016 Fair Value Valuation Technique Unobservable Inputs Weighted Average (in thousands) Contingent consideration (Universal Robots) $ 21,301 Monte Carlo simulation Revenues for the period July 1, 2015—December 31, 2017 volatility 10.8% Discount Rate 3.3% $15,981 Monte Carlo simulation Revenues for the period July 1, 2015—December 31, 2018 volatility 10.8% Discount Rate 3.3% Contingent consideration (AIT) $ 1,050(1) (1) Teradyne paid this amount in January 2017. As of December 31, 2016, the significant unobservable inputs used in the Monte Carlo simulation to fair value the Universal Robots contingent consideration include forecasted revenues, 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 remaining Universal Robots earn-outs is $25.0 million. The carrying amounts and fair values of financial instruments at December 31, 2016 and 2015 were as follows: December 31, 2016 December 31, 2015 Carrying Value Fair Value Carrying Value Fair Value (in thousands) Assets Cash and cash equivalents $ 307,884 $ 307,884 $ 264,705 $ 264,705 Marketable securities 1,304,867 1,304,867 743,624 743,624 Derivative assets 1 1 109 109 Liabilities Contingent consideration 38,332 38,332 37,436 37,436 Derivative liabilities 131 131 146 146 Convertible debt (1) 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 amount due to the short term nature of these instruments. The following tables summarize the composition of available for sale marketable securities at December 31, 2016 and 2015: December 31, 2016 Available-for-Sale Fair Market Value of Investments with Unrealized Losses Cost Unrealized Gain Unrealized (Loss) Fair Market Value (in thousands) U.S. Treasury securities $ 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 December 31, 2015 Available-for-Sale Fair Market Value of Investments with Unrealized Losses Cost Unrealized Gain Unrealized (Loss) Fair Market Value (in thousands) U.S. Treasury securities $ 421,060 $ 65 $ (1,167 ) $ 419,958 $ 379,434 Corporate debt securities 163,297 902 (2,565 ) 161,634 145,373 U.S. government agency securities 84,032 42 (122 ) 83,952 55,120 Certificates of deposit and time deposits 43,391 6 (3 ) 43,394 10,527 Commercial paper 20,298 11 (1 ) 20,308 8,646 Equity and debt mutual funds 12,996 1,119 (161 ) 13,954 2,560 Non-U.S. 424 — — 424 — $ 745,498 $ 2,145 $ (4,019 ) $ 743,624 $ 601,660 Reported as follows: Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Marketable securities $ 478,306 $ 38 $ (648 ) $ 477,696 $ 374,785 Long-term marketable securities 267,192 2,107 (3,371 ) 265,928 226,875 $ 745,498 $ 2,145 $ (4,019 ) $ 743,624 $ 601,660 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 greater than one year and $730.1 million had unrealized losses of $2.5 million for less than one year. As of December 31, 2015, the fair market value of investments with unrealized losses totaled $601.7 million. Of this value, $0.9 million had unrealized losses of $0.5 million greater than one year and $600.8 million had unrealized losses of $3.6 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 December 31, 2016 and 2015, were temporary. The contractual maturities of investments held at December 31, 2016 were as follows: Cost Fair Value (in thousands) Due within one year $ 871,321 $ 871,024 Due after 1 year through 5 years 365,873 365,451 Due after 5 years through 10 years 12,839 12,309 Due after 10 years 38,173 37,912 Total $ 1,288,206 $ 1,286,696 Contractual maturities of investments held at December 31, 2016, exclude $18 million of equity and debt mutual funds as they do not have a contractual maturity date. The following table sets forth by fair value hierarchy Teradyne’s non-financial non-recurring July 3, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Other Unobservable Inputs (Level 3)) Total Total Losses (in thousands) Goodwill (1) $ — $ — $ 7,976 $ 7,976 $ 254,946 Definite lived intangible assets (2) — — 5,750 5,750 83,339 $ — $ — $ 13,726 $ 13,726 $ 338,285 (1) In accordance with the provisions of ASC 350-20, Goodwill (2) In accordance with the provisions of ASC 360-10, “Property, Plant and Equipment,” 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 the monetary assets and liabilities denominated in foreign currencies. At December 31, 2016 and 2015, Teradyne had the following contracts to buy and sell non-U.S. non-U.S. December 31, 2016 December 31, 2015 Buy Position Sell Position Net Total Buy Position Sell Position Net Total (in millions) Japanese Yen $ (17.7 ) $ — $ (17.7 ) $ (51.9 ) $ — $ (51.9 ) Korean Won (8.8 ) — (8.8 ) (5.5 ) — (5.5 ) Taiwan Dollar (6.9 ) — (6.9 ) (5.0 ) — (5.0 ) British Pound Sterling (1.3 ) — (1.3 ) (9.5 ) — (9.5 ) Euro — 25.2 25.2 — 27.2 27.2 Singapore Dollar — 24.0 24.0 — 15.0 15.0 Total $ (34.7 ) $ 49.2 $ 14.5 $ (71.9 ) $ 42.2 $ (29.7 ) The fair value of the outstanding contracts was a loss of $0.1 million and $0.0 million, at December 31, 2016 and 2015, respectively. In 2016, 2015 and 2014, Teradyne recorded net realized losses related to foreign currency forward contracts hedging net monetary assets and liabilities of $8.7 million, $3.0 million and $0.2 million, respectively. Gains and losses on foreign currency forward contracts and foreign currency remeasurement gains and losses on monetary assets and liabilities are included in other (income) expense, net. The following table summarizes the fair value of derivative instruments as of December 31, 2016 and 2015: Balance Sheet Location December 31, 2016 December 31, 2015 (in thousands) Derivatives not designated as hedging instruments: Foreign exchange contracts Prepayments $ 1 $ 109 Foreign exchange contracts Other current liabilities (131 ) (146 ) Total derivatives $ (130 ) $ (37 ) The following table summarizes the effect of derivative instruments in statements of operations recognized for the years ended December 31, 2016, 2015 and 2014. The table does not reflect the corresponding gains and losses from the remeasurement of the monetary assets and liabilities denominated in foreign currencies. For the years ended December 31, 2016 and 2015, gains from the remeasurement of the monetary assets and liabilities denominated in foreign currencies were $8.0 million and $2.5 million, respectively. For the year ended December 31, 2014, losses from the remeasurement of the monetary assets and liabilities denominated in foreign currencies were $0.9 million. Location of Losses of Operations December 31, 2016 December 31, 2015 December 31, 2014 (in thousands) Derivatives not designated as hedging instruments: Foreign exchange contracts Other (income) expense, net $ 8,671 $ 3,047 $ 237 See Note H: “Debt” regarding derivatives related to the convertible senior notes. Concentration of Credit Risk Financial instruments which potentially subject Teradyne to concentrations of credit risk consist principally of cash equivalents, marketable securities, forward currency contracts and accounts receivable. Teradyne’s cash equivalents consist primarily of money market funds invested in U.S. Treasuries and government agencies. Teradyne’s fixed income available-for-sale Equity Interest On November 1, 2013, in connection with the acquisition of Empirix, Inc. by Thoma Bravo LLC, Teradyne sold its equity interest in Empirix, Inc., a private company, and received cash proceeds of $34.2 million which was recorded as a gain in other (income) expense, net in the fourth quarter of 2013. An additional $5.4 million of cash proceeds that was held in escrow for 15 months, for potential indemnifications to the buyer, was paid to Teradyne in February 2015 and it was recorded as a gain in other (income) expense, net in the first quarter of 2015.

Debt

Debt	12 Months Ended
	Dec. 31, 2016
Debt	H. DEBT Convertible Senior Notes On December 12, 2016, Teradyne completed a private offering of $460.0 million aggregate principal amount of 1.25% convertible senior unsecured notes (the “Notes”) due December 15, 2023 and received net proceeds, after issuance costs, of approximately $450.8 million, $33.0 million of which was used to pay the net cost of the convertible note hedge transactions and $50.1 million of which was used to repurchase 2.0 million shares of Teradyne’s common stock under its existing stock repurchase program from purchasers of the Notes in privately negotiated transactions effected through one of the initial purchasers or its affiliates conducted concurrently with the pricing of the Note offering. The Notes will mature on December 15, 2023, unless earlier repurchased or converted. The Notes bear interest from December 12, 2016 at a rate of 1.25% per year payable semiannually in arrears on June 15 and December 15 of each year, beginning on June 15, 2017. The Notes will be convertible at the option of the noteholders at any time prior to the close of business on the business day immediately preceding September 15, 2023, only under the following circumstances: (1) during any calendar quarter beginning after March 31, 2017 (and only during such calendar quarter), if the closing sale price of 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 antidilution adjustments, approximately 14.4 million shares of Teradyne’s common stock. Separately and concurrent with the pricing of the Notes, Teradyne entered into warrant transactions with the Option Counterparties (the “Warrant Transactions”) in which it sold net-share-settled The Note Hedge Transactions are expected to reduce the potential dilution to Teradyne’s common stock upon any conversion of the Notes. However, the Warrant Transactions could separately have a dilutive effect to the extent that the market value per share of Teradyne’s common stock exceeds the applicable strike price of the warrant. The net cost of the Note Hedge Transactions, after being partially offset by the proceeds from the sale of the warrants, was approximately $33.0 million. In connection with establishing their initial hedge of these convertible note hedge and warrant transactions, the Option Counterparties have entered into various derivative transactions with respect to Teradyne’s common stock and/or purchased shares of Teradyne’s common stock or other securities, including the Notes, concurrent with, or shortly after, the pricing of the Notes. In addition, the Option Counterparties may modify their hedge positions by entering into or unwinding various derivative transactions with respect to Teradyne’s common stock or by selling Teradyne’s common stock or other securities, including the Notes, in secondary market transactions (and may do so during any observation period related to the conversion of the Notes). These activities could adversely affect the value of Teradyne’s common stock and the Notes. Teradyne considered the guidance of ASC 815-40, “Derivatives and Hedging—Contracts in Entity’s Own Equity,” fixed-for-fixed Teradyne assessed whether the convertible note hedge should be classified as equity under ASC 815-40. 815-40 Teradyne analyzed the Warrant Transactions under ASC 815-40, “Derivatives and Hedging—Contracts in Entity’s Own Equity,” paid-in The provisions of ASC 470-20, Debt with Conversion and Other Options, 470-20 The below tables represents the key components of Teradyne’s convertible senior notes: December 31, (in thousands) Debt principal $ 460,000 Unamortized discount including debt issuance cost 107,331 Net carrying amount of convertible debt $ 352,669 For the year ended (in thousands) Contractual interest expense on the coupon $ 303 Amortization of the discount component and debt issue fees recognized as interest expense 688 Total interest expense on the convertible debt $ 991 As of December 31, 2016, the unamortized discount was $107.3 million, which will be amortized over seven years using the effective interest rate method. The carrying amount of the equity component was $100.8 million. As of December 31, 2016, the conversion rate was equal to the initial conversion price of approximately $31.84 per share. Revolving Credit Facility On April 27, 2015, Teradyne entered into a Credit Agreement (the “Credit Agreement”) with Barclays Bank PLC, as administrative agent and collateral agent, and the lenders party thereto. The Credit Agreement provides for a five-year, senior secured revolving credit facility of up to $350 million (the “Credit Facility”). The Credit Agreement further provides that, subject to customary conditions, Teradyne may seek to obtain from existing or new lenders incremental commitments under the Credit Facility in an aggregate principal amount not to exceed $150 million. Proceeds from the Credit Facility may be used for general corporate purposes and working capital. Teradyne incurred $2.3 million in costs related to the revolving credit facility. These costs are being amortized over the five-year term of the revolving credit facility and are included in interest expense in the statements of operations. As of March 1, 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 December 31, 2016, 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.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss)	I. ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Changes in accumulated other comprehensive income (loss), which is presented net of tax, consists of the following: Foreign Currency Translation Adjustment Unrealized Gains (Losses) on Marketable Securities Retirement Plans Prior Service Credit Total (in thousands) Balance at December 31, 2014, net of tax of $1,598, $(453) $ — $ 2,365 $ 2,324 $ 4,689 Other comprehensive loss before reclassifications, net of tax of $0, $(1,667) (8,759 ) (3,075 ) — (11,834 ) Amounts reclassified from accumulated other comprehensive income, net of tax of $(390), $(169) — (704 ) (295 ) (999 ) Net current period other comprehensive loss, net of tax of $0, $(2,057), $(169) (8,759 ) (3,779 ) (295 ) (12,833 ) Balance at December 31, 2015, net of tax of $0, $(459), $(622) $ (8,759 ) $ (1,414 ) $ 2,029 $ (8,144 ) Other comprehensive (loss) income before reclassifications, net of tax of $0, $923, $34 (13,162 ) 2,037 59 (11,125 ) Amounts reclassified from accumulated other comprehensive income, net of tax of $(255), $(190) — (683 ) (321 ) (945 ) Net current period other comprehensive (loss) income, net of tax of $0, $668, $(156) (13,162 ) 1,354 (262 ) (12,070 ) Balance at December 31, 2016, net of tax of $0, $209, $(778) $ (21,921 ) $ (60 ) $ 1,767 $ (20,214 ) Reclassifications out of accumulated other comprehensive income to the statements of operations for the years ended December 31, 2016, 2015 and 2014, were as follows: Details about Accumulated Other Comprehensive Income Components For the year ended Affected Line Item in the Statements of Operations December 31, 2016 December 31, 2015 December 31, 2014 (in thousands) Available-for-sale Unrealized gains, net of tax of $255, $390, $645 $ 683 $ 704 $ 1,433 Interest income Defined benefit pension and postretirement plans: Amortization of prior service credit, net of tax of $190, $169, $169 321 295 295 (1) Prior service income arising during period, net of tax of $(34), $0, $0 (59 ) — — 262 295 295 Total reclassifications, net of tax of $411, $559, $814 $ 945 $ 999 $ 1,728 Net income (1) The amortization of prior service credit is included in the computation of net periodic pension cost and postretirement benefit; see Note N: “Retirement Plans.”

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2016
Goodwill and Intangible Assets	J. 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, Teradyne has the option to perform a qualitative assessment (“Step zero”) to determine whether it is more-likely-than-not two-step more-likely-than-not two-step two-step In the second quarter of 2016, the Wireless Test reporting unit (which is Teradyne’s Wireless Test operating and reportable segment) reduced headcount by 11% as a result of a sharp decline in projected demand attributable to an estimated smaller future wireless test market. The decrease in projected demand was due to lower forecasted buying from Teradyne’s largest Wireless Test segment customer (who has contributed between 51% and 73% of annual Wireless Test sales since the LitePoint acquisition in 2011 through 2015) as a result of the customer’s numerous operational efficiencies; slower smartphone growth rates; and a slowdown of new wireless technology adoption. Teradyne considered the headcount reduction and sharp decline in projected demand to be a triggering event for an interim goodwill impairment test. Teradyne allocated the fair value of the Wireless Test reporting unit to all of its assets and liabilities (including unrecognized intangible assets). The net book value of raw materials inventory was estimated as an approximation of current replacement costs. The fair value of finished goods inventory was estimated at the present value of selling price less direct selling costs and profit on the selling effort. The selling price used in the inventory fair values was based upon the product gross margins included in Teradyne’s forecast. The fair value of the deferred revenue liability was estimated by assessing the costs required to service the obligation plus a reasonable profit margin. The fair value for personal property assets, which consisted of furniture and fixtures, machinery and equipment, computer equipment, software and leasehold improvements, was estimated using the replacement cost approach, which approximated carrying value. The fair value of intangible assets was estimated using the income approach and, in particular, developed technology and trademarks/trade names were valued using the relief-from-royalty method and customer relationships and customer backlog were valued using the discounted cash flow method. Royalty rates were estimated using rates applicable to wireless testing equipment and other similar technologies. Based upon this allocation, Teradyne determined that the Wireless Test reporting unit goodwill is valued at $8.0 million and recorded an impairment loss of $254.9 million in the second quarter of 2016. In the fourth quarter of 2016, Teradyne performed the annual goodwill impairment test. Teradyne completed step one of the two- In 2015, Teradyne performed step one of the two-step In 2014, as a result of decreased projected demand attributable to an estimated smaller future wireless test market due to reuse of wireless test equipment, price competition and different testing techniques, Teradyne determined that for its Wireless Test reporting unit, the carrying amount of its net assets exceeded its respective fair value, indicating that a potential impairment existed. After completing the second step of the goodwill impairment test, Teradyne recorded a $98.9 million goodwill impairment charge in the fourth quarter of 2014. The fourth quarter 2014 goodwill impairment test of Teradyne’s Defense/Aerospace reporting unit, which is included in Teradyne’s System Test reportable segment, did not identify any goodwill impairment. The changes in the carrying amount of goodwill by reportable segments for the years ended December 31, 2016 and 2015 are as follows: Industrial Automation System Test Wireless Test Semiconductor Test Total (in thousands) Balance at December 31, 2014: Goodwill $ — $ 158,699 $ 361,819 $ 260,540 $ 781,058 Accumulated impairment losses — (148,183 ) (98,897 ) (260,540 ) (507,620 ) — 10,516 262,922 — 273,438 Universal Robots acquisition 221,128 — — — 221,128 Foreign currency translation adjustment (6,153 ) — — — (6,153 ) Balance at December 31, 2015: Goodwill 214,975 158,699 361,819 260,540 996,033 Accumulated impairment losses — (148,183 ) (98,897 ) (260,540 ) (507,620 ) 214,975 10,516 262,922 — 488,413 Foreign currency translation adjustment (10,124 ) — — — (10,124 ) Goodwill impairment losses — — (254,946 ) — (254,946 ) 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 Intangible Assets Teradyne reviews long-lived assets for impairment whenever events or changes in business circumstances indicate that the carrying amount of the assets may not be fully recoverable or that the useful lives of these assets are no longer appropriate. As a result of the Wireless Test segment goodwill impairment review in the second quarter of 2016, Teradyne performed an impairment test of the Wireless Test segment’s intangible and long-lived assets. The impairment test is based on a comparison of the estimated undiscounted cash flows to the carrying value of the asset group. If undiscounted cash flows for the asset group are less than the carrying amount, the asset group is written down to its estimated fair value based on a discounted cash flow analysis. The cash flow estimates used to determine the impairment contain management’s best estimates using appropriate assumptions and projections at that time. The fair value of intangible assets was estimated using the income approach and, in particular, developed technology and trademarks/trade names were valued using the relief-from-royalty method and customer relationships were valued using the discounted cash flow method. Royalty rates were estimated using rates applicable to wireless testing equipment and other similar technologies. As a result of the analysis, Teradyne recorded an $83.3 million impairment charge in the second quarter of 2016 in acquired intangible assets impairment on the statements of operations, resulting in a remaining intangible assets balance of $5.0 million for the Wireless Test segment. There were no events or circumstances indicating that the carrying value of intangible and long-lived assets may not be recoverable in 2015. In 2014, as a result of the Wireless Test segment goodwill impairment charge in the fourth quarter of 2014, Teradyne performed an impairment test of the Wireless Test segment’s intangible and long-lived assets based on a comparison of the estimated undiscounted cash flows to the recorded value of the assets and there was no indication of impairment. Amortizable intangible assets consist of the following and are included in intangible assets, net on the balance sheets: December 31, 2016 Gross Carrying Amount (1) Accumulated Amortization (1)(2) Foreign Net Carrying Amount Weighted Average Useful Life (in thousands) Developed technology $ 270,877 $ 206,376 $ (5,093 ) $ 59,408 6.0 years Customer relationships 92,741 76,707 (538 ) 15,496 7.9 years Tradenames and trademarks 50,100 23,435 (1,308 ) 25,357 9.5 years Non-compete 320 180 — 140 4.0 years Customer backlog 170 170 — — 0.3 years Total intangible assets $ 414,208 $ 306,868 $ (6,939 ) $ 100,401 6.8 years (1) During the year ended December 31, 2016, Teradyne recorded an $83.3 million impairment of Wireless Test amortizable intangible assets. The impairment assets have been eliminated from the gross carrying amount and accumulated amortization. (2) In 2016, $48.1 million of amortizable intangible assets became fully amortized and has been eliminated from the gross carrying amount and accumulated amortization. December 31, 2015 Gross Carrying Amount Accumulated Amortization (1)(2) Foreign Net Carrying Amount Weighted Average Useful Life (in thousands) Developed technology $ 382,262 $ 220,346 $ (2,444 ) $ 159,472 6.0 years Customer relationships 110,602 63,722 (258 ) 46,622 7.9 years Tradenames and trademarks 53,034 18,889 (628 ) 33,517 9.5 years Non-compete 320 100 — 220 4.0 years Customer backlog 170 170 — — 0.3 years Total intangible assets $ 546,388 $ 303,227 $ (3,330 ) $ 239,831 6.7 years (1) During the year ended December 31, 2015, Teradyne recorded intangible assets in the amount of $121.6 million related to its Universal Robots acquisition. (2) During the year ended December 31, 2015, Teradyne wrote off $98.2 million of fully amortized intangible assets. Aggregate intangible assets amortization expense for the years ended December 31, 2016, 2015 and 2014 was $52.6 million, $69.0 million, and $70.8 million, respectively. Estimated intangible assets amortization expense for each of the five succeeding fiscal years is as follows: Year Amortization Expense (in thousands) 2017 $ 28,986 2018 26,848 2019 23,037 2020 10,042 2021 3,435 Thereafter 8,053

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2016
Commitments and Contingencies	K. COMMITMENTS AND CONTINGENCIES Purchase Commitments As of December 31, 2016, Teradyne had entered into non-cancelable Commitments Teradyne leases certain of its office buildings and other facilities under various operating lease arrangements that include renewal options and escalation clauses for adjusting rent payments to reflect changes in price indices. Rental expense for leases with fixed escalation clauses is recognized on a straight line basis over the lease term. Rental expense for the years ended December 31, 2016, 2015 and 2014 was $18.8 million, $15.9 million and $16.0 million, respectively. The following table reflects Teradyne’s non-cancelable Non-cancelable (in thousands) 2017 $ 16,467 2018 15,258 2019 13,733 2020 9,374 2021 7,149 Beyond 2022 10,130 Total $ 72,111 Legal Claims Teradyne is subject to legal proceedings, claims and investigations that arise in the ordinary course of business such as, but not limited to, patent, employment, commercial and environmental matters. Teradyne believes that it has meritorious defenses against all pending claims and intends to vigorously contest them. While it is not possible to predict or determine the outcomes of any pending claims or to provide possible ranges of losses that may arise, Teradyne believes the potential losses associated with all of these actions are unlikely to have a material adverse effect on its business, financial position or results of operations. Guarantees and Indemnification Obligations Teradyne provides indemnification, to the extent permitted by law, to its officers, directors, employees and agents for liabilities arising from certain events or occurrences while the officer, director, employee, or agent, is or was serving, at Teradyne’s request in such capacity. Teradyne has entered into indemnification agreements with certain of its officers and directors. With respect to acquisitions, Teradyne provides indemnifications to or assumes indemnification obligations for the current and former directors, officers and employees of the acquired companies in accordance with the acquired companies’ by-laws Teradyne enters into agreements in the ordinary course of business with customers, resellers, distributors, integrators and suppliers. Most of these agreements require Teradyne to defend and/or indemnify the other party against intellectual property infringement claims brought by a third party with respect to Teradyne’s products. From time to time, Teradyne also indemnifies customers and business partners for damages, losses and liabilities they may suffer or incur relating to personal injury, personal property damage, product liability, breach of confidentiality obligations and environmental claims relating to the use of Teradyne’s products and services or resulting from the acts or omissions of Teradyne, its employees, authorized agents or subcontractors. On occasion, Teradyne has also provided guarantees to customers regarding the delivery and performance of its products in addition to the warranty described below. As a matter of ordinary business course, Teradyne warrants that its products will substantially perform in accordance with its standard published specifications in effect at the time of delivery. Most warranties have a one-year In addition, and in the ordinary course of business, Teradyne provides minimum purchase guarantees to certain vendors to ensure continuity of supply against the market demand. Although some of these guarantees provide penalties for cancellations and/or modifications to the purchase commitments as the market demand decreases, most of the guarantees do not. Therefore, as the market demand decreases, Teradyne re-evaluates With respect to its agreements covering product, business or entity divestitures and acquisitions, Teradyne provides certain representations, warranties and covenants to purchasers and agrees to indemnify and hold such purchasers harmless against breaches of such representations, warranties and covenants. Many of the indemnification claims have a definite expiration date while some remain in force indefinitely. With respect to its acquisitions, Teradyne may, from time to time, assume the liability for certain events or occurrences that took place prior to the date of acquisition. As a matter of ordinary course of business, Teradyne occasionally guarantees certain indebtedness obligations of its subsidiary companies, limited to the borrowings from financial institutions, purchase commitments to certain vendors, and lease commitments to landlords. Based on historical experience and information known as of December 31, 2016 and 2015, except for product warranty, Teradyne has not recorded any liabilities for these guarantees and obligations because the amount would be immaterial.

Net (loss) Income per Common Sh

Net (loss) Income per Common Share	12 Months Ended
	Dec. 31, 2016
Net (loss) Income per Common Share	L. NET (LOSS) INCOME PER COMMON SHARE The following table sets forth the computation of basic and diluted net (loss) income per common share: 2016 2015 2014 (in thousands, except per share amounts) Net (loss) income for basic and diluted net income per share $ (43,421 ) $ 206,477 $ 81,272 Weighted average common shares-basic 202,578 211,544 202,908 Effect of dilutive potential common shares: Incremental shares from assumed conversion of convertible notes (1) — — 5,013 Convertible note hedge warrant shares (2) — — 12,562 Restricted stock units — 1,130 1,092 Stock options — 606 944 Employee stock purchase rights — 41 31 Dilutive potential common shares — 1,777 19,642 Weighted average common shares-diluted 202,578 213,321 222,550 Net (loss) income per common share-basic $ (0.21 ) $ 0.98 $ 0.40 Net (loss) income per common share-diluted $ (0.21 ) $ 0.97 $ 0.37 (1) Incremental shares from the assumed conversion of the convertible notes was calculated using the difference between the average Teradyne stock price for the period and the conversion price of $5.48, multiplied by 34.7 million shares. The result of this calculation, representing the total intrinsic value of the convertible debt, was divided by the average Teradyne stock price for the period. (2) Convertible notes hedge warrant shares were calculated using the difference between the average Teradyne stock price for the period and the warrant price of $7.67, multiplied by 34.7 million shares. The result of this calculation, representing the total intrinsic value of the warrant, was divided by the average Teradyne stock price for the period. Teradyne’s call option on its common stock (convertible note hedge transaction) was excluded from the calculation of diluted shares because the effect was anti-dilutive. The computation of diluted net loss per common share for 2016 excludes the effect of the potential exercise of all outstanding stock options and restricted stock units because Teradyne had a net loss and inclusion would be anti-dilutive. The computation of diluted net income per common share for 2015 excludes the effect of the potential exercise of stock options to purchase approximately 0.2 million shares because the effect would have been anti-dilutive. The computation of diluted net income per common share for 2014 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	12 Months Ended
	Dec. 31, 2016
Restructuring and Other	M. RESTRUCTURING AND OTHER Other During the year ended December 31, 2016, Teradyne recorded $15.9 million of other charges of which $15.3 million was for the increase in the fair value of the Universal Robots contingent consideration liability, $0.6 million for the increase in the fair value of the AIT contingent consideration liability, $4.2 million for an impairment of fixed assets and $1.2 million for expenses related to an earthquake in Kumamoto, Japan, partially offset by $5.4 million of property insurance recovery related to the Japan earthquake. During the year ended December 31, 2015, Teradyne recorded $3.6 million of other charges, of which $5.3 million was for the increase in the fair value of the Universal Robots contingent consideration liability and $1.0 million for acquisition costs related to Universal Robots, partially offset by a $2.9 million gain from fair value adjustments to decrease the acquisition contingent consideration liability related to ZTEC, $1.6 million, and AIT, $1.3 million. During the year ended December 31, 2014, Teradyne recorded a $0.6 million gain from the fair value adjustment to decrease the ZTEC acquisition contingent consideration, partially offset by $0.4 million of acquisition costs related to AIT. Restructuring During the year ended December 31, 2016, Teradyne recorded $6.0 million of severance charges related to headcount reductions of 146 people, of which 102 people were in Wireless Test and 44 people were in Semiconductor Test. During the year ended December 31, 2015, Teradyne recorded $1.5 million of severance charges related to headcount reductions of 23 people primarily in System Test and Semiconductor Test. During the year ended December 31, 2014, Teradyne recorded $1.6 million of severance charges related to headcount reductions of approximately 43 people, primarily in Semiconductor Test and Wireless Test. The remaining accrual for severance of $2.1 million is reflected in the accrued employees’ compensation and withholdings on the balance sheet and is expected to be paid by June 2017.

