MKS Instruments (MKSI) 10-Q 6 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 29, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	MKSI
Entity Registrant Name	MKS INSTRUMENTS INC
Entity Central Index Key	1049502
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		53,371,635

Consolidated_Balance_Sheets_Un

Consolidated Balance Sheets (Unaudited) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$192,713	$305,437
Short-term investments	158,631	129,594
Trade accounts receivable, net	124,445	106,362
Inventories, net	164,412	155,169
Deferred income taxes	13,560	14,017
Other current assets	21,580	27,512
Total current assets	675,341	738,091
Property, plant and equipment, net	70,908	72,776
Long-term investments	237,313	157,201
Goodwill	199,330	192,381
Intangible assets, net	49,553	46,389
Other assets	17,165	17,206
Total assets	1,249,610	1,224,044
Current liabilities:
Accounts payable	37,549	34,166
Accrued compensation	21,349	26,970
Income taxes payable	6,455	6,702
Other current liabilities	38,513	35,789
Total current liabilities	103,866	103,627
Other liabilities	41,055	38,595
Commitments and contingencies (Note 18)
Stockholders' equity:
Preferred Stock, $0.01 par value per share, 2,000,000 shares authorized; none issued and outstanding
Common Stock, no par value, 200,000,000 shares authorized; 53,289,953 and 53,154,666 shares issued and outstanding at March 31, 2015 and December 31, 2014, respectively	113	113
Additional paid-in capital	736,290	734,732
Retained earnings	374,063	349,061
Accumulated other comprehensive loss	-5,777	-2,084
Total stockholders' equity	1,104,689	1,081,822
Total liabilities and stockholders' equity	$1,249,610	$1,224,044

Consolidated_Balance_Sheets_Un1

Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Preferred Stock, par value	$0.01	$0.01
Preferred Stock, shares authorized	2,000,000	2,000,000
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Common Stock, par value	$0	$0
Common Stock, shares authorized	200,000,000	200,000,000
Common Stock, shares issued	53,289,953	53,154,666
Common Stock, shares outstanding	53,289,953	53,154,666

Consolidated_Statements_of_Ope

Consolidated Statements of Operations and Comprehensive Income (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Net revenues:
Products	$186,096		$181,186
Services	27,743		25,167
Total net revenues	213,839		206,353
Cost of revenues:
Cost of products	98,652		100,211
Cost of services	18,141		16,770
Total cost of revenues (exclusive of amortization shown separately below)	116,793		116,981
Gross profit	97,046		89,372
Research and development	16,680		15,618
Selling, general and administrative	30,867		34,591
Acquisition costs	30		228
Restructuring	788		747
Amortization of intangible assets	1,671		410
Income from operations	47,010		37,778
Interest income	541		252
Interest expense	37		17
Income before income taxes	47,514		38,013
Provision for income taxes	13,728		6,768
Net income	33,786		31,245
Other comprehensive income:
Changes in value of financial instruments designated as cash flow hedges, net of tax benefit	-822	[1]	-163	[1]
Foreign currency translation adjustments, net of tax of $0	-3,206		21
Unrealized gain on investments, net of tax expense	334	[2]	36	[2]
Total comprehensive income	$30,092		$31,139
Net income per share:
Basic	$0.63		$0.58
Diluted	$0.63		$0.58
Cash dividends per common share	$0.17		$0.16
Weighted average common shares outstanding:
Basic	53,214		53,411
Diluted	53,529		53,776
[1]	Tax benefit was $133 and $108 for the three months ended March 31, 2015 and 2014, respectively.
[2]	Tax expense was $54 and $24 for the three months ended March 31, 2015 and 2014, respectively.

Consolidated_Statements_of_Ope1

Consolidated Statements of Operations and Comprehensive Income (Unaudited) (Parenthetical) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Tax benefit on changes in value of financial instruments designated as cash flow hedges	$133	$108
Tax on foreign currency translation adjustments	0	0
Tax expense on unrealized (loss) gain on investments	$54	$24

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net income	$33,786	$31,245
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	5,532	4,150
Stock-based compensation	3,212	3,198
Provision for excess and obsolete inventory	2,683	2,613
Provision for bad debt	-172	94
Deferred income taxes	736	-3,974
Excess tax benefits from stock-based compensation	-524	-189
Other	1	-141
Changes in operating assets and liabilities:
Trade accounts receivable	-19,030	-2,784
Inventories	-12,817	-7,402
Income taxes	2,034	-5,462
Other current assets	-5,029	-1,286
Accrued compensation	-4,930	-6,872
Other current and non-current liabilities	2,735	2,512
Accounts payable	3,587	-4,656
Other assets	7,801	-1,143
Net cash provided by operating activities	19,605	9,903
Cash flows from investing activities:
Acquisition of businesses, net of cash acquired	-9,867
Purchases of investments	-164,327	-128,524
Maturities of investments	38,205	104,623
Sales of investments	17,414	24,948
Purchases of property, plant and equipment	-2,504	-3,098
Other	5	79
Net cash used in investing activities	-121,074	-1,972
Cash flows from financing activities:
Repurchase of common stock		-945
Net payments related to employee stock awards	-2,105	-762
Dividend payments to common stockholders	-8,784	-8,553
Excess tax benefits from stock-based compensation	524	189
Net cash used in financing activities	-10,365	-10,071
Effect of exchange rate changes on cash and cash equivalents	-890	328
Decrease in cash and cash equivalents	-112,724	-1,812
Cash and cash equivalents at beginning of period	305,437	288,902
Cash and cash equivalents at end of period	$192,713	$287,090

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation	1)	Basis of Presentation
	The terms “MKS” and the “Company” refer to MKS Instruments, Inc. and its subsidiaries. The interim financial data as of March 31, 2015 and for the three months ended March 31, 2015 and 2014 are unaudited; however, in the opinion of MKS, the interim data includes all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the results for the interim periods. The consolidated balance sheet presented as of December 31, 2014 has been derived from the audited consolidated financial statements as of that date. The unaudited consolidated financial statements presented herein have been prepared in accordance with the instructions to Form 10-Q and do not include all of the information and note disclosures required by United States generally accepted accounting principles (“U.S. GAAP”). The consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the MKS Annual Report on Form 10-K for the year ended December 31, 2014 filed with the Securities and Exchange Commission on February 25, 2015.
	The preparation of these consolidated financial statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. On an on-going basis, management evaluates its estimates and judgments, including those related to revenue recognition, stock-based compensation, inventory, intangible assets, goodwill and other long-lived assets, acquisition expenses, income taxes and investments. Management bases its estimates and judgments on historical experience and on various other factors that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Actual results may differ from these estimates under different assumptions or conditions.

Recently_Issued_Accounting_Pro

Recently Issued Accounting Pronouncements	3 Months Ended
	Mar. 31, 2015
Accounting Changes and Error Corrections [Abstract]
Recently Issued Accounting Pronouncements	2)	Recently Issued Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which supersedes all existing revenue recognition requirements, including most industry-specific guidance. The new standard requires a company to recognize revenue when it transfers goods and services to customers in an amount that reflects the consideration that the company expects to be entitled to in exchange for those goods or services. This ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and assets recognized from costs incurred to obtain or fulfill a contract. This pronouncement is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. However, in March 2015, the FASB proposed a one-year deferral. The two permitted transition methods under the new standard are the full retrospective method, in which case the standard would be applied to each prior reporting period presented, or the modified retrospective method, in which case the cumulative effect of applying the standard would be recognized at the date of initial application. The Company has not yet selected a transition method. The Company is currently evaluating the requirements of ASU No. 2014-09 and has not yet determined its impact on the Company’s consolidated financial statements.
	In August 2014, the FASB issued ASU No. 2014-15, “Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern.” Under this ASU, management will be required to assess an entity’s ability to continue as a going concern, and to provide related footnote disclosures in certain circumstances. The provisions of this ASU are effective for annual periods beginning after December 15, 2016, and for annual and interim periods thereafter. This ASU is not expected to have an impact on the Company’s financial statements or disclosures.

