Waters (WAT) 10-Q 2 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 29, 2018	Oct. 26, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 29, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	WAT
Entity Registrant Name	WATERS CORP /DE/
Entity Central Index Key	1,000,697
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		75,745,720

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 689,373	$ 642,319
Investments	1,394,887	2,751,382
Accounts receivable, net	489,193	533,825
Inventories	313,614	270,294
Other current assets	83,702	72,314
Total current assets	2,970,769	4,270,134
Property, plant and equipment, net	338,472	349,278
Intangible assets, net	252,834	228,395
Goodwill	357,869	359,819
Other assets	123,114	116,728
Total assets	4,043,058	5,324,354
Current liabilities:
Notes payable and debt	284	100,273
Accounts payable	65,810	64,537
Accrued employee compensation	39,860	69,024
Deferred revenue and customer advances	186,485	166,840
Accrued income taxes	59,304	73,008
Accrued warranty	12,193	13,026
Other current liabilities	84,189	119,449
Total current liabilities	448,125	606,157
Long-term liabilities:
Long-term debt	1,148,061	1,897,501
Long-term portion of retirement benefits	63,696	67,334
Long-term income tax liabilities	429,611	456,949
Other long-term liabilities	77,133	62,625
Total long-term liabilities	1,718,501	2,484,409
Total liabilities	2,166,626	3,090,566
Commitments and contingencies (Notes 6, 7 and 11)
Stockholders' equity:
Preferred stock, par value $0.01 per share, 5,000 shares authorized, none issued at September 29, 2018 and December 31, 2017
Common stock, par value $0.01 per share, 400,000 shares authorized, 160,368 and 159,845 shares issued, 75,730 and 79,337 shares outstanding at September 29, 2018 and December 31, 2017, respectively	1,604	1,598
Additional paid-in capital	1,815,428	1,745,088
Retained earnings	5,810,053	5,405,380
Treasury stock, at cost, 84,638 and 80,509 shares at September 29, 2018 and December 31, 2017, respectively	(5,624,860)	(4,808,211)
Accumulated other comprehensive loss	(125,793)	(110,067)
Total stockholders' equity	1,876,432	2,233,788
Total liabilities and stockholders' equity	$ 4,043,058	$ 5,324,354

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 29, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value per share	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	160,368,000	159,845,000
Common stock, shares outstanding	75,730,000	79,337,000
Treasury stock, shares	84,638,000	80,509,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Revenues:
Total net sales	$ 578,021	$ 565,584	$ 1,704,910	$ 1,621,803
Costs and operating expenses:
Selling and administrative expenses	126,997	135,206	394,049	395,972
Research and development expenses	35,173	33,782	105,297	97,471
Litigation (settlement) provision	924		(748)	10,018
Purchased intangibles amortization	2,114	1,682	5,375	5,104
Acquired in-process research and development				5,000
Total costs and operating expenses	406,347	406,562	1,209,668	1,190,179
Operating income	171,674	159,022	495,242	431,624
Other (expense) income	(811)	12	(2,293)	64
Interest expense	(11,435)	(14,750)	(36,965)	(41,558)
Interest income	9,802	9,516	28,356	25,229
Income before income taxes	169,230	153,800	484,340	415,359
Provision for income taxes	28,216	17,696	75,698	41,876
Net income	$ 141,014	$ 136,104	$ 408,642	$ 373,483
Net income per basic common share	$ 1.84	$ 1.71	$ 5.26	$ 4.67
Weighted-average number of basic common shares	76,575	79,712	77,741	79,908
Net income per diluted common share	$ 1.83	$ 1.69	$ 5.21	$ 4.63
Weighted-average number of diluted common shares and equivalents	77,136	80,521	78,395	80,660
Product [Member]
Revenues:
Total net sales	$ 378,522	$ 375,550	$ 1,106,508	$ 1,072,684
Costs and operating expenses:
Costs and operating expenses	155,825	155,621	456,270	436,800
Service [Member]
Revenues:
Total net sales	199,499	190,034	598,402	549,119
Costs and operating expenses:
Costs and operating expenses	$ 85,314	$ 80,271	$ 249,425	$ 239,814

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 141,014	$ 136,104	$ 408,642	$ 373,483
Other comprehensive income (loss):
Foreign currency translation	5,309	26,827	(17,937)	94,209
Unrealized gains on investments before income taxes	1,631	318	108	1,700
Income tax expense	(382)	(9)	(125)	(108)
Unrealized gains (losses) on investments, net of tax	1,249	309	(17)	1,592
Retirement liability adjustment before reclassifications	(177)	(499)	107	(2,030)
Amounts reclassified to other income	904	894	2,720	2,652
Retirement liability adjustment before income taxes	727	395	2,827	622
Income tax expense	(177)	(183)	(599)	(570)
Retirement liability adjustment, net of tax	550	212	2,228	52
Other comprehensive income (loss)	7,108	27,348	(15,726)	95,853
Comprehensive income	$ 148,122	$ 163,452	$ 392,916	$ 469,336

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income	$ 408,642	$ 373,483
Adjustments to reconcile net income to net cash provided by operating activities:
Stock-based compensation	28,184	30,068
Deferred income taxes	278	3,046
Depreciation	44,710	45,454
Amortization of intangibles	38,101	32,795
In-process research and development		5,000
Change in operating assets and liabilities:
Decrease in accounts receivable	36,893	53,358
Increase in inventories	(47,826)	(26,217)
Increase in other current assets	(21,091)	(12,944)
Increase in other assets	(235)	(2,370)
Decrease in accounts payable and other current liabilities	(84,203)	(23,066)
Increase in deferred revenue and customer advances	23,085	29,332
Decrease in other liabilities	(3,641)	(2,483)
Net cash provided by operating activities	422,897	505,456
Cash flows from investing activities:
Additions to property, plant, equipment and software capitalization	(64,215)	(55,257)
Asset acquisitions	(31,486)
Investment in unaffiliated companies	(7,615)	(7,000)
Payments for intellectual property licenses		(5,000)
Purchases of investments	(908,147)	(2,345,259)
Maturities and sales of investments	2,269,181	2,008,528
Net cash provided by (used in) investing activities	1,257,718	(403,988)
Cash flows from financing activities:
Proceeds from debt issuances	10	130,190
Payments on debt	(850,000)	(64)
Proceeds from stock plans	42,377	72,821
Purchases of treasury shares	(816,649)	(245,742)
(Payments for) proceeds from derivative contracts	(2,181)	3,301
Net cash used in financing activities	(1,626,443)	(39,494)
Effect of exchange rate changes on cash and cash equivalents	(7,118)	36,202
Increase in cash and cash equivalents	47,054	98,176
Cash and cash equivalents at beginning of period	642,319	505,631
Cash and cash equivalents at end of period	$ 689,373	$ 603,807

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 29, 2018
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	1 Basis of Presentation and Summary of Significant Accounting Policies Waters Corporation (the “Company”) is a specialty measurement company that has pioneered analytical workflow solutions involving liquid chromatography, mass spectrometry and thermal analysis innovations serving the life, materials and food sciences for 60 years. The Company primarily designs, manufactures, sells and services high performance liquid chromatography (“HPLC”), ultra performance liquid chromatography (“UPLC TM (“LC-MS”) LC-MS TM The Company’s interim fiscal quarter typically ends on the thirteenth Saturday of each quarter. Since the Company’s fiscal year end is December 31, the first and fourth fiscal quarters may have more or less than thirteen complete weeks. The Company’s third fiscal quarters for 2018 and 2017 ended on September 29, 2018 and September 30, 2017, respectively. The accompanying unaudited interim consolidated financial statements have been prepared in accordance with the instructions to the Quarterly Report on Form 10-Q The preparation of consolidated financial statements in conformity with GAAP requires the Company to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent liabilities at the dates of the financial statements. Actual amounts may differ from these estimates under different assumptions or conditions. It is management’s opinion that the accompanying interim consolidated financial statements reflect all adjustments (which are normal and recurring) that are necessary for a fair statement of the results for the interim periods. The interim consolidated financial statements should be read in conjunction with the consolidated financial statements included in the Company’s Annual Report on Form 10-K Translation of Foreign Currencies The functional currency of each of the Company’s foreign operating subsidiaries is the local currency of its country of domicile, except for the Company’s subsidiaries in Hong Kong, Singapore and the Cayman Islands, where the underlying transactional cash flows are denominated in currencies other than the respective local currency of domicile. The functional currency of the Hong Kong, Singapore and Cayman Islands subsidiaries is the U.S. dollar, based on the respective entity’s cash flows. For most of the Company’s foreign operations, assets and liabilities are translated into U.S. dollars at exchange rates prevailing on the balance sheet date, while revenues and expenses are translated at average exchange rates prevailing during the respective period. Any resulting translation gains or losses are included in accumulated other comprehensive income in the consolidated balance sheets. Cash, Cash Equivalents and Investments Cash equivalents represent highly liquid investments, with original maturities of 90 days or less, while investments with longer maturities are classified as investments. The Company maintains cash balances in various operating accounts in excess of federally insured limits, and in foreign subsidiary accounts in currencies other than the U.S. dollar. As of September 29, 2018 and December 31, 2017, $942 million out of $2,084 million and $3,326 million out of $3,394 million, respectively, of the Company’s total cash, cash equivalents and investments were held by foreign subsidiaries. In addition, $341 million out of $2,084 million and $304 million out of $3,394 million of cash, cash equivalents and investments were held in currencies other than the U.S. dollar at September 29, 2018 and December 31, 2017, respectively. Accounts Receivable and Allowance for Doubtful Accounts Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The Company has very limited use of rebates and other cash considerations payable to customers and, as a result, the transaction price determination does not have any material variable consideration. The allowance for doubtful accounts is the best estimate of the amount of probable credit losses in the existing accounts receivable. The allowance is based on a number of factors, including historical experience and the customer’s credit-worthiness. The allowance for doubtful accounts is reviewed on at least a quarterly basis. Past due balances over 90 days and over a specified amount are reviewed individually for collectibility. Account balances are charged against the allowance when the Company determines it is probable that the receivable will not be recovered. The Company does not have any off-balance The following is a summary of the activity of the Company’s allowance for doubtful accounts for the nine months ended September 29, 2018 and September 30, 2017 (in thousands): Balance at Additions Deduction Balance at Allowance for Doubtful Accounts September 29, 2018 $ 6,109 $ 2,752 $ (2,175 ) $ 6,686 September 30, 2017 $ 5,140 $ 2,545 $ (1,586 ) $ 6,099 Fair Value Measurements In accordance with the accounting standards for fair value measurements and disclosures, certain of the Company’s assets and liabilities are measured at fair value on a recurring basis as of September 29, 2018 and December 31, 2017. Fair values determined by Level 1 inputs utilize observable data, such as quoted prices in active markets. Fair values determined by Level 2 inputs utilize data points other than quoted prices in active markets that are observable either directly or indirectly. Fair values determined by Level 3 inputs utilize unobservable data points for which there is little or no market data, which require the reporting entity to develop its own assumptions. The following table represents the Company’s assets and liabilities measured at fair value on a recurring basis at September 29, 2018 (in thousands): Total at Quoted Prices for Identical (Level 1) Significant Significant (Level 3) Assets: U.S. Treasury securities $ 271,918 $ — $ 271,918 $ — Foreign government securities 2,958 — 2,958 — Corporate debt securities 1,063,382 — 1,063,382 — Time deposits 179,271 — 179,271 — Waters 401(k) Restoration Plan assets 37,723 37,723 — — Foreign currency exchange contracts 116 — 116 — Interest rate cross-currency swap agreements 767 — 767 — Total $ 1,556,135 $ 37,723 $ 1,518,412 $ — Liabilities: Contingent consideration $ 3,701 $ — $ — $ 3,701 Foreign currency exchange contracts 828 — 828 — Total $ 4,529 $ — $ 828 $ 3,701 The following table represents the Company’s assets and liabilities measured at fair value on a recurring basis at December 31, 2017 (in thousands): Total at Quoted Prices Significant Significant (Level 3) Assets: U.S. Treasury securities $ 591,988 $ — $ 591,988 $ — Foreign government securities 6,952 — 6,952 — Corporate debt securities 1,975,160 — 1,975,160 — Time deposits 371,511 — 371,511 — Equity securities 147 — 147 — Waters 401(k) Restoration Plan assets 35,645 35,645 — — Foreign currency exchange contracts 566 — 566 — Total $ 2,981,969 $ 35,645 $ 2,946,324 $ — Liabilities: Contingent consideration $ 3,247 $ — $ — $ 3,247 Foreign currency exchange contracts 182 — 182 — Total $ 3,429 $ — $ 182 $ 3,247 Fair Value of 401(k) Restoration Plan Assets The 401(k) Restoration Plan is a nonqualified defined contribution plan and the assets were held in registered mutual funds and have been classified as Level 1. The fair values of the assets in the plan are determined through market and observable sources from daily quoted prices on nationally recognized securities exchanges. Fair Value of Cash Equivalents, Investments, Foreign Currency Exchange Contracts and Interest Rate Cross-Currency Swap Agreements The fair values of the Company’s cash equivalents, investments and foreign currency exchange contracts are determined through market and observable sources and have been classified as Level 2. These assets and liabilities have been initially valued at the transaction price and subsequently valued, typically utilizing third-party pricing services. The pricing services use many inputs to determine value, including reportable trades, benchmark yields, credit spreads, broker/dealer quotes, current spot rates and other industry and economic events. The Company validates the prices provided by third-party pricing services by reviewing their pricing methods and obtaining market values from other pricing sources. Fair Value of Contingent Consideration The fair value of the Company’s liability for contingent consideration relates to earnout payments in connection with the July 2014 acquisition of Medimass Research, Development and Service Kft. and is determined using a probability-weighted discounted cash flow model, which uses significant unobservable inputs, and has been classified as Level 3. Subsequent changes in the fair value of the contingent consideration liability are recorded in the results of operations. The fair value of the contingent consideration liability associated with future earnout payments is based on several factors, including the estimated future results and a discount rate that reflects both the likelihood of achieving the estimated future results and the Company’s creditworthiness. A change in any of these unobservable inputs can significantly change the fair value of the contingent consideration. Although there is no contractual limit, the fair value of future contingent consideration payments was estimated to be $4 million and $3 million at September 29, 2018 and December 31, 2017, respectively, based on the Company’s best estimate, as the earnout is based on future sales of certain products, some of which are currently in development, through 2034. Fair Value of Other Financial Instruments The Company’s accounts receivable, accounts payable and variable interest rate debt are recorded at cost, which approximates fair value due to their short-term nature. The carrying value of the Company’s fixed interest rate debt was $510 million and $610 million at September 29, 2018 and December 31, 2017, respectively. The fair value of the Company’s fixed interest rate debt was estimated using discounted cash flow models, based on estimated current rates offered for similar debt under current market conditions for the Company. The fair value of the Company’s fixed interest rate debt was estimated to be $495 million and $608 million at September 29, 2018 and December 31, 2017, respectively, using Level 2 inputs. Derivative Transactions The Company is a global company that operates in over 35 countries and, as a result, the Company’s net sales, cost of sales, operating expenses and balance sheet amounts are significantly impacted by fluctuations in foreign currency exchange rates. The Company is exposed to currency price risk on foreign currency exchange rate fluctuations when it translates its non-U.S. The Company’s principal strategies in managing exposures to changes in foreign currency exchange rates are to 1) naturally hedge the foreign-currency-denominated liabilities on the Company’s balance sheet against corresponding assets of the same currency, such that any changes in liabilities due to fluctuations in foreign currency exchange rates are typically offset by corresponding changes in assets and 2) mitigate foreign exchange risk exposure of international operations by hedging the variability in the movement of foreign currency exchange rates on a portion of its Euro-denominated net asset investments. The Company presents the derivative transactions in financing activities in the statement of cash flows. Foreign Currency Exchange Contracts The Company does not specifically enter into any derivatives that hedge foreign-currency-denominated assets, liabilities or commitments on its balance sheet, other than a portion of certain third-party accounts receivable and accounts payable, and the Company’s net worldwide intercompany receivables and payables, which are eliminated in consolidation. The Company periodically aggregates its net worldwide balances by currency and then enters into foreign currency exchange contracts that mature within 90 days to hedge a portion of the remaining balance to minimize some of the Company’s currency price risk exposure. The foreign currency exchange contracts are not designated for hedge accounting treatment. Principal hedged currencies include the Euro, Japanese yen, British pound, Mexican peso and Brazilian real. Interest Rate Cross-Currency Swap Agreements In July 2018, the Company entered into a three-year interest rate cross-currency swap derivative agreement with a notional value of $150 million to hedge the variability in the movement of foreign currency exchange rates on a portion of its Euro-denominated net asset investments. Under hedge accounting, the change in fair value of the derivative that relates to changes in the foreign currency spot rate are recorded in the currency translation adjustment in other comprehensive income and remain in accumulated comprehensive income in stockholders’ equity until the sale or substantial liquidation of the foreign operation. The difference between the interest rate received and paid under the interest rate cross-currency swap derivative agreement is recorded in interest income in the statement of operations. The Company’s foreign currency exchange contracts and interest rate cross-currency swap agreements included in the consolidated balance sheets are classified as follows (in thousands): September 29, 2018 December 31, 2017 Notional Value Fair Value Notional Value Fair Value Foreign exchange contracts: Other current assets $ 37,927 $ 116 $ 110,759 $ 566 Other current liabilities $ 105,885 $ 828 $ 37,104 $ 182 Interest rate cross-currency swap agreements: Other assets $ 150,000 $ 767 $ — $ — Accumulated other comprehensive income $ (767 ) $ — The following is a summary of the activity included in the statements of comprehensive income related to the foreign currency exchange contracts (in thousands): Financial Statement Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Foreign currency exchange contracts: Realized (losses) gains on closed contracts Cost of sales $ (23 ) $ 2,871 $ (2,181 ) $ 3,301 Unrealized (losses) gains on open contracts Cost of sales (5 ) (1,258 ) (1,097 ) 819 Cumulative net pre-tax Cost of sales $ (28 ) $ 1,613 $ (3,278 ) $ 4,120 Interest rate cross-currency swap agreements: Interest earned Interest income $ 927 $ — $ 927 $ — Unrealized gains on open contracts Stockholders’ equity $ 767 $ — $ 767 $ — Stockholders’ Equity In April 2018, the Company’s Board of Directors authorized the Company to repurchase up to $3 billion of its outstanding common stock over a three-year period. This new program adds the remaining $526 million from the pre-existing Product Warranty Costs The Company accrues estimated product warranty costs at the time of sale, which are included in cost of sales in the consolidated statements of operations. While the Company engages in extensive product quality programs and processes, including actively monitoring and evaluating the quality of its component suppliers, the Company’s warranty obligation is affected by product failure rates, material usage and service delivery costs incurred in correcting a product failure. The amount of the accrued warranty liability is based on historical information, such as past experience, product failure rates, number of units repaired and estimated costs of material and labor. The liability is reviewed for reasonableness at least quarterly. The following is a summary of the activity of the Company’s accrued warranty liability for the nine months ended September 29, 2018 and September 30, 2017 (in thousands): Balance at Accruals for Settlements Balance at Accrued warranty liability: September 29, 2018 $ 13,026 $ 6,068 $ (6,901 ) $ 12,193 September 30, 2017 $ 13,391 $ 6,287 $ (6,823 ) $ 12,855 Other Commitments In February 2018, the Company’s Board of Directors approved expanding its precision chemistry consumable manufacturing operations in the U.S. The Company anticipates spending an estimated $215 million to build and equip the new state-of-the-art