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2016
Retirement Plans	N. 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. The December 31 balances of these defined benefit pension plans assets and obligations are shown below: 2016 2015 United States Foreign United States Foreign (in thousands) Assets and Obligations Change in benefit obligation: Projected benefit obligation: Beginning of year $ 351,117 $ 62,290 $ 367,619 $ 58,210 Service cost 2,302 761 2,462 1,006 Interest cost 13,630 1,185 13,142 1,444 Actuarial gain (loss) 6,053 5,621 (13,221 ) 7,498 Benefits paid (19,486 ) (1,385 ) (18,885 ) (859 ) Curtailment — — — (634 ) Plan participants’ contributions — — — 64 Expenses paid — (609 ) — — Non-U.S. — (7,125 ) — (4,439 ) End of year 353,616 60,738 351,117 62,290 Change in plan assets: Fair value of plan assets: Beginning of year 298,404 28,141 316,072 29,511 Company contributions 4,489 867 10,517 808 Plan participants’ contributions — — — 64 Actual return on plan assets 23,897 5,142 (9,300 ) (136 ) Benefits paid (19,486 ) (1,148 ) (18,885 ) (859 ) Settlements — — — — Expenses paid — (609 ) — (43 ) Non-U.S. — (4,822 ) — (1,204 ) End of year 307,304 27,571 298,404 28,141 Funded status $ (46,312 ) $ (33,167 ) $ (52,713 ) $ (34,149 ) The following table provides amounts recorded within the account line items of the statements of financial position as of December 31: 2016 2015 United States Foreign United States Foreign (in thousands) Retirement plans assets $ 7,712 $ — $ 636 $ — Accrued employees’ compensation and withholdings (2,591 ) (772 ) (2,564 ) (695 ) Retirement plans liabilities (51,433 ) (32,395 ) (50,785 ) (33,454 ) Funded status $ (46,312 ) $ (33,167 ) $ (52,713 ) $ (34,149 ) The following table provides amounts recognized in accumulated other comprehensive income as of December 31: 2016 2015 United States Foreign United States Foreign (in thousands) Prior service cost, before tax $ 127 $ — $ 224 $ — Deferred taxes 514 — 479 — Total recognized in other comprehensive income, net of tax $ 641 $ — $ 703 $ — The estimated portion of prior service cost remaining in accumulated other comprehensive income that is expected to be recognized as a component of net periodic pension cost in 2017 is $0.1 million. The accumulated benefit obligation for the United States defined benefit pension plans was $342.9 million and $340.1 million at December 31, 2016 and 2015, respectively. The accumulated benefit obligation for foreign defined benefit pension plans was $56.6 million at December 31, 2016 and 2015. Information for pension plans with an accumulated benefit obligation in excess of plan assets as of December 31: 2016 2015 United States Foreign United States Foreign (in millions) Projected benefit obligation $ 54.0 $ 34.3 $ 53.3 $ 35.2 Accumulated benefit obligation 48.0 30.1 47.3 29.5 Fair value of plan assets — 1.1 — 1.0 Expense For the years ended December 31, 2016, 2015 and 2014, Teradyne’s net periodic pension (income) cost was comprised of the following: 2016 2015 2014 United States Foreign United States Foreign United States Foreign (in thousands) Components of Net Periodic Pension (Income) Cost: Service cost $ 2,302 $ 761 $ 2,462 $ 1,006 $ 2,218 $ 897 Interest cost 13,630 1,185 13,142 1,444 12,875 1,837 Expected return on plan assets (13,830 ) (443 ) (14,517 ) (781 ) (12,500 ) (868 ) Amortization of prior service cost 96 — 134 — 135 — Net actuarial (gain) loss (4,013 ) 815 10,596 8,415 43,168 4,651 Curtailment — — — (634 ) — — Total net periodic pension (income) cost $ (1,815 ) $ 2,318 $ 11,817 $ 9,450 $ 45,896 $ 6,517 Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income: Reversal of amortization items: Prior service cost (96 ) — (134 ) — (135 ) — Total recognized in other comprehensive income (96 ) — (134 ) — (135 ) — Total recognized in net periodic pension (income) cost and other comprehensive income $ (1,911 ) $ 2,318 $ 11,683 $ 9,450 $ 45,761 $ 6,517 Weighted Average Assumptions to Determine Net Periodic Pension Cost at January 1: 2016 2015 2014 United States Foreign United States Foreign United States Foreign Discount rate 4.0 % 2.3 % 3.7 % 2.6 % 4.5 % 3.8 % Expected return on plan assets 4.8 2.0 4.8 2.6 5.0 3.4 Salary progression rate 2.7 3.2 2.9 3.2 3.0 3.5 Weighted Average Assumptions to Determine Pension Obligations at December 31 : 2016 2015 United States Foreign United States Foreign Discount rate 3.9 % 1.8 % 4.0 % 2.3 % Salary progression rate 2.6 2.7 2.7 3.2 In developing the expected return on plan assets assumption, Teradyne evaluates input from its investment manager and pension consultants, including their forecast of asset class return expectations. Teradyne believes that 4.8% was an appropriate rate to use for fiscal 2016 for the U.S. Qualified Pension Plan (“U.S. Plan”). Teradyne recognizes net actuarial gains and losses and the change in the fair value of the plan assets in its operating results in the year in which they occur or upon any interim remeasurement of the plans. Teradyne calculates the expected return on plan assets using the fair value of the plan assets. Actuarial gains and losses are generally measured annually as of December 31 and, accordingly, recorded during the fourth quarter of each year or upon any interim remeasurement of the plans. The discount rate utilized to determine future pension obligations for the U.S. Plan is based on Citigroup Pension Index adjusted for the plan’s expected cash flows and was 3.9% at December 31, 2016, down from 4.0% at December 31, 2015. Plan Assets As of December 31, 2016, the fair value of Teradyne’s pension plans’ assets totaled $334.9 million of which $307.3 million was related to the U.S. Plan, $26.5 million was related to the U.K. defined benefit pension plan, and $1.1 million was related to the Taiwan defined benefit pension plan. Substantially all Teradyne’s pension plans’ assets are held in individual trusts, which were established for the investment of assets of Teradyne’s sponsored retirement plans. The following table provides weighted average pension asset allocation by asset category at December 31, 2016 and 2015: 2016 2015 United States Foreign United States Foreign Fixed income securities 88.1 % — % 88.6 % — % Equity securities 9.9 — 9.8 — Other 2.0 100.0 1.6 100.0 100.0 % 100.0 % 100.0 % 100.0 % The assets of the U.S. Plan are overseen by the Teradyne Fiduciary Committee which is comprised of members of senior management drawn from appropriate diversified levels of the management team. The Fiduciary Committee is responsible for setting the policy that provides the framework for management of the U.S. Plan assets. In accordance with its responsibilities, the Fiduciary Committee meets on a regular basis to review the performance of the U.S. Plan assets and compliance with the investment policy. The policy sets forth an investment structure for managing U.S. Plan assets, including setting the asset allocation ranges, which are expected to provide an appropriate level of overall diversification required to maximize the long-term return on plan assets for a prudent and reasonable level of risk given prevailing market conditions, total investment return over the long term, and preservation of capital, while maintaining sufficient liquidity to pay the benefits of the U.S. Plan. The investment portfolio will not, at any time, have a direct investment in Teradyne stock. It may have indirect investment in Teradyne stock, if one of the funds selected by the investment manager invests in Teradyne stock. In developing the asset allocation ranges, third party asset allocation studies are periodically performed that consider the current and expected positions of the plan assets and funded status. Based on this study and other appropriate information, the Fiduciary Committee establishes asset allocation ranges taking into account acceptable risk targets and associated returns. The investment return objectives are to avoid excessive volatility and produce a rate of return that at least matches the Policy Index identified below. The manager’s investment performance is reviewed at least annually. Results for the total portfolio and for each major category of assets are evaluated in comparison with appropriate market indices and the Policy Index. The target asset allocation and the index for each asset category for the U.S. Plan, per the investment policy, are as follows: Asset Category: Policy Index: Target Allocation U.S. corporate fixed income Barclays U.S. Corporate A or Better Index 76 % Global equity MSCI World Minimum Volatility Index 10 U.S. government fixed income Barclays U.S. Long Government Bond Index 8 High yield fixed income Barclays U.S. Corporate High Yield 2% Issuer Cap Index 5 Cash Citigroup Three Month U.S. Treasury Bill Index 1 Teradyne’s U.S. Plan invests primarily in common trust funds. Units held in the common trust funds are valued at the unit price as reported by the investment manager based on the asset value of the underlying investments; underlying investments in equity securities are valued at the last reported sales price, and underlying investments in fixed-income securities are generally valued using methods based upon market transactions for comparable securities. In the fourth quarter of 2015, the Trustees of the U.K. defined benefit pension plan purchased group annuity insurance contracts. The cash flows from the contracts are intended to match the plan’s obligations. During the years ended December 31, 2016 and 2015, there were no transfers of pension assets in or out of Level 1, Level 2 or Level 3. The fair value of pension plan assets by asset category and by level at December 31, 2016 and December 31, 2015 were as follows: December 31, 2016 United States Foreign Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (in thousands) Fixed income securities: Corporate debt securities $ — $ 246,528 $ — $ 246,528 $ — $ — $ — $ — U.S. government securities — 24,322 — 24,322 — — — — Global equity — 30,360 — 30,360 — — — — Group annuity insurance contracts — — 3,071 3,071 — — 26,385 26,385 Other — — — — — 1,124 — 1,124 Cash and cash equivalents 3,023 — — 3,023 62 — — 62 Total $ 3,023 $ 301,210 $ 3,071 $ 307,304 $ 62 $ 1,124 $ 26,385 $ 27,571 December 31, 2015 United States Foreign Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (in thousands) Fixed income securities: Corporate debt securities $ — $ 240,695 $ — $ 240,695 $ — $ — $ — $ — U.S. government securities — 23,761 — 23,761 — — — — Global equity — 29,193 — 29,193 — — — — Group annuity insurance contracts — — 2,982 2,982 — — 26,410 26,410 Other — — — — — 1,029 — 1,029 Cash and cash equivalents 1,773 — — 1,773 702 — — 702 Total $ 1,773 $ 293,649 $ 2,982 $ 298,404 $ 702 $ 1,029 $ 26,410 $ 28,141 The pension plan assets identified as Level 3 above are related to group annuity insurance contracts held by the U.K. defined benefit pension plan and the U.S. Plan. The fair value of these assets was calculated using the present value of future pension payments due under the group annuity insurance contracts. Changes in the fair value of Level 3 group annuity insurance contracts for the years ended December 31, 2016 and 2015 were as follows: Group Annuity Insurance Contracts (in thousands) Balance at December 31, 2014 $ 2,990 Purchases of group annuity insurance contracts 27,313 Interest and market value adjustments (825 ) Benefits paid (67 ) Other (19 ) Balance at December 31, 2015 29,392 Purchases of group annuity insurance contracts 709 Interest and market value adjustments 5,308 Benefits paid (611 ) Other (634 ) Non-U.S. (4,708 ) Balance at December 31, 2016 $ 29,456 Contributions Teradyne’s funding policy is to make contributions to the plans in accordance with local laws and to the extent that such contributions are tax deductible. During 2016, Teradyne contributed $1.9 million to the U.S. Plan, $2.6 million to the U.S. supplemental executive defined benefit pension plan and $0.9 million to certain qualified plans for non-U.S. non-U.S. non-U.S. Expected Future Pension Benefit Payments Future benefit payments are expected to be paid as follows: United States Foreign (in thousands) 2017 $ 19,205 $ 788 2018 18,568 754 2019 19,046 780 2020 19,768 1,054 2021 20,390 882 2022-2026 111,334 5,209 Postretirement Benefit Plans 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. The December 31 balances of the postretirement assets and obligations are shown below: 2016 2015 (in thousands) Assets and Obligations Change in benefit obligation: Projected benefit obligation: Beginning of year $ 6,030 $ 7,162 Service cost 37 48 Interest cost 218 237 Plan amendments (93 ) — Actuarial loss (gain) 5 (648 ) Benefits paid (687 ) (769 ) End of year 5,510 6,030 Change in plan assets: Fair value of plan assets: Beginning of year — — Company contributions 687 769 Benefits paid (687 ) (769 ) End of year — — Funded status $ (5,510 ) $ (6,030 ) The following table provides amounts recorded within the account line items of financial position as of December 31: 2016 2015 (in thousands) Accrued employees’ compensation and withholdings $ (571 ) $ (692 ) Retirement plans liability (4,939 ) (5,338 ) Funded status $ (5,510 ) $ (6,030 ) The following table provides amounts recognized in accumulated other comprehensive income as of December 31: 2016 2015 (in thousands) Prior service credit, before tax $ (1,118 ) $ (1,632 ) Deferred taxes (1,292 ) (1,100 ) Total recognized in other comprehensive income, net of tax $ (2,410 ) $ (2,732 ) The estimated portion of prior service credit remaining in accumulated other comprehensive income that is expected to be recognized as a component of net periodic postretirement benefit income in 2017 is $(0.5) million. Expense For the years ended December 31, 2016, 2015 and 2014, Teradyne’s net periodic postretirement benefit income was comprised of the following: 2016 2015 2014 (in thousands) Components of Net Periodic Postretirement Benefit Income: Service cost $ 37 $ 48 $ 59 Interest cost 218 237 335 Amortization of prior service credit (607 ) (598 ) (598 ) Net actuarial loss (gain) 5 (648 ) (1,255 ) Total net periodic postretirement benefit income (347 ) (961 ) (1,459 ) Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income: Prior service benefit (93 ) — — Reversal of amortization items: Prior service credit 607 598 598 Total recognized in other comprehensive income 514 598 598 Total recognized in net periodic postretirement cost (income) and other comprehensive income $ 167 $ (363 ) $ (861 ) Weighted Average Assumptions to Determine Net Periodic Postretirement Benefit Income as of January 1: 2016 2015 2014 Discount rate 3.9 % 3.5 % 4.1 % Initial health care cost trend rate 7.5 7.5 8.0 Ultimate health care cost trend rate 5.0 5.0 5.0 Year in which ultimate health care cost trend rate is reached 2023 2022 2020 Weighted Average Assumptions to Determine Postretirement Benefit Obligation as of December 31: 2016 2015 2014 Discount rate 3.9 % 3.9 % 3.5 % Initial medical trend 7.3 7.5 7.5 Ultimate health care trend 5.0 5.0 5.0 Medical cost trend rate decrease to ultimate rate in year 2023 2023 2022 Assumed health care trend rates could have a significant effect on the amounts reported for health care plans. A one percentage point change in the assumed health care cost trend rates for the year ended December 31, 2016 would have the following effects: 1 Percentage Point Increase 1 Percentage Point Decrease (in thousands) Effect on total service and interest cost components $ 2 $ (2 ) Effect on postretirement benefit obligations 44 (42 ) Expected Future Benefit Payments Future benefit payments are expected to be paid as follows: Benefit Payments (in thousands) 2017 $ 571 2018 529 2019 456 2020 409 2021 367 2022-2026 1,536

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2016
Stock-Based Compensation	O. STOCK-BASED COMPENSATION Stock Compensation Plans 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 January 2016, Teradyne’s three-year TSR performance will be 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 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. The TSR PRSUs are valued using a Monte Carlo simulation model. During 2016, 2015 and 2014 Teradyne granted 0.1 million, 0.2 million and 0.1 million TSR PRSUs, respectively, with a grant date fair value of $20.29, $18.21 and $22.06, respectively. The fair value was estimated using the Monte Carlo simulation model with the following assumptions: 2016 2015 2014 Risk-free interest rate 0.97 % 0.77 % 0.75 % Teradyne volatility-historical 27.0 % 28.2 % 36.1 % NYSE Composite Index volatility-historical 13.1 % — % — % Philadelphia Semiconductor Index volatility-historical — % 19.7 % 24.6 % Dividend yield 1.24 % 1.33 % 1.25 % Expected volatility was based on the historical volatility of Teradyne’s stock and the NYSE Composite Index for the 2016 grant and Philadelphia Semiconductor Index for the 2015 and 2014 grants, 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 for 2016, 2015 and 2014 was based upon an estimated annual dividend amount of $0.24 per share divided by Teradyne’s stock price on the grant date of $19.43 for the 2016 grants, $18.10 for the 2015 grants, and $19.16 for the 2014 grants. Stock Options Valuation Assumptions: The total number of stock options granted in 2016, 2015 and 2014 were 0.1 million, 0.1 million and 0.1 million, respectively, at the weighted average grant date fair value of $5.30, $4.43 and $5.49 per share, respectively. The fair value of the stock options at grant date was estimated using the Black-Scholes option-pricing model with the following assumptions: 2016 2015 2014 Expected life (years) 5.0 4.0 4.0 Risk-free interest rate 1.4 % 1.1 % 1.2 % Volatility-historical 32.9 % 33.4 % 38.8 % Dividend yield 1.24 % 1.33 % 1.25 % Teradyne determined the stock option’s expected life based upon historical exercise data for executive officers, the age of executives and the terms of the stock option award. Volatility was determined using historical volatility for a period equal to the expected life. The 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 $0.24 per share divided by Teradyne’s stock price on the grant date of $19.43 for the 2016 grants, $18.10 for the 2015 grants, and $19.16 for the 2014 grants. Stock compensation plan activity for the years 2016, 2015 and 2014 follows: 2016 2015 2014 (in thousands) Restricted Stock Units: Non-vested 4,070 4,352 4,636 Awarded 1,471 1,681 1,870 Vested (1,530 ) (1,679 ) (1,965 ) Forfeited (233 ) (284 ) (189 ) Non-vested 3,778 4,070 4,352 Stock Options: Outstanding at January 1 1,121 1,507 2,706 Granted 130 132 89 Exercised (324 ) (518 ) (1,248 ) Forfeited — — (38 ) Expired (2 ) — (2 ) Outstanding at December 31 926 1,121 1,507 Vested and expected to vest at December 31 926 1,121 1,507 Exercisable at December 31 598 779 1,089 Total shares available for the years 2016, 2015 and 2014: 2016 2015 2014 (in thousands) Shares available: Available for grant at January 1 10,914 12,443 14,213 Options granted (130 ) (132 ) (89 ) Restricted stock units awarded (1,471 ) (1,681 ) (1,870 ) Restricted stock units forfeited 233 284 189 Available for grant at December 31 9,546 10,914 12,443 Weighted average restricted stock unit award date fair value information for the years 2016, 2015 and 2014 follows: 2016 2015 2014 Non-vested $ 17.46 $ 17.24 $ 15.60 Awarded 18.68 17.36 18.41 Vested 17.21 16.85 14.38 Forfeited 17.57 17.08 16.97 Non-vested $ 18.03 $ 17.46 $ 17.24 Restricted stock unit awards aggregate intrinsic value information at December 31 for the years 2016, 2015 and 2014 follows: 2016 2015 2014 (in thousands) Vested $ 30,008 $ 32,200 $ 37,160 Outstanding 95,952 84,129 86,113 Expected to vest 91,871 79,611 81,582 Restricted stock units weighted average remaining contractual terms (in years) information at December 31, for the years 2016, 2015 and 2014 follows: 2016 2015 2014 Outstanding 1.04 1.09 1.11 Expected to vest 1.03 1.08 1.10 Weighted average stock options exercise price information for the year ended December 31, 2016 follows: 2016 Outstanding at January 1 $ 10.21 Options granted 19.43 Options exercised 9.06 Options expired 3.07 Outstanding at December 31 11.93 Exercisable at December 31 8.32 The total cash received from employees as a result of employee stock options exercises during the years ended December 31, 2016, 2015 and 2014, was $2.9 million, $2.8 million and $6.7 million, respectively. In connection with these exercises, the tax benefit realized by Teradyne for the years ended December 31, 2016, 2015 and 2014, was $0.8 million, $2.1 million and $5.7 million, respectively. Stock option aggregate intrinsic value information for the years ended December 31, 2016, 2015 and 2014 follows: 2016 2015 2014 (in thousands) Exercised $ 3,729 $ 7,255 $ 17,847 Outstanding 12,468 11,729 17,936 Vested and expected to vest 12,468 11,729 17,936 Exercisable 10,217 10,716 16,101 Stock options weighted average remaining contractual terms (in years) information at December 31, for the years 2016, 2015 and 2014 follows: 2016 2015 2014 Outstanding 3.9 4.2 4.5 Vested and expected to vest 3.9 4.2 4.5 Exercisable 3.2 3.9 4.2 Significant option groups outstanding at December 31, 2016 and related weighted average price and remaining contractual life information follow: Options Outstanding Options Exercisable Range Of Exercise Prices Weighted- Average Remaining Contractual Life (Years) Shares Weighted- Average Exercise Price Shares Weighted- Average Exercise Price (shares in thousands) $1.48 – $2.67 3.74 294 $ 2.31 294 $ 2.31 $3.23 – $7.71 1.77 75 4.26 75 4.26 $16.23 – $18.10 3.51 338 17.18 185 16.87 $19.16 – $19.43 5.26 219 19.32 44 19.16 926 11.93 598 8.32 As of December 31, 2016, total unrecognized expense related to non-vested Effective January 31, 2014, Michael Bradley retired as Chief Executive Officer of Teradyne. On January 22, 2014, Teradyne entered into an agreement (the “Retirement Agreement”) with Mr. Bradley. Under the Retirement Agreement, Mr. Bradley’s unvested restricted stock units and stock options granted prior to his retirement date will continue to vest in accordance with their terms through January 31, 2017; and any vested options or options that vest during that period may be exercised for the remainder of the applicable option term. In the Retirement Agreement, Mr. Bradley agreed to be bound by non-competition non-solicitation one-time Employee Stock Purchase Plan Under the Teradyne 1996 Employee Stock Purchase Plan (“ESPP”), eligible employees may purchase shares of common stock through regular payroll deductions of up to 10% of their compensation, to a maximum of shares with a fair market value of $25,000 per calendar year, not to exceed 6,000 shares. Under the plan, the price paid for the common stock is equal to 85% of the stock price on the last business day of the six-month In July 2016, 0.5 million shares of common stock were issued to employees who participated in the plan during the first half of 2016, at the price of $16.74 per share. In January 2017, Teradyne issued 0.4 million shares of common stock to employees who participated in the plan during the second half of 2016, at the price of $21.59 per share. In July 2015, 0.5 million shares of common stock were issued to employees who participated in the plan during the first half of 2015, at the price of $16.40 per share. In January 2016, Teradyne issued 0.5 million shares of common stock to employees who participated in the plan during the second half of 2015, at the price of $17.57 per share. In July 2014, 0.5 million shares of common stock were issued to employees who participated in the plan during the first half of 2014, at the price of $16.66 per share. In January 2015, Teradyne issued 0.5 million shares of common stock to employees who participated in the plan during the second half of 2014, at the price of $16.82 per share. As of December 31, 2016, there were 3.9 million shares available for grant under the ESPP. The effect to income from operations for recording stock-based compensation for the years ended December 31 was as follows: 2016 2015 2014 (in thousands) Cost of revenues $ 3,153 $ 3,065 $ 3,675 Engineering and development 9,458 9,362 10,146 Selling and administrative 18,139 18,024 26,486 Stock-based compensation 30,750 30,451 40,307 Income tax benefit (8,752 ) (8,528 ) (11,537 ) Total stock-based compensation expense after income taxes $ 21,998 $ 21,923 $ 28,770

Savings Plan

Savings Plan	12 Months Ended
	Dec. 31, 2016
Savings Plan	P. SAVINGS PLAN Teradyne sponsors a defined contribution employee retirement savings plan (“Savings Plan”) covering substantially all U.S. employees. Under the Savings Plan, employees may contribute up to 20% of their compensation (subject to Internal Revenue Service limitations). The Savings Plan provides for a discretionary employer match that is determined each year. In 2016, 2015 and 2014, Teradyne matched 100% of eligible employee contributions up to 4% of their compensation for employees not accruing benefits in the U.S. Qualified Pension Plan. There was no match for employees still actively accruing benefits in the U.S. Qualified Pension Plan. Teradyne’s contributions vest 25% per year for the first four years of employment, and contributions for those employees with four years of service vest immediately. In addition, Teradyne established an unfunded U.S. Supplemental Savings Plan to provide savings benefits in excess of those allowed by Employee Retirement Income Security Act of 1974 and the Internal Revenue Code. The provisions of this plan are the same as the Savings Plan. Teradyne also established defined contribution savings plans for its foreign employees. Under Teradyne’s savings plans, amounts charged to the statements of operations for the years ended December 31, 2016, 2015 and 2014 were $14.5 million, $13.5 million and $12.8 million, respectively.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2016
Income Taxes	Q. INCOME TAXES The components of (loss) income before income taxes and the (benefit) provision for income taxes as shown in the consolidated statements of operations were as follows: 2016 2015 2014 (in thousands) (Loss) income before income taxes: U.S. $ (341,018 ) $ 56,270 $ (151,889 ) Non-U.S. 285,958 196,854 247,265 $ (55,060 ) $ 253,124 $ 95,376 (Benefit) provision for income taxes: Current: U.S. Federal $ 7,750 $ 16,635 $ 5,197 Non-U.S. 41,579 35,707 28,157 State 1,968 1,429 678 51,297 53,771 34,032 Deferred: U.S. Federal (51,482 ) (574 ) (20,449 ) Non-U.S. (9,240 ) (7,761 ) (404 ) State (2,214 ) 1,211 925 (62,936 ) (7,124 ) (19,928 ) Total (benefit) provision for income taxes: $ (11,639 ) $ 46,647 $ 14,104 Income tax benefit for 2016 totaled $11.6 million. Income tax expense for 2015 and 2014 totaled $46.6 million and $14.1 million, respectively. The effective tax rate for 2016, 2015 and 2014 was 21.1%, 18.4% and 14.8%, respectively. The increase in the effective tax rate from 2015 to 2016 resulted from a shift in the geographic distribution of income which decreased income subject to taxation in the U.S. relative to lower tax rate jurisdictions, reductions in uncertain tax positions resulting from the expiration of statutes and the settlement of an audit, and an increase in non-taxable non-deductible The increase in the effective tax rate from 2014 to 2015 resulted from a shift in the geographic distribution of income which increased income subject to taxation in the U.S. relative to lower tax rate jurisdictions and a reduction in the benefit from U.S. research and development tax credits. These increases in the effective tax rate were partially offset by decreases associated with uncertain tax positions and a non-deductible A reconciliation of the effective tax rate for the years 2016, 2015 and 2014 follows: 2016 2015 2014 U.S. statutory federal tax rate 35.0 % 35.0 % 35.0 % Foreign taxes 127.1 (16.5 ) (58.1 ) U.S. research and development credit 15.8 (3.0 ) (7.9 ) Domestic production activities deduction 2.3 (1.0 ) (0.5 ) State income taxes, net of federal tax benefit 2.3 0.4 (0.1 ) Equity compensation (2.7 ) 0.6 (1.8 ) Uncertain tax positions (2.6 ) 2.2 7.9 Goodwill impairment (162.1 ) — 36.3 Other, net 6.0 0.7 4.0 21.1 % 18.4 % 14.8 % 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 attributable to the tax holiday for the years ended December 31, 2016, 2015 and 2014 were $17.0 million or $0.08 per diluted share, $11.5 million or $0.05 per diluted share and $13.2 million or $0.06 per diluted share, respectively. The tax holiday is scheduled to expire on December 31, 2020. Significant components of Teradyne’s deferred tax assets (liabilities) as of December 31, 2016 and 2015 were as follows: 2016 2015 (in thousands) Deferred tax assets: Tax credits $ 57,313 $ 44,684 Pension liabilities 31,581 31,742 Inventory valuations 31,227 29,445 Accruals 27,247 26,563 Deferred revenue 12,806 10,232 Equity compensation 9,922 9,674 Vacation accrual 7,874 7,354 Net operating loss carryforwards 5,244 7,989 Other 630 502 Gross deferred tax assets 183,844 168,185 Less: valuation allowance (48,369 ) (43,039 ) Total deferred tax assets $ 135,475 $ 125,146 Deferred tax liabilities: Intangible assets $ (22,887 ) $ (68,433 ) Depreciation (17,117 ) (20,541 ) Marketable securities (210 ) (458 ) Total deferred tax liabilities $ (40,214 ) $ (89,432 ) Net deferred assets $ 95,261 $ 35,714 During 2016, Teradyne’s valuation allowance increased by $5.3 million primarily due to the increase in the deferred tax assets related to state tax credits generated in 2016. As of December 31, 2016 and 2015, Teradyne evaluated the likelihood that it would realize the deferred income taxes to offset future taxable income and concluded that it is more likely than not that a substantial majority of its deferred tax assets will be realized through consideration of both the positive and negative evidence. At December 31, 2016 and 2015, Teradyne maintained a valuation allowance for certain deferred tax assets of $48.4 million and $43.0 million, respectively, primarily related to state net operating losses and state tax credit carryforwards, due to the uncertainty regarding their realization. Adjustments could be required in the future if Teradyne estimates that the amount of deferred tax assets to be realized is more or less than the net amount recorded. At December 31, 2016, Teradyne had operating loss carryforwards that expire in the following years: State Operating Loss Carryforwards Foreign Operating Loss Carryforwards (in thousands) 2017 $ 10,245 $ — 2018 8,562 — 2019 983 — 2020 1,248 — 2021 3,549 — 2022-2026 18,044 — 2027-2031 38,498 — Beyond 2031 5,464 129 Non-expiring — 6,400 Total $ 86,593 $ 6,529 The operating loss carryforwards do not include any excess tax deduction related to stock-based compensation, which has not been recognized for financial statements purposes. Teradyne has approximately $134.6 million of tax credit carryforwards including federal business tax credits of approximately $45.3 million which expire in the years 2017 through 2036, alternative minimum tax credits of approximately $8.7 million which do not expire, and state tax credits of $80.6 million, of which $47.4 million do not expire and the remainder expires in the years 2017 through 2031. Teradyne has federal tax credits of $39.1 million, that are attributable to stock-based compensation deductions, which will be recorded as an increase to retained earnings and deferred tax assets upon adoption, in the first quarter of 2017, of ASU 2016-09, “Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting.” Teradyne’s gross unrecognized tax benefits for the years ended December 31, 2016, 2015 and 2014 were as follows: 2016 2015 2014 (in thousands) Beginning balance as of January 1 $ 36,792 $ 30,418 $ 21,203 Additions: Tax positions for current year 9,766 6,626 8,414 Tax positions for prior years 187 792 3,781 Reductions: Expiration of statutes (3,532 ) — — Settlements with tax authorities (2,295 ) (336 ) (500 ) Tax positions for prior years (1,960 ) (708 ) (2,480 ) Ending balance as of December 31 $ 38,958 $ 36,792 $ 30,418 Current year and prior year additions include assessment of potential transfer pricing issues worldwide, federal and state tax credits and incentives, capitalization rules, and domestic production activities deductions. Reductions for tax positions for prior years primarily relate to statute expiration and the settlement tax audits. Of the $39.0 million of unrecognized tax benefits as of December 31, 2016, $27.6 million would impact the consolidated income tax rate if ultimately recognized. The remaining $11.4 million would impact deferred taxes if recognized. Teradyne estimates that it is reasonably possible that the balance of unrecognized tax benefits as of December 31, 2016 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 composed primarily of reserves relating to the U.S. research and development credits. Teradyne records all interest and penalties related to income taxes as a component of income tax expense. Accrued interest and penalties related to income tax items at December 31, 2016 and 2015 amounted to $0.4 million and $0.5 million respectively. For the years ended December 31, 2016, 2015 and 2014, benefit of $0.1 million, benefit of $0.2 million and expense of $0.2 million respectively, was recorded for interest and penalties related to income tax items. Teradyne is subject to U.S. federal income tax, as well as income tax in multiple state, local and foreign jurisdictions. As of December 31, 2016, all material state and local income tax matters have been concluded through 2008, all material federal income tax matters have been concluded through 2012 and all material foreign income tax matters have been concluded through 2009. However, in some jurisdictions, including the United States, operating losses and tax credits may be subject to adjustment until such time as they are utilized and the year of utilization is closed to adjustment. As of December 31, 2016, a deferred tax liability has not been established for approximately $1,020 million of cumulative undistributed earnings of non-U.S.