Investments

Investments	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Investments	3)	Investments
	The fair value of short-term investments with maturities or estimated lives of less than one year consists of the following:
			March 31, 2015		December 31, 2014
	Available-for-sale investments:
	Time deposits and certificates of deposit		$	5,400	$	20,900
	Bankers’ acceptance drafts			327		82
	Commercial paper			1,447		—
	Corporate obligations			58,331		24,020
	Municipal bonds			5,798		2,099
	U.S. agency obligations			87,328		82,493
			$	158,631	$	129,594
	The fair value of long-term investments with maturities of more than one year consists of the following:
			March 31, 2015		December 31, 2014
	Available-for-sale investments:
	Time deposits and certificates of deposit		$	—	$	48
	Asset-backed securities			129,242		75,674
	Corporate obligations			90,114		64,669
	Municipal bonds			1,880		1,254
	U.S. agency obligations			16,077		15,556
			$	237,313	$	157,201
	The following tables show the gross unrealized gains and (losses) aggregated by investment category for short-term and long-term available-for-sale investments:
	As of March 31, 2015:		Cost		Gross		Gross			Estimated
					Unrealized		Unrealized			Fair Value
					Gains		(Losses)
	Short-term investments:
	Time deposits and certificates of deposit		$	5,400	$	—	$	—		$	5,400
	Bankers’ acceptance drafts			327		—		—			327
	Commercial paper			1,447		—		—			1,447
	Corporate obligations			58,336		10		(15	)		58,331
	Municipal bonds			5,800		1		(3	)		5,798
	U.S. agency obligations			87,311		23		(6	)		87,328
			$	158,621	$	34	$	(24	)	$	158,631
	Long-term investments:
	Asset-backed securities			129,209	$	66	$	(33	)	$	129,242
	Corporate obligations			90,128		44		(58	)		90,114
	Municipal bonds			1,878		3		(1	)		1,880
	U.S. agency obligations			16,070		8		(1	)		16,077
			$	237,285	$	121	$	(93	)	$	237,313
	As of December 31, 2014:		Cost		Gross		Gross			Estimated
					Unrealized		Unrealized			Fair Value
					Gains		(Losses)
	Short-term investments:
	Time deposits and certificates of deposit		$	20,901	$	—	$	(1	)	$	20,900
	Bankers’ acceptance drafts			82		—		—			82
	Corporate obligations			24,029		2		(11	)		24,020
	Municipal bonds			2,100		—		(1	)		2,099
	U.S. agency obligations			82,488		14		(9	)		82,493
			$	129,600	$	16	$	(22	)	$	129,594
	Long-term investments:
	Time deposits and certificates of deposit		$	48	$	—	$	—		$	48
	Asset-backed securities			75,778		5		(109	)		75,674
	Corporate obligations			64,842		1		(174	)		64,669
	Municipal bonds			1,258		—		(4	)		1,254
	U.S. agency obligations			15,563		2		(9	)		15,556
			$	157,489	$	8	$	(296	)	$	157,201
	Interest income is accrued as earned. Dividend income is recognized as income on the date the stock trades “ex-dividend.” The cost of marketable securities sold is determined by the specific identification method. Realized gains or (losses) are reflected in income and were immaterial for the three months ended March 31, 2015 and 2014.
	In accordance with the Company’s investment policy, no security shall have a maturity or average life longer than three years. The average duration of the portfolio shall be no more than one year. Corporate securities must have ratings of A3/A- or better. Asset-backed securities must be rated AAA. Short-term ratings of A-2/P2/F2 or higher are also permitted. With respect to compliance with these investment guidelines, the rating agencies include Moody’s Investor Service, Standard & Poor’s and Fitch Investor Service. The middle of Moody’s, Standard & Poor’s and Fitch rating shall be used to determine compliance with credit quality guidelines. If a security is rated by two rating agencies, the lower rating will apply. If only one rating exists, that rating shall be used.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	4)	Fair Value Measurements
	In accordance with the provisions of fair value accounting, a fair value measurement assumes that the transaction to sell an asset or transfer a liability occurs in the principal market for the asset or liability or, in the absence of a principal market, the most advantageous market for the asset or liability and defines fair value based upon an exit price model.
	The fair value measurement guidance establishes a fair value hierarchy which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The guidance describes three levels of inputs that may be used to measure fair value:
			Level 1		Quoted prices in active markets for identical assets or liabilities assessed as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis.
			Level 2		Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 2 assets and liabilities include debt securities with quoted prices that are traded less frequently than exchange-traded instruments or securities or derivative contracts that are valued using a pricing model with inputs that are observable in the market or can be derived principally from or corroborated by observable market data.
			Level 3		Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Level 3 assets and liabilities include financial instruments whose value is determined using pricing models, discounted cash flow methodologies, or similar techniques, as well as instruments for which the determination of fair value requires significant management judgment or estimation.
	In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the Company categorizes such assets and liabilities based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability.
	Assets and liabilities of the Company are measured at fair value on a recurring basis as of March 31, 2015 and are summarized as follows:
						Fair Value Measurements at Reporting Date Using
	Description		March 31, 2015			Quoted Prices in		Significant Other		Significant
						Active Markets for		Observable		Unobservable
						Identical Assets		Inputs		Inputs
						(Level 1)		(Level 2)		(Level 3)
	Assets:
	Cash equivalents:
	Money market funds		$	87,790		$	87,790	$	—	$	—
	Bankers’ acceptance drafts			99			—		99		—
	Available-for-sale securities:
	Bankers’ acceptance drafts			327			—		327		—
	Time deposits and certificates of deposit			5,400			—		5,400		—
	Commercial paper			1,447			—		1,447		—
	Asset-backed securities			129,242			—		129,242		—
	Corporate obligations			148,445			—		148,445		—
	Municipal bonds			7,678			—		7,678		—
	U.S. agency obligations			103,405			—		103,405		—
	Derivatives – currency forward contracts			1,240			—		1,240		—
	Total assets		$	485,073		$	87,790	$	397,283	$	—
	Liabilities:
	Derivatives – currency forward contracts		$	318		$	—	$	318	$	—
	Reported as follows:
	Assets:
	Cash and cash equivalents(1)		$	87,889		$	87,790	$	99	$	—
	Short-term investments			158,631			—		158,631		—
	Other current assets			1,240			—		1,240		—
	Total current assets		$	247,760		$	87,790	$	159,970	$	—
	Long-term investments		$	237,313		$	—	$	237,313	$	—
	Liabilities:
	Other current liabilities		$	318		$	—	$	318	$	—
	-1	The cash and cash equivalent amounts presented in the table above do not include cash of $95,212 and non-negotiable time deposits of $9,612 as of March 31, 2015.
	Assets and liabilities of the Company measured at fair value on a recurring basis as of December 31, 2014, are summarized as follows:
						Fair Value Measurements at Reporting Date Using
	Description		December 31, 2014			Quoted Prices in		Significant Other		Significant
						Active Markets for		Observable		Unobservable
						Identical Assets		Inputs		Inputs
						(Level 1)		(Level 2)		(Level 3)
	Assets:
	Cash equivalents:
	Money market funds		$	129,092		$	129,092	$	—	$	—
	Bankers acceptance drafts			131			—		131		—
	Corporate obligations			700			—		700		—
	Available-for-sale investments:
	Time deposits and certificates of deposit			20,948			—		20,948		—
	Asset-backed securities			75,674			—		75,674		—
	Bankers acceptance drafts			82			—		82		—
	Corporate obligations			88,689			—		88,689		—
	Municipal bonds			3,353			—		3,353		—
	U.S. agency obligations			98,049			—		98,049		—
	Derivatives – currency forward contracts			2,110			—		2,110		—
	Total assets		$	418,828		$	129,092	$	289,736	$	—
	Liabilities:
	Derivatives – currency forward contracts		$	—		$	—	$	—	$	—
	Reported as follows:
	Assets:
	Cash and cash equivalents (1)		$	129,923		$	129,092	$	831	$	—
Short-term investments			129,594			—		129,594		—
Other current assets			2,110			—		2,110		—
Total current assets		$	261,627		$	129,092	$	132,535	$	—
Long-term investments		$	157,201		$	—	$	157,201	$	—
Liabilities:
Other current liabilities		$	—		$	—	$	—	$	—
-1	The cash and cash equivalent amounts presented in the table above do not include cash of $167,517 and non-negotiable time deposits of $7,997 as of December 31, 2014.
Money Market Funds
Money market funds are cash and cash equivalents and are classified within Level 1 of the fair value hierarchy.
Bankers’ Acceptance Drafts
Bankers’ acceptance drafts are short-term credit investments created by a non-financial firm and guaranteed by a bank. These drafts are often traded at a discount from face value and may be traded on a secondary market.
Available-For-Sale Investments
As of March 31, 2015 and December 31, 2014, available-for-sale investments consisted of time deposits and drafts denominated in the Euro currency, certificates of deposit, commercial paper, asset-backed securities (which include auto loans, credit card receivables and equipment trust receivables), corporate obligations, municipal bonds and U.S. agency obligations. The Company measures its debt and equity investments at fair value.
Derivatives
As a result of the Company’s global operating activities, the Company is exposed to market risks from changes in foreign currency exchange rates, which may adversely affect its operating results and financial position. When deemed appropriate, the Company minimizes its risks from foreign currency exchange rate fluctuations through the use of derivative financial instruments. The principal market in which the Company executes its foreign currency contracts is the institutional market in an over-the-counter environment with a relatively high level of price transparency. The market participants usually are large commercial banks. The forward foreign currency exchange contracts are valued using broker quotations, or market transactions and are classified within Level 2 of the fair value hierarchy.

Derivatives

Derivatives	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	5)	Derivatives
	The Company enters into derivative instruments for risk management purposes only, including derivatives designated as hedging instruments and those utilized as economic hedges. The Company operates internationally and, in the normal course of business, is exposed to fluctuations in interest rates and foreign exchange rates. These fluctuations can increase the costs of financing, investing and operating the business. The Company has used derivative instruments, such as forward contracts, to manage certain foreign currency exposure.
	By nature, all financial instruments involve market and credit risks. The Company enters into derivative instruments with major investment grade financial institutions and no collateral is required. The Company has policies to monitor the credit risk of these counterparties. While there can be no assurance, the Company does not anticipate any material non-performance by any of these counterparties.
	The Company hedges a portion of its forecasted foreign currency denominated intercompany sales of inventory, over a maximum period of eighteen months, using forward foreign exchange contracts accounted for as cash-flow hedges related to Japanese, South Korean, British, Euro and Taiwanese currencies. To the extent these derivatives are effective in off-setting the variability of the hedged cash flows, and otherwise meet the hedge accounting criteria, changes in the derivatives’ fair value are not included in current earnings but are included in other comprehensive income (loss) (“OCI”) in stockholders’ equity. These changes in fair value will subsequently be reclassified into earnings, as applicable, when the forecasted transaction occurs. To the extent that a previously designated hedging transaction is no longer an effective hedge, any ineffectiveness measured in the hedging relationship is recorded currently in earnings in the period it occurs. The cash flows resulting from forward exchange contracts are classified in the consolidated statements of cash flows as part of cash flows from operating activities. The Company does not enter into derivative instruments for trading or speculative purposes.
	To the extent the hedge accounting criteria is not met, the related foreign currency forward contracts are considered as economic hedges and changes in the fair value of these contracts are recorded immediately in earnings in the period in which they occur. These include hedges that are used to reduce exchange rate risks arising from the change in fair value of certain foreign currency denominated assets and liabilities (i.e., payables, receivables) and other economic hedges where the hedge accounting criteria were not met.
	As of March 31, 2015 and December 31, 2014, the Company had outstanding forward foreign exchange contracts with gross notional values of $84,063 and $28,650, respectively. The following tables provide a summary of the primary net hedging positions and corresponding fair values held as of March 31, 2015 and December 31, 2014:
			March 31, 2015
	Currency Hedged (Buy/Sell)		Gross Notional			Fair Value(1)
			Value			Asset/(Liability)
	U.S. Dollar/Japanese Yen		$	29,708		$	478
	U.S. Dollar/South Korean Won			32,692			133
	U.S. Dollar/Euro			5,009			286
	U.S. Dollar/U.K. Pound Sterling			3,794			74
	U.S. Dollar/Taiwan Dollar			12,860			(49	)
	Total		$	84,063		$	922
	-1	Represents the fair value of the net asset / (liability) amount included in the consolidated balance sheets.
			December 31, 2014
	Currency Hedged (Buy/Sell)		Gross Notional			Fair Value (1)
			Value			Asset/(Liability)
	U.S. Dollar/Japanese Yen		$	8,035		$	1,107
	U.S. Dollar/South Korean Won			12,512			372
	U.S. Dollar/Euro			2,060			185
	U.S. Dollar/U.K. Pound Sterling			1,308			70
	U.S. Dollar/Taiwan Dollar			4,735			232
	Total		$	28,650		$	1,966
	-1	Represents the fair value of the net asset / (liability) amount included in the consolidated balance sheets.
	The following table provides a summary of the fair value amounts of the Company’s derivative instruments:
			March 31, 2015			December 31, 2014
	Derivative assets:
	Forward exchange contracts		$	1,240		$	1,966
	Derivative liabilities:
	Forward exchange contracts			(318	)		—
	Total net derivative asset designated as hedging instruments(1)		$	922		$	1,966
	-1	The derivative asset of $1,240 and derivative liability of $318 are classified in other current assets and other current liabilities in the consolidated balance sheet as of March 31, 2015. The derivative asset of $1,966 is classified in other current assets in the consolidated balance sheet as of December 31, 2014. These foreign exchange contracts are subject to a master netting agreement with one financial institution. However, the Company has elected to record these contracts on a gross basis in the balance sheet.
	The net amount of existing gains or losses as of March 31, 2015 that is expected to be reclassified from accumulated OCI into earnings within the next twelve months is immaterial.
	The following table provides a summary of the gains (losses) on derivatives designated as hedging instruments:
			Three Months Ended March 31,
	Derivatives Designated as Cash Flow Hedging Relationships		2015			2014
	Forward exchange contracts:
	Net (loss) recognized in OCI(1)		$	(2,090	)	$	(334	)
	Net gain (loss) reclassified from accumulated OCI into income(2)		$	1,193		$	(94	)
	-1	Net change in the fair value of the effective portion classified in OCI.
	-2	Effective portion classified in cost of products for the three months ended March 31, 2015 and 2014. The tax effect of the gains or losses reclassified from accumulated OCI into income is immaterial.
	The following table provides a summary of gains on derivatives not designated as hedging instruments:
			Three Months Ended March 31,
	Derivatives Not Designated as Hedging Instruments		2015			2014
	Forward exchange contracts:
	Net gain recognized in income(1)		$	98		$	106
	-1	The Company enters into foreign exchange contracts to hedge against changes in the balance sheet for certain subsidiaries. These derivatives are not designated as hedging instruments and are recorded immediately in selling, general and administrative expenses.