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 29, 2018
Revenue from Contract with Customer [Abstract]
Revenue Recognition	2 Revenue Recognition The Company adopted new accounting guidance regarding the recognition of revenue from contracts with customers as of January 1, 2018. The Company recognizes revenue upon transfer of control of promised products and services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. The Company generally enters into contracts that include a combination of products and services. Revenue is allocated to distinct performance obligations and is recognized net of allowances for returns and discounts. The Company recognizes revenue on product sales at the time control of the product transfers to the customer. In substantially all of the Company’s arrangements, title of our products transfers at shipping point and, as a result, the Company determined control transfers at the point of shipment. In more limited cases, there are destination-based shipping terms and, thus, control is deemed to transfer when the products arrive at the customer site. Incremental costs of obtaining a contract are expensed as and when incurred if the expected amortization period of the asset that would have been recognized is one year or less. Shipping and handling costs are included as a component of cost of sales. In situations where the control of the goods transfers prior to the completion of the Company’s obligation to ship the products to its customers, the Company has elected the practical expedient to account for the shipping services as a fulfillment cost. Accordingly, such costs are recognized when control of the related goods is transferred to the customer. In more rare situations, the Company has revenue associated with products that contain specific customer acceptance criteria and the related revenue is not recognized before the customer acceptance criteria are satisfied. The Company elected to exclude from the measurement of the transaction price all taxes assessed by a governmental authority that are both imposed on and concurrent with specific revenue-producing transactions and collected by the Company from a customer. Generally, the Company’s contracts for products include a performance obligation related to installation. The Company has determined that the installation represents a distinct performance obligation and revenue is recognized separately upon the completion of installation. The Company determines the amount of the transaction price to allocate to the installation service based on the standalone selling price of the product and the service, which requires judgment. The Company determines relative standalone selling price of installation based upon a number of factors, including hourly service billing rates and estimated installation hours. In developing these estimates, the Company considers past history, competition, billing rates of current services and other factors. The Company has sales from standalone software, which is included in instrument systems revenue. These arrangements typically include software licenses and maintenance contracts, both of which the Company has determined are distinct performance obligations. The Company determines the amount of the transaction price to allocate to the license and maintenance contract based on the relative standalone selling price of each performance obligation. Software license revenue is recognized at the point in time when control has been transferred to the customer. The revenue allocated to the software maintenance contract is recognized on a straight-line basis over the maintenance period, which is the contractual term of the contract, as a time-based measure of progress best reflects the Company’s performance in satisfying this obligation. Unspecified rights to software upgrades are typically sold as part of the maintenance contract on a when-and-if-available Payment terms and conditions vary among the Company’s revenue streams, although terms generally include a requirement of payment within 30 to 60 days of product shipment. Prior to providing payment terms to customers, an evaluation of the customer’s credit risk is performed. Returns and customer credits are infrequent and insignificant and are recorded as a reduction to sales. Rights of return are not included in sales arrangements and, therefore, there is minimal variable consideration included in the transaction price of our products. Service revenue includes (i) service and software maintenance contracts and (ii) service calls (time and materials). Instrument service contracts and software maintenance contracts are typically annual contracts, which are billed at the beginning of the contract or maintenance period. The amount of the service and software maintenance contract is recognized on a straight-line basis to revenue over the maintenance service period, which is the contractual term of the contract, as a time-based measure of progress best reflects the Company’s performance in satisfying this obligation. There are no deferred costs associated with the service contract, as the cost of the service is recorded when the service is performed. Service calls are recognized to revenue at the time a service is performed. The Company’s deferred revenue liabilities on the consolidated balance sheets consists of the obligation on instrument service contracts and customer payments received in advance, prior to shipment of the instrument. The Company records deferred revenue primarily related to its service contracts, where consideration is billable at the beginning of the service period. The following is a summary of the activity of the Company’s deferred revenue and customer advances for the nine months ended September 29, 2018 and September 30, 2017 (in thousands): September 29, September 30, Balance at the beginning of the period $ 192,590 $ 173,780 Recognition of revenue included in balance at beginning of the period (147,310 ) (132,435 ) Revenue deferred during the period, net of revenue recognized 179,571 169,337 Balance at the end of the period $ 224,851 $ 210,682 As of September 29, 2018 and December 31, 2017, $38 million and $26 million of deferred revenue and customer advances were classified in other long-term liabilities, respectively. The estimated amount of deferred revenue and customer advances equals the transaction price allocated to unfulfilled performance obligations for the period presented. Such amounts are expected to be recognized in the future as follows (in thousands): September 29, 2018 Deferred revenue and customer advances expected to be recognized: In one year or less $ 186,485 In 13-24 26,316 In 25 months and beyond 12,050 Total $ 224,851

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 29, 2018
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	3 Marketable Securities The Company’s marketable securities within cash equivalents and investments included in the consolidated balance sheets are detailed as follows (in thousands): September 29, 2018 Amortized Unrealized Unrealized Fair Value U.S. Treasury securities $ 272,812 $ — $ (894 ) $ 271,918 Foreign government securities 2,994 — (36 ) 2,958 Corporate debt securities 1,066,088 424 (3,130 ) 1,063,382 Time deposits 179,271 — — 179,271 Total $ 1,521,165 $ 424 $ (4,060 ) $ 1,517,529 Amounts included in: Cash equivalents $ 122,645 $ — $ (3 ) $ 122,642 Investments 1,398,520 424 (4,057 ) 1,394,887 Total $ 1,521,165 $ 424 $ (4,060 ) $ 1,517,529 December 31, 2017 Amortized Unrealized Unrealized Fair Cost Gain Loss Value U.S. Treasury securities $ 593,599 $ 82 $ (1,693 ) $ 591,988 Foreign government securities 6,982 — (30 ) 6,952 Corporate debt securities 1,977,329 897 (3,066 ) 1,975,160 Time deposits 371,515 — (4 ) 371,511 Equity securities 77 70 — 147 Total $ 2,949,502 $ 1,049 $ (4,793 ) $ 2,945,758 Amounts included in: Cash equivalents $ 194,377 $ — $ (1 ) $ 194,376 Investments 2,755,125 1,049 (4,792 ) 2,751,382 Total $ 2,949,502 $ 1,049 $ (4,793 ) $ 2,945,758 The estimated fair value of marketable debt securities by maturity date is as follows (in thousands): September 29, 2018 December 31, 2017 Due in one year or less $ 1,043,082 $ 1,722,553 Due after one year through three years 295,176 851,547 Total $ 1,338,258 $ 2,574,100

Inventories

Inventories	9 Months Ended
	Sep. 29, 2018
Inventory Disclosure [Abstract]
Inventories	4 Inventories Inventories are classified as follows (in thousands): September 29, 2018 December 31, 2017 Raw materials $ 112,588 $ 99,033 Work in progress 18,838 15,324 Finished goods 182,188 155,937 Total inventories $ 313,614 $ 270,294

Acquisitions and Investments in

Acquisitions and Investments in Unaffiliated Companies	9 Months Ended
	Sep. 29, 2018
Business Combinations [Abstract]
Acquisitions and Investments in Unaffiliated Companies	5 Acquisitions and Investments in Unaffiliated Companies In July 2018, the Company acquired the sole intellectual property rights to the Desorption Electrospray Ionization (“DESI”) imaging technology for $30 million in cash and a future contractual obligation to pay a minimum royalty of $3 million over the remaining life of the patent. DESI is a mass spectrometry imaging technique that is used to develop medical therapies. The Company accounted for this transaction as an asset acquisition as it did not meet the definition of a business. The Company allocated $33 million of fair value to a purchased intangible asset which will be amortized over the useful life of 12 years. During the three months ended September 29, 2018, the Company made $4 million of investments in unaffiliated companies, bringing the total investment in unaffiliated companies to $8 million for the nine months ended September 29, 2018.

Goodwill and Other Intangibles

Goodwill and Other Intangibles	9 Months Ended
	Sep. 29, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles	6 Goodwill and Other Intangibles The carrying amount of goodwill was $358 million and $360 million at September 29, 2018 and December 31, 2017, respectively. During the nine months ended September 29, 2018, the effect of foreign currency translation decreased goodwill by $2 million. The Company’s intangible assets included in the consolidated balance sheets are detailed as follows (dollars in thousands): September 29, 2018 December 31, 2017 Gross Accumulated Weighted- Gross Accumulated Weighted- Capitalized software $ 455,312 $ 306,286 5 years $ 438,652 $ 285,461 5 years Purchased intangibles 203,170 143,009 11 years 169,870 138,750 11 years Trademarks and IPR&D 13,827 — — 13,923 — — Licenses 5,733 4,901 6 years 5,840 4,628 6 years Patents and other intangibles 77,175 48,187 8 years 72,815 43,866 8 years Total $ 755,217 $ 502,383 7 years $ 701,100 $ 472,705 7 years The gross carrying value of intangible assets and accumulated amortization for intangible assets decreased by $11 million and $8 million, respectively, in the nine months ended September 29, 2018 due to the effects of foreign currency translation. Amortization expense for intangible assets was $12 million and $11 million for the three months ended September 29, 2018 and September 30, 2017, respectively. Amortization expense for intangible assets was $38 million and $33 million for the nine months ended September 29, 2018 and September 30, 2017, respectively. Amortization expense for intangible assets is estimated to be $53 million per year for each of the next five years.