Operating Segment, Geographic a

Operating Segment, Geographic and Significant Customer Information	12 Months Ended
	Dec. 31, 2016
Operating Segment, Geographic and Significant Customer Information	R. OPERATING SEGMENT, GEOGRAPHIC AND SIGNIFICANT CUSTOMER 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 using several factors, of which the primary financial measure is business segment income (loss) from operations before taxes. The accounting policies of the business segments are the same as those described in Note B: “Accounting Policies.” Segment information for the years ended December 31, 2016, 2015 and 2014 is as follows: Semiconductor Test System Test Industrial Automation Wireless Test Corporate And Eliminations Consolidated (in thousands) 2016 Revenues $ 1,368,169 $ 189,846 $ 99,031 $ 96,204 $ — $ 1,753,250 Income (loss) before taxes (1)(2) 311,939 28,916 (16,783 ) (371,409 ) (7,723 ) (55,060 ) Total assets (3) 557,546 110,361 317,635 62,366 1,714,585 2,762,493 Property additions 70,543 3,788 6,755 4,186 — 85,272 Depreciation and amortization expense 58,087 6,551 26,869 25,921 2,581 120,009 2015 Revenues $ 1,201,530 $ 211,584 $ 41,892 $ 184,572 $ — $ 1,639,578 Income (loss) before taxes (1)(2) 260,154 25,101 (7,574 ) (13,830 ) (10,727 ) 253,124 Total assets (3) 610,869 102,547 344,260 427,880 1,063,118 2,548,674 Property additions 79,052 6,228 1,465 3,133 — 89,878 Depreciation and amortization expense 64,415 4,391 14,500 53,440 4,027 140,773 2014 Revenues $ 1,300,790 $ 162,499 $ — $ 184,535 $ — $ 1,647,824 Income (loss) before taxes (1)(2) 255,803 12,116 — (116,196 ) (56,347 ) 95,376 Total assets (3) 580,501 95,105 — 478,974 1,383,940 2,538,520 Property additions 159,783 5,469 — 3,730 — 168,982 Depreciation and amortization expense 84,990 5,399 — 53,308 8,847 152,544 (1) Interest income, interest expense, other (income) expense, net, contingent consideration adjustments and pension and postretirement plans actuarial gains and losses are included in Corporate and Eliminations. (2) Included in income (loss) before taxes are charges and credits related to restructuring and other, inventory charges, goodwill impairment charges and acquired intangible assets impairment charge. (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 in the following accounts: For the Year Ended December 31, 2016 2015 2014 (in thousands) Cost of revenues—inventory charge $ 9,656 $ 10,508 $ 14,389 Restructuring and other 2,860 499 490 Included in the System Test segment are charges in the following accounts: For the Year Ended December 31, 2016 2015 2014 (in thousands) Cost of revenues—inventory charge $ 630 $ 8,324 $ 2,125 Restructuring and other (49 ) 1,037 742 Included in the Industrial Automation segment are charges in the following accounts: For the Year Ended December 31, 2016 2015 2014 (in thousands) Restructuring and other $ 585 $ — $ — Cost of revenues-inventory step-up — 1,567 — (1) Included in the cost of revenues for the year ended December 31, 2015 is the cost for purchase accounting inventory step-up. Included in the Wireless Test segment are charges in the following accounts: For the Year Ended December 31, 2016 2015 2014 (in thousands) Goodwill impairment charge $ 254,946 $ — $ 98,897 Acquired intangible assets impairment charge 83,339 — — Cost of revenues—inventory charge 7,207 2,500 5,679 Restructuring and other 2,650 — 565 Included in the Corporate and Eliminations segment are charges and credits in the following accounts: For the Year Ended December 31, 2016 2015 2014 (in thousands) Restructuring and other—Universal Robots contingent consideration adjustment $ 15,346 $ 5,339 $ — Restructuring and other—Impairment of fixed assets and expenses related to Japan Earthquake 5,363 — — Restructuring and other—Property insurance recovery (5,363 ) — — Restructuring and other—ZTEC contingent consideration adjustment — (1,600 ) (630 ) Restructuring and other—AIT contingent consideration adjustment 550 (1,250 ) — Restructuring and other—Acquisition costs — 1,104 372 Restructuring and other — — 198 Other (income) expense, net—Gain from the sale of an equity investment — (5,406 ) — Selling and administrative—Stock based compensation expense (1) — — 6,598 Total $ 15,896 $ (1,813 ) $ 6,538 (1) Expense related to the January 2014 retirement of Teradyne’s former chief executive officer; see Note O: “Stock-Based Compensation.” Information as to Teradyne’s revenues by country is as follows: 2016 2015 2014 (in thousands) Revenues from customers (1): Taiwan $ 653,076 $ 436,389 $ 495,942 United States 221,948 217,386 213,104 China 174,876 264,898 292,145 Korea 147,882 120,224 145,608 Japan 135,978 128,228 63,761 Europe 117,671 111,903 111,043 Malaysia 103,472 76,707 83,910 Singapore 73,172 105,216 119,421 Philippines 54,705 96,103 68,662 Thailand 43,097 59,104 44,117 Rest of the World 27,373 23,420 10,111 $ 1,753,250 $ 1,639,578 $ 1,647,824 (1) Revenues attributable to a country are based on location of customer site. In 2016, two customers of Teradyne’s Semiconductor Test segment each accounted for 12% of total consolidated revenues. In 2015, one customer of Teradyne’s Semiconductor Test segment accounted for 13% of total consolidated revenues. In 2014, no single customer accounted for more than 10% of total consolidated revenues. Teradyne estimates product demand driven by a single OEM customer, combining direct sales to that customer with sales to the customer’s outsourced semiconductor assembly and test providers (“OSATs”), accounted for approximately 25%, 23%, and 22% of Teradyne’s consolidated revenues in 2016, 2015 and 2014, respectively. Long-lived assets by geographic area: United States Foreign(1) Total (in thousands) December 31, 2016 $ 189,195 $ 64,626 $ 253,821 December 31, 2015 $ 198,424 $ 74,990 $ 273,414 (1) As of December 31, 2016 and 2015, long-lived assets attributable to Singapore were $31.5 million and $39.9 million, respectively.

Stock Repurchase Program

Stock Repurchase Program	12 Months Ended
	Dec. 31, 2016
Stock Repurchase Program	S. STOCK REPURCHASE PROGRAM In January 2015, the Board of Directors cancelled the November 2010 stock repurchase program and authorized a new stock repurchase program for up to $500 million of common stock. The cumulative repurchases as of December 31, 2016 totaled 22.5 million shares of common stock for $446 million at an average price per share of $19.87. The total price includes commissions and is recorded as a reduction to retained earnings. In December 2016, the Board of Directors approved a new $500 million share repurchase authorization which commenced on January 1, 2017. Teradyne intends to repurchase at least $200 million in 2017. Teradyne’s January 2015 stock repurchase program was terminated on December 31, 2016.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2016
Subsequent Events	T. SUBSEQUENT EVENTS In January 2017, Teradyne’s Board of Directors declared a quarterly cash dividend of $0.07 per share to be paid on March 20, 2017 to shareholders of record as of February 24, 2017. 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.

Supplementary Information

Supplementary Information	12 Months Ended
	Dec. 31, 2016
Supplementary Information	SUPPLEMENTARY INFORMATION (Unaudited) The following sets forth certain unaudited consolidated quarterly statements of operations data for each of Teradyne’s last eight quarters. In management’s opinion, this quarterly information reflects all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement for the periods presented. Such quarterly results are not necessarily indicative of future results of operations and should be read in conjunction with the audited consolidated financial statements of Teradyne and the notes thereto included elsewhere herein. 2016 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter (1)(5) (2)(5) (3)(5) (4)(5) (in thousands, except per share amounts) Revenues: Products $ 358,139 $ 456,832 $ 334,610 $ 303,667 Services 72,855 74,960 75,865 76,322 Total revenues 430,994 531,792 410,475 379,989 Cost of revenues: Cost of products 167,555 215,795 148,266 127,481 Cost of services 33,107 33,127 34,850 33,502 Total cost of revenues (exclusive of acquired intangible assets amortization shown separately below) 200,662 248,922 183,116 160,983 Gross profit 230,332 282,870 227,359 219,006 Operating expenses: Engineering and development 73,464 76,109 71,400 70,052 Selling and administrative 79,174 81,425 78,794 76,289 Acquired intangible assets amortization 19,994 16,244 8,487 7,923 Acquired intangible assets impairment — 83,339 — — Goodwill impairment — 254,946 — — Restructuring and other 1,587 2,608 12,177 5,570 Total operating expenses 174,219 514,671 170,858 159,834 Income (loss) from operations 56,113 (231,801 ) 56,501 59,172 Non-operating Interest income (1,642 ) (1,666 ) (2,892 ) (3,095 ) Interest expense 710 691 633 1,604 Other (income) expense, net (147 ) (9 ) (921 ) 1,779 Income (loss) before income taxes 57,192 (230,817 ) 59,681 58,884 Income tax provision (benefit) 7,206 (7,271 ) (4,113 ) (7,461 ) Net income (loss) $ 49,986 $ (223,546 ) $ 63,794 $ 66,345 Net income (loss) per common share—basic $ 0.24 $ (1.10 ) $ 0.32 $ 0.33 Net income (loss) per common share—diluted $ 0.24 $ (1.10 ) $ 0.31 $ 0.33 Cash dividend declared per common share $ 0.06 $ 0.06 $ 0.06 $ 0.06 (1) Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration. (2) Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake. (3) Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration. (4) Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration. (5) Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: “Accounting Policies” for a discussion of Teradyne’s accounting policy. 2015 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter (3) (4) (1)(2) (in thousands, except per share amounts) Revenues: Products $ 272,325 $ 437,243 $ 386,488 $ 244,510 Services 70,076 75,496 79,506 73,934 Total revenues 342,401 512,739 465,994 318,444 Cost of revenues: Cost of products 118,996 181,491 170,963 120,322 Cost of services 30,982 32,680 36,405 32,096 Total cost of revenues (exclusive of acquired intangible assets amortization shown separately below) 149,978 214,171 207,368 152,418 Gross profit 192,423 298,568 258,626 166,026 Operating expenses: Engineering and development 71,450 75,832 74,027 70,941 Selling and administrative 72,041 77,073 77,481 79,718 Acquired intangible assets amortization 13,808 15,258 20,053 19,911 Restructuring and other — (385 ) 261 5,204 Total operating expenses 157,299 167,778 171,822 175,774 Income (loss) from operations 35,124 130,790 86,804 (9,748 ) Non-operating Interest income (1,816 ) (1,674 ) (1,708 ) (2,017 ) Interest expense 162 444 508 762 Other (income) expense, net (5,660 ) (116 ) 596 364 Income (loss) before income taxes 42,438 132,136 87,408 (8,857 ) Income tax provision (benefit) 9,651 29,257 15,955 (8,216 ) Net income (loss) $ 32,787 $ 102,879 $ 71,453 $ (641 ) Net income (loss) per common share—basic $ 0.15 $ 0.48 $ 0.34 $ (0.00 ) Net income (loss) per common share—diluted $ 0.15 $ 0.48 $ 0.34 $ (0.00 ) Cash dividend declared per common share $ 0.06 $ 0.06 $ 0.06 $ 0.06 (1) Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration. (2) In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: “Accounting Policies” for a discussion of Teradyne’s accounting policy. (3) Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration. (4) Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.

Valuation and Qualifying Accoun

Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2016
Valuation and Qualifying Accounts	TERADYNE, INC. SCHEDULE II—VALUATION AND QUALIFYING ACCOUNTS Column A Column B Column C Column D Column E Column F Description Balance at Beginning of Period Additions Charged to Cost and Expenses Other Deductions Balance at End of Period (in thousands) Valuation reserve deducted in the balance sheet from the asset to which it applies: Accounts receivable: 2016 Allowance for doubtful accounts $ 2,407 $ — $ — $ 51 $ 2,356 2015 Allowance for doubtful accounts $ 2,491 $ — $ — $ 84 $ 2,407 2014 Allowance for doubtful accounts $ 2,912 $ 55 $ — $ 476 $ 2,491 Column A Column B Column C Column D Column E Column F Description Balance at Beginning of Period Additions Charged to Cost and Expenses Other Deductions Balance at End of Period (in thousands) Valuation reserve deducted in the balance sheet from the asset to which it applies: Inventory: 2016 Inventory reserve $ 119,376 $ 17,493 $ 4,417 $ 25,270 $ 116,016 2015 Inventory reserve $ 111,252 $ 21,332 $ 1,680 $ 14,888 $ 119,376 2014 Inventory reserve $ 115,857 $ 22,193 $ 7,064 $ 33,862 $ 111,252 Column A Column B Column C Column D Column E Column F Description Balance at Beginning of Period Additions Charged to Cost and Expenses Other Deductions Balance at End of Period (in thousands) Valuation reserve deducted in the balance sheet from the asset to which it applies: Deferred taxes: 2016 Valuation allowance $ 43,039 $ 5,413 $ — $ 83 $ 48,369 2015 Valuation allowance $ 41,737 $ 1,322 $ — $ 20 $ 43,039 2014 Valuation allowance $ 40,386 $ 1,380 $ — $ 29 $ 41,737

Accounting Policies (Policies)

Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2016
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 reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent liabilities. On an on-going
Revenue Recognition	Revenue Recognition Teradyne recognizes revenues, including revenues from distributors, when there is persuasive evidence of an arrangement, title and risk of loss have passed, delivery has occurred or the services have been rendered, the sales price is fixed or determinable and collection of the related receivable is reasonably assured. Title and risk of loss generally pass to Teradyne’s customers upon shipment or at delivery destination point. In circumstances where either title or risk of loss pass upon destination, acceptance or cash payment, Teradyne defers revenue recognition until such events occur except when title transfer is tied to cash payment outside the United States. Outside the United States, Teradyne recognizes revenue upon shipment or at delivery destination point, even if Teradyne retains a form of title to products delivered to customers, provided the sole purpose is to enable Teradyne to recover the products in the event of customer payment default and the arrangement does not prohibit the customer’s use or resale of the product in the ordinary course of business. Teradyne’s equipment has non-software For multiple element arrangements, Teradyne allocates revenue to all deliverables based on their relative selling prices. In such circumstances, a hierarchy is used to determine the selling price for allocating revenue to deliverables as follows: (i) vendor-specific objective evidence of selling price (“VSOE”), (ii) third-party evidence of selling price (“TPE”), and (iii) best estimate of the selling price (“BESP”). For a delivered item to be considered a separate unit the delivered item must have value to the customer on a standalone basis and the delivery or performance of the undelivered item must be considered probable and substantially in Teradyne’s control. Teradyne’s post-shipment obligations include installation, training services, one-year 605-20, Separately Priced Extended Warranty and Product Maintenance Contracts 605-25, Revenue Recognition Multiple-Element Arrangements. Teradyne’s products are generally subject to warranty and related costs of the warranty are provided for in cost of revenues when product revenue is recognized. Teradyne classifies shipping and handling costs in cost of revenue. Teradyne does not provide its customers with contractual rights of return for any of its products. As of December 31, 2016 and 2015, deferred revenue and customer advances consisted of the following and are included in the short and long-term deferred revenue and customer advances: 2016 2015 (in thousands) Extended warranty $ 46,753 $ 46,499 Equipment maintenance and training 39,037 30,616 Customer advances, undelivered elements and other 22,151 34,157 Total deferred revenue and customer advances $ 107,941 $ 111,272
Product Warranty	Product Warranty Teradyne generally provides a one-year Amount (in thousands) Balance at December 31, 2013 $ 6,660 Accruals for warranties issued during the period 15,406 Accruals related to pre-existing (2,008 ) Settlements made during the period (11,116 ) Balance at December 31, 2014 8,942 Acquisition 409 Accruals for warranties issued during the period 11,539 Accruals related to pre-existing (3,159 ) Settlements made during the period (10,806 ) Balance at December 31, 2015 6,925 Accruals for warranties issued during the period 14,291 Accruals related to pre-existing (1,354 ) Settlements made during the period (12,659 ) Balance at December 31, 2016 $ 7,203 When Teradyne receives revenue for extended warranties, beyond one year, it is deferred and recognized on a straight-line basis over the contract period. Related costs are expensed as incurred. The balance below is included in short and long-term deferred revenue and customer advances: Amount (in thousands) Balance at December 31, 2013 $ 34,909 Deferral of new extended warranty revenue 29,519 Recognition of extended warranty deferred revenue (21,128 ) Balance at December 31, 2014 43,300 Acquisition 870 Deferral of new extended warranty revenue 28,549 Recognition of extended warranty deferred revenue (26,220 ) Balance at December 31, 2015 46,499 Deferral of new extended warranty revenue 27,182 Recognition of extended warranty deferred revenue (26,928 ) Balance at December 31, 2016 $ 46,753
Accounts Receivable and Allowance for Doubtful Accounts	Accounts Receivable and Allowance for Doubtful Accounts Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The volatility of the industries that Teradyne serves can cause certain of its customers to experience shortages of cash flows, which can impact their ability to make required payments. Teradyne maintains allowances for doubtful accounts for estimated losses resulting from the inability of its customers to make required payments. Estimated allowances for doubtful accounts are reviewed periodically taking into account the customer’s recent payment history, the customer’s current financial statements and other information regarding the customer’s credit worthiness. Account balances are written off against the allowance when it is determined the receivable will not be recovered.
Inventories	Inventories Inventories are stated at the lower of cost (first-in, first-out
Investments	Investments 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 • 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. As defined in ASC 820-10, Fair Value Measurements and Disclosures, ASC 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 therefore is considered a Level 2 input. 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. In accordance with ASC 820-10,
Prepayments	Prepayments Prepayments consist of the following and are included in prepayments on the balance sheet: 2016 2015 (in thousands) Contract manufacturer prepayments $ 77,017 $ 66,283 Prepaid maintenance and other services 7,676 8,481 Prepaid taxes 4,664 3,781 Other prepayments 19,097 12,974 Total prepayments $ 108,454 $ 91,519
Retirement and Postretirement Plans	Retirement and Postretirement Plans Teradyne recognizes net actuarial gains and losses and the change in the fair value of the plan assets in its operating results in the year in which they occur or upon any interim remeasurement of the plans. Teradyne calculates the expected return on plan assets using the fair value of the plan assets. Actuarial gains and losses are generally measured annually as of December 31 and, accordingly, recorded during the fourth quarter of each year or upon any interim remeasurement of the plans.
Goodwill, Intangible and Long-Lived Assets	Goodwill, Intangible and Long-Lived Assets Teradyne accounts for goodwill and intangible assets in accordance with ASC 350-10, Intangibles-Goodwill and Other. 350-10, more-likely-than-not two-step more-likely-than-not two-step In accordance with ASC 360-10, Impairment or Disposal of Long-Lived Assets,
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment are stated at cost and depreciated over the estimated useful lives of the assets. Leasehold improvements and major renewals are capitalized and included in property, plant and equipment accounts while expenditures for maintenance and repairs and minor renewals are charged to expense. When assets are retired, the assets and related accumulated depreciation are removed from the accounts and any resulting gain or loss is reflected in the consolidated statements of operations. Teradyne provides for depreciation of its assets principally on the straight-line method with the cost of the assets being charged to expense over their useful lives as follows: Buildings 40 years Building improvements 5 to 10 years Leasehold improvements Lesser of lease term or 10 years Furniture and fixtures 10 years Test systems manufactured internally 6 years Machinery and equipment 3 to 5 years Software 3 to 5 years Test systems manufactured internally are used by Teradyne for customer evaluations and manufacturing and support of its customers. Teradyne depreciates the test systems manufactured internally over a six-year
Engineering and Development Costs	Engineering and Development Costs Teradyne’s products are highly technical in nature and require a large and continuing engineering and development effort. Software development costs incurred prior to the establishment of technological feasibility are charged to expense. Software development costs incurred subsequent to the establishment of technological feasibility are capitalized until the product is available for release to customers. To date, the period between achieving technological feasibility and general availability of the product has been short and software development costs eligible for capitalization have not been material. Engineering and development costs are expensed as incurred and consist primarily of salaries, contractor fees, including non-recurring
Stock Compensation Plans and Employee Stock Purchase Plan	Stock Compensation Plans and Employee Stock Purchase Plan Stock-based compensation expense is based on the grant-date fair value estimated in accordance with the provisions of ASC 718-10, Compensation-Stock Compensation 718-10, Under its stock compensation plans, Teradyne has granted 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”).
Income Taxes	Income Taxes Deferred tax assets and liabilities are determined based on differences between financial reporting and tax basis of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. The measurement of deferred tax assets is reduced by a valuation allowance if it is more likely than not that some or all of the deferred tax assets will not be realized. Teradyne performed the required assessment of positive and negative evidence regarding the realization of the net deferred tax assets in accordance with ASC 740, “Accounting for Income Taxes.” tax-planning non-U.S. non-equity with-and-without
Advertising Costs	Advertising Costs Teradyne expenses all advertising costs as incurred. Advertising costs were $6.4 million, $3.3 million and $1.9 million in 2016, 2015 and 2014, respectively.
Translation of Non-U.S. Currencies	Translation of Non-U.S. The functional currency for all subsidiaries is the U.S. dollar, except for the Industrial Automation segment for which the local currency is its functional currency. All foreign currency denominated monetary assets and liabilities are remeasured on a monthly basis into the functional currency using exchange rates in effect at the end of the period. All foreign currency denominated non-monetary Net foreign exchange gains and losses resulting from remeasurement are included in other (income) expense, net. For the years ended December 31, 2016 and 2015, gains from the remeasurement of the monetary assets and liabilities denominated in foreign currencies were $8.0 million and $2.5 million, respectively. For the year ended December 31, 2014, losses from the remeasurement of the monetary assets and liabilities denominated in foreign currencies were $0.9 million. These amounts do not reflect the corresponding gains (losses) from foreign exchange contracts. See Note G: “Financial Instruments” regarding foreign exchange contracts.
Net Income (Loss) per Common Share	Net Income (Loss) per Common Share Basic net (loss) income per common share is calculated by dividing net (loss) income by the weighted average number of common shares outstanding during the period. Except where the result would be antidilutive, diluted net (loss) income per common share is calculated by dividing net (loss) income by the sum of the weighted average number of common shares plus common stock equivalents, if applicable. For the year ended December 31, 2014, dilutive potential common shares included incremental shares from the assumed conversion of the convertible notes and the convertible notes hedge warrant shares. Incremental shares from the assumed conversion of the convertible notes were calculated using the difference between the average Teradyne stock price for the period and the conversion price of $5.48, multiplied by 34.7 million shares. The result of this calculation, representing the total intrinsic value of the convertible debt, was divided by the average Teradyne stock price for the period. Convertible notes hedge warrant shares were calculated using the difference between the average Teradyne stock price for the period and the warrant price of $7.67, multiplied by 34.7 million shares. The result of this calculation, representing the total intrinsic value of the warrant, was divided by the average Teradyne stock price for the period. Teradyne’s call option for 34.7 million shares at an exercise price of $5.48 was not used in the GAAP earnings per share calculation as its effect was anti-dilutive. In 2014, Teradyne settled its conversion spread (i.e., the intrinsic value of the embedded option feature contained in the convertible debt) in shares. Teradyne accounted for its conversion spread using the treasury stock method. Teradyne determined that it had the ability and intent to settle the principal amount of the convertible debt in cash; accordingly, the principal amount was excluded from the determination of diluted earnings per share. With respect to its convertible debt issued in 2016, Teradyne has determined that it has the ability and intent to settle the principal of the convertible debt in cash; accordingly, the principal amount is excluded from the determination of diluted earnings per share. As a result, Teradyne is accounting for the conversion spread using the treasury stock method.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) includes net income, unrealized pension and postretirement prior service costs and benefits, unrealized gains and losses on investments in debt and equity marketable securities and foreign currency translation adjustment.

Accounting Policies (Tables)

Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2016
Deferred Revenue and Customer Advances	As of December 31, 2016 and 2015, deferred revenue and customer advances consisted of the following and are included in the short and long-term deferred revenue and customer advances: 2016 2015 (in thousands) Extended warranty $ 46,753 $ 46,499 Equipment maintenance and training 39,037 30,616 Customer advances, undelivered elements and other 22,151 34,157 Total deferred revenue and customer advances $ 107,941 $ 111,272
Warranty Accrual Included in Other Accrued Liabilities	The balance below is included in other accrued liabilities: Amount (in thousands) Balance at December 31, 2013 $ 6,660 Accruals for warranties issued during the period 15,406 Accruals related to pre-existing (2,008 ) Settlements made during the period (11,116 ) Balance at December 31, 2014 8,942 Acquisition 409 Accruals for warranties issued during the period 11,539 Accruals related to pre-existing (3,159 ) Settlements made during the period (10,806 ) Balance at December 31, 2015 6,925 Accruals for warranties issued during the period 14,291 Accruals related to pre-existing (1,354 ) Settlements made during the period (12,659 ) Balance at December 31, 2016 $ 7,203
Extended Product Warranty Included in Short and Long-Term Deferred Revenue and Customer Advances	The balance below is included in short and long-term deferred revenue and customer advances: Amount (in thousands) Balance at December 31, 2013 $ 34,909 Deferral of new extended warranty revenue 29,519 Recognition of extended warranty deferred revenue (21,128 ) Balance at December 31, 2014 43,300 Acquisition 870 Deferral of new extended warranty revenue 28,549 Recognition of extended warranty deferred revenue (26,220 ) Balance at December 31, 2015 46,499 Deferral of new extended warranty revenue 27,182 Recognition of extended warranty deferred revenue (26,928 ) Balance at December 31, 2016 $ 46,753
Schedule of Prepayments	Prepayments consist of the following and are included in prepayments on the balance sheet: 2016 2015 (in thousands) Contract manufacturer prepayments $ 77,017 $ 66,283 Prepaid maintenance and other services 7,676 8,481 Prepaid taxes 4,664 3,781 Other prepayments 19,097 12,974 Total prepayments $ 108,454 $ 91,519
Useful Lives of Assets	Teradyne provides for depreciation of its assets principally on the straight-line method with the cost of the assets being charged to expense over their useful lives as follows: Buildings 40 years Building improvements 5 to 10 years Leasehold improvements Lesser of lease term or 10 years Furniture and fixtures 10 years Test systems manufactured internally 6 years Machinery and equipment 3 to 5 years Software 3 to 5 years

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2016
Universal Robots
Final Allocation of Purchase Price	The following table represents the final allocation of the purchase price: Purchase Price Allocation (in thousands) Goodwill $ 221,128 Intangible assets 121,590 Tangible assets acquired and liabilities assumed: Current assets 10,853 Non-current 3,415 Accounts payable and current liabilities (11,976 ) Long-term deferred tax liabilities (26,653 ) Long-term other liabilities (2,920 ) Total purchase price $ 315,437
Components of Intangible Assets and Their Estimated Useful Lives at Acquisition Date	Components of these intangible assets and their estimated useful lives at the acquisition date are as follows: Fair Value Estimated Useful (in thousands) (in years) Developed technology $ 89,240 4.9 Trademarks and tradenames 22,920 10.0 Customer relationships 9,430 2.0 Total intangible assets $ 121,590 5.6
Pro Forma Results Under Acquisitions	The unaudited pro forma results are not necessarily indicative of what actually would have occurred had the acquisition been in effect for the periods presented: For the Year Ended December 31, 2014 (in thousands, except per share amounts) Revenues $ 1,655,038 Net income $ 82,169 Income per common share: Basic $ 0.40 Diluted $ 0.37
Avionics Interface Technologies, LLC
Final Allocation of Purchase Price	The following represents the final allocation of the purchase price: Purchase Price Allocation (in thousands) Goodwill $ 10,516 Intangible assets 9,080 Tangible assets acquired and liabilities assumed: Current assets 2,452 Non-current 359 Accounts payable and current liabilities (1,164 ) Total purchase price $ 21,243
Components of Intangible Assets and Their Estimated Useful Lives at Acquisition Date	Components of these intangible assets and their estimated useful lives at the acquisition date are as follows: Fair Value Estimated Useful (in thousands) (in years) Customer relationships $ 5,630 5.0 Developed technology 2,580 4.8 Trademarks and tradenames 380 5.0 Non-compete 320 4.0 Customer order backlog 170 0.3 Total intangible assets $ 9,080 4.8
Pro Forma Results Under Acquisitions	The unaudited pro forma results are not necessarily indicative of what actually would have occurred had the acquisition been in effect for the periods presented: For the Years Ended December 31, December 31, (in thousands, except per Revenue $ 1,657,626 $ 1,686,689 Net income $ 199,784 $ 61,078 Net income per common share: Basic $ 0.94 $ 0.30 Diluted $ 0.94 $ 0.27

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2016
Composition of Inventories, Net	Inventories, net consisted of the following at December 31, 2016 and 2015: 2016 2015 (in thousands) Raw material $ 58,530 $ 73,117 Work-in-process 22,946 32,825 Finished goods 54,482 47,646 $ 135,958 $ 153,588

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2016
Property Plant and Equipment, Net	Property, plant and equipment, net consisted of the following at December 31, 2016 and 2015: 2016 2015 (in thousands) Land $ 16,561 $ 16,561 Buildings 98,031 108,797 Machinery and equipment 601,835 595,445 Furniture and fixtures, and software 82,897 82,612 Leasehold improvements 46,612 43,328 Construction in progress 3,032 2,630 848,968 849,373 Less: accumulated depreciation 595,147 575,959 $ 253,821 $ 273,414