Inventories

Inventories	3 Months Ended
	Mar. 31, 2015
Inventory Disclosure [Abstract]
Inventories	6)	Inventories
	Inventories consist of the following:
			March 31, 2015		December 31, 2014
	Raw materials		$	85,622	$	81,121
	Work-in-process			27,374		26,604
	Finished goods			51,416		47,444
			$	164,412	$	155,169

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
Acquisitions	7)	Acquisitions
	Precisive, LLC
	On March 17, 2015, the Company acquired 100% of Precisive, LLC (“Precisive”), for $12,155, net of cash acquired of $435, subject to final working capital adjustments. The purchase price includes a deferred payment amount of $2,600 to cover any potential indemnification claims, which amount will be paid to the sellers after 15 months assuming there are no indemnification claims. Precisive is an innovative developer of optical analyzers based on Tunable Filter Spectroscopy (TFS), which provide real-time gas analysis in the natural gas and hydrocarbon processing industries, including refineries, hydrocarbon processing plants, gas-to-power machines, biogas processes and fuel gas transportation and metering, while delivering customers a lower total cost of ownership.
	The following table summarizes the preliminary estimated fair value of the assets acquired and liabilities assumed at the date of acquisition.
	Current assets		$	285
	Non-current assets			18
	Intangible assets			5,110
	Goodwill			7,085
	Total assets acquired			12,498
	Total current liabilities assumed			343
	Total purchase price, net of cash acquired of $435		$	12,155
	The entire purchase price is expected to be deductible for tax purposes. The following table reflects the allocation of the acquired intangible assets and related estimates of useful lives. These acquired intangibles will be amortized on a straight-line basis, which approximates the pattern of use.
	Order backlog		$	50	18 months
	Customer relationships			1,430	12 years
	Exclusive patent license			2,600	10 years
	Trade names			210	10 years
	Current developed technology			820	10 years
			$	5,110
	The fair value of the acquired intangibles was determined using the income approach. This acquisition resulted in a purchase price that exceeded the estimated fair value of tangible and intangible assets, which excess was allocated to goodwill. The Company believes the amount of goodwill relative to identifiable intangible assets relates to several factors including: (1) potential buyer-specific synergies related to market opportunities for a combined product offering; (2) potential to leverage the Company’s sales force and intellectual property to attract new customers and revenue; and (3) potential to strengthen and expand into new but complementary markets, including targeting new applications such as natural gas processing, hydrocarbon processing and other oil and gas segments.
	The results of this acquisition were included in the Company’s consolidated operations beginning on March 17, 2015. The pro forma consolidated statements reflecting the operating results of Precisive, had it been acquired January 1, 2014, would not differ materially from the operating results of the Company as reported for the three months ended March 31, 2015. Precisive is included in the Company’s Instruments, Controls and Vacuum Products group and the Advanced Manufacturing Capital Equipment reportable segment. The revenue and net earnings from Precisive, since the date of acquisition through the period ended March 31, 2015, were immaterial.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	8)	Goodwill and Intangible Assets
	Goodwill
	The Company’s methodology for allocating the purchase price relating to purchase acquisitions is determined through established and generally accepted valuation techniques. Goodwill is measured as the excess of the cost of the acquisition over the sum of the amounts assigned to tangible and identifiable intangible assets acquired less liabilities assumed. The Company assigns assets acquired (including goodwill) and liabilities assumed to one or more reporting units as of the date of acquisition. Typically acquisitions relate to a single reporting unit and thus do not require the allocation of goodwill to multiple reporting units. If the products obtained in an acquisition are assigned to multiple reporting units, the goodwill is distributed to the respective reporting units as part of the purchase price allocation process.
	Goodwill and purchased intangible assets with indefinite useful lives are not amortized, but are reviewed for impairment annually during the fourth quarter of each fiscal year and whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. The process of evaluating the potential impairment of goodwill and intangible assets requires significant judgment. The Company regularly monitors current business conditions and other factors including, but not limited to, adverse industry or economic trends, restructuring actions and lower projections of profitability that may impact future operating results.
	The changes in the carrying amount of goodwill and accumulated impairment (loss) during the three months ended March 31, 2015 and year ended December 31, 2014 were as follows:
			2015									2014
			Gross			Accumulated			Net			Gross			Accumulated			Net
			Carrying			Impairment						Carrying			Impairment
			Amount			(Loss)						Amount			(Loss)
	Beginning balance at January 1		$	331,795		$	(139,414	)	$	192,381		$	290,323		$	(139,414	)	$	150,909
	Acquired goodwill (1)			7,085			—			7,085			41,993			—			41,993
	Foreign currency translation			(136	)		—			(136	)		(521	)		—			(521	)
	Ending balance at March 31, 2015 and December 31, 2014		$	338,744		$	(139,414	)	$	199,330		$	331,795		$	(139,414	)	$	192,381
	-1	During the first quarter of 2015, the Company recorded $7,085 of goodwill related to the Precisive acquisition. During the second quarter of 2014, the Company recorded $41,612 of goodwill related to the May 30, 2014 acquisition of the Granville-Phillips division of Brooks Automation, Inc. During the first quarter of 2014, the Company recorded a purchase accounting adjustment of $381 related to the March 12, 2013 purchase of Alter S.r.l.
	Intangible Assets
	Components of the Company’s intangible assets are comprised of the following:
	As of March 31, 2015:		Gross			Accumulated			Foreign			Net
						Amortization			Currency
									Translation
	Completed technology (1)		$	101,200		$	(80,477	)	$	(78	)	$	20,645
	Customer relationships (1)			37,251			(13,610	)		228			23,869
	Patents, trademarks, trade names and other (1)			30,396			(25,383	)		26			5,039
			$	168,847		$	(119,470	)	$	176		$	49,553
	-1	During the three months ended March 31, 2015, the Company recorded $5,110 of separately identified intangible assets of which $820 was completed technology, $1,430 was customer relationships and $2,860 was trademarks, trade names and other, related to the Precisive acquisition.
	As of December 31, 2014:		Gross			Accumulated			Foreign			Net
						Amortization			Currency
									Translation
	Completed technology (2)		$	100,380		$	(79,875	)	$	135		$	20,640
	Customer relationships (2)			35,821			(12,634	)		280			23,467
	Patents, trademarks, trade names and other (2)			27,536			(25,290	)		36			2,282
			$	163,737		$	(117,799	)	$	451		$	46,389
	-2	During 2014, the Company recorded $38,850 of separately identified intangible assets related to the May 30, 2014 acquisition of the Granville-Phillips division of Brooks Automation, Inc., of which $15,700 was completed technology, $21,250 was customer relationships and $1,900 was trademarks and trade names.
	Aggregate amortization expense related to acquired intangibles for the three months ended March 31, 2015 and 2014 was $1,671 and $410, respectively. Estimated amortization expense for each of the remaining fiscal years is as follows:
	Year		Amount
	2015 (remaining)		$	5,106
	2016			6,701
	2017			6,628
	2018			6,613
	2019			6,582
	2020			6,514
	Thereafter			11,409

Other_Assets

Other Assets	3 Months Ended
	Mar. 31, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets	9)	Other Assets
			March 31, 2015		December 31, 2014
	Other Current Assets:
	Income tax receivable		$	161	$	10,322
	Other			21,419		17,190
	Total other current assets		$	21,580	$	27,512
	Other Assets:
	Deferred tax assets, net		$	6,868	$	7,202
	Long-term income tax receivable			8,175		8,092
	Other			2,122		1,912
	Total other assets		$	17,165	$	17,206

Other_Liabilities

Other Liabilities	3 Months Ended
	Mar. 31, 2015
Other Liabilities Disclosure [Abstract]
Other Liabilities	10)	Other Liabilities
			March 31, 2015		December 31, 2014
	Other Current Liabilities:
	Product warranties		$	6,064	$	6,266
	Deferred revenue			5,997		8,283
	Other			26,452		21,240
	Total other current liabilities		$	38,513	$	35,789
	Other Liabilities:
	Long-term income tax payable		$	20,337	$	20,203
	Accrued compensation			12,312		12,068
	Other			8,406		6,324
	Total other liabilities		$	41,055	$	38,595

Debt

Debt	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Debt	11)	Debt
	The Company’s Japanese subsidiary has lines of credit and short-term borrowing arrangements with two financial institutions which generally expire and are renewed at three month intervals. The lines of credit provided for aggregate borrowings as of March 31, 2015 of up to an equivalent of $19,155 U.S. dollars. One of the borrowing arrangements has an interest rate based on the Tokyo Interbank Offer Rate at the time of borrowing and the other has an interest rate based on the Japanese Short-term Prime Lending Rate. There were no borrowings outstanding under these arrangements at March 31, 2015 and December 31, 2014.

Product_Warranties

Product Warranties	3 Months Ended
	Mar. 31, 2015
Guarantees [Abstract]
Product Warranties	12)	Product Warranties
	The Company provides for the estimated costs to fulfill customer warranty obligations upon the recognition of the related revenue. 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 shipment volume, product failure rates, utilization levels, material usage, and supplier warranties on parts delivered to the Company. Should actual product failure rates, utilization levels, material usage, or supplier warranties on parts differ from the Company’s estimates, revisions to the estimated warranty liability would be required. The product warranty liability is included in other current liabilities in the consolidated balance sheets.
	Product warranty activities were as follows:
			Three Months Ended March 31,
			2015			2014
	Beginning of period		$	6,266		$	6,956
	Provision for product warranties			1,109			704
	Direct charges to warranty liability			(1,244	)		(656	)
	Foreign currency translation			(67	)		9
	End of period		$	6,064		$	7,013

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	13)	Income Taxes
	The Company’s effective tax rate for the three months ended March 31, 2015 and 2014 was 28.9% and 17.8%, respectively. The effective tax rate for the three months ended March 31, 2015 was lower than the U.S. statutory tax rate primarily due the impact of lower tax rates on foreign income and the deduction for domestic production activities. The effective tax rate for the three months ended March 31, 2014 was lower than the U.S. statutory tax rate primarily due to the discrete release of income tax reserves related to the effective settlement of a foreign tax examination. The geographic mix of income and profits earned by the Company’s international subsidiaries being taxed at rates lower than the U.S. statutory rate also had a significant impact on the effective tax rate for the three months ended March 31, 2014.
	At March 31, 2015, the total amount of gross unrecognized tax benefits, which excludes interest and penalties, was approximately $19,508. At December 31, 2014, the total amount of gross unrecognized tax benefits, which excludes interest and penalties, was approximately $19,610. The net decrease from December 31, 2014 was attributable to a release of reserves for uncertain tax positions due to the expiration of the statute of limitations related to a previously open tax year. As of March 31, 2015, if these benefits were recognized in a future period, the timing of which is not estimable, the net unrecognized tax benefit of $11,524, excluding interest and penalties, would impact the Company’s effective tax rate. The Company accrues interest expense, and if applicable penalties, for any uncertain tax positions. Interest and penalties are classified as a component of income tax expense. At March 31, 2015 and December 31, 2014, the Company had accrued interest on unrecognized tax benefits of approximately $638 and $578, respectively.
	The Company and its subsidiaries are subject to examination by federal, state and foreign tax authorities. The Internal Revenue Service commenced an examination of the Company’s U.S. federal tax filings for tax years 2011 through 2013 during the quarter ended March 31, 2015. As a result, the U.S. statute of limitations remains open between tax years 2011 through present. However, carryforward amounts from prior years may still be adjusted upon examination by tax authorities if they are used in a future period. The U.S. statute of limitations for the Company’s tax filings in other jurisdictions varies between fiscal years 2008 through the present.