Debt

Debt	9 Months Ended
	Sep. 29, 2018
Debt Disclosure [Abstract]
Debt	7 Debt In November 2017, the Company entered into a new credit agreement (the “2017 Credit Agreement”) that provides for a $1.5 billion revolving facility and a $300 million term loan. The revolving facility and term loan both mature on November 30, 2022 and require no scheduled prepayments before that date. The interest rates applicable to the 2017 Credit Agreement are, at the Company’s option, equal to either the alternate base rate (which is a rate per annum equal to the greatest of (a) the prime rate in effect on such day, (b) the Federal Reserve Bank of New York Rate on such day plus 1/2 of 1% per annum and (c) the adjusted LIBO rate on such day (or if such day is not a business day, the immediately preceding business day) for a deposit in U.S. dollars with a maturity of one month plus 1% per annum) or the applicable 1, 2, 3 or 6 month adjusted LIBO rate or EURIBO rate for Euro-denominated loans, in each case, plus an interest rate margin based upon the Company’s leverage ratio, which can range between 0 and 12.5 basis points for alternate base rate loans and between 80 and 112.5 basis points for LIBO rate or EURIBO rate loans. The facility fee on the 2017 Credit Agreement ranges between 7.5 and 25 basis points per annum, based on the leverage ratio, of the amount of the revolving facility commitments and the outstanding term loan. The 2017 Credit Agreement requires that the Company comply with an interest coverage ratio test of not less than 3.50:1 as of the end of any fiscal quarter for any period of four consecutive fiscal quarters and a leverage ratio test of not more than 3.50:1 as of the end of any fiscal quarter. In addition, the 2017 Credit Agreement includes negative covenants, affirmative covenants, representations and warranties and events of default that are customary for investment grade credit facilities. As of September 29, 2018 and December 31, 2017, the Company had a total of $560 million and $700 million of outstanding senior unsecured notes, respectively. Interest on the fixed rate senior unsecured notes is payable semi-annually each year. Interest on the floating rate senior unsecured notes is payable quarterly. The Company may prepay all or some of the senior unsecured notes at any time in an amount not less than 10% of the aggregate principal amount outstanding, plus the applicable make-whole amount or prepayment premium for Series H and J senior unsecured notes. In the event of a change in control of the Company (as defined in the note purchase agreement), the Company may be required to prepay the senior unsecured notes at a price equal to 100% of the principal amount thereof, plus accrued and unpaid interest. These senior unsecured notes require that the Company comply with an interest coverage ratio test of not less than 3.50:1 for any period of four consecutive fiscal quarters and a leverage ratio test of not more than 3.50:1 as of the end of any fiscal quarter. In addition, these senior unsecured notes include customary negative covenants, affirmative covenants, representations and warranties and events of default. In July 2018, the Company entered into a $150 million U.S.-to-Euro The Company had the following outstanding debt at September 29, 2018 and December 31, 2017 (in thousands): September 29, 2018 December 31, 2017 Foreign subsidiary lines of credit $ 284 $ 273 Senior unsecured notes - Series D - 3.22%, due March 2018 — 100,000 Total notes payable and debt, current 284 100,273 Senior unsecured notes - Series B - 5.00%, due February 2020 100,000 100,000 Senior unsecured notes - Series E - 3.97%, due March 2021 50,000 50,000 Senior unsecured notes - Series F - 3.40%, due June 2021 100,000 100,000 Senior unsecured notes - Series G - 3.92%, due June 2024 50,000 50,000 Senior unsecured notes - Series H - floating rate*, due June 2024 50,000 50,000 Senior unsecured notes - Series I - 3.13%, due May 2023 50,000 50,000 Senior unsecured notes - Series J - floating rate**, due May 2024 — 40,000 Senior unsecured notes - Series K - 3.44%, due May 2026 160,000 160,000 Credit agreement 590,000 1,300,000 Unamortized debt issuance costs (1,939 ) (2,499 ) Total long-term debt 1,148,061 1,897,501 Total debt $ 1,148,345 $ 1,997,774 * Series H senior unsecured notes bear interest at a 3-month ** Series J senior unsecured notes bore interest at a 3-month As of September 29, 2018 and December 31, 2017, the Company had a total amount available to borrow under existing credit agreements of $1,208 million and $498 million, respectively, after outstanding letters of credit. During the nine months ended September 29, 2018, the Company reduced its outstanding debt by $850 million using cash repatriated under the 2017 Tax Cuts and Jobs Act. The weighted-average interest rates applicable to the senior unsecured notes and credit agreement borrowings collectively were 3.64% and 2.98% at September 29, 2018 and December 31, 2017, respectively. As of September 29, 2018, the Company was in compliance with all debt covenants. The Company and its foreign subsidiaries also had available short-term lines of credit totaling $90 million and $91 million at September 29, 2018 and December 31, 2017, respectively, for the purpose of short-term borrowing and issuance of commercial guarantees. The weighted-average interest rate applicable to these short-term borrowings was 1.48% for both September 29, 2018 and December 31, 2017.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 29, 2018
Income Tax Disclosure [Abstract]
Income Taxes	8 Income Taxes In December 2017, the U.S. enacted legislation informally referred to as the Tax Cuts and Jobs Act (the “2017 Tax Act”). For the year ended December 31, 2017 the Company accrued a $550 million tax provision related to the 2017 Tax Act. The $550 million expense consisted of $490 million related to the federal toll charge, $40 million for state income taxes and foreign withholding taxes and $20 million for the revaluation of the Company’s deferred tax assets and liabilities at the new federal tax rate of 21%. During the third quarter of 2018, the Internal Revenue Service issued proposed regulations on the federal toll charge and various states issued additional guidance. The Company revised its analysis and calculation of the federal toll charge. In addition, the Company was able to conclude upon the treatment in certain state jurisdictions and expects to complete its analysis in the fourth quarter of 2018. As a result of the new guidance issued and additional work to complete the calculation of its federal toll charge, the Company reduced its provisional accrual for federal, state and foreign taxes by net $19 million during the three months ended September 29, 2018. In addition, the Company also assessed its uncertain tax positions related to these taxes and accrued income tax reserves of $18 million during both the three months ended and nine months ended September 29, 2018. The Company will continue to analyze any new guidance from the tax authorities, as well as any new information, and expects to finalize its analysis of the toll charge and related liabilities, including uncertain tax positions, in the fourth quarter of 2018 pursuant to SEC Staff Accounting Bulletin No. 118. As part of the 2017 Tax Act, there is a provision for the taxation of certain off-shore Low-Taxed off-shore The four principal jurisdictions in which the Company manufactures are the U.S., Ireland, the U.K. and Singapore, where the statutory tax rates are 21%, 12.5%, 19% and 17%, respectively, as of September 29, 2018. The Company has a contractual tax rate of 0% on qualifying activities in Singapore through March 2021, based upon the achievement of certain contractual milestones, which the Company expects to continue to meet. The effect of applying the contractual tax rate rather than the statutory tax rate to income from qualifying activities in Singapore increased the Company’s net income for the nine months ended September 29, 2018 and September 30, 2017 by $21 million and $18 million, respectively, and increased the Company’s net income per diluted share by $0.26 and $0.23, respectively. The Company’s effective tax rate for the three months ended September 29, 2018 and September 30, 2017 was 16.7% and 11.5%, respectively. The Company’s effective tax rate for the nine months ended September 29, 2018 and September 30, 2017 was 15.6% and 10.1%, respectively. The increase in the effective tax rate of 5.2 percentage points and 5.5 percentage points for the three and nine months ended September 29, 2018, respectively, can be primarily attributed to the following: • The impact of the change in foreign currency exchange rates on the earnings taxed in December 2017 under the toll charge of the 2017 Tax Act and other related matters, which increased our effective tax rate by 1.4 percentage points (or $2 million) and 1.3 percentage points (or $6 million) for the three and nine months ended September 29, 2018, respectively, as compared to the previous periods in 2017. • The impact of the reduction in tax benefit related to stock-based compensation, which increased the effective tax rate by 1.6 percentage points (or $2 million) and 1.8 percentage points ($6 million) for the three and nine months ended September 29, 2018, respectively, as compared to the previous periods in 2017. • The impact of the increase in income tax reserves for uncertain tax positions and settlement of audits in 2018 as compared with the release of income tax reserves in 2017, which resulted in an increase in the Company’s effective tax rate of .7 percentage points for both the three and nine months ended September 29, 2018. The 2018 increase in the tax reserve for uncertain tax positions and settlement of audits added $2 million of tax expense to 2018. During the same period during 2017, there was a $3 million release of reserves due to the lapsing of the statutes of limitation. This movement in income tax reserves is without regard to the change for U.S. Tax Reform items noted above. • The most significant ongoing changes applicable to the Company under the 2017 Tax Act are the reduction in the U.S. federal income tax rate from 35% to 21% and the new GILTI provision described above. The impact of the GILTI provision is an increase of approximately 2.4 percentage points to the Company’s effective tax rates for both the three and nine months ended September 29, 2018. This detriment is significantly offset by the overall federal rate reduction, for no net impact in comparison to the same periods in the prior year. • The remaining differences between the effective tax rates can primarily be attributed to differences in the proportionate amounts of pre-tax The Company accounts for its uncertain tax return reporting positions in accordance with the accounting standards for income taxes, which require financial statement reporting of the expected future tax consequences of uncertain tax reporting positions on the presumption that all concerned tax authorities possess full knowledge of those tax reporting positions, as well as all of the pertinent facts and circumstances, but prohibit any discounting of unrecognized tax benefits associated with those reporting positions for the time value of money. The Company continues to classify interest and penalties related to unrecognized tax benefits as a component of the provision for income taxes. The following is a summary of the activity of the Company’s uncertain tax positions for the nine months ended September 29, 2018 and September 30, 2017 (in thousands): September 29, 2018 September 30, 2017 Balance at the beginning of the period $ 5,843 $ 9,964 Net changes in uncertain tax positions 19,097 (2,953 ) Balance at the end of the period $ 24,940 $ 7,011 As noted above, during the quarter and nine months ended September 29, 2018, the Company increased its income tax reserves for uncertain tax positions by $18 million related to the 2017 federal toll charge. With limited exceptions, the Company is no longer subject to tax audit examinations in significant jurisdictions for the years ended on or before December 31, 2013. However, carryforward tax attributes that were generated in years beginning on or before January 1, 2014 may still be adjusted upon examination by tax authorities if the attributes are utilized. The Company continuously monitors the lapsing of statutes of limitations on potential tax assessments for related changes in the measurement of unrecognized tax benefits, related net interest and penalties, and deferred tax assets and liabilities. As of September 29, 2018, the Company expects to record additional reductions in the measurement of its unrecognized tax benefits and related net interest and penalties of less than $1 million within the next twelve months due to potential tax audit settlements and the lapsing of statutes of limitations on potential tax assessments. The Company does not expect to record any other material reductions in the measurement of its unrecognized tax benefits within the next twelve months. The Company adopted new accounting guidance which eliminates the deferral of tax effects on intra-entity transfers other than inventory and requires an entity to recognize the income tax consequences when the transfer occurs. The Company adopted this standard as of January 1, 2018 with a $4 million charge to beginning retained earnings in the consolidated balance sheet.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 29, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	9 Stock-Based Compensation The Company maintains various shareholder-approved, stock-based compensation plans which allow for the issuance of incentive or non-qualified The Company accounts for stock-based compensation costs in accordance with the accounting standards for stock-based compensation, which require that all share-based payments to employees be recognized in the statements of operations, based on their grant date fair values. The Company recognizes the expense using the straight-line attribution method. The stock-based compensation expense recognized in the consolidated statements of operations is based on awards that ultimately are expected to vest; therefore, the amount of expense has been reduced for estimated forfeitures. Forfeitures are estimated based on historical experience. If actual results differ significantly from these estimates, stock-based compensation expense and the Company’s results of operations could be materially impacted. In addition, if the Company employs different assumptions in the application of these standards, the compensation expense that the Company records in the future periods may differ significantly from what the Company has recorded in the current period. The consolidated statements of operations for the three and nine months ended September 29, 2018 and September 30, 2017 include the following stock-based compensation expense related to stock option awards, restricted stock awards, restricted stock unit awards, performance stock unit awards and the employee stock purchase plan (in thousands): Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Cost of sales $ 488 $ 726 $ 1,696 $ 2,251 Selling and administrative expenses 6,731 10,768 22,855 25,558 Research and development expenses 1,994 780 3,633 2,259 Total stock-based compensation $ 9,213 $ 12,274 $ 28,184 $ 30,068 Stock Options In determining the fair value of the stock options, the Company makes a variety of assumptions and estimates, including volatility measures, expected yields and expected stock option lives. The fair value of each option grant was estimated on the date of grant using the Black-Scholes option pricing model. The Company uses implied volatility on its publicly-traded options as the basis for its estimate of expected volatility. The Company believes that implied volatility is the most appropriate indicator of expected volatility because it is generally reflective of historical volatility and expectations of how future volatility will differ from historical volatility. The expected life assumption for grants is based on historical experience for the population of non-qualified zero-coupon Nine Months Ended Options Issued and Significant Assumptions Used to Estimate Option Fair Values September 29, September 30, Options issued in thousands 147 217 Risk-free interest rate 2.7 % 2.2 % Expected life in years 6 6 Expected volatility 23.2 % 23.0 % Expected dividends — — Nine Months Ended Weighted-Average Exercise Price and Fair Value of Options on the Date of Grant September 29, September 30, Exercise price $ 205.37 $ 151.24 Fair value $ 57.99 $ 40.49 The following table summarizes stock option activity for the plans for the nine months ended September 29, 2018 (in thousands, except per share data): Number of Exercise Price per Share Weighted-Average Outstanding at December 31, 2017 2,039 $ 38.09 to $ 194.26 $ 124.41 Granted 147 $ 188.26 to $ 208.47 $ 205.37 Exercised (357 ) $ 38.09 to $ 154.33 $ 102.44 Canceled (137 ) $ 98.21 to $ 154.33 $ 126.13 Outstanding at September 29, 2018 1,692 $ 38.09 to $ 208.47 $ 135.94 Restricted Stock During the nine months ended September 29, 2018, the Company granted five thousand shares of restricted stock. The weighted-average fair value per share of these awards on the grant date was $194.73. Restricted Stock Units The following table summarizes the unvested restricted stock unit award activity for the nine months ended September 29, 2018 (in thousands, except per share data): Shares Weighted-Average Unvested at December 31, 2017 374 $ 124.81 Granted 91 $ 207.85 Vested (123 ) $ 117.68 Forfeited (18 ) $ 126.43 Unvested at September 29, 2018 324 $ 150.75 Restricted stock units are generally granted annually in February and vest in equal annual installments over a five-year period. Performance Stock Units The Company’s performance stock units are equity compensation awards with a market vesting condition based on the Company’s Total Shareholder Return (“TSR”) relative to the TSR of the components of the S&P Health Care Index. TSR is the change in value of a stock price over time, including the reinvestment of dividends. The vesting schedule ranges from 0% to 200% of the target shares awarded. In determining the fair value of the performance stock units, the Company makes a variety of assumptions and estimates, including volatility measures, expected yields and expected terms. The fair value of each performance stock unit grant was estimated on the date of grant using the Monte Carlo simulation model. The Company uses implied volatility on its publicly-traded options as the basis for its estimate of expected volatility. The Company believes that implied volatility is the most appropriate indicator of expected volatility because it is generally reflective of historical volatility and expectations of how future volatility will differ from historical volatility. The expected life assumption for grants is based on the performance period of the underlying performance stock units. The risk-free interest rate is the yield currently available on U.S. Treasury zero-coupon Nine Months Ended Performance Stock Units Issued and Significant Assumptions Used to Estimate Fair Values September 29, September 30, Performance stock units issued (in thousands) 16 20 Risk-free interest rate 2.0 % 1.5 % Expected life in years 2.8 3.0 Expected volatility 23.4 % 23.2 % Average volatility of peer companies 25.8 % 26.1 % Correlation coefficient 37.2 % 38.5 % Expected dividends — — The following table summarizes the unvested performance stock unit award activity for the nine months ended September 29, 2018 (in thousands, except per share data): Shares Weighted-Average Unvested at December 31, 2017 64 $ 196.29 Granted 16 $ 253.44 Forfeited (5 ) $ 188.45 Unvested at September 29, 2018 75 $ 209.00

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 29, 2018
Earnings Per Share [Abstract]
Earnings Per Share	10 Earnings Per Share Basic and diluted EPS calculations are detailed as follows (in thousands, except per share data): Three Months Ended September 29, 2018 Net Income Weighted- Per Share (Numerator) (Denominator) Amount Net income per basic common share $ 141,014 76,575 $ 1.84 Effect of dilutive stock option, restricted stock, performance stock unit and restricted stock unit securities — 561 (0.01 ) Net income per diluted common share $ 141,014 77,136 $ 1.83 Three Months Ended September 30, 2017 Net Income Weighted- Per Share (Numerator) (Denominator) Amount Net income per basic common share $ 136,104 79,712 $ 1.71 Effect of dilutive stock option, restricted stock, performance stock unit and restricted stock unit securities — 809 (0.02 ) Net income per diluted common share $ 136,104 80,521 $ 1.69 Nine Months Ended September 29, 2018 Net Income Weighted- Per Share (Numerator) (Denominator) Amount Net income per basic common share $ 408,642 77,741 $ 5.26 Effect of dilutive stock option, restricted stock, performance stock unit and restricted stock unit securities — 654 (0.05 ) Net income per diluted common share $ 408,642 78,395 $ 5.21 Nine Months Ended September 30, 2017 Net Income Weighted- Per Share (Numerator) (Denominator) Amount Net income per basic common share $ 373,483 79,908 $ 4.67 Effect of dilutive stock option, restricted stock, performance stock unit and restricted stock unit securities — 752 (0.04 ) Net income per diluted common share $ 373,483 80,660 $ 4.63 For the three and nine months ended September 29, 2018, the Company had 0.3 million and 0.1 million stock options that were antidilutive, respectively, due to having higher exercise prices than the Company’s average stock price during the period. For the three and nine months ended September 30, 2017, the Company had 0.4 million and 0.5 million stock options that were antidilutive, respectively. These securities were not included in the computation of diluted EPS. The effect of dilutive securities was calculated using the treasury stock method.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 29, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income	11 Accumulated Other Comprehensive Income The components of accumulated other comprehensive income (loss) are detailed as follows (in thousands): Currency Unrealized Gain Unrealized Gain Accumulated Balance at December 31, 2017 $ (69,418 ) $ (37,103 ) $ (3,546 ) $ (110,067 ) Other comprehensive (loss) income, net of tax (17,937 ) 2,228 (17 ) (15,726 ) Balance at September 29, 2018 $ (87,355 ) $ (34,875 ) $ (3,563 ) $ (125,793 )

Retirement Plans

Retirement Plans	9 Months Ended
	Sep. 29, 2018
Retirement Benefits [Abstract]
Retirement Plans	12 Retirement Plans The Company sponsors various retirement plans. The Company adopted new accounting guidance which requires that an employer disaggregate the service cost component from other components of net benefit cost. As a result of the adoption of this standard, the components of net periodic benefit cost other than the service cost component are included in other income in the consolidated statements of operations and all previous periods have been adjusted accordingly. The summary of the components of net periodic pension costs for the plans for the three and nine months ended September 29, 2018 and September 30, 2017 is as follows (in thousands): Three Months Ended September 29, 2018 September 30, 2017 U.S. U.S. Retiree Non-U.S. U.S. U.S. Retiree Non-U.S. Pension Healthcare Pension Pension Healthcare Pension Plans Plan Plans Plans Plan Plans Service cost $ 142 $ 142 $ 1,311 $ 113 $ 137 $ 1,311 Interest cost 1,622 159 406 1,707 155 386 Expected return on plan assets (1,708 ) (177 ) (486 ) (2,574 ) (146 ) (434 ) Net amortization: Prior service credit — (4 ) (30 ) — — (47 ) Net actuarial loss 771 — 167 693 — 248 Net periodic pension cost (benefit) $ 827 $ 120 $ 1,368 $ (61 ) $ 146 $ 1,464 Nine Months Ended September 29, 2018 September 30, 2017 U.S. U.S. Retiree Non-U.S. U.S. U.S. Retiree Non-U.S. Pension Healthcare Pension Pension Healthcare Pension Plans Plan Plans Plans Plan Plans Service cost $ 426 $ 425 $ 4,024 $ 338 $ 410 $ 3,802 Interest cost 4,868 477 1,250 5,122 464 1,112 Expected return on plan assets (5,123 ) (530 ) (1,442 ) (7,724 ) (440 ) (1,250 ) Net amortization: Prior service credit — (14 ) (93 ) — — (140 ) Net actuarial loss 2,312 — 515 2,078 — 714 Net periodic pension cost (benefit) $ 2,483 $ 358 $ 4,254 $ (186 ) $ 434 $ 4,238 In 2018, the Company’s board of directors approved the termination of its frozen U.S. defined benefit pension plans. The Company anticipates that it will take three to six months to settle all of these plans’ obligations and, during this timeframe, the Company may incur pension accounting charges in connection with the termination of these plans. During the three and nine months ended September 29, 2018, the Company contributed $5 million to the non-U.S.