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2016
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 December 31, 2016 and 2015: 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 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 current liabilities $ — $ 131 $ — $ 131 Contingent consideration — — 1,050 1,050 Long-term contingent consideration — — 37,282 37,282 $ — $ 131 $ 38,332 $ 38,463 December 31, 2015 Quoted Prices in Active Markets for Identical Instruments (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Total (in thousands) Assets Cash $ 213,336 $ — $ — $ 213,336 Cash equivalents 49,241 2,128 — 51,369 Available-for-sale U.S. Treasury securities — 419,958 — 419,958 Corporate debt securities — 161,634 — 161,634 U.S. government agency securities — 83,952 — 83,952 Certificates of deposit and time deposits — 43,394 — 43,394 Commercial paper — 20,308 — 20,308 Equity and debt mutual funds 13,954 — — 13,954 Non-U.S. — 424 — 424 Total $ 276,531 $ 731,798 $ — $ 1,008,329 Derivative assets — 109 — 109 Total $ 276,531 $ 731,907 $ — $ 1,008,438 Liabilities Contingent consideration $ — $ — $ 37,436 $ 37,436 Derivative liabilities — 146 — 146 Total $ — $ 146 $ 37,436 $ 37,582 Reported as follows: (Level 1) (Level 2) (Level 3) Total (in thousands) Assets Cash and cash equivalents $ 262,577 $ 2,128 $ — $ 264,705 Marketable securities — 477,696 — 477,696 Long-term marketable securities 13,954 251,974 — 265,928 Prepayments — 109 — 109 $ 276,531 $ 731,907 $ — $ 1,008,438 Liabilities Other current liabilities $ — $ 146 $ — $ 146 Contingent consideration — — 15,500 15,500 Long-term contingent consideration — — 21,936 21,936 $ — $ 146 $ 37,436 $ 37,582
Schedule of Changes in Fair Value of Level 3 Contingent Consideration	Changes in the fair value of Level 3 contingent consideration for the years ended December 31, 2016 and 2015 were as follows: Contingent Consideration (in thousands) Balance at December 31, 2014 $ 3,350 Acquisition of Universal Robots 31,597 Fair value adjustment of Universal Robots (1) 5,339 Fair value adjustment of AIT (2) (1,250 ) Fair value adjustment of ZTEC (3) (1,600 ) Balance at December 31, 2015 37,436 Payments (4) (15,000 ) Fair value adjustment of AIT (5) 550 Fair value adjustment of Universal Robots (5) 15,346 Balance at December 31, 2016 $ 38,332 (1) During the year ended December 31, 2015, the fair value of contingent consideration for the earn-out (2) During the year ended December 31, 2015, the fair value of contingent consideration for the earn-out (3) During the year ended December 31, 2015, the fair value measurement of the contingent consideration for the earn-out earn-out earn-out (4) During the year ended December 31, 2016, based on Universal Robots’ calendar year 2015 EBITDA results, Teradyne paid $15 million or 100% of the eligible EBITDA contingent consideration amount. (5) During the year ended December 31, 2016, the fair value of contingent consideration for the earn-out 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 instrument: Liability December 31, 2016 Fair Value Valuation Technique Unobservable Inputs Weighted Average (in thousands) Contingent consideration (Universal Robots) $ 21,301 Monte Carlo simulation Revenues for the period July 1, 2015—December 31, 2017 volatility 10.8% Discount Rate 3.3% $15,981 Monte Carlo simulation Revenues for the period July 1, 2015—December 31, 2018 volatility 10.8% Discount Rate 3.3% Contingent consideration (AIT) $ 1,050(1) (1) Teradyne paid this amount in January 2017.
Schedule of Carrying Amounts and Fair Values of Financial Instruments	The carrying amounts and fair values of financial instruments at December 31, 2016 and 2015 were as follows: December 31, 2016 December 31, 2015 Carrying Value Fair Value Carrying Value Fair Value (in thousands) Assets Cash and cash equivalents $ 307,884 $ 307,884 $ 264,705 $ 264,705 Marketable securities 1,304,867 1,304,867 743,624 743,624 Derivative assets 1 1 109 109 Liabilities Contingent consideration 38,332 38,332 37,436 37,436 Derivative liabilities 131 131 146 146 Convertible debt (1) 352,669 486,754 — — (1) The carrying value represents the bifurcated debt component only, while the fair value is based on quoted market prices for the convertible note which includes the equity conversion features.
Schedule of Available-for-Sale Marketable Securities	The following tables summarize the composition of available for sale marketable securities at December 31, 2016 and 2015: December 31, 2016 Available-for-Sale Fair Market Value of Investments with Unrealized Losses Cost Unrealized Gain Unrealized (Loss) Fair Market Value (in thousands) U.S. Treasury securities $ 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 December 31, 2015 Available-for-Sale Fair Market Value of Investments with Unrealized Losses Cost Unrealized Gain Unrealized (Loss) Fair Market Value (in thousands) U.S. Treasury securities $ 421,060 $ 65 $ (1,167 ) $ 419,958 $ 379,434 Corporate debt securities 163,297 902 (2,565 ) 161,634 145,373 U.S. government agency securities 84,032 42 (122 ) 83,952 55,120 Certificates of deposit and time deposits 43,391 6 (3 ) 43,394 10,527 Commercial paper 20,298 11 (1 ) 20,308 8,646 Equity and debt mutual funds 12,996 1,119 (161 ) 13,954 2,560 Non-U.S. 424 — — 424 — $ 745,498 $ 2,145 $ (4,019 ) $ 743,624 $ 601,660 Reported as follows: Cost Unrealized Gain Unrealized (Loss) Fair Market Value Fair Market Value of Investments with Unrealized Losses (in thousands) Marketable securities $ 478,306 $ 38 $ (648 ) $ 477,696 $ 374,785 Long-term marketable securities 267,192 2,107 (3,371 ) 265,928 226,875 $ 745,498 $ 2,145 $ (4,019 ) $ 743,624 $ 601,660
Contractual Maturities of Investments Held	The contractual maturities of investments held at December 31, 2016 were as follows: Cost Fair Value (in thousands) Due within one year $ 871,321 $ 871,024 Due after 1 year through 5 years 365,873 365,451 Due after 5 years through 10 years 12,839 12,309 Due after 10 years 38,173 37,912 Total $ 1,288,206 $ 1,286,696
Non-Financial Assets Measured at Fair Value on Non-Recurring Basis	The following table sets forth by fair value hierarchy Teradyne’s non-financial non-recurring July 3, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Other Unobservable Inputs (Level 3)) Total Total Losses (in thousands) Goodwill (1) $ — $ — $ 7,976 $ 7,976 $ 254,946 Definite lived intangible assets (2) — — 5,750 5,750 83,339 $ — $ — $ 13,726 $ 13,726 $ 338,285 (1) In accordance with the provisions of ASC 350-20, Goodwill (2) In accordance with the provisions of ASC 360-10, “Property, Plant and Equipment,”
Schedule of Notional Amount of Derivatives	At December 31, 2016 and 2015, Teradyne had the following contracts to buy and sell non-U.S. non-U.S. December 31, 2016 December 31, 2015 Buy Position Sell Position Net Total Buy Position Sell Position Net Total (in millions) Japanese Yen $ (17.7 ) $ — $ (17.7 ) $ (51.9 ) $ — $ (51.9 ) Korean Won (8.8 ) — (8.8 ) (5.5 ) — (5.5 ) Taiwan Dollar (6.9 ) — (6.9 ) (5.0 ) — (5.0 ) British Pound Sterling (1.3 ) — (1.3 ) (9.5 ) — (9.5 ) Euro — 25.2 25.2 — 27.2 27.2 Singapore Dollar — 24.0 24.0 — 15.0 15.0 Total $ (34.7 ) $ 49.2 $ 14.5 $ (71.9 ) $ 42.2 $ (29.7 )
Schedule of Derivative Instruments in Statement of Financial Position at Fair Value	The following table summarizes the fair value of derivative instruments as of December 31, 2016 and 2015: Balance Sheet Location December 31, 2016 December 31, 2015 (in thousands) Derivatives not designated as hedging instruments: Foreign exchange contracts Prepayments $ 1 $ 109 Foreign exchange contracts Other current liabilities (131 ) (146 ) Total derivatives $ (130 ) $ (37 )
Schedule of Effect of Derivative Instruments on Statements of Operations Recognized	The following table summarizes the effect of derivative instruments in statements of operations recognized for the years ended December 31, 2016, 2015 and 2014. The table does not reflect the corresponding gains and losses from the remeasurement of the monetary assets and liabilities denominated in foreign currencies. For the years ended December 31, 2016 and 2015, gains from the remeasurement of the monetary assets and liabilities denominated in foreign currencies were $8.0 million and $2.5 million, respectively. For the year ended December 31, 2014, losses from the remeasurement of the monetary assets and liabilities denominated in foreign currencies were $0.9 million. Location of Losses of Operations December 31, 2016 December 31, 2015 December 31, 2014 (in thousands) Derivatives not designated as hedging instruments: Foreign exchange contracts Other (income) expense, net $ 8,671 $ 3,047 $ 237

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2016
Components of Convertible Senior Notes	The below tables represents the key components of Teradyne’s convertible senior notes: December 31, (in thousands) Debt principal $ 460,000 Unamortized discount including debt issuance cost 107,331 Net carrying amount of convertible debt $ 352,669 For the year ended (in thousands) Contractual interest expense on the coupon $ 303 Amortization of the discount component and debt issue fees recognized as interest expense 688 Total interest expense on the convertible debt $ 991

Accumulated Other Comprehensi39

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2016
Changes in accumulated other comprehensive income (loss)	Changes in accumulated other comprehensive income (loss), which is presented net of tax, consists of the following: Foreign Currency Translation Adjustment Unrealized Gains (Losses) on Marketable Securities Retirement Plans Prior Service Credit Total (in thousands) Balance at December 31, 2014, net of tax of $1,598, $(453) $ — $ 2,365 $ 2,324 $ 4,689 Other comprehensive loss before reclassifications, net of tax of $0, $(1,667) (8,759 ) (3,075 ) — (11,834 ) Amounts reclassified from accumulated other comprehensive income, net of tax of $(390), $(169) — (704 ) (295 ) (999 ) Net current period other comprehensive loss, net of tax of $0, $(2,057), $(169) (8,759 ) (3,779 ) (295 ) (12,833 ) Balance at December 31, 2015, net of tax of $0, $(459), $(622) $ (8,759 ) $ (1,414 ) $ 2,029 $ (8,144 ) Other comprehensive (loss) income before reclassifications, net of tax of $0, $923, $34 (13,162 ) 2,037 59 (11,125 ) Amounts reclassified from accumulated other comprehensive income, net of tax of $(255), $(190) — (683 ) (321 ) (945 ) Net current period other comprehensive (loss) income, net of tax of $0, $668, $(156) (13,162 ) 1,354 (262 ) (12,070 ) Balance at December 31, 2016, net of tax of $0, $209, $(778) $ (21,921 ) $ (60 ) $ 1,767 $ (20,214 )
Reclassifications Out of Accumulated Other Comprehensive Income to Statements of Operations	Reclassifications out of accumulated other comprehensive income to the statements of operations for the years ended December 31, 2016, 2015 and 2014, were as follows: Details about Accumulated Other Comprehensive Income Components For the year ended Affected Line Item in the Statements of Operations December 31, 2016 December 31, 2015 December 31, 2014 (in thousands) Available-for-sale Unrealized gains, net of tax of $255, $390, $645 $ 683 $ 704 $ 1,433 Interest income Defined benefit pension and postretirement plans: Amortization of prior service credit, net of tax of $190, $169, $169 321 295 295 (1) Prior service income arising during period, net of tax of $(34), $0, $0 (59 ) — — 262 295 295 Total reclassifications, net of tax of $411, $559, $814 $ 945 $ 999 $ 1,728 Net income (1) The amortization of prior service credit is included in the computation of net periodic pension cost and postretirement benefit; see Note N: “Retirement Plans.”

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2016
Changes in Carrying Amount of Goodwill by Segment	The changes in the carrying amount of goodwill by reportable segments for the years ended December 31, 2016 and 2015 are as follows: Industrial Automation System Test Wireless Test Semiconductor Test Total (in thousands) Balance at December 31, 2014: Goodwill $ — $ 158,699 $ 361,819 $ 260,540 $ 781,058 Accumulated impairment losses — (148,183 ) (98,897 ) (260,540 ) (507,620 ) — 10,516 262,922 — 273,438 Universal Robots acquisition 221,128 — — — 221,128 Foreign currency translation adjustment (6,153 ) — — — (6,153 ) Balance at December 31, 2015: Goodwill 214,975 158,699 361,819 260,540 996,033 Accumulated impairment losses — (148,183 ) (98,897 ) (260,540 ) (507,620 ) 214,975 10,516 262,922 — 488,413 Foreign currency translation adjustment (10,124 ) — — — (10,124 ) Goodwill impairment losses — — (254,946 ) — (254,946 ) 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
Schedule of Amortizable Intangible Assets	Amortizable intangible assets consist of the following and are included in intangible assets, net on the balance sheets: December 31, 2016 Gross Carrying Amount (1) Accumulated Amortization (1)(2) Foreign Net Carrying Amount Weighted Average Useful Life (in thousands) Developed technology $ 270,877 $ 206,376 $ (5,093 ) $ 59,408 6.0 years Customer relationships 92,741 76,707 (538 ) 15,496 7.9 years Tradenames and trademarks 50,100 23,435 (1,308 ) 25,357 9.5 years Non-compete 320 180 — 140 4.0 years Customer backlog 170 170 — — 0.3 years Total intangible assets $ 414,208 $ 306,868 $ (6,939 ) $ 100,401 6.8 years (1) During the year ended December 31, 2016, Teradyne recorded an $83.3 million impairment of Wireless Test amortizable intangible assets. The impairment assets have been eliminated from the gross carrying amount and accumulated amortization. (2) In 2016, $48.1 million of amortizable intangible assets became fully amortized and has been eliminated from the gross carrying amount and accumulated amortization. December 31, 2015 Gross Carrying Amount Accumulated Amortization (1)(2) Foreign Net Carrying Amount Weighted Average Useful Life (in thousands) Developed technology $ 382,262 $ 220,346 $ (2,444 ) $ 159,472 6.0 years Customer relationships 110,602 63,722 (258 ) 46,622 7.9 years Tradenames and trademarks 53,034 18,889 (628 ) 33,517 9.5 years Non-compete 320 100 — 220 4.0 years Customer backlog 170 170 — — 0.3 years Total intangible assets $ 546,388 $ 303,227 $ (3,330 ) $ 239,831 6.7 years (1) During the year ended December 31, 2015, Teradyne recorded intangible assets in the amount of $121.6 million related to its Universal Robots acquisition. (2) During the year ended December 31, 2015, Teradyne wrote off $98.2 million of fully amortized intangible assets.
Schedule of Estimated Intangible Assets Amortization Expense	Estimated intangible assets amortization expense for each of the five succeeding fiscal years is as follows: Year Amortization Expense (in thousands) 2017 $ 28,986 2018 26,848 2019 23,037 2020 10,042 2021 3,435 Thereafter 8,053

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2016
Non-Cancelable Operating Lease Commitments	The following table reflects Teradyne’s non-cancelable Non-cancelable (in thousands) 2017 $ 16,467 2018 15,258 2019 13,733 2020 9,374 2021 7,149 Beyond 2022 10,130 Total $ 72,111

Net (loss) Income per Common 42

Net (loss) Income per Common Share (Tables)	12 Months Ended
	Dec. 31, 2016
Computation of Basic and Diluted Net (Loss) Income Per Common Share	The following table sets forth the computation of basic and diluted net (loss) income per common share: 2016 2015 2014 (in thousands, except per share amounts) Net (loss) income for basic and diluted net income per share $ (43,421 ) $ 206,477 $ 81,272 Weighted average common shares-basic 202,578 211,544 202,908 Effect of dilutive potential common shares: Incremental shares from assumed conversion of convertible notes (1) — — 5,013 Convertible note hedge warrant shares (2) — — 12,562 Restricted stock units — 1,130 1,092 Stock options — 606 944 Employee stock purchase rights — 41 31 Dilutive potential common shares — 1,777 19,642 Weighted average common shares-diluted 202,578 213,321 222,550 Net (loss) income per common share-basic $ (0.21 ) $ 0.98 $ 0.40 Net (loss) income per common share-diluted $ (0.21 ) $ 0.97 $ 0.37 (1) Incremental shares from the assumed conversion of the convertible notes was calculated using the difference between the average Teradyne stock price for the period and the conversion price of $5.48, multiplied by 34.7 million shares. The result of this calculation, representing the total intrinsic value of the convertible debt, was divided by the average Teradyne stock price for the period. (2) Convertible notes hedge warrant shares were calculated using the difference between the average Teradyne stock price for the period and the warrant price of $7.67, multiplied by 34.7 million shares. The result of this calculation, representing the total intrinsic value of the warrant, was divided by the average Teradyne stock price for the period. Teradyne’s call option on its common stock (convertible note hedge transaction) was excluded from the calculation of diluted shares because the effect was anti-dilutive.

Retirement Plans (Tables)

Retirement Plans (Tables)	12 Months Ended
	Dec. 31, 2016
Defined Benefit Pension Plans
Defined Benefit Pension and Postretirement Benefit Plan Assets and Obligations	The December 31 balances of these defined benefit pension plans assets and obligations are shown below: 2016 2015 United States Foreign United States Foreign (in thousands) Assets and Obligations Change in benefit obligation: Projected benefit obligation: Beginning of year $ 351,117 $ 62,290 $ 367,619 $ 58,210 Service cost 2,302 761 2,462 1,006 Interest cost 13,630 1,185 13,142 1,444 Actuarial gain (loss) 6,053 5,621 (13,221 ) 7,498 Benefits paid (19,486 ) (1,385 ) (18,885 ) (859 ) Curtailment — — — (634 ) Plan participants’ contributions — — — 64 Expenses paid — (609 ) — — Non-U.S. — (7,125 ) — (4,439 ) End of year 353,616 60,738 351,117 62,290 Change in plan assets: Fair value of plan assets: Beginning of year 298,404 28,141 316,072 29,511 Company contributions 4,489 867 10,517 808 Plan participants’ contributions — — — 64 Actual return on plan assets 23,897 5,142 (9,300 ) (136 ) Benefits paid (19,486 ) (1,148 ) (18,885 ) (859 ) Settlements — — — — Expenses paid — (609 ) — (43 ) Non-U.S. — (4,822 ) — (1,204 ) End of year 307,304 27,571 298,404 28,141 Funded status $ (46,312 ) $ (33,167 ) $ (52,713 ) $ (34,149 )
Amounts Recorded within Statement of Financial Position	The following table provides amounts recorded within the account line items of the statements of financial position as of December 31: 2016 2015 United States Foreign United States Foreign (in thousands) Retirement plans assets $ 7,712 $ — $ 636 $ — Accrued employees’ compensation and withholdings (2,591 ) (772 ) (2,564 ) (695 ) Retirement plans liabilities (51,433 ) (32,395 ) (50,785 ) (33,454 ) Funded status $ (46,312 ) $ (33,167 ) $ (52,713 ) $ (34,149 )
Amounts Recognized in Accumulated Other Comprehensive Income	The following table provides amounts recognized in accumulated other comprehensive income as of December 31: 2016 2015 United States Foreign United States Foreign (in thousands) Prior service cost, before tax $ 127 $ — $ 224 $ — Deferred taxes 514 — 479 — Total recognized in other comprehensive income, net of tax $ 641 $ — $ 703 $ —
Pension Plans with Accumulated Benefit Obligation and Projected Benefit Obligation in Excess of Plan Assets	Information for pension plans with an accumulated benefit obligation in excess of plan assets as of December 31: 2016 2015 United States Foreign United States Foreign (in millions) Projected benefit obligation $ 54.0 $ 34.3 $ 53.3 $ 35.2 Accumulated benefit obligation 48.0 30.1 47.3 29.5 Fair value of plan assets — 1.1 — 1.0
Net Periodic Pension and Postretirement Benefit Costs	For the years ended December 31, 2016, 2015 and 2014, Teradyne’s net periodic pension (income) cost was comprised of the following: 2016 2015 2014 United States Foreign United States Foreign United States Foreign (in thousands) Components of Net Periodic Pension (Income) Cost: Service cost $ 2,302 $ 761 $ 2,462 $ 1,006 $ 2,218 $ 897 Interest cost 13,630 1,185 13,142 1,444 12,875 1,837 Expected return on plan assets (13,830 ) (443 ) (14,517 ) (781 ) (12,500 ) (868 ) Amortization of prior service cost 96 — 134 — 135 — Net actuarial (gain) loss (4,013 ) 815 10,596 8,415 43,168 4,651 Curtailment — — — (634 ) — — Total net periodic pension (income) cost $ (1,815 ) $ 2,318 $ 11,817 $ 9,450 $ 45,896 $ 6,517 Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income: Reversal of amortization items: Prior service cost (96 ) — (134 ) — (135 ) — Total recognized in other comprehensive income (96 ) — (134 ) — (135 ) — Total recognized in net periodic pension (income) cost and other comprehensive income $ (1,911 ) $ 2,318 $ 11,683 $ 9,450 $ 45,761 $ 6,517
Weighted Average Assumptions to Determine Net Periodic Cost and Benefit Obligation	Weighted Average Assumptions to Determine Net Periodic Pension Cost at January 1: 2016 2015 2014 United States Foreign United States Foreign United States Foreign Discount rate 4.0 % 2.3 % 3.7 % 2.6 % 4.5 % 3.8 % Expected return on plan assets 4.8 2.0 4.8 2.6 5.0 3.4 Salary progression rate 2.7 3.2 2.9 3.2 3.0 3.5 Weighted Average Assumptions to Determine Pension Obligations at December 31 : 2016 2015 United States Foreign United States Foreign Discount rate 3.9 % 1.8 % 4.0 % 2.3 % Salary progression rate 2.6 2.7 2.7 3.2
Weighted Average Pension Asset Allocations by Category	The following table provides weighted average pension asset allocation by asset category at December 31, 2016 and 2015: 2016 2015 United States Foreign United States Foreign Fixed income securities 88.1 % — % 88.6 % — % Equity securities 9.9 — 9.8 — Other 2.0 100.0 1.6 100.0 100.0 % 100.0 % 100.0 % 100.0 %
Target Asset Allocation and Index for Each Asset Category	The target asset allocation and the index for each asset category for the U.S. Plan, per the investment policy, are as follows: Asset Category: Policy Index: Target Allocation U.S. corporate fixed income Barclays U.S. Corporate A or Better Index 76 % Global equity MSCI World Minimum Volatility Index 10 U.S. government fixed income Barclays U.S. Long Government Bond Index 8 High yield fixed income Barclays U.S. Corporate High Yield 2% Issuer Cap Index 5 Cash Citigroup Three Month U.S. Treasury Bill Index 1
Changes in Fair Value of Pension Assets	The fair value of pension plan assets by asset category and by level at December 31, 2016 and December 31, 2015 were as follows: December 31, 2016 United States Foreign Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (in thousands) Fixed income securities: Corporate debt securities $ — $ 246,528 $ — $ 246,528 $ — $ — $ — $ — U.S. government securities — 24,322 — 24,322 — — — — Global equity — 30,360 — 30,360 — — — — Group annuity insurance contracts — — 3,071 3,071 — — 26,385 26,385 Other — — — — — 1,124 — 1,124 Cash and cash equivalents 3,023 — — 3,023 62 — — 62 Total $ 3,023 $ 301,210 $ 3,071 $ 307,304 $ 62 $ 1,124 $ 26,385 $ 27,571 December 31, 2015 United States Foreign Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total (in thousands) Fixed income securities: Corporate debt securities $ — $ 240,695 $ — $ 240,695 $ — $ — $ — $ — U.S. government securities — 23,761 — 23,761 — — — — Global equity — 29,193 — 29,193 — — — — Group annuity insurance contracts — — 2,982 2,982 — — 26,410 26,410 Other — — — — — 1,029 — 1,029 Cash and cash equivalents 1,773 — — 1,773 702 — — 702 Total $ 1,773 $ 293,649 $ 2,982 $ 298,404 $ 702 $ 1,029 $ 26,410 $ 28,141
Expected Future Benefit Payments	Future benefit payments are expected to be paid as follows: United States Foreign (in thousands) 2017 $ 19,205 $ 788 2018 18,568 754 2019 19,046 780 2020 19,768 1,054 2021 20,390 882 2022-2026 111,334 5,209
Postretirement Benefit Plans
Defined Benefit Pension and Postretirement Benefit Plan Assets and Obligations	The December 31 balances of the postretirement assets and obligations are shown below: 2016 2015 (in thousands) Assets and Obligations Change in benefit obligation: Projected benefit obligation: Beginning of year $ 6,030 $ 7,162 Service cost 37 48 Interest cost 218 237 Plan amendments (93 ) — Actuarial loss (gain) 5 (648 ) Benefits paid (687 ) (769 ) End of year 5,510 6,030 Change in plan assets: Fair value of plan assets: Beginning of year — — Company contributions 687 769 Benefits paid (687 ) (769 ) End of year — — Funded status $ (5,510 ) $ (6,030 )
Amounts Recorded within Statement of Financial Position	The following table provides amounts recorded within the account line items of financial position as of December 31: 2016 2015 (in thousands) Accrued employees’ compensation and withholdings $ (571 ) $ (692 ) Retirement plans liability (4,939 ) (5,338 ) Funded status $ (5,510 ) $ (6,030 )
Amounts Recognized in Accumulated Other Comprehensive Income	The following table provides amounts recognized in accumulated other comprehensive income as of December 31: 2016 2015 (in thousands) Prior service credit, before tax $ (1,118 ) $ (1,632 ) Deferred taxes (1,292 ) (1,100 ) Total recognized in other comprehensive income, net of tax $ (2,410 ) $ (2,732 )
Net Periodic Pension and Postretirement Benefit Costs	For the years ended December 31, 2016, 2015 and 2014, Teradyne’s net periodic postretirement benefit income was comprised of the following: 2016 2015 2014 (in thousands) Components of Net Periodic Postretirement Benefit Income: Service cost $ 37 $ 48 $ 59 Interest cost 218 237 335 Amortization of prior service credit (607 ) (598 ) (598 ) Net actuarial loss (gain) 5 (648 ) (1,255 ) Total net periodic postretirement benefit income (347 ) (961 ) (1,459 ) Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income: Prior service benefit (93 ) — — Reversal of amortization items: Prior service credit 607 598 598 Total recognized in other comprehensive income 514 598 598 Total recognized in net periodic postretirement cost (income) and other comprehensive income $ 167 $ (363 ) $ (861 )
Weighted Average Assumptions to Determine Net Periodic Cost and Benefit Obligation	Weighted Average Assumptions to Determine Net Periodic Postretirement Benefit Income as of January 1: 2016 2015 2014 Discount rate 3.9 % 3.5 % 4.1 % Initial health care cost trend rate 7.5 7.5 8.0 Ultimate health care cost trend rate 5.0 5.0 5.0 Year in which ultimate health care cost trend rate is reached 2023 2022 2020 Weighted Average Assumptions to Determine Postretirement Benefit Obligation as of December 31: 2016 2015 2014 Discount rate 3.9 % 3.9 % 3.5 % Initial medical trend 7.3 7.5 7.5 Ultimate health care trend 5.0 5.0 5.0 Medical cost trend rate decrease to ultimate rate in year 2023 2023 2022
Expected Future Benefit Payments	Future benefit payments are expected to be paid as follows: Benefit Payments (in thousands) 2017 $ 571 2018 529 2019 456 2020 409 2021 367 2022-2026 1,536
One Percentage Point Change in Assumed Health Care Cost Trend Rates for Year	A one percentage point change in the assumed health care cost trend rates for the year ended December 31, 2016 would have the following effects: 1 Percentage Point Increase 1 Percentage Point Decrease (in thousands) Effect on total service and interest cost components $ 2 $ (2 ) Effect on postretirement benefit obligations 44 (42 )
Group Annuity Insurance Contracts
Changes in Fair Value of Pension Assets	Changes in the fair value of Level 3 group annuity insurance contracts for the years ended December 31, 2016 and 2015 were as follows: Group Annuity Insurance Contracts (in thousands) Balance at December 31, 2014 $ 2,990 Purchases of group annuity insurance contracts 27,313 Interest and market value adjustments (825 ) Benefits paid (67 ) Other (19 ) Balance at December 31, 2015 29,392 Purchases of group annuity insurance contracts 709 Interest and market value adjustments 5,308 Benefits paid (611 ) Other (634 ) Non-U.S. (4,708 ) Balance at December 31, 2016 $ 29,456

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2016
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: 2016 2015 2014 Risk-free interest rate 0.97 % 0.77 % 0.75 % Teradyne volatility-historical 27.0 % 28.2 % 36.1 % NYSE Composite Index volatility-historical 13.1 % — % — % Philadelphia Semiconductor Index volatility-historical — % 19.7 % 24.6 % Dividend yield 1.24 % 1.33 % 1.25 %
Fair Value of Stock Options Using Assumptions	The fair value of the stock options at grant date was estimated using the Black-Scholes option-pricing model with the following assumptions: 2016 2015 2014 Expected life (years) 5.0 4.0 4.0 Risk-free interest rate 1.4 % 1.1 % 1.2 % Volatility-historical 32.9 % 33.4 % 38.8 % Dividend yield 1.24 % 1.33 % 1.25 %
Stock Compensation Plan Activity	Stock compensation plan activity for the years 2016, 2015 and 2014 follows: 2016 2015 2014 (in thousands) Restricted Stock Units: Non-vested 4,070 4,352 4,636 Awarded 1,471 1,681 1,870 Vested (1,530 ) (1,679 ) (1,965 ) Forfeited (233 ) (284 ) (189 ) Non-vested 3,778 4,070 4,352 Stock Options: Outstanding at January 1 1,121 1,507 2,706 Granted 130 132 89 Exercised (324 ) (518 ) (1,248 ) Forfeited — — (38 ) Expired (2 ) — (2 ) Outstanding at December 31 926 1,121 1,507 Vested and expected to vest at December 31 926 1,121 1,507 Exercisable at December 31 598 779 1,089
Share Based Compensation Total Shares Available	Total shares available for the years 2016, 2015 and 2014: 2016 2015 2014 (in thousands) Shares available: Available for grant at January 1 10,914 12,443 14,213 Options granted (130 ) (132 ) (89 ) Restricted stock units awarded (1,471 ) (1,681 ) (1,870 ) Restricted stock units forfeited 233 284 189 Available for grant at December 31 9,546 10,914 12,443
Weighted-Average Restricted Stock Unit Award Date Fair Value	Weighted average restricted stock unit award date fair value information for the years 2016, 2015 and 2014 follows: 2016 2015 2014 Non-vested $ 17.46 $ 17.24 $ 15.60 Awarded 18.68 17.36 18.41 Vested 17.21 16.85 14.38 Forfeited 17.57 17.08 16.97 Non-vested $ 18.03 $ 17.46 $ 17.24
Restricted Stock Unit Awards Aggregate Intrinsic Value	Restricted stock unit awards aggregate intrinsic value information at December 31 for the years 2016, 2015 and 2014 follows: 2016 2015 2014 (in thousands) Vested $ 30,008 $ 32,200 $ 37,160 Outstanding 95,952 84,129 86,113 Expected to vest 91,871 79,611 81,582
Restricted Stock Units Weighted Average Remaining Contractual Terms	Restricted stock units weighted average remaining contractual terms (in years) information at December 31, for the years 2016, 2015 and 2014 follows: 2016 2015 2014 Outstanding 1.04 1.09 1.11 Expected to vest 1.03 1.08 1.10
Weighted Average Stock Options Exercise Price	Weighted average stock options exercise price information for the year ended December 31, 2016 follows: 2016 Outstanding at January 1 $ 10.21 Options granted 19.43 Options exercised 9.06 Options expired 3.07 Outstanding at December 31 11.93 Exercisable at December 31 8.32
Stock Option Aggregate Intrinsic Value Information	Stock option aggregate intrinsic value information for the years ended December 31, 2016, 2015 and 2014 follows: 2016 2015 2014 (in thousands) Exercised $ 3,729 $ 7,255 $ 17,847 Outstanding 12,468 11,729 17,936 Vested and expected to vest 12,468 11,729 17,936 Exercisable 10,217 10,716 16,101
Stock Options Weighted Average Remaining Contractual Terms	Stock options weighted average remaining contractual terms (in years) information at December 31, for the years 2016, 2015 and 2014 follows: 2016 2015 2014 Outstanding 3.9 4.2 4.5 Vested and expected to vest 3.9 4.2 4.5 Exercisable 3.2 3.9 4.2
Significant Option Groups Outstanding	Significant option groups outstanding at December 31, 2016 and related weighted average price and remaining contractual life information follow: Options Outstanding Options Exercisable Range Of Exercise Prices Weighted- Average Remaining Contractual Life (Years) Shares Weighted- Average Exercise Price Shares Weighted- Average Exercise Price (shares in thousands) $1.48 – $2.67 3.74 294 $ 2.31 294 $ 2.31 $3.23 – $7.71 1.77 75 4.26 75 4.26 $16.23 – $18.10 3.51 338 17.18 185 16.87 $19.16 – $19.43 5.26 219 19.32 44 19.16 926 $ 11.93 598 $ 8.32
Effect to Income (Loss) from Operations for Recording Stock-Based Compensation	The effect to income from operations for recording stock-based compensation for the years ended December 31 was as follows: 2016 2015 2014 (in thousands) Cost of revenues $ 3,153 $ 3,065 $ 3,675 Engineering and development 9,458 9,362 10,146 Selling and administrative 18,139 18,024 26,486 Stock-based compensation 30,750 30,451 40,307 Income tax benefit (8,752 ) (8,528 ) (11,537 ) Total stock-based compensation expense after income taxes $ 21,998 $ 21,923 $ 28,770