Net_Income_Per_Share

Net Income Per Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Net Income Per Share	14)	Net Income Per Share
	The following table sets forth the computation of basic and diluted net income per share:
			Three Months Ended March 31,
			2015		2014
	Numerator:
	Net income		$	33,786	$	31,245
	Denominator:
	Shares used in net income per common share – basic			53,214,000		53,411,000
	Effect of dilutive securities:
	Stock options, restricted stock and employee stock purchase plan			315,000		365,000
	Shares used in net income per common share – diluted			53,529,000		53,776,000
	Net income per common share:
	Basic		$	0.63	$	0.58
	Diluted		$	0.63	$	0.58
	Basic earnings per share (“EPS”) is computed by dividing income available to common stockholders by the weighted-average number of common shares outstanding during the period. The computation of diluted EPS is similar to the computation of basic EPS except that the denominator is increased to include the number of additional common shares that would have been outstanding (using the treasury stock method) if securities containing potentially dilutive common shares (stock options and restricted stock units) had been converted to such common shares, and if such assumed conversion is dilutive.
	As of March 31, 2015, stock options and restricted stock units related to an aggregate of approximately 760,000 shares were outstanding. For the three months ended March 31, 2015 and 2014, the potential dilutive effect of 0 and approximately 1,400 weighted-average shares, respectively, of restricted stock units and stock options were excluded from the computation of diluted weighted-average shares outstanding as the shares would have an anti-dilutive effect on EPS.

Stockholders_Equity

Stockholder's Equity	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Stockholder's Equity	15)	Stockholder’s Equity
	Stock Repurchase Program
	On July 25, 2011, the Company’s Board of Directors approved a share repurchase program for the repurchase of up to an aggregate of $200,000 of its outstanding common stock from time to time in open market purchases, privately negotiated transactions or through other appropriate means. The timing and quantity of any shares repurchased depends upon a variety of factors, including business conditions, stock market conditions and business development activities, including, but not limited to, merger and acquisition opportunities. These repurchases may be commenced, suspended or discontinued at any time without prior notice.
	During the three months ended March 31, 2015, the Company did not repurchase any shares common stock. During the three months ended March 31, 2014, the Company repurchased approximately 32,000 shares of common stock for $945, or an average price of $29.81 per share.
	Cash Dividends
	Holders of the Company’s common stock are entitled to receive dividends when they are declared by the Company’s Board of Directors. During the three months ended March 31, 2015, the Board of Directors authorized a cash dividend of $0.165 per share, which totaled $8,784. During the three months ended March 31, 2014, the Board of Directors authorized a cash dividend of $0.16 per share, which totaled $8,553.
	On May 4, 2015, our Board of Directors declared a quarterly cash dividend of $0.17 per share to be paid on June 12, 2015 to shareholders of record as of June 1, 2015. Future dividend declarations, if any, as well as the record and payment dates for such dividends, are subject to the final determination of the Company’s Board of Directors.

Business_Segment_Geographic_Ar

Business Segment, Geographic Area, Product and Significant Customer Information	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Business Segment, Geographic Area, Product and Significant Customer Information	16)	Business Segment, Geographic Area, Product and Significant Customer Information
	The Company develops, manufactures, sells and services products that measure, control, power and monitor critical parameters of advanced manufacturing processes. The Company’s Chief Operating Decision Maker (“CODM”) utilizes consolidated financial information to make decisions about allocating resources and assessing performance for the entire Company. In addition, certain disaggregated financial information is also provided to the CODM, which is used in the decision making process to assess performance. Based upon the information provided to the CODM, the Company has determined it has four reportable segments.
	Effective January 1, 2015, the Company changed the structure of its reportable segments based upon a change in the information that is provided to the Company’s CODM. The Company’s four reportable segments prior to the change in structure were: Advanced Manufacturing Capital Equipment, Analytical Solutions Group, Europe Region Sales & Service and Asia Region Sales & Service. The Company’s new structure still reflects four reportable segments; however, the composition of the segments has changed.
	The Company’s new reportable segments are Advanced Manufacturing Capital Equipment, Global Service, Asia Region Sales and Other. The primary change to the segment structure was to separate worldwide service from product sales and create a separate reportable segment known as Global Service. Product sales in the Advanced Manufacturing Capital Equipment segment remained with this segment. Asia product sales became a separate reportable segment. The product sales from the operating segments that made up the Analytical Solutions Group and Europe Region sales were combined into the Other segment and are not reported separately as they are individually immaterial and collectively below the separate segment reporting guidelines. The Company has reported corporate expenses and certain intercompany pricing transactions in a Corporate and Eliminations reconciling column. Due to these changes, the results presented under segment reporting for the three months ended March 31, 2014 and as of December 31, 2014 reflect the new segments to conform to the current period segment reporting presentation with no impact to the consolidated results of operations.
	The Advanced Manufacturing Capital Equipment segment includes the development, manufacturing and sales of instruments and control products, power and reactive gas products, materials delivery products and vacuum products, all of which are utilized in semiconductor processing and other similar advanced manufacturing processes. Sales in this segment include both external sales and intercompany product sales, which are recorded at transfer prices in accordance with applicable tax requirements.
	The Global Service segment includes the worldwide servicing of instruments and control products, power and reactive gas products, materials delivery products and vacuum products, all of which are utilized in semiconductor processing and other similar advanced manufacturing processes. It also includes sales of custom fabrication services.
	The Asia Region Sales segment mainly resells products from the Advanced Manufacturing Capital Equipment and Other segments into Asia regions.
	The Other segment includes operating segments that are not required to be reported separately as a reportable segment and includes sales for products that are re-sold from the Advanced Manufacturing Capital Equipment into Europe regions as well as sales from other operating segments.
	MKS derives the segment results directly from the manner in which results are reported in its management reporting system. The accounting policies MKS uses to derive reportable segment results are substantially the same as those used for external reporting purposes except that a substantial portion of the sales of the Advanced Manufacturing Capital Equipment and Other segments are intercompany sales to the regions at tax-based transfer prices and certain significant costs, including stock-based compensation and management incentive compensation, are not allocated to the segments and are included in Corporate and Eliminations. The CODM reviews several metrics of each operating segment, including net revenues and gross profit (loss).
	The Company does not maintain balance sheets for the majority of its operating segments and, as such, amounts have not been allocated to the reportable segments. The Company does not disclose external or intersegment revenues separately by reportable segment as this information is not presented to the CODM for decision making purposes.
	The following is net revenues by reportable segment:
			Three Months Ended March 31,
			2015			2014
	Advanced Manufacturing Capital Equipment		$	179,233		$	165,498
	Global Service			27,743			25,167
	Asia Region Sales (1)			55,377			52,099
	Other			21,216			20,893
	Corporate and Eliminations			(69,730	)		(57,304	)
			$	213,839		$	206,353
	The following is a reconciliation of segment gross profit to consolidated net income:
			Three Months Ended March 31,
			2015			2014
	Gross profit by reportable segment:
	Advanced Manufacturing Capital Equipment		$	78,688		$	67,107
	Global Service			9,603			8,397
	Asia Region Sales (1)			6,920			9,077
	Other			6,843			6,747
	Corporate and Eliminations			(5,008	)		(1,956	)
	Total gross profit by reportable segment			97,046			89,372
	Operating expenses:
	Research and development			16,680			15,618
	Selling, general and administrative			30,867			34,591
	Acquisition costs			30			228
	Restructuring			788			747
	Amortization of intangible assets			1,671			410
	Income from operations			47,010			37,778
	Net interest income			504			235
	Income before income taxes			47,514			38,013
	Provision for income taxes			13,728			6,768
	Net income		$	33,786		$	31,245
	-1	The Asia Region Sales segment does not represent total geographical Asia financial information. This sales operation only represents the sales from the resale of Advanced Manufacturing Capital Equipment and Other segment products in their respective regions. The Advanced Manufacturing Capital Equipment and Other segments both have sales in this region. Accordingly, total geographical sales include sales from multiple reportable segments.
	The following is capital expenditures by reportable segment for the three months ended March 31, 2015 and 2014:
			Advanced			Global Service			Asia Region		Other		Corporate and		Total
			Manufacturing						Sales				Eliminations
			Capital Equipment
	Three Months Ended March 31, 2015:
	Capital expenditures		$	1,522		$	122		$	42	$	74	$	744	$	2,504
			Advanced			Global Service			Asia Region		Other		Corporate and		Total
			Manufacturing						Sales				Eliminations
			Capital Equipment
	Three Months Ended March 31, 2014:
	Capital expenditures		$	2,574		$	170		$	41	$	75	$	238	$	3,098
	The following is depreciation and amortization by reportable segment for the three months ended March 31, 2015 and 2014:
			Advanced			Global Service			Asia Region		Other		Corporate and		Total
			Manufacturing						Sales				Eliminations
			Capital Equipment
	Three Months Ended March 31, 2015:
	Depreciation and amortization		$	4,247		$	256		$	85	$	310	$	634	$	5,532
			Advanced			Global Service			Asia Region		Other		Corporate and		Total
			Manufacturing						Sales				Eliminations
			Capital Equipment
	Three Months Ended March 31, 2014:
	Depreciation and amortization		$	2,926		$	272		$	99	$	208	$	645	$	4,150
	In connection with the new segment structure, goodwill was allocated to each reportable segment on a relative fair value basis. The Company performed an interim quantitative impairment test as of January 1, 2015 and concluded that the fair values of each reporting unit exceeded their respective carrying values.
Goodwill associated with each of our reportable segments is as follows:
		March 31, 2015			December 31, 2014
Reportable segment:
Advanced Manufacturing Capital Equipment		$	173,510		$	166,946
Global Service			19,728			19,728
Asia Region Sales			—			—
Other			6,228			6,228
Foreign currency translation			(136	)		(521	)
Total goodwill		$	199,330		$	192,381
Worldwide Product Information
Because the reportable segment information above does not reflect worldwide sales of the Company’s products, the Company groups its products into three groups of similar products based upon the similarity of product function. Worldwide net revenue for each group of products is as follows:
		Three Months Ended March 31,
		2015			2014
Instruments, Control and Vacuum Products		$	110,436		$	101,657
Power and Reactive Gas Products			88,499			90,602
Analytical Solutions Group Products			14,904			14,094
		$	213,839		$	206,353
Sales of Instruments, Control and Vacuum Products and Power and Reactive Gas Products are included in the Company’s Advanced Manufacturing Capital Equipment, Asia Region Sales, Global Service and Other segments because the products are sold through these segments. Sales of the Analytical Solutions Group products are included in the Asia Region Sales, Global Service and Other segments because the products are sold through these segments.
Geographic
Information about the Company’s operations in different geographic regions is presented in the tables below. Net revenues to unaffiliated customers are based on the location in which the sale originated. Transfers between geographic areas are at negotiated transfer prices and have been eliminated from consolidated net revenues.
		Three Months Ended March 31,
		2015			2014
Net revenues:
United States		$	120,181		$	117,377
Korea			32,072			27,591
Japan			17,256			16,928
Asia (excluding Korea and Japan)			23,683			24,902
Europe			20,647			19,555
		$	213,839		$	206,353
		March 31, 2015			December 31, 2014
Long-lived assets: (1)
United States		$	57,337		$	57,701
Europe			5,531			6,099
Asia			10,162			10,887
		$	73,030		$	74,687
-1	Long-lived assets include property, plant and equipment, net and certain other long-term assets, excluding long-term income tax receivable.
Major Customers
The Company had two customers with net revenues greater than 10% of total net revenues in the periods shown as follows:
		Three Months Ended March 31,
		2015			2014
Customer A			17.4	%		20.3	%
Customer B			12.1	%		13.1	%

Restructuring

Restructuring	3 Months Ended
	Mar. 31, 2015
Restructuring and Related Activities [Abstract]
Restructuring	17)	Restructuring
	The Company recorded restructuring charges of $788 during the three months ended March 31, 2015. The restructuring charges were primarily for severance associated with a reduction in workforce of approximately 120 people, primarily at one of the Company’s foreign manufacturing sites arising from the outsourcing of a non-core manufacturing process.
	The activity related to the Company’s restructuring accrual is shown below:
			Three Months Ended March 31, 2015
	Balance at December 31		$	92
	Charged to expense			788
	Payments			(348	)
	Balance at March 31		$	532

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	18)	Commitments and Contingencies
	The Company is subject to various legal proceedings and claims, which have arisen in the ordinary course of business. In the opinion of management, the ultimate disposition of these matters will not have a material adverse effect on the Company’s results of operations, financial condition or cash flows.