Business Segment Information

Business Segment Information	9 Months Ended
	Sep. 29, 2018
Segment Reporting [Abstract]
Business Segment Information	13 Business Segment Information The Company’s business activities, for which discrete financial information is available, are regularly reviewed and evaluated by the chief operating decision maker. As a result of this evaluation, the Company determined that it has two operating segments: Waters TM TM The Waters operating segment is primarily in the business of designing, manufacturing, distributing and servicing LC and MS instruments, columns and other precision chemistry consumables that can be integrated and used along with other analytical instruments. The TA operating segment is primarily in the business of designing, manufacturing, distributing and servicing thermal analysis, rheometry and calorimetry instruments. The Company’s two operating segments have similar economic characteristics; product processes; products and services; types and classes of customers; methods of distribution; and regulatory environments. Because of these similarities, the two segments have been aggregated into one reporting segment for financial statement purposes. Please refer to the consolidated financial statements for financial information regarding the one reportable segment of the Company. Net sales for the Company’s products and services are as follows for the three and nine months ended September 29, 2018 and September 30, 2017 (in thousands): Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Product net sales: Waters instrument systems $ 238,986 $ 238,431 $ 677,017 $ 674,768 Chemistry consumables 95,979 92,879 293,818 271,606 TA instrument systems 43,557 44,240 135,673 126,310 Total product sales 378,522 375,550 1,106,508 1,072,684 Service net sales: Waters service 180,830 172,594 543,411 498,736 TA service 18,669 17,440 54,991 50,383 Total service sales 199,499 190,034 598,402 549,119 Total net sales $ 578,021 $ 565,584 $ 1,704,910 $ 1,621,803 Geographic sales information is presented below for the three and nine months ended September 29, 2018 and September 30, 2017 (in thousands): Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Net Sales: Asia: China $ 109,713 $ 96,141 $ 313,250 $ 275,367 Japan 43,549 42,202 129,497 125,058 Asia Other 68,934 70,996 216,634 219,723 Total Asia 222,196 209,339 659,381 620,148 Americas: United States 170,766 171,053 479,072 474,661 Americas Other 36,037 31,960 107,567 99,588 Total Americas 206,803 203,013 586,639 574,249 Europe 149,022 153,232 458,890 427,406 Total net sales $ 578,021 $ 565,584 $ 1,704,910 $ 1,621,803 Net sales by customer class are as follows for the three and nine months ended September 29, 2018 and September 30, 2017 (in thousands): Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Pharmaceutical $ 325,166 $ 321,963 $ 968,848 $ 921,423 Industrial 171,985 168,349 517,979 504,183 Governmental and academic 80,870 75,272 218,083 196,197 Total net sales $ 578,021 $ 565,584 $ 1,704,910 $ 1,621,803 Net sales for the Company recognized at a point in time versus over time are as follows for the three and nine months ended September 29, 2018 and September 30, 2017 (in thousands): Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Net sales recognized at a point in time: Instrument systems $ 282,543 $ 282,671 $ 812,690 $ 801,078 Chemistry consumables 95,979 92,879 293,818 271,606 Service sales recognized at a point in time (time & materials) 75,769 72,221 228,685 212,660 Total net sales recognized at a point in time 454,291 447,771 1,335,193 1,285,344 Net sales recognized over time: Service and software sales recognized over time (contracts) 123,730 117,813 369,717 336,459 Total net sales $ 578,021 $ 565,584 $ 1,704,910 $ 1,621,803