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2016
Schedule of (Loss) Income Before Income Taxes and (Benefit) Provision for Income Taxes from Operations	The components of (loss) income before income taxes and the (benefit) provision for income taxes as shown in the consolidated statements of operations were as follows: 2016 2015 2014 (in thousands) (Loss) income before income taxes: U.S. $ (341,018 ) $ 56,270 $ (151,889 ) Non-U.S. 285,958 196,854 247,265 $ (55,060 ) $ 253,124 $ 95,376 (Benefit) provision for income taxes: Current: U.S. Federal $ 7,750 $ 16,635 $ 5,197 Non-U.S. 41,579 35,707 28,157 State 1,968 1,429 678 51,297 53,771 34,032 Deferred: U.S. Federal (51,482 ) (574 ) (20,449 ) Non-U.S. (9,240 ) (7,761 ) (404 ) State (2,214 ) 1,211 925 (62,936 ) (7,124 ) (19,928 ) Total (benefit) provision for income taxes: $ (11,639 ) $ 46,647 $ 14,104
Reconciliation of Effective Tax Rate	A reconciliation of the effective tax rate for the years 2016, 2015 and 2014 follows: 2016 2015 2014 U.S. statutory federal tax rate 35.0 % 35.0 % 35.0 % Foreign taxes 127.1 (16.5 ) (58.1 ) U.S. research and development credit 15.8 (3.0 ) (7.9 ) Domestic production activities deduction 2.3 (1.0 ) (0.5 ) State income taxes, net of federal tax benefit 2.3 0.4 (0.1 ) Equity compensation (2.7 ) 0.6 (1.8 ) Uncertain tax positions (2.6 ) 2.2 7.9 Goodwill impairment (162.1 ) — 36.3 Other, net 6.0 0.7 4.0 21.1 % 18.4 % 14.8 %
Deferred Tax Assets (Liabilities)	Significant components of Teradyne’s deferred tax assets (liabilities) as of December 31, 2016 and 2015 were as follows: 2016 2015 (in thousands) Deferred tax assets: Tax credits $ 57,313 $ 44,684 Pension liabilities 31,581 31,742 Inventory valuations 31,227 29,445 Accruals 27,247 26,563 Deferred revenue 12,806 10,232 Equity compensation 9,922 9,674 Vacation accrual 7,874 7,354 Net operating loss carryforwards 5,244 7,989 Other 630 502 Gross deferred tax assets 183,844 168,185 Less: valuation allowance (48,369 ) (43,039 ) Total deferred tax assets $ 135,475 $ 125,146 Deferred tax liabilities: Intangible assets $ (22,887 ) $ (68,433 ) Depreciation (17,117 ) (20,541 ) Marketable securities (210 ) (458 ) Total deferred tax liabilities $ (40,214 ) $ (89,432 ) Net deferred assets $ 95,261 $ 35,714
Operating Loss Carryforwards	At December 31, 2016, Teradyne had operating loss carryforwards that expire in the following years: State Operating Loss Carryforwards Foreign Operating Loss Carryforwards (in thousands) 2017 $ 10,245 $ — 2018 8,562 — 2019 983 — 2020 1,248 — 2021 3,549 — 2022-2026 18,044 — 2027-2031 38,498 — Beyond 2031 5,464 129 Non-expiring — 6,400 Total $ 86,593 $ 6,529
Unrecognized Tax Benefits	Teradyne’s gross unrecognized tax benefits for the years ended December 31, 2016, 2015 and 2014 were as follows: 2016 2015 2014 (in thousands) Beginning balance as of January 1 $ 36,792 $ 30,418 $ 21,203 Additions: Tax positions for current year 9,766 6,626 8,414 Tax positions for prior years 187 792 3,781 Reductions: Expiration of statutes (3,532 ) — — Settlements with tax authorities (2,295 ) (336 ) (500 ) Tax positions for prior years (1,960 ) (708 ) (2,480 ) Ending balance as of December 31 $ 38,958 $ 36,792 $ 30,418

Operating Segment, Geographic46

Operating Segment, Geographic and Significant Customer Information (Tables)	12 Months Ended
	Dec. 31, 2016
Segment Information	Segment information for the years ended December 31, 2016, 2015 and 2014 is as follows: Semiconductor Test System Test Industrial Automation Wireless Test Corporate And Eliminations Consolidated (in thousands) 2016 Revenues $ 1,368,169 $ 189,846 $ 99,031 $ 96,204 $ — $ 1,753,250 Income (loss) before taxes (1)(2) 311,939 28,916 (16,783 ) (371,409 ) (7,723 ) (55,060 ) Total assets (3) 557,546 110,361 317,635 62,366 1,714,585 2,762,493 Property additions 70,543 3,788 6,755 4,186 — 85,272 Depreciation and amortization expense 58,087 6,551 26,869 25,921 2,581 120,009 2015 Revenues $ 1,201,530 $ 211,584 $ 41,892 $ 184,572 $ — $ 1,639,578 Income (loss) before taxes (1)(2) 260,154 25,101 (7,574 ) (13,830 ) (10,727 ) 253,124 Total assets (3) 610,869 102,547 344,260 427,880 1,063,118 2,548,674 Property additions 79,052 6,228 1,465 3,133 — 89,878 Depreciation and amortization expense 64,415 4,391 14,500 53,440 4,027 140,773 2014 Revenues $ 1,300,790 $ 162,499 $ — $ 184,535 $ — $ 1,647,824 Income (loss) before taxes (1)(2) 255,803 12,116 — (116,196 ) (56,347 ) 95,376 Total assets (3) 580,501 95,105 — 478,974 1,383,940 2,538,520 Property additions 159,783 5,469 — 3,730 — 168,982 Depreciation and amortization expense 84,990 5,399 — 53,308 8,847 152,544 (1) Interest income, interest expense, other (income) expense, net, contingent consideration adjustments and pension and postretirement plans actuarial gains and losses are included in Corporate and Eliminations. (2) Included in income (loss) before taxes are charges and credits related to restructuring and other, inventory charges, goodwill impairment charges and acquired intangible assets impairment charge. (3) Total business assets are directly attributable to each business. Corporate assets consist of cash and cash equivalents, marketable securities and certain other assets.
Revenues by Country	Information as to Teradyne’s revenues by country is as follows: 2016 2015 2014 (in thousands) Revenues from customers (1): Taiwan $ 653,076 $ 436,389 $ 495,942 United States 221,948 217,386 213,104 China 174,876 264,898 292,145 Korea 147,882 120,224 145,608 Japan 135,978 128,228 63,761 Europe 117,671 111,903 111,043 Malaysia 103,472 76,707 83,910 Singapore 73,172 105,216 119,421 Philippines 54,705 96,103 68,662 Thailand 43,097 59,104 44,117 Rest of the World 27,373 23,420 10,111 $ 1,753,250 $ 1,639,578 $ 1,647,824 (1) Revenues attributable to a country are based on location of customer site.
Long-Lived Assets by Geographic Area	Long-lived assets by geographic area: United States Foreign(1) Total (in thousands) December 31, 2016 $ 189,195 $ 64,626 $ 253,821 December 31, 2015 $ 198,424 $ 74,990 $ 273,414 (1) As of December 31, 2016 and 2015, long-lived assets attributable to Singapore were $31.5 million and $39.9 million, respectively.
System Test
Schedule of Segment Reporting Information by Segment Charges	Included in the System Test segment are charges in the following accounts: For the Year Ended December 31, 2016 2015 2014 (in thousands) Cost of revenues—inventory charge $ 630 $ 8,324 $ 2,125 Restructuring and other (49 ) 1,037 742
Semiconductor Test
Schedule of Segment Reporting Information by Segment Charges	Included in the Semiconductor Test segment are charges in the following accounts: For the Year Ended December 31, 2016 2015 2014 (in thousands) Cost of revenues—inventory charge $ 9,656 $ 10,508 $ 14,389 Restructuring and other 2,860 499 490
Corporate And Eliminations
Schedule of Segment Reporting Information by Segment Charges	Included in the Corporate and Eliminations segment are charges and credits in the following accounts: For the Year Ended December 31, 2016 2015 2014 (in thousands) Restructuring and other—Universal Robots contingent consideration adjustment $ 15,346 $ 5,339 $ — Restructuring and other—Impairment of fixed assets and expenses related to Japan Earthquake 5,363 — — Restructuring and other—Property insurance recovery (5,363 ) — — Restructuring and other—ZTEC contingent consideration adjustment — (1,600 ) (630 ) Restructuring and other—AIT contingent consideration adjustment 550 (1,250 ) — Restructuring and other—Acquisition costs — 1,104 372 Restructuring and other — — 198 Other (income) expense, net—Gain from the sale of an equity investment — (5,406 ) — Selling and administrative—Stock based compensation expense (1) — — 6,598 Total $ 15,896 $ (1,813 ) $ 6,538 (1) Expense related to the January 2014 retirement of Teradyne’s former chief executive officer; see Note O: “Stock-Based Compensation.”
Industrial Automation
Schedule of Segment Reporting Information by Segment Charges	Included in the Industrial Automation segment are charges in the following accounts: For the Year Ended December 31, 2016 2015 2014 (in thousands) Restructuring and other $ 585 $ — $ — Cost of revenues-inventory step-up — 1,567 — (1) Included in the cost of revenues for the year ended December 31, 2015 is the cost for purchase accounting inventory step-up.
Wireless Test
Schedule of Segment Reporting Information by Segment Charges	Included in the Wireless Test segment are charges in the following accounts: For the Year Ended December 31, 2016 2015 2014 (in thousands) Goodwill impairment charge $ 254,946 $ — $ 98,897 Acquired intangible assets impairment charge 83,339 — — Cost of revenues—inventory charge 7,207 2,500 5,679 Restructuring and other 2,650 — 565

Supplementary Information (Tabl

Supplementary Information (Tables)	12 Months Ended
	Dec. 31, 2016
Consolidated Quarterly Statements of Operations	The following sets forth certain unaudited consolidated quarterly statements of operations data for each of Teradyne’s last eight quarters. In management’s opinion, this quarterly information reflects all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement for the periods presented. Such quarterly results are not necessarily indicative of future results of operations and should be read in conjunction with the audited consolidated financial statements of Teradyne and the notes thereto included elsewhere herein. 2016 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter (1)(5) (2)(5) (3)(5) (4)(5) (in thousands, except per share amounts) Revenues: Products $ 358,139 $ 456,832 $ 334,610 $ 303,667 Services 72,855 74,960 75,865 76,322 Total revenues 430,994 531,792 410,475 379,989 Cost of revenues: Cost of products 167,555 215,795 148,266 127,481 Cost of services 33,107 33,127 34,850 33,502 Total cost of revenues (exclusive of acquired intangible assets amortization shown separately below) 200,662 248,922 183,116 160,983 Gross profit 230,332 282,870 227,359 219,006 Operating expenses: Engineering and development 73,464 76,109 71,400 70,052 Selling and administrative 79,174 81,425 78,794 76,289 Acquired intangible assets amortization 19,994 16,244 8,487 7,923 Acquired intangible assets impairment — 83,339 — — Goodwill impairment — 254,946 — — Restructuring and other 1,587 2,608 12,177 5,570 Total operating expenses 174,219 514,671 170,858 159,834 Income (loss) from operations 56,113 (231,801 ) 56,501 59,172 Non-operating Interest income (1,642 ) (1,666 ) (2,892 ) (3,095 ) Interest expense 710 691 633 1,604 Other (income) expense, net (147 ) (9 ) (921 ) 1,779 Income (loss) before income taxes 57,192 (230,817 ) 59,681 58,884 Income tax provision (benefit) 7,206 (7,271 ) (4,113 ) (7,461 ) Net income (loss) $ 49,986 $ (223,546 ) $ 63,794 $ 66,345 Net income (loss) per common share—basic $ 0.24 $ (1.10 ) $ 0.32 $ 0.33 Net income (loss) per common share—diluted $ 0.24 $ (1.10 ) $ 0.31 $ 0.33 Cash dividend declared per common share $ 0.06 $ 0.06 $ 0.06 $ 0.06 (1) Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration. (2) Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake. (3) Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration. (4) Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration. (5) Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: “Accounting Policies” for a discussion of Teradyne’s accounting policy. 2015 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter (3) (4) (1)(2) (in thousands, except per share amounts) Revenues: Products $ 272,325 $ 437,243 $ 386,488 $ 244,510 Services 70,076 75,496 79,506 73,934 Total revenues 342,401 512,739 465,994 318,444 Cost of revenues: Cost of products 118,996 181,491 170,963 120,322 Cost of services 30,982 32,680 36,405 32,096 Total cost of revenues (exclusive of acquired intangible assets amortization shown separately below) 149,978 214,171 207,368 152,418 Gross profit 192,423 298,568 258,626 166,026 Operating expenses: Engineering and development 71,450 75,832 74,027 70,941 Selling and administrative 72,041 77,073 77,481 79,718 Acquired intangible assets amortization 13,808 15,258 20,053 19,911 Restructuring and other — (385 ) 261 5,204 Total operating expenses 157,299 167,778 171,822 175,774 Income (loss) from operations 35,124 130,790 86,804 (9,748 ) Non-operating Interest income (1,816 ) (1,674 ) (1,708 ) (2,017 ) Interest expense 162 444 508 762 Other (income) expense, net (5,660 ) (116 ) 596 364 Income (loss) before income taxes 42,438 132,136 87,408 (8,857 ) Income tax provision (benefit) 9,651 29,257 15,955 (8,216 ) Net income (loss) $ 32,787 $ 102,879 $ 71,453 $ (641 ) Net income (loss) per common share—basic $ 0.15 $ 0.48 $ 0.34 $ (0.00 ) Net income (loss) per common share—diluted $ 0.15 $ 0.48 $ 0.34 $ (0.00 ) Cash dividend declared per common share $ 0.06 $ 0.06 $ 0.06 $ 0.06 (1) Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration. (2) In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: “Accounting Policies” for a discussion of Teradyne’s accounting policy. (3) Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration. (4) Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.

The Company - Additional inform

The Company - Additional information (Detail) - Universal Robots	Jun. 11, 2015USD ($)
Business Acquisition [Line Items]
Cash paid to acquire outstanding common and preferred stock	$ 283,800,000
Arrangement range of outcomes value high	$ 65,000,000

Deferred Revenue and Customer A

Deferred Revenue and Customer Advances (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Deferred Revenue Arrangement
Extended warranty	$ 46,753	$ 46,499	$ 43,300	$ 34,909
Equipment maintenance and training	39,037	30,616
Customer advances, undelivered elements and other	22,151	34,157
Total deferred revenue and customer advances	$ 107,941	$ 111,272

Warranty Accrual Included in Ot

Warranty Accrual Included in Other Accrued Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Product Warranty Liability [Line Items]
Balance at beginning of period	$ 6,925	$ 8,942	$ 6,660
Acquisition		409
Accruals for warranties issued during the period	14,291	11,539	15,406
Accruals related to pre-existing warranties	(1,354)	(3,159)	(2,008)
Settlements made during the period	(12,659)	(10,806)	(11,116)
Balance at end of period	$ 7,203	$ 6,925	$ 8,942

Extended Product Warranty Inclu

Extended Product Warranty Included in Short and Long-Term Deferred Revenue and Customer Advances (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Product Warranty Liability [Line Items]
Balance at beginning of period	$ 46,499	$ 43,300	$ 34,909
Acquisition		870
Deferral of new extended warranty revenue	27,182	28,549	29,519
Recognition of extended warranty deferred revenue	(26,928)	(26,220)	(21,128)
Balance at end of period	$ 46,753	$ 46,499	$ 43,300

Schedule of Prepayments (Detail

Schedule of Prepayments (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Prepaid And Other Current Assets [Line Items]
Contract manufacturer prepayments	$ 77,017	$ 66,283
Prepaid maintenance and other services	7,676	8,481
Prepaid taxes	4,664	3,781
Other prepayments	19,097	12,974
Total prepayments	$ 108,454	$ 91,519

Useful Lives of Assets (Detail)

Useful Lives of Assets (Detail)	12 Months Ended
	Dec. 31, 2016
Buildings
Property, Plant and Equipment [Line Items]
Useful lives, maximum years	40 years
Building Improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful lives, maximum years	5 years
Building Improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful lives, maximum years	10 years
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Useful lives, description	Lesser of lease term or 10 years
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Useful lives, maximum years	10 years
Test Systems Manufactured Internally
Property, Plant and Equipment [Line Items]
Useful lives, maximum years	6 years
Machinery and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful lives, maximum years	3 years
Machinery and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful lives, maximum years	5 years
Software | Minimum
Property, Plant and Equipment [Line Items]
Useful lives, maximum years	3 years
Software | Maximum
Property, Plant and Equipment [Line Items]
Useful lives, maximum years	5 years

Accounting Policies - Additiona

Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Summary Of Significant Accounting Policies [Line Items]
Depreciation over life to cost of revenues and selling and administrative expenses, years	6 years
Net book value of internally manufactured test systems sold	$ 11.4	$ 50.7	$ 9.7
Advertising costs	6.4	3.3	1.9
Gains (losses) on foreign currency transactions	$ 8	$ 2.5	$ 0.9
Convertible Notes
Summary Of Significant Accounting Policies [Line Items]
Initial debt conversion price	$ 5.48		$ 5.48
Shares that would be issued upon conversion	34.7		34.7
Convertible Notes Hedge Warrant
Summary Of Significant Accounting Policies [Line Items]
Initial debt conversion price	$ 7.67		$ 7.67
Shares that would be issued upon conversion	34.7		34.7

Recently Issued Accounting Pr55

Recently Issued Accounting Pronouncements - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
New Accounting Pronouncements or Change in Accounting Principle
Excess tax benefit recorded in additional paid in capital	$ 6,087	$ 4,625	$ 209
ASU 2016-09
New Accounting Pronouncements or Change in Accounting Principle
Cumulative effect adjustment to increase retained earnings and deferred tax assets	39,000
Excess tax benefit recorded in additional paid in capital	$ 6,100	$ 4,600	$ 200

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($)	Jun. 11, 2015	Oct. 31, 2014	Jan. 31, 2017	Dec. 31, 2014	Mar. 31, 2016	Oct. 04, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Payments of contingent consideration							$ 11,697,000
Universal Robots
Business Acquisition [Line Items]
Total purchase price	$ 315,437,000
Cash paid to acquire outstanding common and preferred stock	283,800,000
Contingent consideration	31,600,000
Arrangement range of outcomes value high	65,000,000
Payments of contingent consideration					$ 15,000,000		$ 15,000,000
EBITDA contingent consideration amount, percentage					100.00%		100.00%
Maximum payment per earn-out							$ 25,000,000
Goodwill, not deductible for tax purposes	$ 221,100,000
Revenues						$ 41,900,000
Income (loss) before income taxes						$ (7,600,000)
Net income								$ 199,784,000	$ 61,078,000
Universal Robots | Fair Value Adjustment to Inventory
Business Acquisition [Line Items]
Net income								1,600,000	1,600,000
Universal Robots | Acquisition Related Costs
Business Acquisition [Line Items]
Net income								$ 1,000,000	1,000,000
Avionics Interface Technologies, LLC
Business Acquisition [Line Items]
Total purchase price		$ 21,243,000
Cash paid to acquire outstanding common and preferred stock		19,400,000
Contingent consideration		$ 1,800,000
Revenues				$ 600,000
Income (loss) before income taxes				$ (800,000)
Net income									$ 82,169,000
Discount rate		4.70%
Goodwill, expected tax deduction		$ 10,500,000
Avionics Interface Technologies, LLC | Subsequent Event
Business Acquisition [Line Items]
Payments of contingent consideration			$ 1,100,000

Allocation of Final Purchase Pr

Allocation of Final Purchase Price (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Jun. 11, 2015	Dec. 31, 2014	Oct. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 223,343	$ 488,413		$ 273,438
Universal Robots
Business Acquisition [Line Items]
Goodwill			$ 221,128
Intangible assets			121,590
Current assets			10,853
Non-current assets			3,415
Accounts payable and current liabilities			(11,976)
Long-term deferred tax liabilities			(26,653)
Long-term other liabilities			(2,920)
Total purchase price			$ 315,437
Avionics Interface Technologies, LLC
Business Acquisition [Line Items]
Goodwill					$ 10,516
Intangible assets					9,080
Current assets					2,452
Non-current assets					359
Accounts payable and current liabilities					(1,164)
Total purchase price					$ 21,243

Components of Intangible Assets

Components of Intangible Assets and Their Estimated Useful Lives at Acquisition Date (Detail) - USD ($) $ in Thousands	Jun. 11, 2015	Oct. 31, 2014	Dec. 31, 2015
Universal Robots
Business Acquisition [Line Items]
Total intangible assets, fair value	$ 121,590		$ 121,600
Total intangible assets, estimated useful life, years	5 years 7 months 6 days
Avionics Interface Technologies, LLC
Business Acquisition [Line Items]
Total intangible assets, fair value		$ 9,080
Total intangible assets, estimated useful life, years		4 years 9 months 18 days
Developed technology | Universal Robots
Business Acquisition [Line Items]
Total intangible assets, fair value	$ 89,240
Total intangible assets, estimated useful life, years	4 years 10 months 24 days
Developed technology | Avionics Interface Technologies, LLC
Business Acquisition [Line Items]
Total intangible assets, fair value		$ 2,580
Total intangible assets, estimated useful life, years		4 years 9 months 18 days
Trademarks and tradenames | Universal Robots
Business Acquisition [Line Items]
Total intangible assets, fair value	$ 22,920
Total intangible assets, estimated useful life, years	10 years
Trademarks and tradenames | Avionics Interface Technologies, LLC
Business Acquisition [Line Items]
Total intangible assets, fair value		$ 380
Total intangible assets, estimated useful life, years		5 years
Customer Relationships | Universal Robots
Business Acquisition [Line Items]
Total intangible assets, fair value	$ 9,430
Total intangible assets, estimated useful life, years	2 years
Customer Relationships | Avionics Interface Technologies, LLC
Business Acquisition [Line Items]
Total intangible assets, fair value		$ 5,630
Total intangible assets, estimated useful life, years		5 years
Non-compete Agreements | Avionics Interface Technologies, LLC
Business Acquisition [Line Items]
Total intangible assets, fair value		$ 320
Total intangible assets, estimated useful life, years		4 years
Customer backlog | Avionics Interface Technologies, LLC
Business Acquisition [Line Items]
Total intangible assets, fair value		$ 170
Total intangible assets, estimated useful life, years		3 months 18 days

Pro Forma Results Under Acquisi

Pro Forma Results Under Acquisition (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Universal Robots
Business Acquisition [Line Items]
Revenue	$ 1,657,626	$ 1,686,689
Net income	$ 199,784	$ 61,078
Net income per common share, basic	$ 0.94	$ 0.30
Net income per common share, diluted	$ 0.94	$ 0.27
Avionics Interface Technologies, LLC
Business Acquisition [Line Items]
Revenue		$ 1,655,038
Net income		$ 82,169
Net income per common share, basic		$ 0.40
Net income per common share, diluted		$ 0.37

Composition of Inventories, Net

Composition of Inventories, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Inventory [Line Items]
Raw material	$ 58,530	$ 73,117
Work-in-process	22,946	32,825
Finished goods	54,482	47,646
Inventories, net	$ 135,958	$ 153,588

Inventories - Additional Inform

Inventories - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Inventory [Line Items]
Inventory reserves	$ 116	$ 119.4

Property Plant and Equipment, N

Property Plant and Equipment, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Land	$ 16,561	$ 16,561
Buildings	98,031	108,797
Machinery and equipment	601,835	595,445
Furniture and fixtures, and software	82,897	82,612
Leasehold improvements	46,612	43,328
Construction in progress	3,032	2,630
Property, Plant and Equipment, Gross, Total	848,968	849,373
Less: accumulated depreciation	595,147	575,959
Property, plant and equipment, net	$ 253,821	$ 273,414

Property, Plant and Equipment -

Property, Plant and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Depreciation of property, plant and equipment	$ 64,782	$ 68,181	$ 73,390
Machinery and equipment	601,835	595,445
Accumulated depreciation	595,147	575,959
Test Systems Leased By Customers
Property, Plant and Equipment [Line Items]
Machinery and equipment	19,400	20,400
Accumulated depreciation	$ 10,500	$ 8,500

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Dec. 31, 2013	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financial Instruments and Fair Value [Line Items]
Available-for-sale securities, realized loss			$ 500,000	$ 400,000	$ 0
Available-for-sale securities, realized gain			1,600,000	1,700,000	2,400,000
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses			732,979,000	601,660,000
Fair market value of investments with unrealized losses greater than one year			2,900,000	900,000
Aggregate loss of investments with unrealized losses greater than one year			300,000	500,000
Fair market value of investments with unrealized losses less than one year			730,100,000	600,800,000
Aggregate loss of investments with unrealized losses less than one year			2,500,000	3,600,000
Gains (losses) on foreign currency transactions			8,000,000	2,500,000	900,000
Realized (losses) gains on foreign currency contracts			$ (8,700,000)	(3,000,000)	$ (200,000)
Proceeds from sale of equity interest	$ 5,400,000	$ 34,200,000		$ 5,406,000
Accounts Receivable | Customer 1 | Minimum
Financial Instruments and Fair Value [Line Items]
Concentration risk, percentage			10.00%
Accounts Receivable | Customer 2 | Minimum
Financial Instruments and Fair Value [Line Items]
Concentration risk, percentage				10.00%
Foreign Currency Forward Contracts
Financial Instruments and Fair Value [Line Items]
Gains (losses) on foreign currency transactions			$ (100,000)	$ 0
Equity And Debt Mutual Funds
Financial Instruments and Fair Value [Line Items]
Available for sale securities with out contractual maturity date			18,000,000
Universal Robots
Financial Instruments and Fair Value [Line Items]
Maximum payment per earn-out			$ 25,000,000

Schedule of Fair Value of Finan

Schedule of Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	$ 1,304,867	$ 743,624
U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	900,038	419,958
Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	100,153	161,634
U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	42,014	83,952
Certificates of Deposit and Time Deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	82,133	43,394
Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	161,630	20,308
Equity And Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	18,171	13,954
Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	728	424
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	1,612,751	1,008,329
Derivative assets	1	109
Total	1,612,752	1,008,438
Contingent consideration	38,332	37,436
Derivative liabilities	131	146
Total	38,463	37,582
Fair Value, Measurements, Recurring | Cash
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	214,722	213,336
Fair Value, Measurements, Recurring | Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash and cash equivalents	93,162	51,369
Fair Value, Measurements, Recurring | U.S. Treasury Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	900,038	419,958
Fair Value, Measurements, Recurring | Corporate Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	100,153	161,634
Fair Value, Measurements, Recurring | U.S. Government Agency Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	42,014	83,952
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	82,133	43,394
Fair Value, Measurements, Recurring | Commercial Paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	161,630	20,308
Fair Value, Measurements, Recurring | Equity And Debt Mutual Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	18,171	13,954
Fair Value, Measurements, Recurring | Non-U.S. Government Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Available for sale securities	728	424
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	270,351	276,531
Total	270,351	276,531
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	214,722	213,336
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	37,458	49,241
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	18,171	13,954
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Total	1,342,400	731,798
Derivative assets	1	109
Total	1,342,401	731,907
Derivative liabilities	131	146
Total	131	146
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	55,704	2,128
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	900,038	419,958
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	100,153	161,634
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	42,014	83,952
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	82,133	43,394
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	161,630	20,308
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	728	424
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Contingent consideration	38,332	37,436
Total	$ 38,332	$ 37,436

Schedule of Reported Financial

Schedule of Reported Financial Assets and Liabilities (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	$ 1,612,752	$ 1,008,438
Liabilities	38,463	37,582
Other Current Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	131	146
Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	307,884	264,705
Marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	871,024	477,696
Long-term marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	433,843	265,928
Prepayments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	1	109
Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	1,050	15,500
Long Term Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	37,282	21,936
Quoted Prices in Active Markets for Identical Instruments (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	270,351	276,531
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	252,180	262,577
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	18,171	13,954
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	1,342,401	731,907
Liabilities	131	146
Significant Other Observable Inputs (Level 2) | Other Current Liabilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	131	146
Significant Other Observable Inputs (Level 2) | Cash and Cash Equivalents
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	55,704	2,128
Significant Other Observable Inputs (Level 2) | Marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	871,024	477,696
Significant Other Observable Inputs (Level 2) | Long-term marketable securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	415,672	251,974
Significant Other Observable Inputs (Level 2) | Prepayments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Assets	1	109
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	38,332	37,436
Significant Unobservable Inputs (Level 3) | Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	1,050	15,500
Significant Unobservable Inputs (Level 3) | Long Term Contingent Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Liabilities	$ 37,282	$ 21,936

Schedule of Changes in Fair Val

Schedule of Changes in Fair Value of Level 3 Contingent Consideration (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016		Dec. 31, 2015
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period		$ 37,436		$ 3,350
Ending Balance		38,332		37,436
Payments	[1]	(15,000)
Universal Robots
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Acquisition				31,597
Fair value adjustment		15,346	[2]	5,339	[3]
Avionics Interface Technologies, LLC
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value adjustment		$ 550	[2]	(1,250)	[4]
ZTEC Instruments, Inc.
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value adjustment	[5]			$ (1,600)
[1]	During the year ended December 31, 2016, based on Universal Robots' calendar year 2015 EBITDA results, Teradyne paid $15 million or 100% of the eligible EBITDA contingent consideration amount.
[2]	During the year ended December 31, 2016, the fair value of contingent consideration for the earn-out in connection with the acquisition of Universal Robots was increased by $15.3 million primarily due to an increase in forecasted revenues and a decrease in the discount rate. During the year ended 2016, the fair value of contingent consideration for the earn-out in connection with the acquisition of AIT was increased by $0.6 million due to an increase in forecasted revenues. The AIT contingent consideration in the amount of $1.1 million was paid in January 2017.
[3]	During the year ended December 31, 2015, the fair value of contingent consideration for the earn-out in connection with the acquisition of Universal Robots was increased by $5.3 million primarily due to an increase in forecasted revenues.
[4]	During the year ended December 31, 2015, the fair value of contingent consideration for the earn-out in connection with the acquisition of AIT was reduced by $1.3 million due to a decrease in the forecasted revenues.
[5]	During the year ended December 31, 2015, the fair value measurement of the contingent consideration for the earn-out in connection with the acquisition of ZTEC Instruments, Inc. ("ZTEC") was reduced by $1.6 million, to $0, because Teradyne and the Securityholder Representative, on behalf of the ZTEC securityholders, agreed to terminate the earn-out prior to the end of the December 31, 2015 earn-out period, with no payout in connection with the resolution of indemnity claims asserted by both Teradyne and the Securityholder Representative.