Recently_Issued_Accounting_Pro1

Recently Issued Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2015
Accounting Changes and Error Corrections [Abstract]
Recently Issued Accounting Pronouncements	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” which supersedes all existing revenue recognition requirements, including most industry-specific guidance. The new standard requires a company to recognize revenue when it transfers goods and services to customers in an amount that reflects the consideration that the company expects to be entitled to in exchange for those goods or services. This ASU also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and assets recognized from costs incurred to obtain or fulfill a contract. This pronouncement is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. However, in March 2015, the FASB proposed a one-year deferral. The two permitted transition methods under the new standard are the full retrospective method, in which case the standard would be applied to each prior reporting period presented, or the modified retrospective method, in which case the cumulative effect of applying the standard would be recognized at the date of initial application. The Company has not yet selected a transition method. The Company is currently evaluating the requirements of ASU No. 2014-09 and has not yet determined its impact on the Company’s consolidated financial statements.
	In August 2014, the FASB issued ASU No. 2014-15, “Presentation of Financial Statements—Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern.” Under this ASU, management will be required to assess an entity’s ability to continue as a going concern, and to provide related footnote disclosures in certain circumstances. The provisions of this ASU are effective for annual periods beginning after December 15, 2016, and for annual and interim periods thereafter. This ASU is not expected to have an impact on the Company’s financial statements or disclosures.

Investments_Tables

Investments (Tables)	3 Months Ended
	Mar. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Fair Value of Short-Term Available-for-Sale Investments	The fair value of short-term investments with maturities or estimated lives of less than one year consists of the following:
		March 31, 2015		December 31, 2014
	Available-for-sale investments:
	Time deposits and certificates of deposit	$	5,400	$	20,900
	Bankers’ acceptance drafts		327		82
	Commercial paper		1,447		—
	Corporate obligations		58,331		24,020
	Municipal bonds		5,798		2,099
	U.S. agency obligations		87,328		82,493
		$	158,631	$	129,594
Fair Value of Long-Term Available-for-Sale Investments	The fair value of long-term investments with maturities of more than one year consists of the following:
		March 31, 2015		December 31, 2014
	Available-for-sale investments:
	Time deposits and certificates of deposit	$	—	$	48
	Asset-backed securities		129,242		75,674
	Corporate obligations		90,114		64,669
	Municipal bonds		1,880		1,254
	U.S. agency obligations		16,077		15,556
		$	237,313	$	157,201
Gross Unrealized Gains and (Losses) Aggregated by Investment Category Short-Term and Long-Term Securities	The following tables show the gross unrealized gains and (losses) aggregated by investment category for short-term and long-term available-for-sale investments:
	As of March 31, 2015:	Cost		Gross		Gross			Estimated
				Unrealized		Unrealized			Fair Value
				Gains		(Losses)
	Short-term investments:
	Time deposits and certificates of deposit	$	5,400	$	—	$	—		$	5,400
	Bankers’ acceptance drafts		327		—		—			327
	Commercial paper		1,447		—		—			1,447
	Corporate obligations		58,336		10		(15	)		58,331
	Municipal bonds		5,800		1		(3	)		5,798
	U.S. agency obligations		87,311		23		(6	)		87,328
		$	158,621	$	34	$	(24	)	$	158,631
	Long-term investments:
	Asset-backed securities		129,209	$	66	$	(33	)	$	129,242
	Corporate obligations		90,128		44		(58	)		90,114
	Municipal bonds		1,878		3		(1	)		1,880
	U.S. agency obligations		16,070		8		(1	)		16,077
		$	237,285	$	121	$	(93	)	$	237,313
	As of December 31, 2014:	Cost		Gross		Gross			Estimated
				Unrealized		Unrealized			Fair Value
				Gains		(Losses)
	Short-term investments:
	Time deposits and certificates of deposit	$	20,901	$	—	$	(1	)	$	20,900
	Bankers’ acceptance drafts		82		—		—			82
	Corporate obligations		24,029		2		(11	)		24,020
	Municipal bonds		2,100		—		(1	)		2,099
	U.S. agency obligations		82,488		14		(9	)		82,493
		$	129,600	$	16	$	(22	)	$	129,594
	Long-term investments:
	Time deposits and certificates of deposit	$	48	$	—	$	—		$	48
	Asset-backed securities		75,778		5		(109	)		75,674
	Corporate obligations		64,842		1		(174	)		64,669
	Municipal bonds		1,258		—		(4	)		1,254
	U.S. agency obligations		15,563		2		(9	)		15,556
		$	157,489	$	8	$	(296	)	$	157,201

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis	Assets and liabilities of the Company are measured at fair value on a recurring basis as of March 31, 2015 and are summarized as follows:
					Fair Value Measurements at Reporting Date Using
	Description		March 31, 2015		Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable		Unobservable
					Identical Assets		Inputs		Inputs
					(Level 1)		(Level 2)		(Level 3)
	Assets:
	Cash equivalents:
	Money market funds		$	87,790	$	87,790	$	—	$	—
	Bankers’ acceptance drafts			99		—		99		—
	Available-for-sale securities:
	Bankers’ acceptance drafts			327		—		327		—
	Time deposits and certificates of deposit			5,400		—		5,400		—
	Commercial paper			1,447		—		1,447		—
	Asset-backed securities			129,242		—		129,242		—
	Corporate obligations			148,445		—		148,445		—
	Municipal bonds			7,678		—		7,678		—
	U.S. agency obligations			103,405		—		103,405		—
	Derivatives – currency forward contracts			1,240		—		1,240		—
	Total assets		$	485,073	$	87,790	$	397,283	$	—
	Liabilities:
	Derivatives – currency forward contracts		$	318	$	—	$	318	$	—
	Reported as follows:
	Assets:
	Cash and cash equivalents(1)		$	87,889	$	87,790	$	99	$	—
	Short-term investments			158,631		—		158,631		—
	Other current assets			1,240		—		1,240		—
	Total current assets		$	247,760	$	87,790	$	159,970	$	—
	Long-term investments		$	237,313	$	—	$	237,313	$	—
	Liabilities:
	Other current liabilities		$	318	$	—	$	318	$	—
	-1	The cash and cash equivalent amounts presented in the table above do not include cash of $95,212 and non-negotiable time deposits of $9,612 as of March 31, 2015.
	Assets and liabilities of the Company measured at fair value on a recurring basis as of December 31, 2014, are summarized as follows:
					Fair Value Measurements at Reporting Date Using
	Description		December 31, 2014		Quoted Prices in		Significant Other		Significant
					Active Markets for		Observable		Unobservable
					Identical Assets		Inputs		Inputs
					(Level 1)		(Level 2)		(Level 3)
	Assets:
	Cash equivalents:
	Money market funds		$	129,092	$	129,092	$	—	$	—
	Bankers acceptance drafts			131		—		131		—
	Corporate obligations			700		—		700		—
	Available-for-sale investments:
	Time deposits and certificates of deposit			20,948		—		20,948		—
	Asset-backed securities			75,674		—		75,674		—
	Bankers acceptance drafts			82		—		82		—
	Corporate obligations			88,689		—		88,689		—
	Municipal bonds			3,353		—		3,353		—
	U.S. agency obligations			98,049		—		98,049		—
	Derivatives – currency forward contracts			2,110		—		2,110		—
	Total assets		$	418,828	$	129,092	$	289,736	$	—
	Liabilities:
	Derivatives – currency forward contracts		$	—	$	—	$	—	$	—
	Reported as follows:
	Assets:
	Cash and cash equivalents (1)		$	129,923	$	129,092	$	831	$	—
	Short-term investments			129,594		—		129,594		—
	Other current assets			2,110		—		2,110		—
	Total current assets		$	261,627	$	129,092	$	132,535	$	—
	Long-term investments		$	157,201	$	—	$	157,201	$	—
	Liabilities:
	Other current liabilities		$	—	$	—	$	—	$	—
	-1	The cash and cash equivalent amounts presented in the table above do not include cash of $167,517 and non-negotiable time deposits of $7,997 as of December 31, 2014.

Derivatives_Tables

Derivatives (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Primary Net Hedging Positions and Corresponding Fair Values	The following tables provide a summary of the primary net hedging positions and corresponding fair values held as of March 31, 2015 and December 31, 2014:
			March 31, 2015
	Currency Hedged (Buy/Sell)		Gross Notional			Fair Value(1)
			Value			Asset/(Liability)
	U.S. Dollar/Japanese Yen		$	29,708		$	478
	U.S. Dollar/South Korean Won			32,692			133
	U.S. Dollar/Euro			5,009			286
	U.S. Dollar/U.K. Pound Sterling			3,794			74
	U.S. Dollar/Taiwan Dollar			12,860			(49	)
	Total		$	84,063		$	922
	-1	Represents the fair value of the net asset / (liability) amount included in the consolidated balance sheets.
			December 31, 2014
	Currency Hedged (Buy/Sell)		Gross Notional			Fair Value (1)
			Value			Asset/(Liability)
	U.S. Dollar/Japanese Yen		$	8,035		$	1,107
	U.S. Dollar/South Korean Won			12,512			372
	U.S. Dollar/Euro			2,060			185
	U.S. Dollar/U.K. Pound Sterling			1,308			70
	U.S. Dollar/Taiwan Dollar			4,735			232
	Total		$	28,650		$	1,966
	-1	Represents the fair value of the net asset / (liability) amount included in the consolidated balance sheets.
Summary of Fair Value Amounts of Company's Derivative Instruments	The following table provides a summary of the fair value amounts of the Company’s derivative instruments:
			March 31, 2015			December 31, 2014
	Derivative assets:
	Forward exchange contracts		$	1,240		$	1,966
	Derivative liabilities:
	Forward exchange contracts			(318	)		—
	Total net derivative asset designated as hedging instruments(1)		$	922		$	1,966
	-1	The derivative asset of $1,240 and derivative liability of $318 are classified in other current assets and other current liabilities in the consolidated balance sheet as of March 31, 2015. The derivative asset of $1,966 is classified in other current assets in the consolidated balance sheet as of December 31, 2014. These foreign exchange contracts are subject to a master netting agreement with one financial institution. However, the Company has elected to record these contracts on a gross basis in the balance sheet.
Summary of Gains (Losses) on Derivatives Designated as Hedging Instruments	The following table provides a summary of the gains (losses) on derivatives designated as hedging instruments:
			Three Months Ended March 31,
	Derivatives Designated as Cash Flow Hedging Relationships		2015			2014
	Forward exchange contracts:
	Net (loss) recognized in OCI(1)		$	(2,090	)	$	(334	)
	Net gain (loss) reclassified from accumulated OCI into income(2)		$	1,193		$	(94	)
	-1	Net change in the fair value of the effective portion classified in OCI.
	-2	Effective portion classified in cost of products for the three months ended March 31, 2015 and 2014.
Summary of Gains on Derivatives Not Designated as Hedging Instruments	The following table provides a summary of gains on derivatives not designated as hedging instruments:
			Three Months Ended March 31,
	Derivatives Not Designated as Hedging Instruments		2015			2014
	Forward exchange contracts:
	Net gain recognized in income(1)		$	98		$	106
	-1	The Company enters into foreign exchange contracts to hedge against changes in the balance sheet for certain subsidiaries. These derivatives are not designated as hedging instruments and are recorded immediately in selling, general and administrative expenses.