Recent Accounting Standard Chan

Recent Accounting Standard Changes and Developments	9 Months Ended
	Sep. 29, 2018
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Standard Changes and Developments	14 Recent Accounting Standard Changes and Developments Recently Adopted Accounting Standards In May 2014, amended accounting guidance was issued regarding the recognition of revenue from contracts with customers. The objective of this guidance is to significantly enhance comparability and clarify principles of revenue recognition practices across entities, industries, jurisdictions and capital markets. This guidance was originally effective for annual and interim reporting periods beginning after December 15, 2016; however, the Financial Accounting Standards Board (“FASB”) amended the standard in August 2015 to delay the effective period date by one year to annual and interim periods beginning after December 15, 2017. Adoption prior to December 15, 2016 was not permitted. In March 2016, the FASB clarified the implementation guidance on principal versus agent considerations and, in April 2016, clarification was made regarding certain aspects of identifying performance obligations and licensing implementation guidance. In May 2016, additional guidance was issued related to disclosure of remaining performance obligations, as well as other amendments to guidance on collectibility, non-cash In January 2016, accounting guidance was issued which primarily affects the classification and measurement of certain financial instruments, principally equity investments and certain financial liabilities. Under the new guidance, there will no longer be an available-for-sale In August 2016, accounting guidance was issued that clarifies the classification of certain cash flows. The new guidance addresses eight specific areas where current accounting guidance is either unclear or does not specifically address classification issues. This guidance is effective for annual and interim periods beginning after December 15, 2017 and early adoption is permitted. The Company adopted this standard as of January 1, 2018 and the adoption of this standard did not have a material impact on the Company’s cash flows. In October 2016, accounting guidance was issued regarding intra-entity transfers of assets other than inventory. The new guidance eliminates the deferral of tax effects on intra-entity transfers other than inventory and requires an entity to recognize the income tax consequences when the transfer occurs. The Company adopted this standard as of January 1, 2018 with a $4 million charge to beginning retained earnings in the consolidated balance sheet. Please see Note 8, “Income Taxes”, for additional information. In January 2017, accounting guidance was issued that clarifies the definition of a business. The new guidance provides a more robust framework to use in determining when a set of assets and activities is a business, thus narrowing the definition and the amount of transactions accounted for as business combinations. The Company adopted this standard as of January 1, 2018 and will apply this guidance prospectively to any business combination transactions that take place in the future. In March 2017, accounting guidance was issued regarding the presentation of net periodic pension cost and net periodic postretirement benefit cost. The new guidance requires that an employer disaggregate the service cost component from other components of net benefit cost, with service cost reported in the same line items as other compensation costs and the other components of net benefit costs presented outside income from operations. The Company adopted this standard as of January 1, 2018 and has reported the components of net periodic benefit cost other than the service cost component in other income on the consolidated statements of operations for all periods presented. Please see Note 12, “Retirement Plans”, for additional information. In May 2017, accounting guidance was issued that clarifies the accounting for a change to the terms or conditions of a share-based payment award. The standard provides more specific guidance for determining when a change to an award requires modification accounting and when it should be deemed purely administrative in nature. The Company adopted this standard as of January 1, 2018 and the adoption of this standard did not have a material impact on the Company’s financial position, results of operations and cash flows. In August 2017, accounting guidance was issued which simplifies the application of hedge accounting and enables companies to better portray the economics of their risk management activities in their financial statements. The Company adopted this standard in the second quarter of 2018, and this adoption did not have a material impact on the Company’s financial position, results of operations and cash flows. Recently Issued Accounting Standards In February 2016, accounting guidance was issued regarding the accounting for leases. This new comprehensive lease standard amends various aspects of existing accounting guidance for leases. The core principle of the new guidance will require lessees to present the assets and liabilities that arise from leases on their balance sheets. This guidance is effective for annual and interim reporting periods beginning after December 15, 2018 and early adoption is permitted. The Company will apply the prospective method of adoption and expects that the adoption of this standard will have a material effect on the Company’s balance sheet; however, it is not expected to have an overall material impact on the Company’s results of operations and cash flows. In June 2016, accounting guidance was issued that modifies the recognition of credit losses related to financial assets, such as debt securities, trade receivables, net investments in leases, off-balance available-for-sale. available-for-sale non-credit In January 2017, accounting guidance was issued that simplifies the accounting for goodwill impairment. The guidance eliminates step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. This guidance is effective for annual and interim periods beginning after December 15, 2019 and early adoption is permitted. The Company currently does not expect that the adoption of this standard will have a material effect on the Company’s financial position, results of operations and cash flows. In March 2017, accounting guidance was issued to amend the amortization period for certain purchased callable debt securities held at a premium. Specifically, the amortization period for certain callable debt securities will be shortened to end at the earliest call date. This guidance is effective for annual and interim periods beginning after December 15, 2018 and early adoption is permitted. The Company currently does not believe that the adoption of this standard will have a material impact on the Company’s financial position, results of operations and cash flows. In February 2018, accounting guidance was issued to address the impact of the 2017 Tax Cuts and Jobs Act on items recorded in accumulated other comprehensive income. Current accounting guidance requires deferred tax liabilities and assets to be adjusted for the effect of a change in tax laws or rates with the effect recorded in income from continuing operations, even if the related tax effects were originally recognized in other comprehensive income, the new guidance allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the 2017 Tax Act. This guidance is effective for annual and interim periods beginning after December 15, 2018 and early adoption is permitted. The Company is currently evaluating the potential impact that the adoption of this standard will have on the Company’s financial position, results of operations and cash flows.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 29, 2018
Accounting Policies [Abstract]
Fiscal Period	The Company’s interim fiscal quarter typically ends on the thirteenth Saturday of each quarter. Since the Company’s fiscal year end is December 31, the first and fourth fiscal quarters may have more or less than thirteen complete weeks. The Company’s third fiscal quarters for 2018 and 2017 ended on September 29, 2018 and September 30, 2017, respectively.
Basis of Accounting	The accompanying unaudited interim consolidated financial statements have been prepared in accordance with the instructions to the Quarterly Report on Form 10-Q
Principles of Consolidation	The consolidated financial statements include the accounts of the Company and its subsidiaries, which are wholly owned. All inter-company balances and transactions have been eliminated.
Use of Estimates	The preparation of consolidated financial statements in conformity with GAAP requires the Company to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent liabilities at the dates of the financial statements. Actual amounts may differ from these estimates under different assumptions or conditions.
Translation of Foreign Currencies	Translation of Foreign Currencies The functional currency of each of the Company’s foreign operating subsidiaries is the local currency of its country of domicile, except for the Company’s subsidiaries in Hong Kong, Singapore and the Cayman Islands, where the underlying transactional cash flows are denominated in currencies other than the respective local currency of domicile. The functional currency of the Hong Kong, Singapore and Cayman Islands subsidiaries is the U.S. dollar, based on the respective entity’s cash flows. For most of the Company’s foreign operations, assets and liabilities are translated into U.S. dollars at exchange rates prevailing on the balance sheet date, while revenues and expenses are translated at average exchange rates prevailing during the respective period. Any resulting translation gains or losses are included in accumulated other comprehensive income in the consolidated balance sheets.
Cash, Cash Equivalents and Investments	Cash, Cash Equivalents and Investments Cash equivalents represent highly liquid investments, with original maturities of 90 days or less, while investments with longer maturities are classified as investments. The Company maintains cash balances in various operating accounts in excess of federally insured limits, and in foreign subsidiary accounts in currencies other than the U.S. dollar. As of September 29, 2018 and December 31, 2017, $942 million out of $2,084 million and $3,326 million out of $3,394 million, respectively, of the Company’s total cash, cash equivalents and investments were held by foreign subsidiaries. In addition, $341 million out of $2,084 million and $304 million out of $3,394 million of cash, cash equivalents and investments were held in currencies other than the U.S. dollar at September 29, 2018 and December 31, 2017, respectively.
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 Company has very limited use of rebates and other cash considerations payable to customers and, as a result, the transaction price determination does not have any material variable consideration. The allowance for doubtful accounts is the best estimate of the amount of probable credit losses in the existing accounts receivable. The allowance is based on a number of factors, including historical experience and the customer’s credit-worthiness. The allowance for doubtful accounts is reviewed on at least a quarterly basis. Past due balances over 90 days and over a specified amount are reviewed individually for collectibility. Account balances are charged against the allowance when the Company determines it is probable that the receivable will not be recovered. The Company does not have any off-balance The following is a summary of the activity of the Company’s allowance for doubtful accounts for the nine months ended September 29, 2018 and September 30, 2017 (in thousands): Balance at Additions Deduction Balance at Allowance for Doubtful Accounts September 29, 2018 $ 6,109 $ 2,752 $ (2,175 ) $ 6,686 September 30, 2017 $ 5,140 $ 2,545 $ (1,586 ) $ 6,099
Fair Value Measurements	Fair Value Measurements In accordance with the accounting standards for fair value measurements and disclosures, certain of the Company’s assets and liabilities are measured at fair value on a recurring basis as of September 29, 2018 and December 31, 2017. Fair values determined by Level 1 inputs utilize observable data, such as quoted prices in active markets. Fair values determined by Level 2 inputs utilize data points other than quoted prices in active markets that are observable either directly or indirectly. Fair values determined by Level 3 inputs utilize unobservable data points for which there is little or no market data, which require the reporting entity to develop its own assumptions. The following table represents the Company’s assets and liabilities measured at fair value on a recurring basis at September 29, 2018 (in thousands): Total at Quoted Prices for Identical (Level 1) Significant Significant (Level 3) Assets: U.S. Treasury securities $ 271,918 $ — $ 271,918 $ — Foreign government securities 2,958 — 2,958 — Corporate debt securities 1,063,382 — 1,063,382 — Time deposits 179,271 — 179,271 — Waters 401(k) Restoration Plan assets 37,723 37,723 — — Foreign currency exchange contracts 116 — 116 — Interest rate cross-currency swap agreements 767 — 767 — Total $ 1,556,135 $ 37,723 $ 1,518,412 $ — Liabilities: Contingent consideration $ 3,701 $ — $ — $ 3,701 Foreign currency exchange contracts 828 — 828 — Total $ 4,529 $ — $ 828 $ 3,701 The following table represents the Company’s assets and liabilities measured at fair value on a recurring basis at December 31, 2017 (in thousands): Total at Quoted Prices Significant Significant (Level 3) Assets: U.S. Treasury securities $ 591,988 $ — $ 591,988 $ — Foreign government securities 6,952 — 6,952 — Corporate debt securities 1,975,160 — 1,975,160 — Time deposits 371,511 — 371,511 — Equity securities 147 — 147 — Waters 401(k) Restoration Plan assets 35,645 35,645 — — Foreign currency exchange contracts 566 — 566 — Total $ 2,981,969 $ 35,645 $ 2,946,324 $ — Liabilities: Contingent consideration $ 3,247 $ — $ — $ 3,247 Foreign currency exchange contracts 182 — 182 — Total $ 3,429 $ — $ 182 $ 3,247 Fair Value of 401(k) Restoration Plan Assets The 401(k) Restoration Plan is a nonqualified defined contribution plan and the assets were held in registered mutual funds and have been classified as Level 1. The fair values of the assets in the plan are determined through market and observable sources from daily quoted prices on nationally recognized securities exchanges. Fair Value of Cash Equivalents, Investments, Foreign Currency Exchange Contracts and Interest Rate Cross-Currency Swap Agreements The fair values of the Company’s cash equivalents, investments and foreign currency exchange contracts are determined through market and observable sources and have been classified as Level 2. These assets and liabilities have been initially valued at the transaction price and subsequently valued, typically utilizing third-party pricing services. The pricing services use many inputs to determine value, including reportable trades, benchmark yields, credit spreads, broker/dealer quotes, current spot rates and other industry and economic events. The Company validates the prices provided by third-party pricing services by reviewing their pricing methods and obtaining market values from other pricing sources. Fair Value of Contingent Consideration The fair value of the Company’s liability for contingent consideration relates to earnout payments in connection with the July 2014 acquisition of Medimass Research, Development and Service Kft. and is determined using a probability-weighted discounted cash flow model, which uses significant unobservable inputs, and has been classified as Level 3. Subsequent changes in the fair value of the contingent consideration liability are recorded in the results of operations. The fair value of the contingent consideration liability associated with future earnout payments is based on several factors, including the estimated future results and a discount rate that reflects both the likelihood of achieving the estimated future results and the Company’s creditworthiness. A change in any of these unobservable inputs can significantly change the fair value of the contingent consideration. Although there is no contractual limit, the fair value of future contingent consideration payments was estimated to be $4 million and $3 million at September 29, 2018 and December 31, 2017, respectively, based on the Company’s best estimate, as the earnout is based on future sales of certain products, some of which are currently in development, through 2034. Fair Value of Other Financial Instruments The Company’s accounts receivable, accounts payable and variable interest rate debt are recorded at cost, which approximates fair value due to their short-term nature. The carrying value of the Company’s fixed interest rate debt was $510 million and $610 million at September 29, 2018 and December 31, 2017, respectively. The fair value of the Company’s fixed interest rate debt was estimated using discounted cash flow models, based on estimated current rates offered for similar debt under current market conditions for the Company. The fair value of the Company’s fixed interest rate debt was estimated to be $495 million and $608 million at September 29, 2018 and December 31, 2017, respectively, using Level 2 inputs.
Derivative Transactions	Derivative Transactions The Company is a global company that operates in over 35 countries and, as a result, the Company’s net sales, cost of sales, operating expenses and balance sheet amounts are significantly impacted by fluctuations in foreign currency exchange rates. The Company is exposed to currency price risk on foreign currency exchange rate fluctuations when it translates its non-U.S. The Company’s principal strategies in managing exposures to changes in foreign currency exchange rates are to 1) naturally hedge the foreign-currency-denominated liabilities on the Company’s balance sheet against corresponding assets of the same currency, such that any changes in liabilities due to fluctuations in foreign currency exchange rates are typically offset by corresponding changes in assets and 2) mitigate foreign exchange risk exposure of international operations by hedging the variability in the movement of foreign currency exchange rates on a portion of its Euro-denominated net asset investments. The Company presents the derivative transactions in financing activities in the statement of cash flows. Foreign Currency Exchange Contracts The Company does not specifically enter into any derivatives that hedge foreign-currency-denominated assets, liabilities or commitments on its balance sheet, other than a portion of certain third-party accounts receivable and accounts payable, and the Company’s net worldwide intercompany receivables and payables, which are eliminated in consolidation. The Company periodically aggregates its net worldwide balances by currency and then enters into foreign currency exchange contracts that mature within 90 days to hedge a portion of the remaining balance to minimize some of the Company’s currency price risk exposure. The foreign currency exchange contracts are not designated for hedge accounting treatment. Principal hedged currencies include the Euro, Japanese yen, British pound, Mexican peso and Brazilian real. Interest Rate Cross-Currency Swap Agreements In July 2018, the Company entered into a three-year interest rate cross-currency swap derivative agreement with a notional value of $150 million to hedge the variability in the movement of foreign currency exchange rates on a portion of its Euro-denominated net asset investments. Under hedge accounting, the change in fair value of the derivative that relates to changes in the foreign currency spot rate are recorded in the currency translation adjustment in other comprehensive income and remain in accumulated comprehensive income in stockholders’ equity until the sale or substantial liquidation of the foreign operation. The difference between the interest rate received and paid under the interest rate cross-currency swap derivative agreement is recorded in interest income in the statement of operations. The Company’s foreign currency exchange contracts and interest rate cross-currency swap agreements included in the consolidated balance sheets are classified as follows (in thousands): September 29, 2018 December 31, 2017 Notional Value Fair Value Notional Value Fair Value Foreign exchange contracts: Other current assets $ 37,927 $ 116 $ 110,759 $ 566 Other current liabilities $ 105,885 $ 828 $ 37,104 $ 182 Interest rate cross-currency swap agreements: Other assets $ 150,000 $ 767 $ — $ — Accumulated other comprehensive income $ (767 ) $ — The following is a summary of the activity included in the statements of comprehensive income related to the foreign currency exchange contracts (in thousands): Financial Statement Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Foreign currency exchange contracts: Realized (losses) gains on closed contracts Cost of sales $ (23 ) $ 2,871 $ (2,181 ) $ 3,301 Unrealized (losses) gains on open contracts Cost of sales (5 ) (1,258 ) (1,097 ) 819 Cumulative net pre-tax Cost of sales $ (28 ) $ 1,613 $ (3,278 ) $ 4,120 Interest rate cross-currency swap agreements: Interest earned Interest income $ 927 $ — $ 927 $ — Unrealized gains on open contracts Stockholders’ equity $ 767 $ — $ 767 $ —
Stockholders' Equity	Stockholders’ Equity In April 2018, the Company’s Board of Directors authorized the Company to repurchase up to $3 billion of its outstanding common stock over a three-year period. This new program adds the remaining $526 million from the pre-existing
Product Warranty Costs	Product Warranty Costs The Company accrues estimated product warranty costs at the time of sale, which are included in cost of sales in the consolidated statements of operations. While the Company engages in extensive product quality programs and processes, including actively monitoring and evaluating the quality of its component suppliers, the Company’s warranty obligation is affected by product failure rates, material usage and service delivery costs incurred in correcting a product failure. The amount of the accrued warranty liability is based on historical information, such as past experience, product failure rates, number of units repaired and estimated costs of material and labor. The liability is reviewed for reasonableness at least quarterly. The following is a summary of the activity of the Company’s accrued warranty liability for the nine months ended September 29, 2018 and September 30, 2017 (in thousands): Balance at Accruals for Settlements Balance at Accrued warranty liability: September 29, 2018 $ 13,026 $ 6,068 $ (6,901 ) $ 12,193 September 30, 2017 $ 13,391 $ 6,287 $ (6,823 ) $ 12,855
Revenue Recognition	2 Revenue Recognition The Company adopted new accounting guidance regarding the recognition of revenue from contracts with customers as of January 1, 2018. The Company recognizes revenue upon transfer of control of promised products and services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. The Company generally enters into contracts that include a combination of products and services. Revenue is allocated to distinct performance obligations and is recognized net of allowances for returns and discounts. The Company recognizes revenue on product sales at the time control of the product transfers to the customer. In substantially all of the Company’s arrangements, title of our products transfers at shipping point and, as a result, the Company determined control transfers at the point of shipment. In more limited cases, there are destination-based shipping terms and, thus, control is deemed to transfer when the products arrive at the customer site. Incremental costs of obtaining a contract are expensed as and when incurred if the expected amortization period of the asset that would have been recognized is one year or less. Shipping and handling costs are included as a component of cost of sales. In situations where the control of the goods transfers prior to the completion of the Company’s obligation to ship the products to its customers, the Company has elected the practical expedient to account for the shipping services as a fulfillment cost. Accordingly, such costs are recognized when control of the related goods is transferred to the customer. In more rare situations, the Company has revenue associated with products that contain specific customer acceptance criteria and the related revenue is not recognized before the customer acceptance criteria are satisfied. The Company elected to exclude from the measurement of the transaction price all taxes assessed by a governmental authority that are both imposed on and concurrent with specific revenue-producing transactions and collected by the Company from a customer. Generally, the Company’s contracts for products include a performance obligation related to installation. The Company has determined that the installation represents a distinct performance obligation and revenue is recognized separately upon the completion of installation. The Company determines the amount of the transaction price to allocate to the installation service based on the standalone selling price of the product and the service, which requires judgment. The Company determines relative standalone selling price of installation based upon a number of factors, including hourly service billing rates and estimated installation hours. In developing these estimates, the Company considers past history, competition, billing rates of current services and other factors. The Company has sales from standalone software, which is included in instrument systems revenue. These arrangements typically include software licenses and maintenance contracts, both of which the Company has determined are distinct performance obligations. The Company determines the amount of the transaction price to allocate to the license and maintenance contract based on the relative standalone selling price of each performance obligation. Software license revenue is recognized at the point in time when control has been transferred to the customer. The revenue allocated to the software maintenance contract is recognized on a straight-line basis over the maintenance period, which is the contractual term of the contract, as a time-based measure of progress best reflects the Company’s performance in satisfying this obligation. Unspecified rights to software upgrades are typically sold as part of the maintenance contract on a when-and-if-available Payment terms and conditions vary among the Company’s revenue streams, although terms generally include a requirement of payment within 30 to 60 days of product shipment. Prior to providing payment terms to customers, an evaluation of the customer’s credit risk is performed. Returns and customer credits are infrequent and insignificant and are recorded as a reduction to sales. Rights of return are not included in sales arrangements and, therefore, there is minimal variable consideration included in the transaction price of our products. Service revenue includes (i) service and software maintenance contracts and (ii) service calls (time and materials). Instrument service contracts and software maintenance contracts are typically annual contracts, which are billed at the beginning of the contract or maintenance period. The amount of the service and software maintenance contract is recognized on a straight-line basis to revenue over the maintenance service period, which is the contractual term of the contract, as a time-based measure of progress best reflects the Company’s performance in satisfying this obligation. There are no deferred costs associated with the service contract, as the cost of the service is recorded when the service is performed. Service calls are recognized to revenue at the time a service is performed. The Company’s deferred revenue liabilities on the consolidated balance sheets consists of the obligation on instrument service contracts and customer payments received in advance, prior to shipment of the instrument. The Company records deferred revenue primarily related to its service contracts, where consideration is billable at the beginning of the service period.
Income Taxes	The Company accounts for its uncertain tax return reporting positions in accordance with the accounting standards for income taxes, which require financial statement reporting of the expected future tax consequences of uncertain tax reporting positions on the presumption that all concerned tax authorities possess full knowledge of those tax reporting positions, as well as all of the pertinent facts and circumstances, but prohibit any discounting of unrecognized tax benefits associated with those reporting positions for the time value of money. The Company continues to classify interest and penalties related to unrecognized tax benefits as a component of the provision for income taxes. The Company adopted new accounting guidance which eliminates the deferral of tax effects on intra-entity transfers other than inventory and requires an entity to recognize the income tax consequences when the transfer occurs. The Company adopted this standard as of January 1, 2018 with a $4 million charge to beginning retained earnings in the consolidated balance sheet.
Stock-based Compensation	The Company accounts for stock-based compensation costs in accordance with the accounting standards for stock-based compensation, which require that all share-based payments to employees be recognized in the statements of operations, based on their grant date fair values. The Company recognizes the expense using the straight-line attribution method. The stock-based compensation expense recognized in the consolidated statements of operations is based on awards that ultimately are expected to vest; therefore, the amount of expense has been reduced for estimated forfeitures. Forfeitures are estimated based on historical experience. If actual results differ significantly from these estimates, stock-based compensation expense and the Company’s results of operations could be materially impacted. In addition, if the Company employs different assumptions in the application of these standards, the compensation expense that the Company records in the future periods may differ significantly from what the Company has recorded in the current period. Stock Options In determining the fair value of the stock options, the Company makes a variety of assumptions and estimates, including volatility measures, expected yields and expected stock option lives. The fair value of each option grant was estimated on the date of grant using the Black-Scholes option pricing model. The Company uses implied volatility on its publicly-traded options as the basis for its estimate of expected volatility. The Company believes that implied volatility is the most appropriate indicator of expected volatility because it is generally reflective of historical volatility and expectations of how future volatility will differ from historical volatility. The expected life assumption for grants is based on historical experience for the population of non-qualified zero-coupon Performance Stock Units The Company’s performance stock units are equity compensation awards with a market vesting condition based on the Company’s Total Shareholder Return (“TSR”) relative to the TSR of the components of the S&P Health Care Index. TSR is the change in value of a stock price over time, including the reinvestment of dividends. The vesting schedule ranges from 0% to 200% of the target shares awarded. In determining the fair value of the performance stock units, the Company makes a variety of assumptions and estimates, including volatility measures, expected yields and expected terms. The fair value of each performance stock unit grant was estimated on the date of grant using the Monte Carlo simulation model. The Company uses implied volatility on its publicly-traded options as the basis for its estimate of expected volatility. The Company believes that implied volatility is the most appropriate indicator of expected volatility because it is generally reflective of historical volatility and expectations of how future volatility will differ from historical volatility. The expected life assumption for grants is based on the performance period of the underlying performance stock units. The risk-free interest rate is the yield currently available on U.S. Treasury zero-coupon
Earnings Per Share	The effect of dilutive securities was calculated using the treasury stock method.
Retirement Plans	The Company adopted new accounting guidance which requires that an employer disaggregate the service cost component from other components of net benefit cost. As a result of the adoption of this standard, the components of net periodic benefit cost other than the service cost component are included in other income in the consolidated statements of operations and all previous periods have been adjusted accordingly.
New Accounting Pronouncements	Recently Adopted Accounting Standards In May 2014, amended accounting guidance was issued regarding the recognition of revenue from contracts with customers. The objective of this guidance is to significantly enhance comparability and clarify principles of revenue recognition practices across entities, industries, jurisdictions and capital markets. This guidance was originally effective for annual and interim reporting periods beginning after December 15, 2016; however, the Financial Accounting Standards Board (“FASB”) amended the standard in August 2015 to delay the effective period date by one year to annual and interim periods beginning after December 15, 2017. Adoption prior to December 15, 2016 was not permitted. In March 2016, the FASB clarified the implementation guidance on principal versus agent considerations and, in April 2016, clarification was made regarding certain aspects of identifying performance obligations and licensing implementation guidance. In May 2016, additional guidance was issued related to disclosure of remaining performance obligations, as well as other amendments to guidance on collectibility, non-cash In January 2016, accounting guidance was issued which primarily affects the classification and measurement of certain financial instruments, principally equity investments and certain financial liabilities. Under the new guidance, there will no longer be an available-for-sale In August 2016, accounting guidance was issued that clarifies the classification of certain cash flows. The new guidance addresses eight specific areas where current accounting guidance is either unclear or does not specifically address classification issues. This guidance is effective for annual and interim periods beginning after December 15, 2017 and early adoption is permitted. The Company adopted this standard as of January 1, 2018 and the adoption of this standard did not have a material impact on the Company’s cash flows. In October 2016, accounting guidance was issued regarding intra-entity transfers of assets other than inventory. The new guidance eliminates the deferral of tax effects on intra-entity transfers other than inventory and requires an entity to recognize the income tax consequences when the transfer occurs. The Company adopted this standard as of January 1, 2018 with a $4 million charge to beginning retained earnings in the consolidated balance sheet. Please see Note 8, “Income Taxes”, for additional information. In January 2017, accounting guidance was issued that clarifies the definition of a business. The new guidance provides a more robust framework to use in determining when a set of assets and activities is a business, thus narrowing the definition and the amount of transactions accounted for as business combinations. The Company adopted this standard as of January 1, 2018 and will apply this guidance prospectively to any business combination transactions that take place in the future. In March 2017, accounting guidance was issued regarding the presentation of net periodic pension cost and net periodic postretirement benefit cost. The new guidance requires that an employer disaggregate the service cost component from other components of net benefit cost, with service cost reported in the same line items as other compensation costs and the other components of net benefit costs presented outside income from operations. The Company adopted this standard as of January 1, 2018 and has reported the components of net periodic benefit cost other than the service cost component in other income on the consolidated statements of operations for all periods presented. Please see Note 12, “Retirement Plans”, for additional information. In May 2017, accounting guidance was issued that clarifies the accounting for a change to the terms or conditions of a share-based payment award. The standard provides more specific guidance for determining when a change to an award requires modification accounting and when it should be deemed purely administrative in nature. The Company adopted this standard as of January 1, 2018 and the adoption of this standard did not have a material impact on the Company’s financial position, results of operations and cash flows. In August 2017, accounting guidance was issued which simplifies the application of hedge accounting and enables companies to better portray the economics of their risk management activities in their financial statements. The Company adopted this standard in the second quarter of 2018, and this adoption did not have a material impact on the Company’s financial position, results of operations and cash flows. Recently Issued Accounting Standards In February 2016, accounting guidance was issued regarding the accounting for leases. This new comprehensive lease standard amends various aspects of existing accounting guidance for leases. The core principle of the new guidance will require lessees to present the assets and liabilities that arise from leases on their balance sheets. This guidance is effective for annual and interim reporting periods beginning after December 15, 2018 and early adoption is permitted. The Company will apply the prospective method of adoption and expects that the adoption of this standard will have a material effect on the Company’s balance sheet; however, it is not expected to have an overall material impact on the Company’s results of operations and cash flows. In June 2016, accounting guidance was issued that modifies the recognition of credit losses related to financial assets, such as debt securities, trade receivables, net investments in leases, off-balance available-for-sale. available-for-sale non-credit In January 2017, accounting guidance was issued that simplifies the accounting for goodwill impairment. The guidance eliminates step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. This guidance is effective for annual and interim periods beginning after December 15, 2019 and early adoption is permitted. The Company currently does not expect that the adoption of this standard will have a material effect on the Company’s financial position, results of operations and cash flows. In March 2017, accounting guidance was issued to amend the amortization period for certain purchased callable debt securities held at a premium. Specifically, the amortization period for certain callable debt securities will be shortened to end at the earliest call date. This guidance is effective for annual and interim periods beginning after December 15, 2018 and early adoption is permitted. The Company currently does not believe that the adoption of this standard will have a material impact on the Company’s financial position, results of operations and cash flows. In February 2018, accounting guidance was issued to address the impact of the 2017 Tax Cuts and Jobs Act on items recorded in accumulated other comprehensive income. Current accounting guidance requires deferred tax liabilities and assets to be adjusted for the effect of a change in tax laws or rates with the effect recorded in income from continuing operations, even if the related tax effects were originally recognized in other comprehensive income, the new guidance allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the 2017 Tax Act. This guidance is effective for annual and interim periods beginning after December 15, 2018 and early adoption is permitted. The Company is currently evaluating the potential impact that the adoption of this standard will have on the Company’s financial position, results of operations and cash flows.