Schedule of Changes in Fair V68

Schedule of Changes in Fair Value of Level 3 Contingent Consideration (Parenthetical) (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended							12 Months Ended
	Jan. 31, 2017	Dec. 31, 2016	Oct. 02, 2016	Apr. 03, 2016	Mar. 31, 2016	Dec. 31, 2015	Oct. 04, 2015	Jul. 05, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jun. 11, 2015	Oct. 31, 2014
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Increase(decrease)in contingent consideration									$ 15,896	$ 2,489	$ (630)
Payments of contingent consideration									11,697
Universal Robots
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Increase(decrease)in contingent consideration		$ 5,400	$ 8,000	$ 1,200		$ 5,339			15,300	5,300
Contingent consideration												$ 31,600
Payments of contingent consideration					$ 15,000				$ 15,000
EBITDA contingent consideration amount, percentage		100.00%			100.00%				100.00%
Avionics Interface Technologies, LLC
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Increase(decrease)in contingent consideration						(300)	$ (1,000)		$ 600	(1,300)
Contingent consideration													$ 1,800
Avionics Interface Technologies, LLC | Subsequent Event
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Payments of contingent consideration	$ 1,100
ZTEC Instruments, Inc.
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Increase(decrease)in contingent consideration								$ (1,600)		(1,600)	$ (600)
Contingent consideration						$ 0				$ 0

Quantitative Information Associ

Quantitative Information Associated With Fair Value Measurement of Level 3 Financial Instrument (Detail) - USD ($) $ in Thousands		Oct. 31, 2014	Dec. 31, 2016	Jun. 11, 2015
Universal Robots
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Contingent consideration				$ 31,600
Avionics Interface Technologies, LLC
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Contingent consideration		$ 1,800
Discount rate		4.70%
Significant Unobservable Inputs (Level 3) | Avionics Interface Technologies, LLC
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Contingent consideration	[1]		$ 1,050
Monte Carlo simulation model | Significant Unobservable Inputs (Level 3)
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Contingent consideration			15,981
Monte Carlo simulation model | Significant Unobservable Inputs (Level 3) | Universal Robots
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Contingent consideration			$ 21,301
Monte Carlo simulation model | Revenue for the period July 1, 2015-December 31, 2017 | Universal Robots
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Target achievement, volatility			10.80%
Discount rate			3.30%
Monte Carlo simulation model | Revenue for the period July 1, 2015-December 31, 2018 | Universal Robots
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Target achievement, volatility			10.80%
Discount rate			3.30%
[1]	Teradyne paid this amount in January 2017.

Schedule of Carrying Amounts an

Schedule of Carrying Amounts and Fair Values of Financial Instruments (Detail) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and cash equivalents		$ 307,884	$ 264,705
Marketable securities		1,304,867	743,624
Derivative assets		1	109
Contingent consideration		38,332	37,436
Derivative liabilities		131	146
Convertible debt	[1]	486,754
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Cash and cash equivalents		307,884	264,705
Marketable securities		1,304,867	743,624
Derivative assets		1	109
Contingent consideration		38,332	37,436
Derivative liabilities		131	146
Convertible debt	[1]	352,669
Marketable securities		$ 1,304,867	$ 743,624
[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	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	$ 1,304,711	$ 745,498
Available-for-sale marketable securities, Unrealized Gain	2,977	2,145
Available-for-sale marketable securities, Unrealized (Loss)	(2,821)	(4,019)
Available-for-sale marketable securities, Fair Market Value	1,304,867	743,624
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	732,979	601,660
U.S. Treasury Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	901,975	421,060
Available-for-sale marketable securities, Unrealized Gain	97	65
Available-for-sale marketable securities, Unrealized (Loss)	(2,034)	(1,167)
Available-for-sale marketable securities, Fair Market Value	900,038	419,958
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	572,284	379,434
Corporate Debt Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	99,708	163,297
Available-for-sale marketable securities, Unrealized Gain	1,065	902
Available-for-sale marketable securities, Unrealized (Loss)	(620)	(2,565)
Available-for-sale marketable securities, Fair Market Value	100,153	161,634
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	53,642	145,373
U.S. Government Agency Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	42,026	84,032
Available-for-sale marketable securities, Unrealized Gain	7	42
Available-for-sale marketable securities, Unrealized (Loss)	(19)	(122)
Available-for-sale marketable securities, Fair Market Value	42,014	83,952
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	13,461	55,120
Certificates of Deposit and Time Deposits
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	82,080	43,391
Available-for-sale marketable securities, Unrealized Gain	54	6
Available-for-sale marketable securities, Unrealized (Loss)	(1)	(3)
Available-for-sale marketable securities, Fair Market Value	82,133	43,394
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	7,760	10,527
Commercial Paper
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	161,672	20,298
Available-for-sale marketable securities, Unrealized Gain	24	11
Available-for-sale marketable securities, Unrealized (Loss)	(66)	(1)
Available-for-sale marketable securities, Fair Market Value	161,630	20,308
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	84,034	8,646
Equity And Debt Mutual Funds
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	16,505	12,996
Available-for-sale marketable securities, Unrealized Gain	1,724	1,119
Available-for-sale marketable securities, Unrealized (Loss)	(58)	(161)
Available-for-sale marketable securities, Fair Market Value	18,171	13,954
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	1,661	2,560
Non-U.S. Government Securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	745	424
Available-for-sale marketable securities, Unrealized Gain	6
Available-for-sale marketable securities, Unrealized (Loss)	(23)
Available-for-sale marketable securities, Fair Market Value	728	$ 424
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	Dec. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	$ 1,304,711	$ 745,498
Available-for-sale marketable securities, Unrealized Gain	2,977	2,145
Available-for-sale marketable securities, Unrealized (Loss)	(2,821)	(4,019)
Available-for-sale marketable securities, Fair Market Value	1,304,867	743,624
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	732,979	601,660
Marketable securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	871,321	478,306
Available-for-sale marketable securities, Unrealized Gain	134	38
Available-for-sale marketable securities, Unrealized (Loss)	(431)	(648)
Available-for-sale marketable securities, Fair Market Value	871,024	477,696
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	423,128	374,785
Long-term marketable securities
Schedule of Available-for-sale Securities
Available-for-sale marketable securities, Cost	433,390	267,192
Available-for-sale marketable securities, Unrealized Gain	2,843	2,107
Available-for-sale marketable securities, Unrealized (Loss)	(2,390)	(3,371)
Available-for-sale marketable securities, Fair Market Value	433,843	265,928
Available-for-sale marketable securities, Fair Market Value of Investments with Unrealized Losses	$ 309,851	$ 226,875

Contractual Maturities of Inves

Contractual Maturities of Investments Held (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Schedule of Available-for-sale Securities
Due within one year, cost	$ 871,321
Due after 1 year through 5 years, cost	365,873
Due after 5 years through 10 years, cost	12,839
Due after 10 years, cost	38,173
Total, cost	1,288,206
Due within one year, fair value	871,024
Due after 1 year through 5 years, fair value	365,451
Due after 5 years through 10 years, fair value	12,309
Due after 10 years, fair value	37,912
Total, fair value	$ 1,286,696

Non-Financial Assets Measured A

Non-Financial Assets Measured At Fair Value On Non-Recurring Basis (Detail) - USD ($) $ in Thousands		3 Months Ended				6 Months Ended	12 Months Ended
		Dec. 31, 2016	Jul. 03, 2016		Dec. 31, 2014	Jul. 03, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Goodwill, impairment loss		$ 0	$ 254,946	[1],[2]	$ 98,897		$ 254,946	$ (254,946)	$ 98,897
Definite lived intangible assets, impairment loss			83,339	[1],[2]			$ 83,339	$ 98,200
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Goodwill, fair value	[3]		7,976			$ 7,976
Definite lived intangible assets, fair value	[4]		5,750			5,750
Total			13,726			13,726
Goodwill, impairment loss	[3]					254,946
Definite lived intangible assets, impairment loss	[4]					83,339
Asset Impairment Charges, Total						338,285
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Goodwill, fair value	[3]		7,976			7,976
Definite lived intangible assets, fair value	[4]		5,750			5,750
Total			$ 13,726			$ 13,726
[1]	Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.
[2]	Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[3]	In accordance with the provisions of ASC 350-20, "Goodwill" goodwill in the Wireless Test reporting unit with a carrying amount of $262.9 million was written down in the second quarter of 2016 to its implied fair value of $8.0 million, resulting in an impairment charge of $254.9 million. See Note J: "Goodwill and Intangible Assets" regarding goodwill impairment.
[4]	In accordance with the provisions of ASC 360-10, "Property, Plant and Equipment," definite lived intangible assets in the Wireless Test reporting unit with a carrying amount of $89.2 million were written down in the second quarter of 2016 to their implied fair value of $5.8 million, resulting in an impairment charge of $83.3 million. See Note J: "Goodwill and Intangible Assets" regarding definite lived intangible assets impairment.

Non-Financial Assets Measured75

Non-Financial Assets Measured At Fair Value On Non-Recurring Basis (Parenthetical) (Detail) - USD ($) $ in Thousands		3 Months Ended					6 Months Ended	12 Months Ended
		Dec. 31, 2016		Jul. 03, 2016		Dec. 31, 2014	Jul. 03, 2016	Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Goodwill, carrying value		$ 985,909				$ 781,058		$ 985,909		$ 996,033	$ 781,058
Goodwill, impairment loss		0		$ 254,946	[1],[2]	98,897		254,946		(254,946)	98,897
Definite lived intangible assets, carrying value		414,208	[3]					414,208	[3]	546,388
Definite lived intangible assets, impairment loss				83,339	[1],[2]			83,339		98,200
Wireless Test
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Goodwill, carrying value		$ 361,819				$ 361,819		361,819		361,819	361,819
Goodwill, fair value				8,000			$ 8,000
Goodwill, impairment loss				254,946				254,946		$ (254,946)	$ 98,897
Definite lived intangible assets, impairment loss								$ 83,339
Fair Value, Measurements, Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Goodwill, fair value	[4]			7,976			7,976
Goodwill, impairment loss	[4]						254,946
Definite lived intangible assets, fair value	[5]			5,750			5,750
Definite lived intangible assets, impairment loss	[5]						83,339
Fair Value, Measurements, Nonrecurring | Wireless Test
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Goodwill, carrying value				262,900			262,900
Goodwill, fair value				8,000			8,000
Goodwill, impairment loss				254,946
Definite lived intangible assets, carrying value				89,200			89,200
Definite lived intangible assets, fair value				5,800			$ 5,800
Definite lived intangible assets, impairment loss				$ 83,300
[1]	Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.
[2]	Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[3]	During the year ended December 31, 2016, Teradyne recorded an $83.3 million impairment of Wireless Test amortizable intangible assets. The impairment assets have been eliminated from the gross carrying amount and accumulated amortization.
[4]	In accordance with the provisions of ASC 350-20, "Goodwill" goodwill in the Wireless Test reporting unit with a carrying amount of $262.9 million was written down in the second quarter of 2016 to its implied fair value of $8.0 million, resulting in an impairment charge of $254.9 million. See Note J: "Goodwill and Intangible Assets" regarding goodwill impairment.
[5]	In accordance with the provisions of ASC 360-10, "Property, Plant and Equipment," definite lived intangible assets in the Wireless Test reporting unit with a carrying amount of $89.2 million were written down in the second quarter of 2016 to their implied fair value of $5.8 million, resulting in an impairment charge of $83.3 million. See Note J: "Goodwill and Intangible Assets" regarding definite lived intangible assets impairment.

Schedule of Notional Amount of

Schedule of Notional Amount of Derivatives (Detail) - Foreign Currency Forward Contracts - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	$ 14.5	$ (29.7)
Buy Position
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	(34.7)	(71.9)
Sell Position
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	49.2	42.2
Japanese Yen
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	(17.7)	(51.9)
Japanese Yen | Buy Position
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	(17.7)	(51.9)
British Pound Sterling
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	(1.3)	(9.5)
British Pound Sterling | Buy Position
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	(1.3)	(9.5)
Korean Won
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	(8.8)	(5.5)
Korean Won | Buy Position
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	(8.8)	(5.5)
Taiwan Dollar
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	(6.9)	(5)
Taiwan Dollar | Buy Position
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	(6.9)	(5)
Euro
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	25.2	27.2
Euro | Sell Position
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	25.2	27.2
Singapore Dollar
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	24	15
Singapore Dollar | Sell Position
Intercompany Foreign Currency Balance [Line Items]
Notional amounts	$ 24	$ 15

Schedule of Derivative Instrume

Schedule of Derivative Instruments in Statement of Financial Position at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Derivative assets (liabilities), net	$ (130)	$ (37)
Not Designated as Hedging Instrument | Foreign Currency Forward Contracts | Prepayments
Derivatives, Fair Value [Line Items]
Derivative assets	1	109
Not Designated as Hedging Instrument | Foreign Currency Forward Contracts | Other Current Liabilities
Derivatives, Fair Value [Line Items]
Derivative liabilities	$ (131)	$ (146)

Schedule of Effect of Derivativ

Schedule of Effect of Derivative Instruments in Statements of Operations Recognized (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Other (income) expense, net
Derivative Instruments, Gain (Loss) [Line Items]
Foreign exchange contracts derivatives not designated as hedging instruments, Losses Recognized in Statement of Operations	$ 8,671	$ 3,047	$ 237

Debt - Additional Information (

Debt - Additional Information (Detail) $ / shares in Units, shares in Millions	Dec. 12, 2016USD ($)d$ / sharesshares	Apr. 27, 2015USD ($)	Dec. 31, 2016USD ($)$ / shares	Dec. 31, 2015USD ($)
Debt Instrument
Debt instrument, net proceeds after issuance costs			$ 450,800,000
Repurchase of common stock			146,331,000	$ 299,949,000
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
Aggregate principal amount	$ 460,000,000		$ 460,000,000
Debt instrument, interest rate, stated percentage	1.25%
Debt instrument, net proceeds after issuance costs	$ 450,800,000
Payment for net cost of convertible note hedges net of warrant proceeds	33,000,000
Repurchase of common stock	$ 50,100,000
Repurchase of stock, shares | shares	2
Senior notes maturity date	Dec. 15, 2023
Debt instrument, frequency of periodic payment	Payable semiannually in arrears on June 15 and December 15 of each year
Debt instrument, date of first required payment	Jun. 15, 2017
Debt instrument, conversion option expiration date	Sep. 15, 2023
Debt instrument conversion ratio	0.0314102
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, convertible, carrying amount of equity component	$ 100,800,000		$ 100,800,000
Debt instrument, effective annual interest rate			5.00%
Financing cost	$ 7,200,000		$ 7,100,000
Debt issuance costs, amortization period			7 years
Unamortized discount			$ 107,300,000
Debt Instrument, convertible, remaining discount amortization period			7 years
1.25% Convertible Senior Unsecured Notes Due December 15, 2023 | Conversion option one
Debt Instrument
Trading days measurement period | d	20
Consecutive trading days measurement period	30 days
Percentage of conversion price	130.00%
1.25% Convertible Senior Unsecured Notes Due December 15, 2023 | 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
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	Dec. 31, 2016	Dec. 12, 2016
Debt Instrument
Net carrying amount of convertible debt	$ 352,669
1.25% Convertible Senior Unsecured Notes Due December 15, 2023
Debt Instrument
Debt principal	460,000	$ 460,000
Unamortized discount including debt issuance cost	107,331
Net carrying amount of convertible debt	$ 352,669

Interest Expense on Convertible

Interest Expense on Convertible Senior Notes (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Debt Instrument
Contractual interest expense on the coupon	$ 303
Amortization of the discount component and debt issue fees recognized as interest expense	688
Total interest expense on the convertible debt	$ 991

Changes in Accumulated Other Co

Changes in Accumulated Other Comprehensive Income (Loss) Balances (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 1,965,786	$ 2,078,980	$ 1,985,094
Other comprehensive (loss) income before reclassifications, net of tax of $0, $(1,667)	(11,125)	(11,834)
Amounts reclassified from accumulated other comprehensive income, net of tax of $(255), $(190)	(945)	(999)
Other comprehensive (loss) income	(12,070)	(12,833)	689
Balance	1,828,659	1,965,786	2,078,980
Foreign currency translation reclassification adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(8,759)
Other comprehensive (loss) income before reclassifications, net of tax of $0, $(1,667)	(13,162)	(8,759)
Other comprehensive (loss) income	(13,162)	(8,759)
Balance	(21,921)	(8,759)
Unrealized Gains (Losses) on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(1,414)	2,365
Other comprehensive (loss) income before reclassifications, net of tax of $0, $(1,667)	2,037	(3,075)
Amounts reclassified from accumulated other comprehensive income, net of tax of $(255), $(190)	(683)	(704)
Other comprehensive (loss) income	1,354	(3,779)
Balance	(60)	(1,414)	2,365
Amortization of prior service credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	2,029	2,324
Other comprehensive (loss) income before reclassifications, net of tax of $0, $(1,667)	59
Amounts reclassified from accumulated other comprehensive income, net of tax of $(255), $(190)	(321)	(295)	(295)
Other comprehensive (loss) income	(262)	(295)
Balance	1,767	2,029	2,324
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(8,144)	4,689	4,000
Amounts reclassified from accumulated other comprehensive income, net of tax of $(255), $(190)	(945)	(999)	(1,728)
Balance	$ (20,214)	$ (8,144)	$ 4,689

Changes in Accumulated Other 83

Changes in Accumulated Other Comprehensive Income (Loss) Balances (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from accumulated other comprehensive income, tax	$ 190	$ 169	$ 169
Amounts reclassified from accumulated other comprehensive income, tax	(411)	(559)	(814)
Foreign currency translation adjustments, tax	0	0
Unrealized gains on marketable securities, tax	209	(459)	1,598
Retirement plans prior service benefit, tax	(778)	(622)	(453)
Foreign currency translation reclassification adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive (loss) income before reclassifications, 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	923	(1,667)
Amounts reclassified from accumulated other comprehensive income, tax	(255)
Amounts reclassified from accumulated other comprehensive income, tax	(255)	(390)	(645)
Other comprehensive income (loss), tax	668	(2,057)
Amortization of prior service credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive (loss) income before reclassifications, tax	34
Amounts reclassified from accumulated other comprehensive income, tax	(190)
Amounts reclassified from accumulated other comprehensive income, tax	(190)	(169)	$ (169)
Other comprehensive income (loss), tax	$ (156)	$ (169)

Reclassification Out of Accumul

Reclassification Out of Accumulated Other Comprehensive Income to Statements of Operations (Detail) - USD ($) $ in Thousands

3 Months Ended

12 Months Ended

Dec. 31, 2016

[1],[2]

Oct. 02, 2016

[2],[3]

Jul. 03, 2016

[2],[4]

Apr. 03, 2016

[2],[5]

Dec. 31, 2015

[6],[7]

Oct. 04, 2015

[8]

Jul. 05, 2015

[9]

Apr. 05, 2015

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]

Interest income

$ (3,095)

$ (2,892)

$ (1,666)

$ (1,642)

$ (2,017)

$ (1,708)

$ (1,674)

$ (1,816)

$ (9,296)

$ (7,214)

$ (6,259)

Reclassifications, net of tax

945

999

Unrealized Gains (Losses) on Marketable Securities

Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]

Reclassifications, net of tax

683

704

Amortization of prior service credit

Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]

Reclassifications, net of tax

321

295

295

Prior service cost arising during period

Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]

Reclassifications, net of tax

(59)

Retirement Plans Prior Service Credit

Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]

Reclassifications, net of tax

262

295

295

Accumulated Other Comprehensive Income (Loss)

Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]

Reclassifications, net of tax

945

999

1,728

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

$ 683

$ 704

$ 1,433

[1]

Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.

[2]

Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.

[3]

Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.

[4]

Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.

[5]

Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.

[6]

In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.

[7]

Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration.

[8]

Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.

[9]

Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration.

Reclassification Out of Accum85

Reclassification Out of Accumulated Other Comprehensive Income to Statements of Operations (Parenthetical) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	$ 411	$ 559	$ 814
Unrealized Gains (Losses) on Marketable Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	255	390	645
Amortization of prior service credit
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	190	169	169
Prior service cost arising during period
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, tax	$ (34)	$ 0	$ 0

Goodwill and Intangible Asset86

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands

3 Months Ended

12 Months Ended

Dec. 31, 2016

Oct. 02, 2016

[2],[4]

Jul. 03, 2016

Apr. 03, 2016

[2],[5]

Dec. 31, 2015

Oct. 04, 2015

[8]

Jul. 05, 2015

[9]

Apr. 05, 2015

Dec. 31, 2014

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Goodwill and Intangible Assets Disclosure [Line Items]

Goodwill impairment charge

$ 0

$ 254,946

[1],[2]

$ 98,897

$ 254,946

$ (254,946)

$ 98,897

Intangible assets impairment

83,339

[1],[2]

83,339

98,200

Intangible assets remaining balance

100,401

$ 239,831

100,401

239,831

Acquired intangible assets amortization

$ 7,923

[2],[3]

$ 8,487

$ 16,244

[1],[2]

$ 19,994

$ 19,911

[6],[7]

$ 20,053

$ 15,258

$ 13,808

52,648

69,031

70,771

System Test

Goodwill and Intangible Assets Disclosure [Line Items]

Goodwill impairment charge

$ 0

Wireless Test

Goodwill and Intangible Assets Disclosure [Line Items]

Employee reduction, percentage

11.00%

Goodwill, fair value

$ 8,000

Goodwill impairment charge

254,946

254,946

$ (254,946)

$ 98,897

Intangible assets impairment

$ 83,339

Intangible assets remaining balance

$ 5,000

Wireless Test | Sales Revenue, Segment | Customer Concentration Risk | Minimum

Goodwill and Intangible Assets Disclosure [Line Items]

Concentration risk, percentage

51.00%

Wireless Test | Sales Revenue, Segment | Customer Concentration Risk | Maximum

Goodwill and Intangible Assets Disclosure [Line Items]

Concentration risk, percentage

73.00%

[1]

Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.

[2]

Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.

[3]

Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.

[4]

Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.

[5]

Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.

[6]

In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.

[7]

Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration.

[8]

Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.

[9]

Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration.

Changes in Carrying Amount of G

Changes in Carrying Amount of Goodwill by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2016	Jul. 03, 2016		Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Jun. 11, 2015
Goodwill [Line Items]
Goodwill	$ 985,909			$ 781,058	$ 985,909	$ 996,033	$ 781,058
Accumulated impairment losses	(762,566)			(507,620)	(762,566)	(507,620)	(507,620)
Goodwill	223,343			273,438	223,343	488,413	273,438
Foreign currency translation adjustment						(10,124)	(6,153)
Goodwill impairment losses	0	$ 254,946	[1],[2]	98,897	254,946	(254,946)	98,897
Universal Robots
Goodwill [Line Items]
Goodwill								$ 221,128
Universal Robots acquisition							221,128
Industrial Automation
Goodwill [Line Items]
Goodwill	204,851				204,851	214,975
Goodwill	204,851				204,851	214,975
Foreign currency translation adjustment						(10,124)	(6,153)
Industrial Automation | Universal Robots
Goodwill [Line Items]
Universal Robots acquisition							221,128
System Test
Goodwill [Line Items]
Goodwill	158,699			158,699	158,699	158,699	158,699
Accumulated impairment losses	(148,183)			(148,183)	(148,183)	(148,183)	(148,183)
Goodwill	10,516			10,516	10,516	10,516	10,516
Goodwill impairment losses				0
Wireless Test
Goodwill [Line Items]
Goodwill	361,819			361,819	361,819	361,819	361,819
Accumulated impairment losses	(353,843)			(98,897)	(353,843)	(98,897)	(98,897)
Goodwill	7,976			262,922	7,976	262,922	262,922
Goodwill impairment losses		$ 254,946			254,946	(254,946)	98,897
Semiconductor Test
Goodwill [Line Items]
Goodwill	260,540			260,540	260,540	260,540	260,540
Accumulated impairment losses	$ (260,540)			$ (260,540)	$ (260,540)	$ (260,540)	$ (260,540)
[1]	Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.
[2]	Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.

Schedule of Amortizable Intangi

Schedule of Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016		Dec. 31, 2015
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 414,208	[1]	$ 546,388
Accumulated Amortization	306,868	[1],[2]	303,227	[3],[4]
Foreign Currency Translation Adjustment	(6,939)		(3,330)
Net Carrying Amount	$ 100,401		$ 239,831
Weighted Average Useful Life, years	6 years 9 months 18 days		6 years 8 months 12 days
Developed technology
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 270,877	[1]	$ 382,262
Accumulated Amortization	206,376	[1],[2]	220,346	[3],[4]
Foreign Currency Translation Adjustment	(5,093)		(2,444)
Net Carrying Amount	$ 59,408		$ 159,472
Weighted Average Useful Life, years	6 years		6 years
Customer Relationships
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 92,741	[1]	$ 110,602
Accumulated Amortization	76,707	[1],[2]	63,722	[3],[4]
Foreign Currency Translation Adjustment	(538)		(258)
Net Carrying Amount	$ 15,496		$ 46,622
Weighted Average Useful Life, years	7 years 10 months 24 days		7 years 10 months 24 days
Trademarks and tradenames
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 50,100	[1]	$ 53,034
Accumulated Amortization	23,435	[1],[2]	18,889	[3],[4]
Foreign Currency Translation Adjustment	(1,308)		(628)
Net Carrying Amount	$ 25,357		$ 33,517
Weighted Average Useful Life, years	9 years 6 months		9 years 6 months
Non-compete Agreements
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 320	[1]	$ 320
Accumulated Amortization	180	[1],[2]	100	[3],[4]
Net Carrying Amount	$ 140		$ 220
Weighted Average Useful Life, years	4 years		4 years
Customer backlog
Finite-Lived Intangible Assets
Gross Carrying Amount	$ 170	[1]	$ 170
Accumulated Amortization	$ 170	[1],[2]	$ 170	[3],[4]
Weighted Average Useful Life, years	3 months 18 days		3 months 18 days
[1]	During the year ended December 31, 2016, Teradyne recorded an $83.3 million impairment of Wireless Test amortizable intangible assets. The impairment assets have been eliminated from the gross carrying amount and accumulated amortization.
[2]	In 2016, $48.1 million of amortizable intangible assets became fully amortized and has been eliminated from the gross carrying amount and accumulated amortization.
[3]	During the year ended December 31, 2015, Teradyne recorded intangible assets in the amount of $121.6 million related to its Universal Robots acquisition.
[4]	During the year ended December 31, 2015, Teradyne wrote off $98.2 million of fully amortized intangible assets.

Schedule of Amortizable Intan89

Schedule of Amortizable Intangible Assets (Parenthetical) (Detail) - USD ($) $ in Thousands	Jun. 11, 2015	Jul. 03, 2016		Dec. 31, 2016		Dec. 31, 2015
Finite-Lived Intangible Assets
Fully amortized intangible assets wrote off		$ 83,339	[1],[2]	$ 83,339		$ 98,200
Gross Carrying Amount				414,208	[3]	546,388
Accumulated Amortization				306,868	[3],[4]	303,227	[5],[6]
Net Carrying Amount				100,401		239,831
Universal Robots
Finite-Lived Intangible Assets
Intangible assets	$ 121,590					$ 121,600
Wireless Test
Finite-Lived Intangible Assets
Fully amortized intangible assets wrote off				83,339
Net Carrying Amount		$ 5,000
Fully Amortized Intangibles
Finite-Lived Intangible Assets
Gross Carrying Amount				48,100
Accumulated Amortization				48,100
Net Carrying Amount				$ 0
[1]	Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.
[2]	Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[3]	During the year ended December 31, 2016, Teradyne recorded an $83.3 million impairment of Wireless Test amortizable intangible assets. The impairment assets have been eliminated from the gross carrying amount and accumulated amortization.
[4]	In 2016, $48.1 million of amortizable intangible assets became fully amortized and has been eliminated from the gross carrying amount and accumulated amortization.
[5]	During the year ended December 31, 2015, Teradyne recorded intangible assets in the amount of $121.6 million related to its Universal Robots acquisition.
[6]	During the year ended December 31, 2015, Teradyne wrote off $98.2 million of fully amortized intangible assets.