Inventories_Tables

Inventories (Tables)	3 Months Ended
	Mar. 31, 2015
Inventory Disclosure [Abstract]
Summary of Inventories	Inventories consist of the following:
		March 31, 2015		December 31, 2014
	Raw materials	$	85,622	$	81,121
	Work-in-process		27,374		26,604
	Finished goods		51,416		47,444
		$	164,412	$	155,169

Acquisitions_Tables

Acquisitions (Tables) (Precisive, LLC [Member])	3 Months Ended
	Mar. 31, 2015
Precisive, LLC [Member]
Summary of Preliminary Estimated Fair Value of Assets Acquired and Liabilities Assumed	The following table summarizes the preliminary estimated fair value of the assets acquired and liabilities assumed at the date of acquisition.
	Current assets	$	285
	Non-current assets		18
	Intangible assets		5,110
	Goodwill		7,085
	Total assets acquired		12,498
	Total current liabilities assumed		343
	Total purchase price, net of cash acquired of $435	$	12,155
Allocation of Acquired Intangible Assets and Related Estimates of Useful Lives	The entire purchase price is expected to be deductible for tax purposes. The following table reflects the allocation of the acquired intangible assets and related estimates of useful lives. These acquired intangibles will be amortized on a straight-line basis, which approximates the pattern of use.
	Order backlog	$	50	18 months
	Customer relationships		1,430	12 years
	Exclusive patent license		2,600	10 years
	Trade names		210	10 years
	Current developed technology		820	10 years
		$	5,110

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	The changes in the carrying amount of goodwill and accumulated impairment (loss) during the three months ended March 31, 2015 and year ended December 31, 2014 were as follows:
			2015									2014
			Gross			Accumulated			Net			Gross			Accumulated			Net
			Carrying			Impairment						Carrying			Impairment
			Amount			(Loss)						Amount			(Loss)
	Beginning balance at January 1		$	331,795		$	(139,414	)	$	192,381		$	290,323		$	(139,414	)	$	150,909
	Acquired goodwill (1)			7,085			—			7,085			41,993			—			41,993
	Foreign currency translation			(136	)		—			(136	)		(521	)		—			(521	)
	Ending balance at March 31, 2015 and December 31, 2014		$	338,744		$	(139,414	)	$	199,330		$	331,795		$	(139,414	)	$	192,381
	-1	During the first quarter of 2015, the Company recorded $7,085 of goodwill related to the Precisive acquisition. During the second quarter of 2014, the Company recorded $41,612 of goodwill related to the May 30, 2014 acquisition of the Granville-Phillips division of Brooks Automation, Inc. During the first quarter of 2014, the Company recorded a purchase accounting adjustment of $381 related to the March 12, 2013 purchase of Alter S.r.l.
Intangible Assets	Components of the Company’s intangible assets are comprised of the following:
	As of March 31, 2015:		Gross			Accumulated			Foreign			Net
						Amortization			Currency
									Translation
	Completed technology (1)		$	101,200		$	(80,477	)	$	(78	)	$	20,645
	Customer relationships (1)			37,251			(13,610	)		228			23,869
	Patents, trademarks, trade names and other (1)			30,396			(25,383	)		26			5,039
			$	168,847		$	(119,470	)	$	176		$	49,553
	-1	During the three months ended March 31, 2015, the Company recorded $5,110 of separately identified intangible assets of which $820 was completed technology, $1,430 was customer relationships and $2,860 was trademarks, trade names and other, related to the Precisive acquisition.
	As of December 31, 2014:		Gross			Accumulated			Foreign			Net
						Amortization			Currency
									Translation
	Completed technology (2)		$	100,380		$	(79,875	)	$	135		$	20,640
	Customer relationships (2)			35,821			(12,634	)		280			23,467
	Patents, trademarks, trade names and other (2)			27,536			(25,290	)		36			2,282
			$	163,737		$	(117,799	)	$	451		$	46,389
	-2	During 2014, the Company recorded $38,850 of separately identified intangible assets related to the May 30, 2014 acquisition of the Granville-Phillips division of Brooks Automation, Inc., of which $15,700 was completed technology, $21,250 was customer relationships and $1,900 was trademarks and trade names.
Estimated Amortization Expense	Aggregate amortization expense related to acquired intangibles for the three months ended March 31, 2015 and 2014 was $1,671 and $410, respectively. Estimated amortization expense for each of the remaining fiscal years is as follows:
	Year		Amount
	2015 (remaining)		$	5,106
	2016			6,701
	2017			6,628
	2018			6,613
	2019			6,582
	2020			6,514
	Thereafter			11,409

Other_Assets_Tables

Other Assets (Tables)	3 Months Ended
	Mar. 31, 2015
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Other Assets
		March 31, 2015		December 31, 2014
	Other Current Assets:
	Income tax receivable	$	161	$	10,322
	Other		21,419		17,190
	Total other current assets	$	21,580	$	27,512
	Other Assets:
	Deferred tax assets, net	$	6,868	$	7,202
	Long-term income tax receivable		8,175		8,092
	Other		2,122		1,912
	Total other assets	$	17,165	$	17,206

Other_Liabilities_Tables

Other Liabilities (Tables)	3 Months Ended
	Mar. 31, 2015
Other Liabilities Disclosure [Abstract]
Schedule of Other Liabilities
		March 31, 2015		December 31, 2014
	Other Current Liabilities:
	Product warranties	$	6,064	$	6,266
	Deferred revenue		5,997		8,283
	Other		26,452		21,240
	Total other current liabilities	$	38,513	$	35,789
	Other Liabilities:
	Long-term income tax payable	$	20,337	$	20,203
	Accrued compensation		12,312		12,068
	Other		8,406		6,324
	Total other liabilities	$	41,055	$	38,595

Product_Warranties_Tables

Product Warranties (Tables)	3 Months Ended
	Mar. 31, 2015
Guarantees [Abstract]
Product Warranty Activities	Product warranty activities were as follows:
		Three Months Ended March 31,
		2015			2014
	Beginning of period	$	6,266		$	6,956
	Provision for product warranties		1,109			704
	Direct charges to warranty liability		(1,244	)		(656	)
	Foreign currency translation		(67	)		9
	End of period	$	6,064		$	7,013

Net_Income_Per_Share_Tables

Net Income Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Income Per Share	The following table sets forth the computation of basic and diluted net income per share:
		Three Months Ended March 31,
		2015		2014
	Numerator:
	Net income	$	33,786	$	31,245
	Denominator:
	Shares used in net income per common share – basic		53,214,000		53,411,000
	Effect of dilutive securities:
	Stock options, restricted stock and employee stock purchase plan		315,000		365,000
	Shares used in net income per common share – diluted		53,529,000		53,776,000
	Net income per common share:
	Basic	$	0.63	$	0.58
	Diluted	$	0.63	$	0.58

Business_Segment_Geographic_Ar1

Business Segment, Geographic Area, Product and Significant Customer Information (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Net Revenues by Reportable Segment	The following is net revenues by reportable segment:
			Three Months Ended March 31,
			2015			2014
	Advanced Manufacturing Capital Equipment		$	179,233		$	165,498
	Global Service			27,743			25,167
	Asia Region Sales (1)			55,377			52,099
	Other			21,216			20,893
	Corporate and Eliminations			(69,730	)		(57,304	)
			$	213,839		$	206,353
Reconciliation of Segment Gross Profit to Consolidated Net Income	The following is a reconciliation of segment gross profit to consolidated net income:
			Three Months Ended March 31,
			2015			2014
	Gross profit by reportable segment:
	Advanced Manufacturing Capital Equipment		$	78,688		$	67,107
	Global Service			9,603			8,397
	Asia Region Sales (1)			6,920			9,077
	Other			6,843			6,747
	Corporate and Eliminations			(5,008	)		(1,956	)
	Total gross profit by reportable segment			97,046			89,372
	Operating expenses:
	Research and development			16,680			15,618
	Selling, general and administrative			30,867			34,591
	Acquisition costs			30			228
	Restructuring			788			747
	Amortization of intangible assets			1,671			410
	Income from operations			47,010			37,778
	Net interest income			504			235
	Income before income taxes			47,514			38,013
	Provision for income taxes			13,728			6,768
	Net income		$	33,786		$	31,245
	-1	The Asia Region Sales segment does not represent total geographical Asia financial information. This sales operation only represents the sales from the resale of Advanced Manufacturing Capital Equipment and Other segment products in their respective regions. The Advanced Manufacturing Capital Equipment and Other segments both have sales in this region. Accordingly, total geographical sales include sales from multiple reportable segments.
Schedule of Capital Expenditures, Depreciation and Amortization Expense by Reportable Segment	The following is capital expenditures by reportable segment for the three months ended March 31, 2015 and 2014:
			Advanced			Global Service			Asia Region		Other		Corporate and		Total
			Manufacturing						Sales				Eliminations
			Capital Equipment
	Three Months Ended March 31, 2015:
	Capital expenditures		$	1,522		$	122		$	42	$	74	$	744	$	2,504
			Advanced			Global Service			Asia Region		Other		Corporate and		Total
			Manufacturing						Sales				Eliminations
			Capital Equipment
	Three Months Ended March 31, 2014:
	Capital expenditures		$	2,574		$	170		$	41	$	75	$	238	$	3,098
	The following is depreciation and amortization by reportable segment for the three months ended March 31, 2015 and 2014:
			Advanced			Global Service			Asia Region		Other		Corporate and		Total
			Manufacturing						Sales				Eliminations
			Capital Equipment
	Three Months Ended March 31, 2015:
	Depreciation and amortization		$	4,247		$	256		$	85	$	310	$	634	$	5,532
			Advanced			Global Service			Asia Region		Other		Corporate and		Total
			Manufacturing						Sales				Eliminations
			Capital Equipment
	Three Months Ended March 31, 2014:
	Depreciation and amortization		$	2,926		$	272		$	99	$	208	$	645	$	4,150
Summary of Goodwill Associated with Reportable Segments	Goodwill associated with each of our reportable segments is as follows:
			March 31, 2015			December 31, 2014
	Reportable segment:
	Advanced Manufacturing Capital Equipment		$	173,510		$	166,946
	Global Service			19,728			19,728
	Asia Region Sales			—			—
	Other			6,228			6,228
	Foreign currency translation			(136	)		(521	)
	Total goodwill		$	199,330		$	192,381
Worldwide Net Revenue for Each Group of Products	Worldwide net revenue for each group of products is as follows:
			Three Months Ended March 31,
			2015			2014
	Instruments, Control and Vacuum Products		$	110,436		$	101,657
	Power and Reactive Gas Products			88,499			90,602
	Analytical Solutions Group Products			14,904			14,094
			$	213,839		$	206,353
Schedule of Net Revenues and Long-Lived Assets by Geographic Regions	Transfers between geographic areas are at negotiated transfer prices and have been eliminated from consolidated net revenues.
			Three Months Ended March 31,
			2015			2014
	Net revenues:
	United States		$	120,181		$	117,377
	Korea			32,072			27,591
	Japan			17,256			16,928
	Asia (excluding Korea and Japan)			23,683			24,902
	Europe			20,647			19,555
			$	213,839		$	206,353
			March 31, 2015			December 31, 2014
	Long-lived assets: (1)
	United States		$	57,337		$	57,701
	Europe			5,531			6,099
	Asia			10,162			10,887
			$	73,030		$	74,687
	-1	Long-lived assets include property, plant and equipment, net and certain other long-term assets, excluding long-term income tax receivable.
Customers with Net Revenues Greater than 10% of Total Net Revenues	The Company had two customers with net revenues greater than 10% of total net revenues in the periods shown as follows:
			Three Months Ended March 31,
			2015			2014
	Customer A			17.4	%		20.3	%
	Customer B			12.1	%		13.1	%