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 29, 2018
Accounting Policies [Abstract]
Allowance for Doubtful Accounts Roll Forward	The following is a summary of the activity of the Company’s allowance for doubtful accounts for the nine months ended September 29, 2018 and September 30, 2017 (in thousands): Balance at Additions Deduction Balance at Allowance for Doubtful Accounts September 29, 2018 $ 6,109 $ 2,752 $ (2,175 ) $ 6,686 September 30, 2017 $ 5,140 $ 2,545 $ (1,586 ) $ 6,099
Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis	The following table represents the Company’s assets and liabilities measured at fair value on a recurring basis at September 29, 2018 (in thousands): Total at Quoted Prices for Identical (Level 1) Significant Significant (Level 3) Assets: U.S. Treasury securities $ 271,918 $ — $ 271,918 $ — Foreign government securities 2,958 — 2,958 — Corporate debt securities 1,063,382 — 1,063,382 — Time deposits 179,271 — 179,271 — Waters 401(k) Restoration Plan assets 37,723 37,723 — — Foreign currency exchange contracts 116 — 116 — Interest rate cross-currency swap agreements 767 — 767 — Total $ 1,556,135 $ 37,723 $ 1,518,412 $ — Liabilities: Contingent consideration $ 3,701 $ — $ — $ 3,701 Foreign currency exchange contracts 828 — 828 — Total $ 4,529 $ — $ 828 $ 3,701 The following table represents the Company’s assets and liabilities measured at fair value on a recurring basis at December 31, 2017 (in thousands): Total at Quoted Prices Significant Significant (Level 3) Assets: U.S. Treasury securities $ 591,988 $ — $ 591,988 $ — Foreign government securities 6,952 — 6,952 — Corporate debt securities 1,975,160 — 1,975,160 — Time deposits 371,511 — 371,511 — Equity securities 147 — 147 — Waters 401(k) Restoration Plan assets 35,645 35,645 — — Foreign currency exchange contracts 566 — 566 — Total $ 2,981,969 $ 35,645 $ 2,946,324 $ — Liabilities: Contingent consideration $ 3,247 $ — $ — $ 3,247 Foreign currency exchange contracts 182 — 182 — Total $ 3,429 $ — $ 182 $ 3,247
Summary of Foreign Currency Exchange Contracts and Interest Rate Cross-Currency Swap Agreements	The Company’s foreign currency exchange contracts and interest rate cross-currency swap agreements included in the consolidated balance sheets are classified as follows (in thousands): September 29, 2018 December 31, 2017 Notional Value Fair Value Notional Value Fair Value Foreign exchange contracts: Other current assets $ 37,927 $ 116 $ 110,759 $ 566 Other current liabilities $ 105,885 $ 828 $ 37,104 $ 182 Interest rate cross-currency swap agreements: Other assets $ 150,000 $ 767 $ — $ — Accumulated other comprehensive income $ (767 ) $ —
Gains (Losses) on Foreign Exchange Contracts	The following is a summary of the activity included in the statements of comprehensive income related to the foreign currency exchange contracts (in thousands): Financial Statement Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Foreign currency exchange contracts: Realized (losses) gains on closed contracts Cost of sales $ (23 ) $ 2,871 $ (2,181 ) $ 3,301 Unrealized (losses) gains on open contracts Cost of sales (5 ) (1,258 ) (1,097 ) 819 Cumulative net pre-tax Cost of sales $ (28 ) $ 1,613 $ (3,278 ) $ 4,120 Interest rate cross-currency swap agreements: Interest earned Interest income $ 927 $ — $ 927 $ — Unrealized gains on open contracts Stockholders’ equity $ 767 $ — $ 767 $ —
Summary of Activity of Company's Accrued Warranty Liability	The following is a summary of the activity of the Company’s accrued warranty liability for the nine months ended September 29, 2018 and September 30, 2017 (in thousands): Balance at Accruals for Settlements Balance at Accrued warranty liability: September 29, 2018 $ 13,026 $ 6,068 $ (6,901 ) $ 12,193 September 30, 2017 $ 13,391 $ 6,287 $ (6,823 ) $ 12,855

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
	Sep. 29, 2018
Revenue from Contract with Customer [Abstract]
Summary of Activity of Deferred Revenue and Customer Advances	The following is a summary of the activity of the Company’s deferred revenue and customer advances for the nine months ended September 29, 2018 and September 30, 2017 (in thousands): September 29, September 30, Balance at the beginning of the period $ 192,590 $ 173,780 Recognition of revenue included in balance at beginning of the period (147,310 ) (132,435 ) Revenue deferred during the period, net of revenue recognized 179,571 169,337 Balance at the end of the period $ 224,851 $ 210,682
Schedule of Estimated Amount of Deferred Revenue and Customer Advances	The estimated amount of deferred revenue and customer advances equals the transaction price allocated to unfulfilled performance obligations for the period presented. Such amounts are expected to be recognized in the future as follows (in thousands): September 29, 2018 Deferred revenue and customer advances expected to be recognized: In one year or less $ 186,485 In 13-24 26,316 In 25 months and beyond 12,050 Total $ 224,851

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 29, 2018
Investments, Debt and Equity Securities [Abstract]
Schedule of Available-for-Sale Securities Reconciliation	The Company’s marketable securities within cash equivalents and investments included in the consolidated balance sheets are detailed as follows (in thousands): September 29, 2018 Amortized Unrealized Unrealized Fair Value U.S. Treasury securities $ 272,812 $ — $ (894 ) $ 271,918 Foreign government securities 2,994 — (36 ) 2,958 Corporate debt securities 1,066,088 424 (3,130 ) 1,063,382 Time deposits 179,271 — — 179,271 Total $ 1,521,165 $ 424 $ (4,060 ) $ 1,517,529 Amounts included in: Cash equivalents $ 122,645 $ — $ (3 ) $ 122,642 Investments 1,398,520 424 (4,057 ) 1,394,887 Total $ 1,521,165 $ 424 $ (4,060 ) $ 1,517,529 December 31, 2017 Amortized Unrealized Unrealized Fair Cost Gain Loss Value U.S. Treasury securities $ 593,599 $ 82 $ (1,693 ) $ 591,988 Foreign government securities 6,982 — (30 ) 6,952 Corporate debt securities 1,977,329 897 (3,066 ) 1,975,160 Time deposits 371,515 — (4 ) 371,511 Equity securities 77 70 — 147 Total $ 2,949,502 $ 1,049 $ (4,793 ) $ 2,945,758 Amounts included in: Cash equivalents $ 194,377 $ — $ (1 ) $ 194,376 Investments 2,755,125 1,049 (4,792 ) 2,751,382 Total $ 2,949,502 $ 1,049 $ (4,793 ) $ 2,945,758
Investments Classified By Contractual Maturity Date	The estimated fair value of marketable debt securities by maturity date is as follows (in thousands): September 29, 2018 December 31, 2017 Due in one year or less $ 1,043,082 $ 1,722,553 Due after one year through three years 295,176 851,547 Total $ 1,338,258 $ 2,574,100

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 29, 2018
Inventory Disclosure [Abstract]
Inventory, Net of Reserves	Inventories are classified as follows (in thousands): September 29, 2018 December 31, 2017 Raw materials $ 112,588 $ 99,033 Work in progress 18,838 15,324 Finished goods 182,188 155,937 Total inventories $ 313,614 $ 270,294

Goodwill and Other Intangibles

Goodwill and Other Intangibles (Tables)	9 Months Ended
	Sep. 29, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	The Company’s intangible assets included in the consolidated balance sheets are detailed as follows (dollars in thousands): September 29, 2018 December 31, 2017 Gross Accumulated Weighted- Gross Accumulated Weighted- Capitalized software $ 455,312 $ 306,286 5 years $ 438,652 $ 285,461 5 years Purchased intangibles 203,170 143,009 11 years 169,870 138,750 11 years Trademarks and IPR&D 13,827 — — 13,923 — — Licenses 5,733 4,901 6 years 5,840 4,628 6 years Patents and other intangibles 77,175 48,187 8 years 72,815 43,866 8 years Total $ 755,217 $ 502,383 7 years $ 701,100 $ 472,705 7 years

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 29, 2018
Debt Disclosure [Abstract]
Summary of Outstanding Debt	The Company had the following outstanding debt at September 29, 2018 and December 31, 2017 (in thousands): September 29, 2018 December 31, 2017 Foreign subsidiary lines of credit $ 284 $ 273 Senior unsecured notes - Series D - 3.22%, due March 2018 — 100,000 Total notes payable and debt, current 284 100,273 Senior unsecured notes - Series B - 5.00%, due February 2020 100,000 100,000 Senior unsecured notes - Series E - 3.97%, due March 2021 50,000 50,000 Senior unsecured notes - Series F - 3.40%, due June 2021 100,000 100,000 Senior unsecured notes - Series G - 3.92%, due June 2024 50,000 50,000 Senior unsecured notes - Series H - floating rate*, due June 2024 50,000 50,000 Senior unsecured notes - Series I - 3.13%, due May 2023 50,000 50,000 Senior unsecured notes - Series J - floating rate**, due May 2024 — 40,000 Senior unsecured notes - Series K - 3.44%, due May 2026 160,000 160,000 Credit agreement 590,000 1,300,000 Unamortized debt issuance costs (1,939 ) (2,499 ) Total long-term debt 1,148,061 1,897,501 Total debt $ 1,148,345 $ 1,997,774 * Series H senior unsecured notes bear interest at a 3-month ** Series J senior unsecured notes bore interest at a 3-month

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 29, 2018
Income Tax Disclosure [Abstract]
Uncertain Tax Positions Roll Forward	The following is a summary of the activity of the Company’s uncertain tax positions for the nine months ended September 29, 2018 and September 30, 2017 (in thousands): September 29, 2018 September 30, 2017 Balance at the beginning of the period $ 5,843 $ 9,964 Net changes in uncertain tax positions 19,097 (2,953 ) Balance at the end of the period $ 24,940 $ 7,011

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 29, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Stock-Based Compensation Expense	The consolidated statements of operations for the three and nine months ended September 29, 2018 and September 30, 2017 include the following stock-based compensation expense related to stock option awards, restricted stock awards, restricted stock unit awards, performance stock unit awards and the employee stock purchase plan (in thousands): Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Cost of sales $ 488 $ 726 $ 1,696 $ 2,251 Selling and administrative expenses 6,731 10,768 22,855 25,558 Research and development expenses 1,994 780 3,633 2,259 Total stock-based compensation $ 9,213 $ 12,274 $ 28,184 $ 30,068
Relevant Data Used to Determine the Value of Stock Options Granted During the Period	The relevant data used to determine the value of the stock options granted during the nine months ended September 29, 2018 and September 30, 2017 are as follows: Nine Months Ended Options Issued and Significant Assumptions Used to Estimate Option Fair Values September 29, September 30, Options issued in thousands 147 217 Risk-free interest rate 2.7 % 2.2 % Expected life in years 6 6 Expected volatility 23.2 % 23.0 % Expected dividends — — Nine Months Ended Weighted-Average Exercise Price and Fair Value of Options on the Date of Grant September 29, September 30, Exercise price $ 205.37 $ 151.24 Fair value $ 57.99 $ 40.49
Stock Options Outstanding Roll Forward	The following table summarizes stock option activity for the plans for the nine months ended September 29, 2018 (in thousands, except per share data): Number of Exercise Price per Share Weighted-Average Outstanding at December 31, 2017 2,039 $ 38.09 to $ 194.26 $ 124.41 Granted 147 $ 188.26 to $ 208.47 $ 205.37 Exercised (357 ) $ 38.09 to $ 154.33 $ 102.44 Canceled (137 ) $ 98.21 to $ 154.33 $ 126.13 Outstanding at September 29, 2018 1,692 $ 38.09 to $ 208.47 $ 135.94
Restricted Stock Units Unvested Roll Forward	The following table summarizes the unvested restricted stock unit award activity for the nine months ended September 29, 2018 (in thousands, except per share data): Shares Weighted-Average Unvested at December 31, 2017 374 $ 124.81 Granted 91 $ 207.85 Vested (123 ) $ 117.68 Forfeited (18 ) $ 126.43 Unvested at September 29, 2018 324 $ 150.75
Relevant Data Used to Determine the Value of Performance Shares	The relevant data used to determine the value of the performance stock units granted during the nine months ended September 29, 2018 and September 30, 2017 are as follows: Nine Months Ended Performance Stock Units Issued and Significant Assumptions Used to Estimate Fair Values September 29, September 30, Performance stock units issued (in thousands) 16 20 Risk-free interest rate 2.0 % 1.5 % Expected life in years 2.8 3.0 Expected volatility 23.4 % 23.2 % Average volatility of peer companies 25.8 % 26.1 % Correlation coefficient 37.2 % 38.5 % Expected dividends — —
Performance Stock Units Unvested Roll Forward	The following table summarizes the unvested performance stock unit award activity for the nine months ended September 29, 2018 (in thousands, except per share data): Shares Weighted-Average Unvested at December 31, 2017 64 $ 196.29 Granted 16 $ 253.44 Forfeited (5 ) $ 188.45 Unvested at September 29, 2018 75 $ 209.00

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 29, 2018
Earnings Per Share [Abstract]
Earnings Per Share Reconciliation	Basic and diluted EPS calculations are detailed as follows (in thousands, except per share data): Three Months Ended September 29, 2018 Net Income Weighted- Per Share (Numerator) (Denominator) Amount Net income per basic common share $ 141,014 76,575 $ 1.84 Effect of dilutive stock option, restricted stock, performance stock unit and restricted stock unit securities — 561 (0.01 ) Net income per diluted common share $ 141,014 77,136 $ 1.83 Three Months Ended September 30, 2017 Net Income Weighted- Per Share (Numerator) (Denominator) Amount Net income per basic common share $ 136,104 79,712 $ 1.71 Effect of dilutive stock option, restricted stock, performance stock unit and restricted stock unit securities — 809 (0.02 ) Net income per diluted common share $ 136,104 80,521 $ 1.69 Nine Months Ended September 29, 2018 Net Income Weighted- Per Share (Numerator) (Denominator) Amount Net income per basic common share $ 408,642 77,741 $ 5.26 Effect of dilutive stock option, restricted stock, performance stock unit and restricted stock unit securities — 654 (0.05 ) Net income per diluted common share $ 408,642 78,395 $ 5.21 Nine Months Ended September 30, 2017 Net Income Weighted- Per Share (Numerator) (Denominator) Amount Net income per basic common share $ 373,483 79,908 $ 4.67 Effect of dilutive stock option, restricted stock, performance stock unit and restricted stock unit securities — 752 (0.04 ) Net income per diluted common share $ 373,483 80,660 $ 4.63

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 29, 2018
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income	The components of accumulated other comprehensive income (loss) are detailed as follows (in thousands): Currency Unrealized Gain Unrealized Gain Accumulated Balance at December 31, 2017 $ (69,418 ) $ (37,103 ) $ (3,546 ) $ (110,067 ) Other comprehensive (loss) income, net of tax (17,937 ) 2,228 (17 ) (15,726 ) Balance at September 29, 2018 $ (87,355 ) $ (34,875 ) $ (3,563 ) $ (125,793 )

Retirement Plans (Tables)

Retirement Plans (Tables)	9 Months Ended
	Sep. 29, 2018
Retirement Benefits [Abstract]
Defined Benefit Plan, Net Periodic Benefit Cost	The summary of the components of net periodic pension costs for the plans for the three and nine months ended September 29, 2018 and September 30, 2017 is as follows (in thousands): Three Months Ended September 29, 2018 September 30, 2017 U.S. U.S. Retiree Non-U.S. U.S. U.S. Retiree Non-U.S. Pension Healthcare Pension Pension Healthcare Pension Plans Plan Plans Plans Plan Plans Service cost $ 142 $ 142 $ 1,311 $ 113 $ 137 $ 1,311 Interest cost 1,622 159 406 1,707 155 386 Expected return on plan assets (1,708 ) (177 ) (486 ) (2,574 ) (146 ) (434 ) Net amortization: Prior service credit — (4 ) (30 ) — — (47 ) Net actuarial loss 771 — 167 693 — 248 Net periodic pension cost (benefit) $ 827 $ 120 $ 1,368 $ (61 ) $ 146 $ 1,464 Nine Months Ended September 29, 2018 September 30, 2017 U.S. U.S. Retiree Non-U.S. U.S. U.S. Retiree Non-U.S. Pension Healthcare Pension Pension Healthcare Pension Plans Plan Plans Plans Plan Plans Service cost $ 426 $ 425 $ 4,024 $ 338 $ 410 $ 3,802 Interest cost 4,868 477 1,250 5,122 464 1,112 Expected return on plan assets (5,123 ) (530 ) (1,442 ) (7,724 ) (440 ) (1,250 ) Net amortization: Prior service credit — (14 ) (93 ) — — (140 ) Net actuarial loss 2,312 — 515 2,078 — 714 Net periodic pension cost (benefit) $ 2,483 $ 358 $ 4,254 $ (186 ) $ 434 $ 4,238

Business Segment Information (T

Business Segment Information (Tables)	9 Months Ended
	Sep. 29, 2018
Segment Reporting [Abstract]
Summary of Net Sales for Company's Products and Services	Net sales for the Company’s products and services are as follows for the three and nine months ended September 29, 2018 and September 30, 2017 (in thousands): Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Product net sales: Waters instrument systems $ 238,986 $ 238,431 $ 677,017 $ 674,768 Chemistry consumables 95,979 92,879 293,818 271,606 TA instrument systems 43,557 44,240 135,673 126,310 Total product sales 378,522 375,550 1,106,508 1,072,684 Service net sales: Waters service 180,830 172,594 543,411 498,736 TA service 18,669 17,440 54,991 50,383 Total service sales 199,499 190,034 598,402 549,119 Total net sales $ 578,021 $ 565,584 $ 1,704,910 $ 1,621,803
Summary of Geographic Sales Information	Geographic sales information is presented below for the three and nine months ended September 29, 2018 and September 30, 2017 (in thousands): Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Net Sales: Asia: China $ 109,713 $ 96,141 $ 313,250 $ 275,367 Japan 43,549 42,202 129,497 125,058 Asia Other 68,934 70,996 216,634 219,723 Total Asia 222,196 209,339 659,381 620,148 Americas: United States 170,766 171,053 479,072 474,661 Americas Other 36,037 31,960 107,567 99,588 Total Americas 206,803 203,013 586,639 574,249 Europe 149,022 153,232 458,890 427,406 Total net sales $ 578,021 $ 565,584 $ 1,704,910 $ 1,621,803
Summary of Net Sales by Customer Class	Net sales by customer class are as follows for the three and nine months ended September 29, 2018 and September 30, 2017 (in thousands): Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Pharmaceutical $ 325,166 $ 321,963 $ 968,848 $ 921,423 Industrial 171,985 168,349 517,979 504,183 Governmental and academic 80,870 75,272 218,083 196,197 Total net sales $ 578,021 $ 565,584 $ 1,704,910 $ 1,621,803
Summary of Net Sales of Company Recognized at a Point in Time Versus Over Time	Net sales for the Company recognized at a point in time versus over time are as follows for the three and nine months ended September 29, 2018 and September 30, 2017 (in thousands): Three Months Ended Nine Months Ended September 29, September 30, September 29, September 30, Net sales recognized at a point in time: Instrument systems $ 282,543 $ 282,671 $ 812,690 $ 801,078 Chemistry consumables 95,979 92,879 293,818 271,606 Service sales recognized at a point in time (time & materials) 75,769 72,221 228,685 212,660 Total net sales recognized at a point in time 454,291 447,771 1,335,193 1,285,344 Net sales recognized over time: Service and software sales recognized over time (contracts) 123,730 117,813 369,717 336,459 Total net sales $ 578,021 $ 565,584 $ 1,704,910 $ 1,621,803