Schedule of Estimated Intangibl

Schedule of Estimated Intangible Asset Amortization Expense (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Finite-Lived Intangible Assets
2,017	$ 28,986
2,018	26,848
2,019	23,037
2,020	10,042
2,021	3,435
Thereafter	$ 8,053

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Purchase Commitment, Excluding Long-term Commitment
Aggregate purchase commitments	$ 260.7
Purchase commitments less than one year	247.9
Rental expense under lease commitments	$ 18.8	$ 15.9	$ 16
Warranty period	1 year
Product warranty accrual	$ 7.2	6.9
Revenue deferrals related to extended warranties	$ 46.8	$ 46.5

Non Cancelable Operating Lease

Non Cancelable Operating Lease Commitments (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Commitments and Contingencies Disclosure [Line Items]
2,017	$ 16,467
2,018	15,258
2,019	13,733
2,020	9,374
2,021	7,149
Beyond 2,022	10,130
Total	$ 72,111

Computation of Basic and Dilute

Computation of Basic and Diluted Net (Loss) Income Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended															12 Months Ended
		Dec. 31, 2016	[1],[2]	Oct. 02, 2016	[2],[3]	Jul. 03, 2016	[2],[4]	Apr. 03, 2016	[2],[5]	Dec. 31, 2015	[6],[7]	Oct. 04, 2015	[8]	Jul. 05, 2015	[9]	Apr. 05, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net Income Loss Per Common Share
Net (loss) income for basic and diluted net income per share		$ 66,345		$ 63,794		$ (223,546)		$ 49,986		$ (641)		$ 71,453		$ 102,879		$ 32,787	$ (43,421)	$ 206,477	$ 81,272
Weighted average common shares-basic																	202,578	211,544	202,908
Incremental shares from assumed conversion of convertible notes	[10]																		5,013
Convertible note hedge warrant shares	[11]																		12,562
Employee stock purchase rights																		41	31
Dilutive potential common shares																		1,777	19,642
Weighted average common shares-diluted																	202,578	213,321	222,550
Net (loss) income per common share-basic		$ 0.33		$ 0.32		$ (1.10)		$ 0.24		$ 0		$ 0.34		$ 0.48		$ 0.15	$ (0.21)	$ 0.98	$ 0.40
Net (loss) income per common share-diluted		$ 0.33		$ 0.31		$ (1.10)		$ 0.24		$ 0		$ 0.34		$ 0.48		$ 0.15	$ (0.21)	$ 0.97	$ 0.37
Restricted Stock Units
Net Income Loss Per Common Share
Incremental shares attributable to share based payment arrangements																		1,130	1,092
Stock Options
Net Income Loss Per Common Share
Incremental shares attributable to share based payment arrangements																		606	944
[1]	Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[2]	Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[3]	Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[4]	Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.
[5]	Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[6]	In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[7]	Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[8]	Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[9]	Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration.
[10]	Incremental shares from the assumed conversion of the convertible notes was calculated using the difference between the average Teradyne stock price for the period and the conversion price of $5.48, multiplied by 34.7 million shares. The result of this calculation, representing the total intrinsic value of the convertible debt, was divided by the average Teradyne stock price for the period.
[11]	Convertible notes hedge warrant shares were calculated using the difference between the average Teradyne stock price for the period and the warrant price of $7.67, multiplied by 34.7 million shares. The result of this calculation, representing the total intrinsic value of the warrant, was divided by the average Teradyne stock price for the period. Teradyne's call option on its common stock (convertible note hedge transaction) was excluded from the calculation of diluted shares because the effect was anti-dilutive.

Computation of Basic and Dilu94

Computation of Basic and Diluted Net (Loss) Income Per Common Share (Parenthetical) (Detail) - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2014
Convertible Notes
Net Income Loss Per Common Share
Initial debt conversion price	$ 5.48	$ 5.48
Shares that would be issued upon conversion	34.7	34.7
Convertible Notes Hedge Warrant
Net Income Loss Per Common Share
Initial debt conversion price	$ 7.67	$ 7.67
Shares that would be issued upon conversion	34.7	34.7

Net Income Per Common Share - A

Net Income Per Common Share - Additional Information (Detail) - shares shares in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Net Income Loss Per Common Share
Exercise of stock options	0.2	0.3

Restructuring and Other - Addit

Restructuring and Other - Additional Information (Detail) $ in Thousands	3 Months Ended						12 Months Ended
	Dec. 31, 2016USD ($)	Oct. 02, 2016USD ($)	Apr. 03, 2016USD ($)	Dec. 31, 2015USD ($)	Oct. 04, 2015USD ($)	Jul. 05, 2015USD ($)	Dec. 31, 2016USD ($)Employee	Dec. 31, 2015USD ($)Employee	Dec. 31, 2014USD ($)Employee
Restructuring Cost and Reserve
Other restructuring charges							$ 15,900	$ 3,600
Contingent consideration adjustment							15,896	2,489	$ (630)
Severance benefit and charges							2,100
Property, Plant and Equipment
Restructuring Cost and Reserve
Impairment of fixed assets and other expenses							4,200
Impairment of fixed assets and expenses related to the Japan earthquake
Restructuring Cost and Reserve
Property insurance, recovery							5,400
Impairment of fixed assets and expenses related to the Japan earthquake | Earthquake Related Expenses
Restructuring Cost and Reserve
Impairment of fixed assets and other expenses							1,200
Universal Robots
Restructuring Cost and Reserve
Contingent consideration adjustment	$ 5,400	$ 8,000	$ 1,200	$ 5,339			15,300	5,300
Acquisition related costs								1,000
Avionics Interface Technologies, LLC
Restructuring Cost and Reserve
Contingent consideration adjustment				$ (300)	$ (1,000)		600	(1,300)
Acquisition related costs									400
ZTEC Corporation and Avionics Interface Technologies LLC
Restructuring Cost and Reserve
Contingent consideration adjustment								(2,900)
ZTEC Instruments, Inc.
Restructuring Cost and Reserve
Contingent consideration adjustment						$ (1,600)		(1,600)	(600)
Semiconductor Test and Wireless Test
Restructuring Cost and Reserve
Severance benefit and charges							$ 6,000		$ 1,600
Reduction in employees headcount | Employee							146		43
Semiconductor Test and Wireless Test | Wireless Test
Restructuring Cost and Reserve
Reduction in employees headcount | Employee							102
Semiconductor Test and Wireless Test | Semiconductor Test
Restructuring Cost and Reserve
Reduction in employees headcount | Employee							44
System Test and Semiconductor Test
Restructuring Cost and Reserve
Severance benefit and charges								$ 1,500
Reduction in employees headcount | Employee								23

Schedule of Defined Benefit Pen

Schedule of Defined Benefit Pension and Postretirement Benefit Plan Assets and Obligation (Detail) - USD ($) $ in Thousands	3 Months Ended					12 Months Ended
	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure
Actuarial gain (loss)	$ 2,000	$ (700)	$ 700	$ 1,200	$ (17,700)
Ending Balance	334,900					$ 334,900
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Projected benefit obligation, Beginning of year				351,117		351,117	$ 367,619
Service cost						2,302	2,462	$ 2,218
Interest cost						13,630	13,142	12,875
Actuarial gain (loss)						6,053	(13,221)
Benefits paid						(19,486)	(18,885)
Projected benefit obligation, End of year	353,616				351,117	353,616	351,117	367,619
Beginning Balance				298,404		298,404	316,072
Company contributions						4,489	10,517
Benefits paid						(19,486)	(18,885)
Actual return on plan assets						23,897	(9,300)
Benefits paid						(19,486)	(18,885)
Settlements						0	0
Ending Balance	307,304				298,404	307,304	298,404	316,072
Funded status	(46,312)				(52,713)	(46,312)	(52,713)
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Projected benefit obligation, Beginning of year				62,290		62,290	58,210
Service cost						761	1,006	897
Interest cost						1,185	1,444	1,837
Actuarial gain (loss)						5,621	7,498
Benefits paid						(1,385)	(859)
Curtailment							(634)
Plan participants' contributions							64
Expenses paid						(609)	(43)
Non-U.S. currency movement						(7,125)	(4,439)
Projected benefit obligation, End of year	60,738				62,290	60,738	62,290	58,210
Beginning Balance				28,141		28,141	29,511
Company contributions						867	808
Plan participants' contributions							64
Benefits paid						(1,385)	(859)
Actual return on plan assets						5,142	(136)
Benefits paid						(1,148)	(859)
Settlements						0	0
Expenses paid						(609)	(43)
Non-U.S. currency movement						(4,822)	(1,204)
Ending Balance	27,571				28,141	27,571	28,141	29,511
Funded status	(33,167)				(34,149)	(33,167)	(34,149)
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Projected benefit obligation, Beginning of year				$ 6,030		6,030	7,162
Service cost						37	48	59
Interest cost						218	237	335
Plan amendments						(93)
Actuarial gain (loss)						5	(648)
Benefits paid						(687)	(769)
Projected benefit obligation, End of year	5,510				6,030	5,510	6,030	$ 7,162
Company contributions						687	769
Benefits paid						(687)	(769)
Funded status	$ (5,510)				$ (6,030)	$ (5,510)	$ (6,030)

Schedule of Amounts Recorded wi

Schedule of Amounts Recorded within Statements of Financial Position (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Retirement plans assets	$ 7,712	$ 636
Accrued employees' compensation and withholdings	(2,591)	(2,564)
Retirement plans liabilities	(51,433)	(50,785)
Funded status	(46,312)	(52,713)
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Accrued employees' compensation and withholdings	(772)	(695)
Retirement plans liabilities	(32,395)	(33,454)
Funded status	(33,167)	(34,149)
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Accrued employees' compensation and withholdings	(571)	(692)
Retirement plans liabilities	(4,939)	(5,338)
Funded status	$ (5,510)	$ (6,030)

Schedule of Amounts Recognized

Schedule of Amounts Recognized in Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure
Deferred taxes	$ (9,808)	$ (10,597)	$ (12,018)
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Prior service cost, before tax	127	224
Deferred taxes	514	479
Total recognized in other comprehensive income, net of tax	641	703
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Prior service cost, before tax	(1,118)	(1,632)
Deferred taxes	(1,292)	(1,100)
Total recognized in other comprehensive income, net of tax	$ (2,410)	$ (2,732)

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure
Accumulated other comprehensive income (loss), prior service cost expected to be recognized in 2017	$ 100
Fair value of pension plans assets totaled	$ 334,900
United States Plans
Defined Benefit Plan Disclosure
Percentage of expected return on plan assets assumption	4.80%
Discount rate utilized to determine future pension obligations	3.90%	4.00%
Fair value of pension plans assets totaled	$ 307,300
Contribution to defined benefit pension plans	1,900	$ 8,000
Contribution to defined benefit pension plans in 2016	1,900
U.K. Defined Benefit Pension Plan
Defined Benefit Plan Disclosure
Fair value of pension plans assets totaled	26,500
Taiwan Defined Benefit Pension Plan
Defined Benefit Plan Disclosure
Fair value of pension plans assets totaled	1,100
U.S. Supplemental Executive Defined Benefit Pension Plan
Defined Benefit Plan Disclosure
Contribution to defined benefit pension plans	2,600	2,500
Contribution to defined benefit pension plans in 2016	2,600
Non-United States Subsidiaries
Defined Benefit Plan Disclosure
Contribution to defined benefit pension plans	900	800
Contribution to defined benefit pension plans in 2016	800
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Accumulated benefit obligation for defined benefit pension plans	$ 342,900	$ 340,100
Percentage of expected return on plan assets assumption	4.80%	4.80%	5.00%
Discount rate utilized to determine future pension obligations	3.90%	4.00%
Fair value of pension plans assets totaled	$ 307,304	$ 298,404	$ 316,072
Contribution to defined benefit pension plans	4,489	10,517
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Accumulated benefit obligation for defined benefit pension plans	$ 56,600	$ 56,600
Percentage of expected return on plan assets assumption	2.00%	2.60%	3.40%
Discount rate utilized to determine future pension obligations	1.80%	2.30%
Fair value of pension plans assets totaled	$ 27,571	$ 28,141	$ 29,511
Contribution to defined benefit pension plans	867	$ 808
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Accumulated other comprehensive income (loss), prior service cost expected to be recognized in 2017	$ (500)
Discount rate utilized to determine future pension obligations	3.90%	3.90%	3.50%
Contribution to defined benefit pension plans	$ 687	$ 769

Schedule of Pension Plans with

Schedule of Pension Plans with Accumulated Benefit Obligation and Projected Benefit Obligation in Excess of Plan Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Projected benefit obligation	$ 54	$ 53.3
Accumulated benefit obligation	48	47.3
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Projected benefit obligation	34.3	35.2
Accumulated benefit obligation	30.1	29.5
Fair value of plan assets	$ 1.1	$ 1

Schedule of Net Periodic Pensio

Schedule of Net Periodic Pension and Postretirement (income) Cost (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure
Net actuarial (gain) loss	$ (3,203)	$ 17,732	$ 46,564
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Service cost	2,302	2,462	2,218
Interest cost	13,630	13,142	12,875
Expected return on plan assets	(13,830)	(14,517)	(12,500)
Amortization of prior service cost	96	134	135
Net actuarial (gain) loss	(4,013)	10,596	43,168
Total net periodic pension (income) cost	(1,815)	11,817	45,896
Prior service cost	(96)	(134)	(135)
Total recognized in other comprehensive income	(96)	(134)	(135)
Total recognized in net periodic pension (income) cost and other comprehensive income	(1,911)	11,683	45,761
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Service cost	761	1,006	897
Interest cost	1,185	1,444	1,837
Expected return on plan assets	(443)	(781)	(868)
Net actuarial (gain) loss	815	8,415	4,651
Curtailment		(634)
Total net periodic pension (income) cost	2,318	9,450	6,517
Total recognized in net periodic pension (income) cost and other comprehensive income	2,318	9,450	6,517
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Service cost	37	48	59
Interest cost	218	237	335
Amortization of prior service cost	(607)	(598)	(598)
Net actuarial (gain) loss	5	(648)	(1,255)
Total net periodic pension (income) cost	(347)	(961)	(1,459)
Prior service benefit	(93)
Prior service credit	607	598	598
Total recognized in other comprehensive income	514	598	598
Total recognized in net periodic pension (income) cost and other comprehensive income	$ 167	$ (363)	$ (861)

Schedule of Weighted Average -

Schedule of Weighted Average - Assumptions to Determine Net Periodic Pension Cost (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Discount rate	4.00%	3.70%	4.50%
Expected return on plan assets	4.80%	4.80%	5.00%
Salary progression rate	2.70%	2.90%	3.00%
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Discount rate	2.30%	2.60%	3.80%
Expected return on plan assets	2.00%	2.60%	3.40%
Salary progression rate	3.20%	3.20%	3.50%
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Discount rate	3.90%	3.50%	4.10%
Initial health care cost trend rate	7.50%	7.50%	8.00%
Ultimate health care cost trend rate	5.00%	5.00%	5.00%
Year in which ultimate health care cost trend rate is reached	2,023	2,022	2,020

Schedule of Weighted Average As

Schedule of Weighted Average Assumptions to Determine Pension Obligations (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Discount rate	3.90%	4.00%
Salary progression rate	2.60%	2.70%
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Discount rate	1.80%	2.30%
Salary progression rate	2.70%	3.20%
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
Discount rate	3.90%	3.90%	3.50%
Initial medical trend	7.30%	7.50%	7.50%
Ultimate health care trend	5.00%	5.00%	5.00%
Medical cost trend rate decrease to ultimate rate in year	2,023	2,023	2,022

Schedule of Weighted Average Pe

Schedule of Weighted Average Pension Assets Allocations by Category (Detail)	Dec. 31, 2016	Dec. 31, 2015
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Total	100.00%	100.00%
United States Pension Plans, Defined Benefit | Fixed income securities
Defined Benefit Plan Disclosure
Total	88.10%	88.60%
United States Pension Plans, Defined Benefit | Equity securities
Defined Benefit Plan Disclosure
Total	9.90%	9.80%
United States Pension Plans, Defined Benefit | Other than Securities Investment
Defined Benefit Plan Disclosure
Total	2.00%	1.60%
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Total	100.00%	100.00%
Foreign Pension Plans, Defined Benefit | Other than Securities Investment
Defined Benefit Plan Disclosure
Total	100.00%	100.00%

Schedule of Target Assets Alloc

Schedule of Target Assets Allocation (Detail)	12 Months Ended
	Dec. 31, 2016
Barclays Corporate A or Better Index | U.S. corporate fixed income
Defined Benefit Plan Disclosure
Target assets allocation percentage	76.00%
MSCI World Minimum Volatility Index | Global equity Securities
Defined Benefit Plan Disclosure
Target assets allocation percentage	10.00%
Barclays U.S. Long Government/Credit Bond Index | U.S. government fixed income
Defined Benefit Plan Disclosure
Target assets allocation percentage	8.00%
Barclays Corporate High Yield Issuer Cap Index | High yield fixed income
Defined Benefit Plan Disclosure
Target assets allocation percentage	5.00%
Citi Group Three Month Treasury Bill Index | Cash
Defined Benefit Plan Disclosure
Target assets allocation percentage	1.00%

Schedule of Fair Value of Pensi

Schedule of Fair Value of Pensions Plan Assets by Asset Category (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure
Total	$ 334,900
Group Annuity Insurance Contracts | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure
Total	29,456	$ 29,392	$ 2,990
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Total	307,304	298,404	316,072
United States Pension Plans, Defined Benefit | Quoted Prices in Active Markets for Identical Instruments (Level 1)
Defined Benefit Plan Disclosure
Total	3,023	1,773
United States Pension Plans, Defined Benefit | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure
Total	301,210	293,649
United States Pension Plans, Defined Benefit | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure
Total	3,071	2,982
United States Pension Plans, Defined Benefit | Corporate Debt Securities
Defined Benefit Plan Disclosure
Total	246,528	240,695
United States Pension Plans, Defined Benefit | Corporate Debt Securities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure
Total	246,528	240,695
United States Pension Plans, Defined Benefit | US Government Debt Securities
Defined Benefit Plan Disclosure
Total	24,322	23,761
United States Pension Plans, Defined Benefit | US Government Debt Securities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure
Total	24,322	23,761
United States Pension Plans, Defined Benefit | Global equity Securities
Defined Benefit Plan Disclosure
Total	30,360	29,193
United States Pension Plans, Defined Benefit | Global equity Securities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure
Total	30,360	29,193
United States Pension Plans, Defined Benefit | Group Annuity Insurance Contracts
Defined Benefit Plan Disclosure
Total	3,071	2,982
United States Pension Plans, Defined Benefit | Group Annuity Insurance Contracts | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure
Total	3,071	2,982
United States Pension Plans, Defined Benefit | Cash and Cash Equivalents
Defined Benefit Plan Disclosure
Total	3,023	1,773
United States Pension Plans, Defined Benefit | Cash and Cash Equivalents | Quoted Prices in Active Markets for Identical Instruments (Level 1)
Defined Benefit Plan Disclosure
Total	3,023	1,773
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Total	27,571	28,141	$ 29,511
Foreign Pension Plans, Defined Benefit | Quoted Prices in Active Markets for Identical Instruments (Level 1)
Defined Benefit Plan Disclosure
Total	62	702
Foreign Pension Plans, Defined Benefit | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure
Total	1,124	1,029
Foreign Pension Plans, Defined Benefit | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure
Total	26,385	26,410
Foreign Pension Plans, Defined Benefit | Group Annuity Insurance Contracts
Defined Benefit Plan Disclosure
Total	26,385	26,410
Foreign Pension Plans, Defined Benefit | Group Annuity Insurance Contracts | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure
Total	26,385	26,410
Foreign Pension Plans, Defined Benefit | Other
Defined Benefit Plan Disclosure
Total	1,124	1,029
Foreign Pension Plans, Defined Benefit | Other | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure
Total	1,124	1,029
Foreign Pension Plans, Defined Benefit | Cash and Cash Equivalents
Defined Benefit Plan Disclosure
Total	62	702
Foreign Pension Plans, Defined Benefit | Cash and Cash Equivalents | Quoted Prices in Active Markets for Identical Instruments (Level 1)
Defined Benefit Plan Disclosure
Total	$ 62	$ 702

Schedule of Defined Benefit Pla

Schedule of Defined Benefit Plans Disclosures (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure
Ending Balance	$ 334,900
Significant Unobservable Inputs (Level 3) | Group Annuity Insurance Contracts
Defined Benefit Plan Disclosure
Beginning Balance	29,392	$ 2,990
Purchases of group annuity insurance contracts	709	27,313
Interest and market value adjustments	5,308	(825)
Benefits paid	(611)	(67)
Other	(634)	(19)
Non-U.S. currency movement	(4,708)
Ending Balance	$ 29,456	$ 29,392

Schedule of Expected Future Ben

Schedule of Expected Future Benefit Payments (Detail) $ in Thousands	Dec. 31, 2016USD ($)
United States Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
2,017	$ 19,205
2,018	18,568
2,019	19,046
2,020	19,768
2,021	20,390
2022-2026	111,334
Foreign Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
2,017	788
2,018	754
2,019	780
2,020	1,054
2,021	882
2022-2026	5,209
Postretirement Benefit Plans
Defined Benefit Plan Disclosure
2,017	571
2,018	529
2,019	456
2,020	409
2,021	367
2022-2026	$ 1,536

Schedule of One Percent Point C

Schedule of One Percent Point Change in assumed Health Care Cost Trends Rate (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Defined Benefit Plan Disclosure
Effect of one percentage point increase on total service and interest cost components	$ 2
Effect of one percentage point increase on postretirement benefit obligations	44
Effect of one percentage point decrease on total service and interest cost components	(2)
Effect of one percentage point decrease on postretirement benefit obligations	$ (42)

Stock Based Compensation - Addi

Stock Based Compensation - Additional Information (Detail) - USD ($)	1 Months Ended							12 Months Ended
	Jan. 31, 2017	Jul. 31, 2016	Jan. 31, 2016	Jul. 31, 2015	Jan. 31, 2015	Jul. 31, 2014	Jan. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award
Percentage of common stock price paid								85.00%
Stock options term								7 years
Restricted stock unit awards granted								1,471,000	1,681,000	1,870,000
Weighted average grant date fair value of restricted stock units granted								$ 18.68	$ 17.36	$ 18.41
Stock options granted								130,000	132,000	89,000
Weighted average grant date fair value								$ 5.30	$ 4.43	$ 5.49
Tax benefit from compensation expense								$ 8,752,000	$ 8,528,000	$ 11,537,000
Total unrecognized expense related to non-vested restricted stock unit awards and stock options								$ 40,600,000
Unrecognized expense related to non-vested restricted stock unit awards and stock options expected to be recognized over weighted average period, in years								2 years 3 months 18 days
Stock based compensation expense							$ 6,600,000	$ 30,750,000	$ 30,451,000	$ 40,307,000
Maximum percent of shares allowed to purchase								10.00%
Fair market value								$ 25,000
Maximum number of shares allowed to purchase								6,000
Common stock issued to employees		500,000	500,000	500,000	500,000	500,000
Value of common stock issued to employees per share		$ 16.74	$ 17.57	$ 16.40	$ 16.82	$ 16.66
Number of shares available for grant								9,546,000	10,914,000	12,443,000	14,213,000
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
Cash received from employees, employee stock options exercises								$ 2,900,000	$ 2,800,000	$ 6,700,000
Tax benefit from compensation expense								$ 800,000	$ 2,100,000	$ 5,700,000
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Restricted stock unit awards granted								1,471,000	1,681,000	1,870,000
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%
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								100,000	200,000	100,000
Weighted average grant date fair value of restricted stock units granted								$ 20.29	$ 18.21	$ 22.06
Estimated annual dividend amount per share								0.24	0.24	0.24
Stock price								$ 19.43	$ 18.10	$ 19.16
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%
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares available for grant								3,900,000
PBIT Performance-Based Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Total shareholder return performance measurement period			3 years
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%
Subsequent Event
Share-based Compensation Arrangement by Share-based Payment Award
Common stock issued to employees	400,000
Value of common stock issued to employees per share	$ 21.59

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	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Risk-free interest rate	0.97%	0.77%	0.75%
Expected historical volatility	27.00%	28.20%	36.10%
Dividend yield	1.24%	1.33%	1.25%
New York Stock Exchange Composite Index
Share-based Compensation Arrangement by Share-based Payment Award
Expected historical volatility	13.10%
Philadelphia Semiconductor Index
Share-based Compensation Arrangement by Share-based Payment Award
Expected historical volatility		19.70%	24.60%

Schedule of Estimated Fair V113

Schedule of Estimated Fair Value of Stock Options Grant Using Black Scholes Option Pricing Model (Detail) - Stock Options	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Expected life (years)	5 years	4 years	4 years
Risk-free interest rate	1.40%	1.10%	1.20%
Volatility-historical	32.90%	33.40%	38.80%
Dividend yield	1.24%	1.33%	1.25%

Schedule of Stock Compensation

Schedule of Stock Compensation Plan Activity (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Awarded	1,471	1,681	1,870
Forfeited	(233)	(284)	(189)
Outstanding at January 1	1,121	1,507	2,706
Granted	130	132	89
Exercised	(324)	(518)	(1,248)
Forfeited			(38)
Expired	(2)		(2)
Outstanding at December 31	926	1,121	1,507
Vested and expected to vest at December 31	926	1,121	1,507
Exercisable at December 31	598	779	1,089
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Non-vested at January 1	4,070	4,352	4,636
Awarded	1,471	1,681	1,870
Vested	(1,530)	(1,679)	(1,965)
Forfeited	(233)	(284)	(189)
Non-vested at December 31	3,778	4,070	4,352

Schedule of Share Based Compens

Schedule of Share Based Compensation Total Shares Available (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Available for grant at January 1	10,914	12,443	14,213
Options granted	(130)	(132)	(89)
Restricted stock units awarded	(1,471)	(1,681)	(1,870)
Restricted stock units forfeited	233	284	189
Available for grant at December 31	9,546	10,914	12,443

Schedule of Weighted-Average Re

Schedule of Weighted-Average Restricted Stock Unit Award Fair Value (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Non-vested at January 1	$ 17.46	$ 17.24	$ 15.60
Awarded	18.68	17.36	18.41
Vested	17.21	16.85	14.38
Forfeited	17.57	17.08	16.97
Non-vested at December 31	$ 18.03	$ 17.46	$ 17.24

Schedule of Restricted Stock Un

Schedule of Restricted Stock Unit Awards Aggregate Intrinsic Value (Detail) - Restricted Stock Units - USD ($) $ / shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Vested	$ 30,008	$ 32,200	$ 37,160
Outstanding	$ 95,952	$ 84,129	$ 86,113
Expected to vest	$ 91,871	$ 79,611	$ 81,582

Schedule of Restricted Stock118

Schedule of Restricted Stock Units Weighted Average Remaining Contractual Terms (Detail) - Restricted Stock Units	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Outstanding	1 year 15 days	1 year 1 month 2 days	1 year 1 month 10 days
Expected to vest	1 year 11 days	1 year 29 days	1 year 1 month 6 days

Schedule of Weighted Average St

Schedule of Weighted Average Stock Options Exercise Price (Detail)	12 Months Ended
	Dec. 31, 2016$ / shares
Share-based Compensation Arrangement by Share-based Payment Award
Outstanding at January 1	$ 10.21
Options granted	19.43
Options exercised	9.06
Options expired	3.07
Outstanding at December 31	11.93
Exercisable at December 31	$ 8.32

Schedule of Stock Option Aggreg

Schedule of Stock Option Aggregated Intrinsic Value Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Exercised	$ 3,729	$ 7,255	$ 17,847
Outstanding	12,468	11,729	17,936
Vested and expected to vest	12,468	11,729	17,936
Exercisable	$ 10,217	$ 10,716	$ 16,101

Schedule of Stock Options Weigh

Schedule of Stock Options Weighted Average Remaining Contractual Terms (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Outstanding	3 years 10 months 24 days	4 years 2 months 12 days	4 years 6 months
Vested and expected to vest	3 years 10 months 24 days	4 years 2 months 12 days	4 years 6 months
Exercisable	3 years 2 months 12 days	3 years 10 months 24 days	4 years 2 months 12 days

Schedule of Significant Option

Schedule of Significant Option Groups Outstanding (Detail) shares in Thousands	12 Months Ended
	Dec. 31, 2016$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Shares | shares	926
Options Exercisable, Shares | shares	598
Options Outstanding, Weighted-Average Exercise Price	$ 11.93
Options Exercisable, Weighted-Average Exercise Price	$ 8.32
$1.48 - $2.67
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	3 years 8 months 27 days
Options Outstanding, Shares | shares	294
Options Exercisable, Shares | shares	294
Range Of Exercise Prices, Lower Limit	$ 1.48
Range Of Exercise Prices, Upper Limit	2.67
Options Outstanding, Weighted-Average Exercise Price	2.31
Options Exercisable, Weighted-Average Exercise Price	$ 2.31
$3.23 - $7.71
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	1 year 9 months 7 days
Options Outstanding, Shares | shares	75
Options Exercisable, Shares | shares	75
Range Of Exercise Prices, Lower Limit	$ 3.23
Range Of Exercise Prices, Upper Limit	7.71
Options Outstanding, Weighted-Average Exercise Price	4.26
Options Exercisable, Weighted-Average Exercise Price	$ 4.26
$16.23 - $18.10
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	3 years 6 months 4 days
Options Outstanding, Shares | shares	338
Options Exercisable, Shares | shares	185
Range Of Exercise Prices, Lower Limit	$ 16.23
Range Of Exercise Prices, Upper Limit	18.10
Options Outstanding, Weighted-Average Exercise Price	17.18
Options Exercisable, Weighted-Average Exercise Price	$ 16.87
$19.16 - $19.43
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	5 years 3 months 4 days
Options Outstanding, Shares | shares	219
Options Exercisable, Shares | shares	44
Range Of Exercise Prices, Lower Limit	$ 19.16
Range Of Exercise Prices, Upper Limit	19.43
Options Outstanding, Weighted-Average Exercise Price	19.32
Options Exercisable, Weighted-Average Exercise Price	$ 19.16

Stock Based Compensation (Detai

Stock Based Compensation (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$ 6,600	$ 30,750	$ 30,451	$ 40,307
Income tax benefit		(8,752)	(8,528)	(11,537)
Total stock-based compensation expense after income taxes		21,998	21,923	28,770
Cost Of Revenues
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		3,153	3,065	3,675
Engineering And Development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		9,458	9,362	10,146
Selling and Administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation		$ 18,139	$ 18,024	$ 26,486

Savings Plan - Additional Infor

Savings Plan - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Savings Plan [Line Items]
Savings plan maximum percentage of employees contribution allowable	20.00%
Percentage of employer contributions vested per year	25.00%
Maximum employment period considered for vesting of employers' contribution, in years	4 years
U.S. Qualified Pension Plan
Savings Plan [Line Items]
Maximum percentage of matching contributions made by the employer	100.00%	100.00%	100.00%
Percentage of employer match on employee contribution	4.00%	4.00%	4.00%
Savings Plan
Savings Plan [Line Items]
Amounts charged to statements of operations	$ 14.5	$ 13.5	$ 12.8

Schedule of (Loss) Income Befor

Schedule of (Loss) Income Before Income Taxes (Detail) - USD ($) $ in Thousands

3 Months Ended

12 Months Ended

Dec. 31, 2016

[1],[2]

Oct. 02, 2016

[2],[3]

Jul. 03, 2016

[2],[4]

Apr. 03, 2016

[2],[5]

Dec. 31, 2015

[6],[7]

Oct. 04, 2015

[8]

Jul. 05, 2015

[9]

Apr. 05, 2015

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Income Tax Disclosure [Line Items]

U.S.