Restructuring_Tables

Restructuring (Tables)	3 Months Ended
	Mar. 31, 2015
Restructuring and Related Activities [Abstract]
Schedule of Company's Restructuring Activity	The activity related to the Company’s restructuring accrual is shown below:
		Three Months Ended March 31, 2015
	Balance at December 31	$	92
	Charged to expense		788
	Payments		(348	)
	Balance at March 31	$	532

Investments_Fair_Value_of_Shor

Investments - Fair Value of Short-Term Available-for-Sale Investments (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	$158,631	$129,594
Time Deposits And Certificates of Deposit [Member]
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	5,400	20,900
Bankers Acceptance Drafts [Member]
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	327	82
Commercial Paper [Member]
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	1,447
Corporate Obligations [Member]
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	58,331	24,020
Municipal Bonds [Member]
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	5,798	2,099
U.S. Agency Obligations [Member]
Schedule of Investments [Line Items]
Fair value of short-term available-for-sale investments	$87,328	$82,493

Investments_Fair_Value_of_Long

Investments - Fair Value of Long-Term Available-for-Sale Investments (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Fair value of long-term available-for-sale investments	$237,313	$157,201
Time Deposits And Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair value of long-term available-for-sale investments		48
Asset Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair value of long-term available-for-sale investments	129,242	75,674
Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair value of long-term available-for-sale investments	90,114	64,669
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair value of long-term available-for-sale investments	1,880	1,254
U.S. Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair value of long-term available-for-sale investments	$16,077	$15,556

Investments_Gross_Unrealized_G

Investments - Gross Unrealized Gains and (Losses) Aggregated by Investment Category Short-Term and Long-Term Securities (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost	$237,285	$157,489
Investments, Gross Unrealized Gains	121	8
Investments, Gross Unrealized (Losses)	-93	-296
Short-term investments, Estimated Fair Value	158,631	129,594
Long-term investments, Estimated Fair Value	237,313	157,201
Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost	90,128	64,842
Investments, Gross Unrealized Gains	44	1
Investments, Gross Unrealized (Losses)	-58	-174
U.S. Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost	16,070	15,563
Investments, Gross Unrealized Gains	8	2
Investments, Gross Unrealized (Losses)	-1	-9
Asset Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost	129,209	75,778
Investments, Gross Unrealized Gains	66	5
Investments, Gross Unrealized (Losses)	-33	-109
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost	1,878	1,258
Investments, Gross Unrealized Gains	3
Investments, Gross Unrealized (Losses)	-1	-4
Time Deposits And Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost	5,400	20,901
Investments, Gross Unrealized (Losses)		-1
Short-term investments, Estimated Fair Value	5,400	20,900
Long-term investments, Estimated Fair Value		48
Bankers Acceptance Drafts [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost	327	82
Short-term investments, Estimated Fair Value	327	82
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost	1,447
Short-term investments, Estimated Fair Value	1,447
Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Short-term investments, Estimated Fair Value	58,331	24,020
Long-term investments, Estimated Fair Value	90,114	64,669
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Short-term investments, Estimated Fair Value	5,798	2,099
U.S. Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Short-term investments, Estimated Fair Value	87,328	82,493
Long-term investments, Estimated Fair Value	16,077	15,556
Asset Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Long-term investments, Estimated Fair Value	129,242	75,674
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Long-term investments, Estimated Fair Value	1,880	1,254
Short-Term [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost	158,621	129,600
Investments, Gross Unrealized Gains	34	16
Investments, Gross Unrealized (Losses)	-24	-22
Short-Term [Member] | Corporate Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost	58,336	24,029
Investments, Gross Unrealized Gains	10	2
Investments, Gross Unrealized (Losses)	-15	-11
Short-Term [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost	5,800	2,100
Investments, Gross Unrealized Gains	1
Investments, Gross Unrealized (Losses)	-3	-1
Short-Term [Member] | U.S. Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost	87,311	82,488
Investments, Gross Unrealized Gains	23	14
Investments, Gross Unrealized (Losses)	-6	-9
Time Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Investments, Cost		$48

Investments_Additional_Informa

Investments - Additional Information (Detail) (Maximum [Member])	3 Months Ended
	Mar. 31, 2015
Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Investment securities maturity period or average life	3 years
Average duration of portfolio	1 year

Fair_Value_Measurements_Schedu

Fair Value Measurements - Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives - currency forward contracts	$1,240	$1,966
Derivatives - currency forward contracts	318
Cash and cash equivalents	95,212	167,517
Short-term investments	158,631	129,594
Other current assets	1,240	1,966
Long-term investments	237,313	157,201
Other current liabilities	318
Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives - currency forward contracts	1,240	2,110
Total assets	485,073	418,828
Derivatives - currency forward contracts	318
Cash and cash equivalents	87,889	129,923
Short-term investments	158,631	129,594
Other current assets	1,240	2,110
Total current assets	247,760	261,627
Long-term investments	237,313	157,201
Other current liabilities	318
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	87,790	129,092
Cash and cash equivalents	87,790	129,092
Total current assets	87,790	129,092
Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives - currency forward contracts	1,240	2,110
Total assets	397,283	289,736
Derivatives - currency forward contracts	318
Cash and cash equivalents	99	831
Short-term investments	158,631	129,594
Other current assets	1,240	2,110
Total current assets	159,970	132,535
Long-term investments	237,313	157,201
Other current liabilities	318
Money Market Funds [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	87,790	129,092
Money Market Funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	87,790	129,092
Bankers Acceptance Drafts [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	99	131
Available-for-sale securities\investments	327	82
Bankers Acceptance Drafts [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	99	131
Available-for-sale securities\investments	327	82
Time Deposits And Certificates of Deposit [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities\investments	5,400	20,948
Time Deposits And Certificates of Deposit [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities\investments	5,400	20,948
Commercial Paper [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities\investments	1,447
Commercial Paper [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities\investments	1,447
Asset Backed Securities [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities\investments	129,242	75,674
Asset Backed Securities [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities\investments	129,242	75,674
Corporate Obligations [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents		700
Available-for-sale securities\investments	148,445	88,689
Corporate Obligations [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents		700
Available-for-sale securities\investments	148,445	88,689
Municipal Bonds [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities\investments	7,678	3,353
Municipal Bonds [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities\investments	7,678	3,353
U.S. Agency Obligations [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities\investments	103,405	98,049
U.S. Agency Obligations [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities\investments	$103,405	$98,049

Fair_Value_Measurements_Schedu1

Fair Value Measurements - Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis (Parenthetical) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Not included in cash and cash equivalent amount	$95,212	$167,517
Non Negotiable Time Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Not included in cash and cash equivalent amount	$9,612	$7,997

Derivatives_Additional_Informa

Derivatives - Additional Information (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Maximum period for hedging a portion of forecasted foreign currency denominated intercompany sales of inventory	18 months
Gross notional values of outstanding forward foreign exchange contracts	$84,063	$28,650
Accumulated other comprehensive income realization period	12 months

Derivatives_Summary_of_Primary

Derivatives - Summary of Primary Net Hedging Positions and Corresponding Fair Values (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Derivative [Line Items]
Currency Hedged (Buy/Sell), Gross Notional Value, Net	$84,063	$28,650
Currency Hedged (Buy/Sell), Fair Value, Asset/(Liability), Net	922	1,966
Forward Exchange Contracts [Member] | U.S. Dollar/Japanese Yen [Member]
Derivative [Line Items]
Currency Hedged (Buy/Sell), Gross Notional Value, Net	29,708	8,035
Currency Hedged (Buy/Sell), Fair Value, Asset/(Liability), Net	478	1,107
Forward Exchange Contracts [Member] | U.S. Dollar/South Korean Won [Member]
Derivative [Line Items]
Currency Hedged (Buy/Sell), Gross Notional Value, Net	32,692	12,512
Currency Hedged (Buy/Sell), Fair Value, Asset/(Liability), Net	133	372
Forward Exchange Contracts [Member] | U.S. Dollar/Euro [Member]
Derivative [Line Items]
Currency Hedged (Buy/Sell), Gross Notional Value, Net	5,009	2,060
Currency Hedged (Buy/Sell), Fair Value, Asset/(Liability), Net	286	185
Forward Exchange Contracts [Member] | U.S. Dollar/U.K. Pound Sterling [Member]
Derivative [Line Items]
Currency Hedged (Buy/Sell), Gross Notional Value, Net	3,794	1,308
Currency Hedged (Buy/Sell), Fair Value, Asset/(Liability), Net	74	70
Forward Exchange Contracts [Member] | U.S. Dollar/Taiwan Dollar [Member]
Derivative [Line Items]
Currency Hedged (Buy/Sell), Gross Notional Value, Net	12,860	4,735
Currency Hedged (Buy/Sell), Fair Value, Asset/(Liability), Net	($49)	$232

Derivatives_Summary_of_Fair_Va

Derivatives - Summary of Fair Value Amounts of Company's Derivative Instruments (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]
Forward exchange contracts, assets	$1,240	$1,966
Forward exchange contracts, liabilities	-318
Total net derivative asset designated as hedging instruments	922	1,966
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Forward exchange contracts, assets	1,240	1,966
Forward exchange contracts, liabilities	-318
Total net derivative asset designated as hedging instruments	$922	$1,966

Derivatives_Summary_of_Fair_Va1

Derivatives - Summary of Fair Value Amounts of Company's Derivative Instruments (Parenthetical) (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative asset classified in other current assets	$1,240	$1,966
Derivative liability classified in other current liabilities	$318

Derivatives_Summary_of_Gains_L

Derivatives - Summary of Gains (Losses) on Derivatives Designated as Hedging Instruments (Detail) (Forward Exchange Contracts [Member], Cash Flow Hedging [Member], USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Forward Exchange Contracts [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net (loss) recognized in OCI	($2,090)	($334)
Net gain (loss) reclassified from OCI into income	$1,193	($94)