Basis of Presentation and Sum_4

Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	1 Months Ended		9 Months Ended
	Jul. 31, 2018	Apr. 30, 2018	Sep. 29, 2018	Sep. 30, 2017	Feb. 28, 2018	Dec. 31, 2017
Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Cash equivalents description			Cash equivalents represent highly liquid investments, with original maturities of 90 days or less, while investments with longer maturities are classified as investments.
Cash, cash equivalents and investments			$ 2,084,000,000			$ 3,394,000,000
Accounts receivable, description			Past due balances over 90 days and over a specified amount are reviewed individually for collectibility.
Contingent consideration			$ 3,701,000			3,247,000
Long-term debt			$ 1,148,061,000			1,897,501,000
Foreign currency exposure			The Company is a global company that operates in over 35 countries and, as a result, the Company’s net sales, cost of sales, operating expenses and balance sheet amounts are significantly impacted by fluctuations in foreign currency exchange rates.
Maturity period of foreign exchange contracts			The Company does not specifically enter into any derivatives that hedge foreign-currency-denominated assets, liabilities or commitments on its balance sheet, other than a portion of certain third-party accounts receivable and accounts payable, and the Company’s net worldwide intercompany receivables and payables, which are eliminated in consolidation. The Company periodically aggregates its net worldwide balances by currency and then enters into foreign currency exchange contracts that mature within 90 days to hedge a portion of the remaining balance to minimize some of the Company’s currency price risk exposure.
Stock repurchase program, remaining authorized repurchase amount terminated		$ 526,000,000
Estimated future payment to build and equip manufacturing facility					$ 215,000,000
Cross Currency Interest Rate Contract [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Term of derivative agreement	3 years
Notional value, derivative asset	$ 150,000,000
Unsecured Debt [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Long-term debt			$ 560,000,000			700,000,000
Unsecured Debt [Member] | Fixed Interest Rate [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Long-term debt			510,000,000			610,000,000
Fair value of fixed interest rate debt			495,000,000			608,000,000
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Contingent consideration			3,701,000			3,247,000
Held In Currencies Other Than Us Dollars [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Cash, cash equivalents and investments			$ 341,000,000			304,000,000
April 2018 Program [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Stock repurchase program additional authorization amount		3,000,000,000
Stock repurchase program authorization amount		$ 3,500,000,000
Stock repurchase program period		3 years
Treasury stock shares acquired			2,800,000
Treasury stock			$ 534,000,000
Stock repurchase program remaining amount authorized for future purchases			$ 3,000,000,000
Programs Authorized by Board of Directors [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Treasury stock shares acquired			4,100,000	1,400,000
Treasury stock			$ 809,000,000	$ 238,000,000
Related to Vesting of Restricted Stock Units [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Treasury stock			9,000,000	$ 8,000,000
Held By Foreign Subsidiaries [Member]
Basis of Presentation and Summary of Significant Accounting Policies [Line Items]
Cash, cash equivalents and investments			$ 942,000,000			$ 3,326,000,000

Basis of Presentation and Sum_5

Basis of Presentation and Summary of Significant Accounting Policies - Allowance for Doubtful Accounts Roll Forward (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning balance	$ 6,109	$ 5,140
Additions	2,752	2,545
Deduction	(2,175)	(1,586)
Ending balance	$ 6,686	$ 6,099

Basis of Presentation and Sum_6

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	$ 1,517,529	$ 2,945,758
Waters 401(k) Restoration Plan assets	37,723	35,645
Total	1,556,135	2,981,969
Contingent consideration	3,701	3,247
Total	4,529	3,429
Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, derivative asset	116	566
Foreign currency exchange contracts	828	182
Cross Currency Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, derivative asset	767
US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	271,918	591,988
Foreign Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	2,958	6,952
Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	1,063,382	1,975,160
Time Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	179,271	371,511
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		147
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Waters 401(k) Restoration Plan assets	37,723	35,645
Total	37,723	35,645
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	1,518,412	2,946,324
Total	828	182
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 2) [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, derivative asset	116	566
Foreign currency exchange contracts	828	182
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 2) [Member] | Cross Currency Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, derivative asset	767
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 2) [Member] | US Treasury Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	271,918	591,988
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 2) [Member] | Foreign Government Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	2,958	6,952
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 2) [Member] | Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	1,063,382	1,975,160
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 2) [Member] | Time Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	179,271	371,511
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 2) [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		147
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	3,701	3,247
Total	$ 3,701	$ 3,247

Basis of Presentation and Sum_7

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Foreign Currency Exchange Contracts and Interest Rate Cross-Currency Swap Agreements (Detail) - USD ($)	Sep. 29, 2018	Jul. 31, 2018	Dec. 31, 2017
Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, derivative asset	$ 116,000		$ 566,000
Fair value, derivative liability	828,000		182,000
Cross Currency Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional value, derivative asset		$ 150,000,000
Fair value, derivative asset	767,000
Other Current Assets [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional value, derivative asset	37,927,000		110,759,000
Fair value, derivative asset	116,000		566,000
Other Current Liabilities [Member] | Foreign Exchange Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional value, derivative liability	105,885,000		37,104,000
Fair value, derivative liability	828,000		$ 182,000
Other Assets [Member] | Cross Currency Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional value, derivative asset	150,000,000
Fair value, derivative asset	767,000
Accumulated Other Comprehensive Income (Loss) [Member] | Cross Currency Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, derivative asset	$ (767,000)

Basis of Presentation and Sum_8

Basis of Presentation and Summary of Significant Accounting Policies - Gains (Losses) on Foreign Exchange Contracts (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Cost of Sales [Member] | Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized (losses) gains on closed contracts	$ (23)	$ 2,871	$ (2,181)	$ 3,301
Unrealized (losses) gains on open contracts	(5)	(1,258)	(1,097)	819
Cumulative net pre-tax(losses) gains	(28)	$ 1,613	(3,278)	$ 4,120
Interest Income [Member] | Cross Currency Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Interest earned	927		927
Stockholders' Equity [Member] | Cross Currency Interest Rate Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized (losses) gains on open contracts	$ 767		$ 767

Basis of Presentation and Sum_9

Basis of Presentation and Summary of Significant Accounting Policies - Summary of Activity of Company's Accrued Warranty Liability (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at Beginning of Period	$ 13,026	$ 13,391
Accruals for Warranties	6,068	6,287
Settlements Made	(6,901)	(6,823)
Balance at End of Period	$ 12,193	$ 12,855

Revenue Recognition - Additiona

Revenue Recognition - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 29, 2018	Dec. 31, 2017
Revenue Recognition [Line Items]
Accounts receivable, payment terms and conditions	Payment terms and conditions vary among the Company’s revenue streams, although terms generally include a requirement of payment within 30 to 60 days of product shipment.
Other Long-Term Liabilities [Member]
Revenue Recognition [Line Items]
Deferred revenue and customer advances	$ 38	$ 26

Revenue Recognition - Summary o

Revenue Recognition - Summary of Activity of Deferred Revenue and Customer Advances (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Revenue Recognition and Deferred Revenue [Abstract]
Balance at Beginning of Period	$ 192,590	$ 173,780
Recognition of revenue included in balance at beginning of the period	(147,310)	(132,435)
Revenue deferred during the period, net of revenue recognized	179,571	169,337
Balance at End of Period	$ 224,851	$ 210,682

Revenue Recognition - Schedule

Revenue Recognition - Schedule of Estimated Amount of Deferred Revenue and Customer Advances (Detail) $ in Thousands	Sep. 29, 2018USD ($)
Revenue Recognition [Line Items]
Deferred revenue and customer advances expected to be recognized	$ 224,851
In One Year or Less [Member]
Revenue Recognition [Line Items]
Deferred revenue and customer advances expected to be recognized	$ 186,485
Deferred revenue and customer advances recognition period	1 year
In 13-24 Months [Member]
Revenue Recognition [Line Items]
Deferred revenue and customer advances expected to be recognized	$ 26,316
Deferred revenue and customer advances recognition period	1 year
In 25 Months and Beyond [Member]
Revenue Recognition [Line Items]
Deferred revenue and customer advances expected to be recognized	$ 12,050
Deferred revenue and customer advances recognition period	0 years

Marketable Securities - Schedul

Marketable Securities - Schedule of Available-for-Sale Securities Reconciliation (Detail) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 1,521,165	$ 2,949,502
Unrealized Gain	424	1,049
Unrealized Loss	(4,060)	(4,793)
Fair Value	1,517,529	2,945,758
US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	272,812	593,599
Unrealized Gain		82
Unrealized Loss	(894)	(1,693)
Fair Value	271,918	591,988
Foreign Government Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,994	6,982
Unrealized Loss	(36)	(30)
Fair Value	2,958	6,952
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,066,088	1,977,329
Unrealized Gain	424	897
Unrealized Loss	(3,130)	(3,066)
Fair Value	1,063,382	1,975,160
Time Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	179,271	371,515
Unrealized Loss		(4)
Fair Value	179,271	371,511
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		77
Unrealized Gain		70
Fair Value		147
Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	122,645	194,377
Unrealized Loss	(3)	(1)
Fair Value	122,642	194,376
Short-term Investments [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,398,520	2,755,125
Unrealized Gain	424	1,049
Unrealized Loss	(4,057)	(4,792)
Fair Value	$ 1,394,887	$ 2,751,382

Marketable Securities - Investm

Marketable Securities - Investments Classified By Contractual Maturity Date (Detail) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, Fair Value [Abstract]
Due in one year or less	$ 1,043,082	$ 1,722,553
Due after one year through three years	295,176	851,547
Total	$ 1,338,258	$ 2,574,100

Inventories - Inventory, Net of

Inventories - Inventory, Net of Reserves (Detail) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 31, 2017
Inventory, Net, Items Net of Reserve Alternative [Abstract]
Raw materials	$ 112,588	$ 99,033
Work in progress	18,838	15,324
Finished goods	182,188	155,937
Total inventories	$ 313,614	$ 270,294

Acquisitions and Investments _2

Acquisitions and Investments in Unaffiliated Companies - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended	9 Months Ended
	Jul. 31, 2018	Sep. 29, 2018	Sep. 29, 2018	Sep. 30, 2017
Business Acquisition [Line Items]
Intangible assets acquired	$ 30,000,000
Allocated fair value to purchased intangible asset	$ 33,000,000
Purchased intangible asset useful life	12 years
Investments in unaffiliated companies		$ 4,000,000	$ 7,615,000	$ 7,000,000
Minimum [Member]
Business Acquisition [Line Items]
Future contractual obligation to pay a minimum royalty	$ 3,000,000

Goodwill and Other Intangible_2

Goodwill and Other Intangibles - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 357,869		$ 357,869		$ 359,819
Goodwill foreign currency translation adjustments			(2,000)
Intangible assets, gross foreign currency translation adjustments			(11,000)
Intangible assets, accumulated amortization foreign currency translation adjustments			(8,000)
Amortization expense	12,000	$ 11,000	38,000	$ 33,000
Future amortization expense, year 1	53,000		53,000
Future amortization expense, year 2	53,000		53,000
Future amortization expense, year 3	53,000		53,000
Future amortization expense, year 4	53,000		53,000
Future amortization expense, year 5	$ 53,000		$ 53,000

Goodwill and Other Intangible_3

Goodwill and Other Intangibles - Schedule of Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 29, 2018	Dec. 31, 2017
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 755,217	$ 701,100
Accumulated Amortization	$ 502,383	$ 472,705
Weighted-Average Amortization Period	7 years	7 years
Trademarks and In Process Research and Development [Member]
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 13,827	$ 13,923
Software Development [Member]
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	455,312	438,652
Accumulated Amortization	$ 306,286	$ 285,461
Weighted-Average Amortization Period	5 years	5 years
Purchased Intangibles [Member]
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 203,170	$ 169,870
Accumulated Amortization	$ 143,009	$ 138,750
Weighted-Average Amortization Period	11 years	11 years
Licensing Agreements [Member]
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 5,733	$ 5,840
Accumulated Amortization	$ 4,901	$ 4,628
Weighted-Average Amortization Period	6 years	6 years
Patents and Other Intangibles [Member]
Finite Lived and Indefinite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 77,175	$ 72,815
Accumulated Amortization	$ 48,187	$ 43,866
Weighted-Average Amortization Period	8 years	8 years

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($)	9 Months Ended		12 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Dec. 31, 2017	Jul. 31, 2018	Nov. 30, 2017
Debt Instrument [Line Items]
Long-term debt	$ 1,148,061,000		$ 1,897,501,000
Payments on debt	850,000,000	$ 64,000
Line of credit maximum borrowing capacity	$ 90,000,000		$ 91,000,000
Line of credit interest rate during the period	1.48%		1.48%
Cross Currency Interest Rate Contract [Member]
Debt Instrument [Line Items]
Notional value, derivative asset				$ 150,000,000
Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Interest rate terms on debt	The interest rates applicable to the 2017 Credit Agreement are, at the Company’s option, equal to either the alternate base rate (which is a rate per annum equal to the greatest of (a) the prime rate in effect on such day, (b) the Federal Reserve Bank of New York Rate on such day plus 1/2 of 1% per annum and (c) the adjusted LIBO rate on such day (or if such day is not a business day, the immediately preceding business day) for a deposit in U.S. dollars with a maturity of one month plus 1% per annum) or the applicable 1, 2, 3 or 6 month adjusted LIBO rate or EURIBO rate for Euro-denominated loans, in each case, plus an interest rate margin based upon the Company’s leverage ratio, which can range between 0 and 12.5 basis points for alternate base rate loans and between 80 and 112.5 basis points for LIBO rate or EURIBO rate loans.
Debt facility fee	The facility fee on the 2017 Credit Agreement ranges between 7.5 and 25 basis points per annum, based on the leverage ratio, of the amount of the revolving facility commitments and the outstanding term loan.
Debt covenant description	The 2017 Credit Agreement requires that the Company comply with an interest coverage ratio test of not less than 3.50:1 as of the end of any fiscal quarter for any period of four consecutive fiscal quarters and a leverage ratio test of not more than 3.50:1 as of the end of any fiscal quarter. In addition, the 2017 Credit Agreement includes negative covenants, affirmative covenants, representations and warranties and events of default that are customary for investment grade credit facilities.
Unused borrowing capacity	$ 1,208,000,000		$ 498,000,000
Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt covenant description	These senior unsecured notes require that the Company comply with an interest coverage ratio test of not less than 3.50:1 for any period of four consecutive fiscal quarters and a leverage ratio test of not more than 3.50:1 as of the end of any fiscal quarter. In addition, these senior unsecured notes include customary negative covenants, affirmative covenants, representations and warranties and events of default.
Long-term debt	$ 560,000,000		$ 700,000,000
Call feature on debt instrument	The Company may prepay all or some of the senior unsecured notes at any time in an amount not less than 10% of the aggregate principal amount outstanding, plus the applicable make-whole amount or prepayment premium for Series H and J senior unsecured notes. In the event of a change in control of the Company (as defined in the note purchase agreement), the Company may be required to prepay the senior unsecured notes at a price equal to 100% of the principal amount thereof, plus accrued and unpaid interest.
Credit Agreements and Unsecured Debt [Member]
Debt Instrument [Line Items]
Weighted-average interest rate	3.64%		2.98%
Revolving Facilities [Member] | Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Face value of debt					$ 1,500,000,000
Term Loan Facility [Member] | Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Face value of debt					$ 300,000,000

Debt - Summary of Outstanding D

Debt - Summary of Outstanding Debt (Detail) - USD ($) $ in Thousands		Sep. 29, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Foreign subsidiary lines of credit		$ 284	$ 273
Total notes payable and debt, current		284	100,273
Unamortized debt issuance costs		(1,939)	(2,499)
Long-term debt		1,148,061	1,897,501
Total debt		1,148,345	1,997,774
Senior Unsecured Notes Series D [Member]
Debt Instrument [Line Items]
Total notes payable and debt, current			100,000
Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Long-term debt		590,000	1,300,000
Senior Unsecured Notes Series B [Member]
Debt Instrument [Line Items]
Long-term debt		100,000	100,000
Senior Unsecured Notes Series E [Member]
Debt Instrument [Line Items]
Long-term debt		50,000	50,000
Senior Unsecured Notes Series F [Member]
Debt Instrument [Line Items]
Long-term debt		100,000	100,000
Senior Unsecured Notes Series G [Member]
Debt Instrument [Line Items]
Long-term debt		50,000	50,000
Senior Unsecured Notes Series H [Member]
Debt Instrument [Line Items]
Long-term debt	[1]	50,000	50,000
Senior Unsecured Notes Series I [Member]
Debt Instrument [Line Items]
Long-term debt		50,000	50,000
Senior Unsecured Notes Series J [Member]
Debt Instrument [Line Items]
Long-term debt	[2]		40,000
Senior Unsecured Notes Series K [Member]
Debt Instrument [Line Items]
Long-term debt		$ 160,000	$ 160,000
[1]	Series H senior unsecured notes bear interest at a 3-month LIBOR for that floating rate interest period plus 1.25%.
[2]	Series J senior unsecured notes bore interest at a 3-month LIBOR for that floating rate interest period plus 1.45%.