$ (341,018)

$ 56,270

$ (151,889)

Non-U.S.

285,958

196,854

247,265

(Loss) income before income taxes

$ 58,884

$ 59,681

$ (230,817)

$ 57,192

$ (8,857)

$ 87,408

$ 132,136

$ 42,438

$ (55,060)

[10],[11]

$ 253,124

[10],[11]

$ 95,376

[10],[11]

[1]

Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.

[2]

Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.

[3]

Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.

[4]

Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.

[5]

Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.

[6]

In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.

[7]

Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration.

[8]

Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.

[9]

Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration.

[10]

Included in income (loss) before taxes are charges and credits related to restructuring and other, inventory charges, goodwill impairment charges and acquired intangible assets impairment charge.

[11]

Interest income, interest expense, other (income) expense, net, contingent consideration adjustments and pension and postretirement plans actuarial gains and losses are included in Corporate and Eliminations.

Schedule of (Benefit) Provision

Schedule of (Benefit) Provision for Income Taxes from Operations (Detail) - USD ($) $ in Thousands	3 Months Ended															12 Months Ended
	Dec. 31, 2016	[1],[2]	Oct. 02, 2016	[2],[3]	Jul. 03, 2016	[2],[4]	Apr. 03, 2016	[2],[5]	Dec. 31, 2015	[6],[7]	Oct. 04, 2015	[8]	Jul. 05, 2015	[9]	Apr. 05, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Line Items]
Current, U.S. Federal																$ 7,750	$ 16,635	$ 5,197
Current, Non-U.S.																41,579	35,707	28,157
Current, State																1,968	1,429	678
Current, Total																51,297	53,771	34,032
Deferred, U.S. Federal																(51,482)	(574)	(20,449)
Deferred, Non-U.S.																(9,240)	(7,761)	(404)
Deferred, State																(2,214)	1,211	925
Deferred, Total																(62,936)	(7,124)	(19,928)
Total (benefit) provision for income taxes	$ (7,461)		$ (4,113)		$ (7,271)		$ 7,206		$ (8,216)		$ 15,955		$ 29,257		$ 9,651	$ (11,639)	$ 46,647	$ 14,104
[1]	Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[2]	Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[3]	Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[4]	Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.
[5]	Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[6]	In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[7]	Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[8]	Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[9]	Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration.

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended															12 Months Ended
	Dec. 31, 2016		Oct. 02, 2016	[2],[3]	Jul. 03, 2016	[2],[4]	Apr. 03, 2016	[2],[5]	Dec. 31, 2015		Oct. 04, 2015	[8]	Jul. 05, 2015	[9]	Apr. 05, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Line Items]
Total (benefit) provision for income taxes	$ (7,461,000)	[1],[2]	$ (4,113,000)		$ (7,271,000)		$ 7,206,000		$ (8,216,000)	[6],[7]	$ 15,955,000		$ 29,257,000		$ 9,651,000	$ (11,639,000)	$ 46,647,000	$ 14,104,000
Effective tax rate																21.10%	18.40%	14.80%
Tax savings due to the tax holiday																$ 17,000,000	$ 11,500,000	$ 13,200,000
Tax savings due to the tax holiday, per share																$ 0.08	$ 0.05	$ 0.06
Tax holiday expiration date																December 31, 2020
Valuation allowance amount decrease/increase																$ 5,300,000
Valuation allowance includes net deferred tax assets	48,369,000								43,039,000							48,369,000	$ 43,039,000
Tax credit carryforwards, approximately	134,600,000															134,600,000
Tax credits carryforwards	57,313,000								44,684,000							57,313,000	44,684,000
Unrecognized tax benefits	38,958,000								36,792,000							38,958,000	36,792,000	$ 30,418,000	$ 21,203,000
Unrecognized tax benefits, if recognized would impact effective tax rate	27,600,000															27,600,000
Unrecognized tax benefits, if recognized would impact deferred taxes	11,400,000															11,400,000
Decrease in unrecognized tax benefits	800,000															800,000
Accrued interest and penalties	400,000								$ 500,000							400,000	500,000
Interest and penalties related to income tax																100,000	$ 200,000	$ 200,000
Deferred tax liability not been established	1,020,000,000															1,020,000,000
Do Not Expire
Income Taxes [Line Items]
Alternative minimum tax credits carryforwards	8,700,000															8,700,000
United States
Income Taxes [Line Items]
Tax credits carryforwards, business	45,300,000															45,300,000
Tax credits carryforwards	39,100,000															$ 39,100,000
United States | Earliest Tax Year
Income Taxes [Line Items]
Tax credit carryforward, expiration date																2,017
United States | Latest Tax Year
Income Taxes [Line Items]
Tax credit carryforward, expiration date																2,036
State and Local Jurisdiction
Income Taxes [Line Items]
Tax credits carryforwards	80,600,000															$ 80,600,000
State and Local Jurisdiction | Earliest Tax Year
Income Taxes [Line Items]
Tax credit carryforward, expiration date																2,017
State and Local Jurisdiction | Latest Tax Year
Income Taxes [Line Items]
Tax credit carryforward, expiration date																2,031
State and Local Jurisdiction | Do Not Expire
Income Taxes [Line Items]
Tax credits carryforwards	$ 47,400,000															$ 47,400,000
[1]	Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[2]	Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[3]	Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[4]	Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.
[5]	Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[6]	In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[7]	Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[8]	Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[9]	Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration.

Schedule of Reconciliation of E

Schedule of Reconciliation of Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Line Items]
U.S. statutory federal tax rate	35.00%	35.00%	35.00%
Foreign taxes	127.10%	(16.50%)	(58.10%)
U.S. research and development credit	15.80%	(3.00%)	(7.90%)
Domestic production activities deduction	2.30%	(1.00%)	(0.50%)
State income taxes, net of federal tax benefit	2.30%	0.40%	(0.10%)
Equity compensation	(2.70%)	0.60%	(1.80%)
Uncertain tax positions	(2.60%)	2.20%	7.90%
Goodwill impairment	(162.10%)		36.30%
Other, net	6.00%	0.70%	4.00%
Effective tax rate, Total	21.10%	18.40%	14.80%

Schedule of Components of Defer

Schedule of Components of Deferred Tax Assets Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Line Items]
Tax credits	$ 57,313	$ 44,684
Pension liabilities	31,581	31,742
Inventory valuations	31,227	29,445
Accruals	27,247	26,563
Deferred revenue	12,806	10,232
Equity compensation	9,922	9,674
Vacation accrual	7,874	7,354
Net operating loss carryforwards	5,244	7,989
Other	630	502
Gross deferred tax assets	183,844	168,185
Less: valuation allowance	(48,369)	(43,039)
Total deferred tax assets	135,475	125,146
Intangible assets	(22,887)	(68,433)
Depreciation	(17,117)	(20,541)
Marketable securities	(210)	(458)
Total deferred tax liabilities	(40,214)	(89,432)
Net deferred assets	$ 95,261	$ 35,714

Summary of Operating Loss Carry

Summary of Operating Loss Carryforwards (Detail) $ in Thousands	Dec. 31, 2016USD ($)
Operating Loss Carryforwards [Line Items]
State Operating Loss Carryforwards	$ 86,593
Foreign Operating Loss Carryforwards	6,529
2,017
Operating Loss Carryforwards [Line Items]
State Operating Loss Carryforwards	10,245
2,018
Operating Loss Carryforwards [Line Items]
State Operating Loss Carryforwards	8,562
2,019
Operating Loss Carryforwards [Line Items]
State Operating Loss Carryforwards	983
2,020
Operating Loss Carryforwards [Line Items]
State Operating Loss Carryforwards	1,248
2,021
Operating Loss Carryforwards [Line Items]
State Operating Loss Carryforwards	3,549
2022-2026
Operating Loss Carryforwards [Line Items]
State Operating Loss Carryforwards	18,044
2027-2031
Operating Loss Carryforwards [Line Items]
State Operating Loss Carryforwards	38,498
Beyond 2,031
Operating Loss Carryforwards [Line Items]
State Operating Loss Carryforwards	5,464
Foreign Operating Loss Carryforwards	129
Non-Expiring
Operating Loss Carryforwards [Line Items]
Foreign Operating Loss Carryforwards	$ 6,400

Schedule of Unrecognized Tax Be

Schedule of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Line Items]
Beginning balance as of January 1	$ 36,792	$ 30,418	$ 21,203
Tax positions for current year, Additions	9,766	6,626	8,414
Tax positions for prior years, Additions	187	792	3,781
Expiration of statutes, Reductions	(3,532)
Settlements with tax authorities, Reductions	(2,295)	(336)	(500)
Tax positions for prior years, Reductions	(1,960)	(708)	(2,480)
Ending balance as of December 31	$ 38,958	$ 36,792	$ 30,418

Operating Segment, Geographi132

Operating Segment, Geographic and Significant Customer Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2016CustomerSegment	Dec. 31, 2015Customer	Dec. 31, 2014Customer
Segment Reporting Information [Line Items]
Operating segments | Segment	4
Number of customer accounted for more than ten percent of consolidated revenue | Customer	2	1	0
Semiconductor Test | Consolidated Revenue | Customer Concentration Risk
Segment Reporting Information [Line Items]
Concentration risk, percentage	25.00%	23.00%	22.00%
Semiconductor Test | Customer 1 | Consolidated Revenue | Revenue from Rights Concentration Risk
Segment Reporting Information [Line Items]
Concentration risk, percentage	12.00%	13.00%

Schedule of Segment Information

Schedule of Segment Information (Detail) - USD ($) $ in Thousands		3 Months Ended															12 Months Ended
		Dec. 31, 2016		Oct. 02, 2016	[2],[3]	Jul. 03, 2016	[2],[4]	Apr. 03, 2016	[2],[5]	Dec. 31, 2015		Oct. 04, 2015	[8]	Jul. 05, 2015	[9]	Apr. 05, 2015	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenues		$ 379,989	[1],[2]	$ 410,475		$ 531,792		$ 430,994		$ 318,444	[6],[7]	$ 465,994		$ 512,739		$ 342,401	$ 1,753,250	[10]	$ 1,639,578	[10]	$ 1,647,824	[10]
Income (loss) before taxes		58,884	[1],[2]	$ 59,681		$ (230,817)		$ 57,192		(8,857)	[6],[7]	$ 87,408		$ 132,136		$ 42,438	(55,060)	[11],[12]	253,124	[11],[12]	95,376	[11],[12]
Total assets	[13]	2,762,493								2,548,674							2,762,493		2,548,674		2,538,520
Property additions																	85,272		89,878		168,982
Depreciation and amortization expense																	120,009		140,773		152,544
Semiconductor Test
Segment Reporting Information [Line Items]
Revenues																	1,368,169		1,201,530		1,300,790
Income (loss) before taxes	[11],[12]																311,939		260,154		255,803
Total assets	[13]	557,546								610,869							557,546		610,869		580,501
Property additions																	70,543		79,052		159,783
Depreciation and amortization expense																	58,087		64,415		84,990
Wireless Test
Segment Reporting Information [Line Items]
Revenues																	96,204		184,572		184,535
Income (loss) before taxes	[11],[12]																(371,409)		(13,830)		(116,196)
Total assets	[13]	62,366								427,880							62,366		427,880		478,974
Property additions																	4,186		3,133		3,730
Depreciation and amortization expense																	25,921		53,440		53,308
System Test
Segment Reporting Information [Line Items]
Revenues																	189,846		211,584		162,499
Income (loss) before taxes	[11],[12]																28,916		25,101		12,116
Total assets	[13]	110,361								102,547							110,361		102,547		95,105
Property additions																	3,788		6,228		5,469
Depreciation and amortization expense																	6,551		4,391		5,399
Industrial Automation
Segment Reporting Information [Line Items]
Revenues																	99,031		41,892
Income (loss) before taxes	[11],[12]																(16,783)		(7,574)
Total assets	[13]	317,635								344,260							317,635		344,260
Property additions																	6,755		1,465
Depreciation and amortization expense																	26,869		14,500
Corporate And Eliminations
Segment Reporting Information [Line Items]
Income (loss) before taxes	[11],[12]																(7,723)		(10,727)		(56,347)
Total assets	[13]	$ 1,714,585								$ 1,063,118							1,714,585		1,063,118		1,383,940
Depreciation and amortization expense																	$ 2,581		$ 4,027		$ 8,847
[1]	Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[2]	Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[3]	Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[4]	Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.
[5]	Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[6]	In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[7]	Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[8]	Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[9]	Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration.
[10]	Revenues attributable to a country are based on location of customer site.
[11]	Included in income (loss) before taxes are charges and credits related to restructuring and other, inventory charges, goodwill impairment charges and acquired intangible assets impairment charge.
[12]	Interest income, interest expense, other (income) expense, net, contingent consideration adjustments and pension and postretirement plans actuarial gains and losses are included in Corporate and Eliminations.
[13]	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		1 Months Ended	3 Months Ended															12 Months Ended
		Jan. 31, 2014	Dec. 31, 2016		Oct. 02, 2016		Jul. 03, 2016		Apr. 03, 2016		Dec. 31, 2015		Oct. 04, 2015		Jul. 05, 2015		Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Goodwill impairment charge			$ 0				$ 254,946	[1],[2]									$ 98,897	$ 254,946	$ (254,946)	$ 98,897
Acquired intangible assets impairment charge							83,339	[1],[2]										83,339	98,200
Restructuring and other			5,570	[2],[3]	$ 12,177	[2],[4]	2,608	[1],[2]	$ 1,587	[2],[5]	$ 5,204	[6],[7]	$ 261	[8]	$ (385)	[9]		21,942	5,080	1,365
Contingent consideration adjustment																		15,896	2,489	(630)
Property insurance recovery																		(5,363)
Other (income) expense, net-Gain from the sale of an equity investment																			(5,406)
Stock based compensation expense		$ 6,600																30,750	30,451	40,307
Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment							1,400
Building impairment and other expenses							4,200
Selling and Administrative
Segment Reporting Information [Line Items]
Stock based compensation expense																		18,139	18,024	26,486
Universal Robots
Segment Reporting Information [Line Items]
Contingent consideration adjustment			$ 5,400		$ 8,000				$ 1,200		5,339							15,300	5,300
Acquisition related costs																			1,000
Universal Robots | Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment							800
Avionics Interface Technologies, LLC
Segment Reporting Information [Line Items]
Contingent consideration adjustment											$ (300)		$ (1,000)					600	(1,300)
Acquisition related costs																				400
Avionics Interface Technologies, LLC | Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment							600
ZTEC Instruments, Inc.
Segment Reporting Information [Line Items]
Contingent consideration adjustment															$ (1,600)				(1,600)	(600)
System Test
Segment Reporting Information [Line Items]
Goodwill impairment charge																	$ 0
Cost of revenues-inventory charge																		630	8,324	2,125
Restructuring and other																		(49)	1,037	742
Corporate And Eliminations
Segment Reporting Information [Line Items]
Restructuring and other																				198
Total																		15,896	(1,813)	6,538
Corporate And Eliminations | Restructuring and other
Segment Reporting Information [Line Items]
Property insurance recovery																		(5,363)
Acquisition related costs																			1,104	372
Corporate And Eliminations | Other (income) expense, net
Segment Reporting Information [Line Items]
Other (income) expense, net-Gain from the sale of an equity investment																			(5,406)
Corporate And Eliminations | Selling and Administrative
Segment Reporting Information [Line Items]
Stock based compensation expense	[10]																			6,598
Corporate And Eliminations | Impairment of fixed assets and expenses related to the Japan earthquake | Restructuring and other
Segment Reporting Information [Line Items]
Building impairment and other expenses																		5,363
Corporate And Eliminations | Universal Robots | Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment																		15,346	5,339
Corporate And Eliminations | Avionics Interface Technologies, LLC | Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment																		550	(1,250)
Corporate And Eliminations | ZTEC Instruments, Inc. | Restructuring and other
Segment Reporting Information [Line Items]
Contingent consideration adjustment																			(1,600)	(630)
Industrial Automation
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge	[11]																		1,567
Restructuring and other																		585
Wireless Test
Segment Reporting Information [Line Items]
Goodwill impairment charge							$ 254,946											254,946	(254,946)	98,897
Acquired intangible assets impairment charge																		83,339
Cost of revenues-inventory charge																		7,207	2,500	5,679
Restructuring and other																		2,650		565
Semiconductor Test
Segment Reporting Information [Line Items]
Cost of revenues-inventory charge																		9,656	10,508	14,389
Restructuring and other																		$ 2,860	$ 499	$ 490
[1]	Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.
[2]	Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[3]	Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[4]	Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[5]	Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[6]	In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[7]	Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[8]	Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[9]	Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration.
[10]	Expense related to the January 2014 retirement of Teradyne's former chief executive officer; see Note O: "Stock-Based Compensation."
[11]	Included in the cost of revenues for the year ended December 31, 2015 is the cost for purchase accounting inventory step-up.

Schedule of Revenues by Country

Schedule of Revenues by Country (Detail) - USD ($) $ in Thousands

3 Months Ended

12 Months Ended

Dec. 31, 2016

[1],[2]

Oct. 02, 2016

[2],[3]

Jul. 03, 2016

[2],[4]

Apr. 03, 2016

[2],[5]

Dec. 31, 2015

[6],[7]

Oct. 04, 2015

[8]

Jul. 05, 2015

[9]

Apr. 05, 2015

Dec. 31, 2016

Dec. 31, 2015

Dec. 31, 2014

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue from unaffiliated customers

$ 379,989

$ 410,475

$ 531,792

$ 430,994

$ 318,444

$ 465,994

$ 512,739

$ 342,401

$ 1,753,250

[10]

$ 1,639,578

[10]

$ 1,647,824

[10]

TAIWAN

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue from unaffiliated customers

[10]

653,076

436,389

495,942

UNITED STATES

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue from unaffiliated customers

[10]

221,948

217,386

213,104

CHINA

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue from unaffiliated customers

[10]

174,876

264,898

292,145

KOREA

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue from unaffiliated customers

[10]

147,882

120,224

145,608

JAPAN

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue from unaffiliated customers

[10]

135,978

128,228

63,761

Europe

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue from unaffiliated customers

[10]

117,671

111,903

111,043

MALAYSIA

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue from unaffiliated customers

[10]

103,472

76,707

83,910

SINGAPORE

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue from unaffiliated customers

[10]

73,172

105,216

119,421

PHILIPPINES

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue from unaffiliated customers

[10]

54,705

96,103

68,662

THAILAND

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue from unaffiliated customers

[10]

43,097

59,104

44,117

Rest Of The World

Revenues from External Customers and Long-Lived Assets [Line Items]

Revenue from unaffiliated customers

[10]

$ 27,373

$ 23,420

$ 10,111

[1]

Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.

[2]

Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.

[3]

Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.

[4]

Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.

[5]

Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.

[6]

In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.

[7]

Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration.

[8]

Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.

[9]

Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration.

[10]

Revenues attributable to a country are based on location of customer site.

Schedule of Long-Lived Assets b

Schedule of Long-Lived Assets by Geographic Area (Detail) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets		$ 253,821	$ 273,414
UNITED STATES
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets		189,195	198,424
Foreign
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	[1]	$ 64,626	$ 74,990
[1]	As of December 31, 2016 and 2015, long-lived assets attributable to Singapore were $31.5 million and $39.9 million, respectively.

Schedule of Long-Lived Asset137

Schedule of Long-Lived Assets by Geographic Area (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 253,821	$ 273,414
SINGAPORE
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 31,500	$ 39,900

Stock Repurchase Program - Addi

Stock Repurchase Program - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 31, 2015
Stock Repurchase Programs [Line Items]
Stock repurchase program, authorized amount		$ 500,000,000
Cumulative repurchases, shares		22.5
Cumulative repurchases, value		$ 446,000,000
Common stock average price		$ 19.87
Repurchase of stock, value		$ 146,331,000	$ 299,949,000
January Twenty Fifteen Share Repurchase Program
Stock Repurchase Programs [Line Items]
Stock repurchase program termination date		Dec. 31, 2016
Maximum
Stock Repurchase Programs [Line Items]
Stock repurchase program, authorized amount				$ 500,000,000
Scenario, Forecast | Minimum
Stock Repurchase Programs [Line Items]
Repurchase of stock, value	$ 200,000,000

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Subsequent Event	1 Months Ended
	Jan. 31, 2017$ / shares
Subsequent Event [Line Items]
Cash Dividends payable, amount per share	$ 0.07
Cash Dividends payable, date to be paid	Mar. 20, 2017
Cash Dividends payable, record date	Feb. 24, 2017

Consolidated Quarterly Statemen

Consolidated Quarterly Statements of Operations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2016		Oct. 02, 2016	[2],[3]	Jul. 03, 2016	[2],[4]	Apr. 03, 2016	[2],[5]	Dec. 31, 2015	[6],[7]	Oct. 04, 2015	[8]	Jul. 05, 2015	[9]	Apr. 05, 2015	Dec. 31, 2014	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Quarterly Financial Information [Line Items]
Products	$ 303,667	[1],[2]	$ 334,610		$ 456,832		$ 358,139		$ 244,510		$ 386,488		$ 437,243		$ 272,325		$ 1,453,248		$ 1,340,566		$ 1,364,024
Services	76,322	[1],[2]	75,865		74,960		72,855		73,934		79,506		75,496		70,076		300,002		299,012		283,800
Total revenues	379,989	[1],[2]	410,475		531,792		430,994		318,444		465,994		512,739		342,401		1,753,250	[10]	1,639,578	[10]	1,647,824	[10]
Cost of products	127,481	[1],[2]	148,266		215,795		167,555		120,322		170,963		181,491		118,996		659,097		591,772		640,787
Cost of services	33,502	[1],[2]	34,850		33,127		33,107		32,096		36,405		32,680		30,982		134,586		132,163		128,229
Total cost of revenues (exclusive of acquired intangible assets amortization shown separately below)	160,983	[1],[2]	183,116		248,922		200,662		152,418		207,368		214,171		149,978		793,683		723,935		769,016
Gross profit	219,006	[1],[2]	227,359		282,870		230,332		166,026		258,626		298,568		192,423		959,567		915,643		878,808
Engineering and development	70,052	[1],[2]	71,400		76,109		73,464		70,941		74,027		75,832		71,450		291,025		292,250		291,639
Selling and administrative	76,289	[1],[2]	78,794		81,425		79,174		79,718		77,481		77,073		72,041		315,682		306,313		319,713
Acquired intangible assets amortization	7,923	[1],[2]	8,487		16,244		19,994		19,911		20,053		15,258		13,808		52,648		69,031		70,771
Acquired intangible assets impairment					83,339												83,339		98,200
Goodwill impairment	0				254,946											$ 98,897	254,946		(254,946)		98,897
Restructuring and other	5,570	[1],[2]	12,177		2,608		1,587		5,204		261		(385)				21,942		5,080		1,365
Total operating expenses	159,834	[1],[2]	170,858		514,671		174,219		175,774		171,822		167,778		157,299		1,019,582		672,674		782,385
Income (loss) from operations	59,172	[1],[2]	56,501		(231,801)		56,113		(9,748)		86,804		130,790		35,124		(60,015)		242,969		96,423
Interest income	(3,095)	[1],[2]	(2,892)		(1,666)		(1,642)		(2,017)		(1,708)		(1,674)		(1,816)		(9,296)		(7,214)		(6,259)
Interest expense	1,604	[1],[2]	633		691		710		762		508		444		162		3,637		1,876		6,934
Other (income) expense, net	1,779	[1],[2]	(921)		(9)		(147)		364		596		(116)		(5,660)		704		(4,817)		372
Income (loss) before income taxes	58,884	[1],[2]	59,681		(230,817)		57,192		(8,857)		87,408		132,136		42,438		(55,060)	[11],[12]	253,124	[11],[12]	95,376	[11],[12]
Income tax provision (benefit)	(7,461)	[1],[2]	(4,113)		(7,271)		7,206		(8,216)		15,955		29,257		9,651		(11,639)		46,647		14,104
Net income (loss)	$ 66,345	[1],[2]	$ 63,794		$ (223,546)		$ 49,986		$ (641)		$ 71,453		$ 102,879		$ 32,787		$ (43,421)		$ 206,477		$ 81,272
Net income (loss) per common share-basic	$ 0.33	[1],[2]	$ 0.32		$ (1.10)		$ 0.24		$ 0		$ 0.34		$ 0.48		$ 0.15		$ (0.21)		$ 0.98		$ 0.40
Net income (loss) per common share-diluted	0.33	[1],[2]	0.31		(1.10)		0.24		0		0.34		0.48		0.15		(0.21)		0.97		0.37
Cash dividend declared per common share	$ 0.06	[1],[2]	$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.06		$ 0.24		$ 0.24		$ 0.18
[1]	Restructuring and other includes a $5.4 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[2]	Teradyne recorded pension and post retirement net actuarial (gains) losses of $(1.2) million, $(0.7) million, $0.7 million and $(2.0) million for the first, second, third and fourth quarter in 2016, respectively. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[3]	Restructuring and other includes an $8.0 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[4]	Restructuring and other includes $4.2 million for an impairment of fixed assets, $0.9 million for expenses related to an earthquake in Kumamoto, Japan, and $1.4 million for the increase in the fair value of contingent consideration liability of which $0.8 million related to Universal Robots, and $0.6 million related to AIT, partially offset by $5.1 million of property insurance recovery related to the Japan earthquake.
[5]	Restructuring and other includes a $1.2 million fair value adjustment to increase the Universal Robots acquisition contingent consideration.
[6]	In the fourth quarter ended December 31, 2015, Teradyne recorded pension and post retirement net actuarial losses of $17.7 million. See Note B: "Accounting Policies" for a discussion of Teradyne's accounting policy.
[7]	Restructuring and other includes a $5.3 million fair value adjustment to increase the Universal Robots acquisition contingent consideration, and a $(0.3) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[8]	Restructuring and other includes a $(1.0) million fair value adjustment to decrease the AIT acquisition contingent consideration.
[9]	Restructuring and other includes a $(1.6) million fair value adjustment to decrease the ZTEC acquisition contingent consideration.
[10]	Revenues attributable to a country are based on location of customer site.
[11]	Included in income (loss) before taxes are charges and credits related to restructuring and other, inventory charges, goodwill impairment charges and acquired intangible assets impairment charge.
[12]	Interest income, interest expense, other (income) expense, net, contingent consideration adjustments and pension and postretirement plans actuarial gains and losses are included in Corporate and Eliminations.

Consolidated Quarterly State141

Consolidated Quarterly Statements of Operations (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended							12 Months Ended
	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2015	Oct. 04, 2015	Jul. 05, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Quarterly Financial Information [Line Items]
Changes to fair value of contingent consideration								$ 15,896	$ 2,489	$ (630)
Pension and post retirement net actuarial losses (gain)	$ (2,000)	$ 700	$ (700)	$ (1,200)	$ 17,700
Restructuring and other
Quarterly Financial Information [Line Items]
Building impairment and other expenses			4,200
Changes to fair value of contingent consideration			1,400
Universal Robots
Quarterly Financial Information [Line Items]
Changes to fair value of contingent consideration	$ 5,400	$ 8,000		$ 1,200	5,339			15,300	5,300
Universal Robots | Restructuring and other
Quarterly Financial Information [Line Items]
Changes to fair value of contingent consideration			800
Avionics Interface Technologies, LLC
Quarterly Financial Information [Line Items]
Changes to fair value of contingent consideration					$ (300)	$ (1,000)		600	(1,300)
Avionics Interface Technologies, LLC | Restructuring and other
Quarterly Financial Information [Line Items]
Changes to fair value of contingent consideration			600
ZTEC Instruments, Inc.
Quarterly Financial Information [Line Items]
Changes to fair value of contingent consideration							$ (1,600)		$ (1,600)	$ (600)
Impairment of fixed assets and expenses related to the Japan earthquake
Quarterly Financial Information [Line Items]
Property insurance recovery								5,400
Impairment of fixed assets and expenses related to the Japan earthquake | Restructuring and other
Quarterly Financial Information [Line Items]
Property insurance recovery			5,100
Impairment of fixed assets and expenses related to the Japan earthquake | Earthquake Related Expenses
Quarterly Financial Information [Line Items]
Building impairment and other expenses								$ 1,200
Impairment of fixed assets and expenses related to the Japan earthquake | Earthquake Related Expenses | Restructuring and other
Quarterly Financial Information [Line Items]
Building impairment and other expenses			$ 900

Valuation and Qualifying Acc142

Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Allowance for Doubtful Accounts
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 2,407	$ 2,491	$ 2,912
Additions Charged to Cost and Expenses			55
Deductions	51	84	476
Balance at End of Period	2,356	2,407	2,491
Inventory Reserve
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	119,376	111,252	115,857
Additions Charged to Cost and Expenses	17,493	21,332	22,193
Other	4,417	1,680	7,064
Deductions	25,270	14,888	33,862
Balance at End of Period	116,016	119,376	111,252
Valuation Allowance of Deferred Tax Assets
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	43,039	41,737	40,386
Additions Charged to Cost and Expenses	5,413	1,322	1,380
Deductions	83	20	29
Balance at End of Period	$ 48,369	$ 43,039	$ 41,737