Debt - Summary of Outstanding_2

Debt - Summary of Outstanding Debt (Parenthetical) (Detail)	9 Months Ended
	Sep. 29, 2018	Dec. 31, 2017
Senior Unsecured Notes Series D [Member]
Debt Instrument [Line Items]
Stated interest rate on debt instrument		3.22%
Senior Unsecured Notes Series B [Member]
Debt Instrument [Line Items]
Stated interest rate on debt instrument	5.00%	5.00%
Senior Unsecured Notes Series E [Member]
Debt Instrument [Line Items]
Stated interest rate on debt instrument	3.97%	3.97%
Senior Unsecured Notes Series F [Member]
Debt Instrument [Line Items]
Stated interest rate on debt instrument	3.40%	3.40%
Senior Unsecured Notes Series G [Member]
Debt Instrument [Line Items]
Stated interest rate on debt instrument	3.92%	3.92%
Senior Unsecured Notes Series H [Member]
Debt Instrument [Line Items]
Interest rate terms on debt	Series H senior unsecured notes bear interest at a 3-month LIBOR for that floating rate interest period plus 1.25%.
Senior Unsecured Notes Series H [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Interest rate margin	1.25%
Senior Unsecured Notes Series I [Member]
Debt Instrument [Line Items]
Stated interest rate on debt instrument	3.13%	3.13%
Senior Unsecured Notes Series J [Member]
Debt Instrument [Line Items]
Interest rate terms on debt	Series J senior unsecured notes bore interest at a 3-month LIBOR for that floating rate interest period plus 1.45%.
Senior Unsecured Notes Series J [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Interest rate margin	1.45%
Senior Unsecured Notes Series K [Member]
Debt Instrument [Line Items]
Stated interest rate on debt instrument	3.44%	3.44%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Jan. 01, 2018	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 31, 2017
Income Taxes [Line Items]
2017 Tax Act						$ 550
2017 Tax Act, Transition tax						490
2017 Tax Act, State income taxes and foreign withholding taxes						40
2017 Tax Act, Remeasurement of deferred taxes						$ 20
Statutory tax rate				21.00%		35.00%
Reduction in provisional accrual for federal, state and foreign taxes		$ 19
Accrued income tax reserve		$ 18		$ 18
2017 Tax Act, GILTI effective tax rate				10.50%
Income tax holiday amount				$ 21	$ 18
Income tax holiday per share benefit				$ 0.26	$ 0.23
Effective income tax rate		16.70%	11.50%	15.60%	10.10%
Increase (decrease) in effective tax rate percentage points		5.20%		5.50%
2017 Tax Act, change in foreign currency exchange rates on earnings, percentage		1.40%		1.30%
2017 Tax Act, change in foreign currency exchange rates on earnings		$ 2		$ 6
Effect of stock-based compensation		$ 2		$ 6
Effective income tax rate reconciliation, share-based compensation, excess tax benefit, percent		1.60%		1.80%
Effective income tax rate reconciliation tax reserve		7.00%		7.00%
Increase (Decrease) in tax reserve for uncertain tax positions and settlement				$ 2
Tax reserves due to lapsing of statutes of limitation					$ 3
GILTI effective tax rate		2.40%		2.40%
Increase in reserve for uncertain tax positions		$ 18		$ 18
Maximum [Member]
Income Taxes [Line Items]
Expected change in unrecognized tax benefits in the next twelve months		$ 1		$ 1
Accounting Standards Update 2016-16 [Member]
Income Taxes [Line Items]
Retained earnings	$ 4
Ireland [Member]
Income Taxes [Line Items]
Statutory tax rate				12.50%
U.K [Member]
Income Taxes [Line Items]
Statutory tax rate				19.00%
Singapore [Member]
Income Taxes [Line Items]
Statutory tax rate				17.00%
Marginal effective income tax rate				0.00%

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits Roll Forward (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at the beginning of the period	$ 5,843	$ 9,964
Net changes in uncertain tax positions	19,097	(2,953)
Balance at the end of the period	$ 24,940	$ 7,011

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 9,213	$ 12,274	$ 28,184	$ 30,068
Cost of Sales [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	488	726	1,696	2,251
Selling and Administrative Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	6,731	10,768	22,855	25,558
Research and Development Expenses [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 1,994	$ 780	$ 3,633	$ 2,259

Stock-Based Compensation - Rele

Stock-Based Compensation - Relevant Data Used to Determine the Value of Stock Options Granted During the Period (Detail) - Equity Option [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Options Issued and Significant Assumptions Used to Estimate Option Fair Values
Options issued	147	217
Fair value assumptions, risk free interest rate	2.70%	2.20%
Fair value assumptions, expected life in years	6 years	6 years
Fair value assumptions, expected volatility	23.20%	23.00%
Fair value assumptions, expected dividends	$ 0	$ 0
Weighted-Average Exercise Price and Fair Value of Options on the Date of Grant
Weighted-average exercise price of options granted	$ 205.37	$ 151.24
Weighted-average grant date fair value of options granted	$ 57.99	$ 40.49

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Options Outstanding Roll Forward (Detail) - Equity Option [Member] - $ / shares shares in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding at December 31, 2017	2,039
Granted	147	217
Exercised	(357)
Canceled	(137)
Outstanding at September 29, 2018	1,692
Weighted-average exercise price of options outstanding at beginning of period	$ 124.41
Weighted-average exercise price of options granted	205.37	$ 151.24
Weighted-average exercise price of options exercised	102.44
Weighted average exercise price of options canceled	126.13
Weighted-average exercise price of options outstanding at end of period	135.94
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average exercise price of options outstanding at beginning of period	38.09
Weighted-average exercise price of options granted	188.26
Weighted-average exercise price of options exercised	38.09
Weighted average exercise price of options canceled	98.21
Weighted-average exercise price of options outstanding at end of period	38.09
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average exercise price of options outstanding at beginning of period	194.26
Weighted-average exercise price of options granted	208.47
Weighted-average exercise price of options exercised	154.33
Weighted average exercise price of options canceled	154.33
Weighted-average exercise price of options outstanding at end of period	$ 208.47

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - $ / shares shares in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	91
Weighted-average grant date fair value of shares granted	$ 207.85
Award vesting period	5 years
Performance Stock Unit Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	16	20
Weighted-average grant date fair value of shares granted	$ 253.44
Performance Stock Unit Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights	0.00%
Performance Stock Unit Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights	200.00%
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	5
Weighted-average grant date fair value of shares granted	$ 194.73

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Units Unvested Roll Forward (Detail) - Restricted Stock Units (RSUs) [Member] shares in Thousands	9 Months Ended
	Sep. 29, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Unvested Beginning balance, Shares | shares	374
Shares, Granted | shares	91
Shares, Vested | shares	(123)
Shares, Forfeited | shares	(18)
Unvested Ending balance, Shares | shares	324
Weighted-average grant date fair value per share of shares unvested at beginning of period | $ / shares	$ 124.81
Weighted-average grant date fair value per share of shares granted | $ / shares	207.85
Weighted-average grant date fair value per share of shares vested | $ / shares	117.68
Weighted-average grant date fair value of shares forfeited | $ / shares	126.43
Weighted-average grant date fair value per share of shares unvested at end of period | $ / shares	$ 150.75

Stock-Based Compensation - Re_2

Stock-Based Compensation - Relevant Data Used to Determine the Value of Performance Shares (Detail) - Performance Stock Unit Plan [Member] - USD ($) shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Performance Stock Units Issued and Significant Assumptions Used to Estimate Fair Values
Shares granted	16	20
Fair value assumptions, risk free interest rate	2.00%	1.50%
Fair value assumptions, expected life in years	2 years 9 months 18 days	3 years
Fair value assumptions, expected volatility	23.40%	23.20%
Fair value assumptions, expected volatility of peer companies	25.80%	26.10%
Fair value assumptions, correlation coefficient	37.20%	38.50%
Fair value assumptions, expected dividends	$ 0	$ 0

Stock-Based Compensation - Perf

Stock-Based Compensation - Performance Stock Units Unvested Roll Forward (Detail) - Performance Stock Unit Plan [Member] - $ / shares shares in Thousands	9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested Beginning balance, Shares	64
Shares granted	16	20
Shares Forfeited	(5)
Unvested Ending balance, Shares	75
Weighted-average grant date fair value per share of shares unvested at beginning of period	$ 196.29
Weighted-average grant date fair value per share of shares granted	253.44
Weighted-average grant date fair value per share of shares forfeited	188.45
Weighted-average grant date fair value per share of shares unvested at end of period	$ 209

Earnings Per Share - Earnings P

Earnings Per Share - Earnings Per Share Reconciliation (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Net income per basic common share, Net Income (Numerator)	$ 141,014	$ 136,104	$ 408,642	$ 373,483
Net income per diluted common share, Net Income (Numerator)	$ 141,014	$ 136,104	$ 408,642	$ 373,483
Net income per basic common share, Weighted-Average Shares (Denominator)	76,575	79,712	77,741	79,908
Effect of dilutive stock option, restricted stock, performance stock unit and restricted stock unit securities, Weighted-Average Shares (Denominator)	561	809	654	752
Net income per diluted common share, Weighted-Average Shares (Denominator)	77,136	80,521	78,395	80,660
Net income per basic common share, Per Share Amount	$ 1.84	$ 1.71	$ 5.26	$ 4.67
Effect of dilutive stock option, restricted stock, performance stock unit and restricted stock unit securities, Per Share Amount	(0.01)	(0.02)	(0.05)	(0.04)
Net income per diluted common share, Per Share Amount	$ 1.83	$ 1.69	$ 5.21	$ 4.63

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share	0.3	0.4	0.1	0.5

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income - Schedule of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			$ 2,233,788
Other comprehensive (loss) income, net of tax	$ 7,108	$ 27,348	(15,726)	$ 95,853
Ending balance	1,876,432		1,876,432
Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(69,418)
Other comprehensive (loss) income, net of tax			(17,937)
Ending balance	(87,355)		(87,355)
Unrealized Gain (Loss) on Retirement Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(37,103)
Other comprehensive (loss) income, net of tax			2,228
Ending balance	(34,875)		(34,875)
Unrealized Gain (Loss) on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(3,546)
Other comprehensive (loss) income, net of tax			(17)
Ending balance	(3,563)		(3,563)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(110,067)
Other comprehensive (loss) income, net of tax			(15,726)
Ending balance	$ (125,793)		$ (125,793)

Retirement Plans - Defined Bene

Retirement Plans - Defined Benefit Plan, Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
United States [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 142	$ 113	$ 426	$ 338
Interest cost	1,622	1,707	4,868	5,122
Expected return on plan assets	(1,708)	(2,574)	(5,123)	(7,724)
Net amortization: Net actuarial loss	771	693	2,312	2,078
Net periodic pension cost (benefit)	827	(61)	2,483	(186)
United States [Member] | Healthcare Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	142	137	425	410
Interest cost	159	155	477	464
Expected return on plan assets	(177)	(146)	(530)	(440)
Net amortization: Prior service (credit) cost	(4)		(14)
Net periodic pension cost (benefit)	120	146	358	434
Non-U.S. Pension Plans [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,311	1,311	4,024	3,802
Interest cost	406	386	1,250	1,112
Expected return on plan assets	(486)	(434)	(1,442)	(1,250)
Net amortization: Prior service (credit) cost	(30)	(47)	(93)	(140)
Net amortization: Net actuarial loss	167	248	515	714
Net periodic pension cost (benefit)	$ 1,368	$ 1,464	$ 4,254	$ 4,238

Retirement Plans - Additional I

Retirement Plans - Additional Information (Detail)	3 Months Ended	9 Months Ended
	Sep. 29, 2018USD ($)	Sep. 29, 2018USD ($)
Non-U.S. Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Company contributions	$ 5,000,000	$ 5,000,000
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in current fiscal year	5,000,000	5,000,000
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated future employer contributions in current fiscal year	$ 10,000,000	$ 10,000,000

Business Segment Information -

Business Segment Information - Additional Information (Detail)	9 Months Ended
	Sep. 29, 2018Segment
Segment Reporting [Abstract]
Number of operating segments	2
Number of reportable segments	1

Business Segment Information _2

Business Segment Information - Summary of Net Sales for Company's Products and Services (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Total net sales	$ 578,021	$ 565,584	$ 1,704,910	$ 1,621,803
Waters Instrument Systems [Member]
Disaggregation of Revenue [Line Items]
Total net sales	238,986	238,431	677,017	674,768
Chemistry Consumables [Member]
Disaggregation of Revenue [Line Items]
Total net sales	95,979	92,879	293,818	271,606
TA Instrument Systems [Member]
Disaggregation of Revenue [Line Items]
Total net sales	43,557	44,240	135,673	126,310
Product [Member]
Disaggregation of Revenue [Line Items]
Total net sales	378,522	375,550	1,106,508	1,072,684
Waters Service [Member]
Disaggregation of Revenue [Line Items]
Total net sales	180,830	172,594	543,411	498,736
TA Service [Member]
Disaggregation of Revenue [Line Items]
Total net sales	18,669	17,440	54,991	50,383
Service [Member]
Disaggregation of Revenue [Line Items]
Total net sales	$ 199,499	$ 190,034	$ 598,402	$ 549,119

Business Segment Information _3

Business Segment Information - Summary of Geographic Sales Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Total net sales	$ 578,021	$ 565,584	$ 1,704,910	$ 1,621,803
China [Member]
Disaggregation of Revenue [Line Items]
Total net sales	109,713	96,141	313,250	275,367
Japan [Member]
Disaggregation of Revenue [Line Items]
Total net sales	43,549	42,202	129,497	125,058
Asia Other [Member]
Disaggregation of Revenue [Line Items]
Total net sales	68,934	70,996	216,634	219,723
Total Asia [Member]
Disaggregation of Revenue [Line Items]
Total net sales	222,196	209,339	659,381	620,148
United States [Member]
Disaggregation of Revenue [Line Items]
Total net sales	170,766	171,053	479,072	474,661
Americas Other [Member]
Disaggregation of Revenue [Line Items]
Total net sales	36,037	31,960	107,567	99,588
Total Americas [Member]
Disaggregation of Revenue [Line Items]
Total net sales	206,803	203,013	586,639	574,249
Europe [Member]
Disaggregation of Revenue [Line Items]
Total net sales	$ 149,022	$ 153,232	$ 458,890	$ 427,406

Business Segment Information _4

Business Segment Information - Summary of Net Sales by Customer Class (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Revenue, Major Customer [Line Items]
Total net sales	$ 578,021	$ 565,584	$ 1,704,910	$ 1,621,803
Pharmaceutical [Member]
Revenue, Major Customer [Line Items]
Total net sales	325,166	321,963	968,848	921,423
Industrial [Member]
Revenue, Major Customer [Line Items]
Total net sales	171,985	168,349	517,979	504,183
Governmental and Academic [Member]
Revenue, Major Customer [Line Items]
Total net sales	$ 80,870	$ 75,272	$ 218,083	$ 196,197

Business Segment Information _5

Business Segment Information - Summary of Net Sales of Company Recognized at a Point in Time Versus Over Time (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Total net sales	$ 578,021	$ 565,584	$ 1,704,910	$ 1,621,803
Chemistry Consumables [Member]
Disaggregation of Revenue [Line Items]
Total net sales	95,979	92,879	293,818	271,606
Service [Member]
Disaggregation of Revenue [Line Items]
Total net sales	199,499	190,034	598,402	549,119
Net Sales Recognized at a Point in Time: [Member]
Disaggregation of Revenue [Line Items]
Total net sales	454,291	447,771	1,335,193	1,285,344
Net Sales Recognized at a Point in Time: [Member] | Instrument Systems [Member]
Disaggregation of Revenue [Line Items]
Total net sales	282,543	282,671	812,690	801,078
Net Sales Recognized at a Point in Time: [Member] | Chemistry Consumables [Member]
Disaggregation of Revenue [Line Items]
Total net sales	95,979	92,879	293,818	271,606
Net Sales Recognized at a Point in Time: [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Total net sales	75,769	72,221	228,685	212,660
Net Sales Recognized Over Time: [Member] | Service [Member]
Disaggregation of Revenue [Line Items]
Total net sales	$ 123,730	$ 117,813	$ 369,717	$ 336,459

Recent Accounting Standard Ch_2

Recent Accounting Standard Changes and Developments - Additional Information (Detail) $ in Millions	Jan. 01, 2018USD ($)
Accounting Standards Update 2016-16 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	$ 4