Derivatives_Summary_of_Gains_o

Derivatives - Summary of Gains on Derivatives Not Designated as Hedging Instruments (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Net gain recognized in income	$98	$106

Inventories_Summary_of_Invento

Inventories - Summary of Inventories (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Raw materials	$85,622	$81,121
Work-in-process	27,374	26,604
Finished goods	51,416	47,444
Inventories	$164,412	$155,169

Acquisitions_Additional_Inform

Acquisitions - Additional Information (Detail) (USD $)	3 Months Ended	0 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 17, 2015
Business Acquisition [Line Items]
Payments to acquire business, net of cash acquired	$9,867
Precisive, LLC [Member]
Business Acquisition [Line Items]
Payments to acquire business, net of cash acquired		12,155
Business acquisition, ownership percentage		100.00%
Business acquisition, cash acquired		435
Business acquisition, deferred consideration payment		$2,600
Business acquisition, deferred consideration payment period		15 months

Acquisitions_Summary_of_Prelim

Acquisitions - Summary of Preliminary Estimated Fair Value of Assets Acquired and Liabilities Assumed (Detail) (USD $)	3 Months Ended	0 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 17, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill	$199,330		$192,381	$150,909
Total purchase price, net of cash acquired of $435	9,867
Precisive, LLC [Member]
Business Acquisition [Line Items]
Current assets		285
Non-current assets		18
Intangible assets		5,110
Goodwill	7,085	7,085
Total assets acquired		12,498
Total current liabilities assumed		343
Total purchase price, net of cash acquired of $435		$12,155

Acquisitions_Summary_of_Prelim1

Acquisitions - Summary of Preliminary Estimated Fair Value of Assets Acquired and Liabilities Assumed (Parenthetical) (Detail) (Precisive, LLC [Member], USD $)	0 Months Ended
In Thousands, unless otherwise specified	Mar. 17, 2015
Precisive, LLC [Member]
Business Acquisition [Line Items]
Business acquisition, cash acquired	$435

Acquisitions_Allocation_of_Acq

Acquisitions - Allocation of Acquired Intangible Assets and Related Estimates of Useful Lives (Detail) (USD $)	3 Months Ended	0 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 17, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	$5,110
Precisive, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		5,110
Order Backlog [Member] | Precisive, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		50
Estimated useful life of finite-lived intangible assets		18 months
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price	1,430
Customer Relationships [Member] | Precisive, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		1,430
Estimated useful life of finite-lived intangible assets		12 years
Exclusive Patent License [Member] | Precisive, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		2,600
Estimated useful life of finite-lived intangible assets		10 years
Trade names [Member] | Precisive, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		210
Estimated useful life of finite-lived intangible assets		10 years
Current Developed Technology [Member] | Precisive, LLC [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets, purchase price		$820
Estimated useful life of finite-lived intangible assets		10 years

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets - Goodwill (Detail) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Beginning balance, Goodwill Gross Carrying Amount	$331,795	$290,323
Acquired goodwill, Gross Carrying Amount	7,085	41,993
Foreign currency translation, Gross Carrying Amount	-136	-521
Ending balance, Goodwill Gross Carrying Amount	338,744	331,795
Beginning balance, Accumulated Impairment (Loss)	-139,414	-139,414
Acquired goodwill, Accumulated Impairment (Loss)	0	0
Foreign currency translation, Accumulated Impairment (Loss)	0	0
Ending balance, Accumulated Impairment (Loss)	-139,414	-139,414
Beginning balance, Goodwill Net	192,381	150,909
Acquired goodwill, Net	7,085	41,993
Foreign currency translation, Net	-136	-521
Ending balance, Goodwill Net	$199,330	$192,381

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets - Goodwill (Parenthetical) (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Mar. 17, 2015	Jun. 30, 2014
Goodwill [Line Items]
Goodwill		$199,330	$192,381	$150,909
Precisive, LLC [Member]
Goodwill [Line Items]
Goodwill		7,085			7,085
Granville-Phillips [Member]
Goodwill [Line Items]
Goodwill						41,612
Alter S.r.l [Member]
Goodwill [Line Items]
Acquisition purchase price	$381

Goodwill_and_Intangible_Assets4

Goodwill and Intangible Assets - Intangible Assets (Detail) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	$168,847	$163,737
Accumulated Amortization	-119,470	-117,799
Foreign Currency Translation	176	451
Intangible assets, net	49,553	46,389
Completed Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	101,200	100,380
Accumulated Amortization	-80,477	-79,875
Foreign Currency Translation	-78	135
Intangible assets, net	20,645	20,640
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	37,251	35,821
Accumulated Amortization	-13,610	-12,634
Foreign Currency Translation	228	280
Intangible assets, net	23,869	23,467
Patents, Trademarks, Trade Names and Other [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets, Gross	30,396	27,536
Accumulated Amortization	-25,383	-25,290
Foreign Currency Translation	26	36
Intangible assets, net	$5,039	$2,282

Goodwill_and_Intangible_Assets5

Goodwill and Intangible Assets - Intangible Assets (Parenthetical) (Detail) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets	$5,110
Completed Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets	820
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets	1,430
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets	2,860
Granville-Phillips [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets		38,850
Granville-Phillips [Member] | Completed Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets		15,700
Granville-Phillips [Member] | Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets		21,250
Granville-Phillips [Member] | Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Acquired intangible assets		$1,900

Goodwill_and_Intangible_Assets6

Goodwill and Intangible Assets - Additional Information (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Aggregate amortization expense related to acquired intangibles	$1,671	$410

Goodwill_and_Intangible_Assets7

Goodwill and Intangible Assets - Estimated Amortization Expense (Detail) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]
2015 (remaining)	$5,106
2016	6,701
2017	6,628
2018	6,613
2019	6,582
2020	6,514
Thereafter	$11,409

Other_Assets_Schedule_of_Other

Other Assets - Schedule of Other Assets (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Other Current Assets:
Income tax receivable	$161	$10,322
Other	21,419	17,190
Total other current assets	21,580	27,512
Other Assets:
Deferred tax assets, net	6,868	7,202
Long-term income tax receivable	8,175	8,092
Other	2,122	1,912
Total other assets	$17,165	$17,206

Other_Liabilities_Schedule_of_

Other Liabilities - Schedule of Other Liabilities (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Other Current Liabilities:
Product warranties	$6,064	$6,266	$7,013	$6,956
Deferred revenue	5,997	8,283
Other	26,452	21,240
Total other current liabilities	38,513	35,789
Other Liabilities:
Long-term income tax payable	20,337	20,203
Accrued compensation	12,312	12,068
Other	8,406	6,324
Total other liabilities	$41,055	$38,595

Debt_Additional_Information_De

Debt - Additional Information (Detail) (Japan [Member], USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
	Institution
Japan [Member]
Debt Instrument [Line Items]
Number of financial institutions for available lines of credit and borrowing arrangements	2
Aggregate borrowings expire and renewed	3 month intervals
Total available line of credit	$19,155,000
Total borrowings outstanding	$0	$0

Product_Warranties_Product_War

Product Warranties - Product Warranty Activities (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Guarantees [Abstract]
Beginning of period	$6,266	$6,956
Provision for product warranties	1,109	704
Direct charges to warranty liability	-1,244	-656
Foreign currency translation	-67	9
End of period	$6,064	$7,013

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Income Taxes [Line Items]
Effective tax rate	28.90%	17.80%
Gross unrecognized tax benefits excluding interest and penalties	$19,508		$19,610
Net unrecognized tax benefit excluding interest and penalties that would impact effective tax rate	11,524
Accrued interest on unrecognized tax benefits	$638		$578
Income tax examination, description	The Company and its subsidiaries are subject to examination by federal, state and foreign tax authorities. The Internal Revenue Service commenced an examination of the Company's U.S. federal tax filings for tax years 2011 through 2013 during the quarter ended March 31, 2015.
Earliest Tax Year [Member]
Income Taxes [Line Items]
Income tax examination period	2011
Earliest Tax Year [Member] | Internal Revenue Service (IRS) [Member]
Income Taxes [Line Items]
Open tax year	2011
Latest Tax Year [Member]
Income Taxes [Line Items]
Income tax examination period	2013

Net_Income_Per_Share_Computati

Net Income Per Share - Computation of Basic and Diluted Net Income Per Share (Detail) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Numerator:
Net income	$33,786	$31,245
Denominator:
Shares used in net income per common share - basic	53,214,000	53,411,000
Effect of dilutive securities:
Stock options, restricted stock and employee stock purchase plan	315,000	365,000
Shares used in net income per common share - diluted	53,529,000	53,776,000
Net income per common share:
Basic	$0.63	$0.58
Diluted	$0.63	$0.58

Net_Income_Per_Share_Additiona

Net Income Per Share - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Stock options and restricted stock units outstanding	760,000
Number of shares excluded from computation of diluted earnings per share	0	1,400

Stockholders_Equity_Additional

Stockholder's Equity - Additional Information (Detail) (USD $)	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	4-May-15	Jul. 25, 2011
Stockholders Equity [Line Items]
Common stock, value of shares authorized to repurchase				$200,000,000
Stock repurchase, shares	0	32,000
Value of shares repurchased		945,000
Average price of repurchased shares		$29.81
Cash dividends per common share	$0.17	$0.16
Dividend payment to common shareholders	$8,784,000	$8,553,000
Subsequent Event [Member]
Stockholders Equity [Line Items]
Dividend declared date			4-May-15
Cash dividend to be paid			$0.17
Dividend to be paid date			12-Jun-15
Dividend declared, shareholders of record date			1-Jun-15

Business_Segment_Geographic_Ar2

Business Segment, Geographic Area, Product and Significant Customer Information - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2015
	Customer
	Segment
	Product
Segment Reporting [Abstract]
Number of reportable segments	4
Number of product groups	3
Number of customers with net revenues greater than 10% of total net revenues	2
Entity wide net revenue major customer percentage minimum	10.00%

Business_Segment_Geographic_Ar3

Business Segment, Geographic Area, Product and Significant Customer Information - Net Revenues by Reportable Segment (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Total net revenues	$213,839	$206,353
Operating Segments [Member] | Advanced Manufacturing Capital Equipment [Member]
Segment Reporting Information [Line Items]
Total net revenues	179,233	165,498
Operating Segments [Member] | Global Service [Member]
Segment Reporting Information [Line Items]
Total net revenues	27,743	25,167
Operating Segments [Member] | Asia Region Sales [Member]
Segment Reporting Information [Line Items]
Total net revenues	55,377	52,099
Operating Segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Total net revenues	21,216	20,893
Corporate and Eliminations [Member]
Segment Reporting Information [Line Items]
Total net revenues	($69,730)	($57,304)

Business_Segment_Geographic_Ar4

Business Segment, Geographic Area, Product and Significant Customer Information - Reconciliation of Segment Gross Profit to Consolidated Net Income (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Gross profit	$97,046	$89,372
Research and development	16,680	15,618
Selling, general and administrative	30,867	34,591
Acquisition costs	30	228
Restructuring	788	747
Amortization of intangible assets	1,671	410
Income from operations	47,010	37,778
Net interest income	504	235
Income before income taxes	47,514	38,013
Provision for income taxes	13,728	6,768
Net income	33,786	31,245
Operating Segments [Member] | Advanced Manufacturing Capital Equipment [Member]
Segment Reporting Information [Line Items]
Gross profit	78,688	67,107
Operating Segments [Member] | Global Service [Member]
Segment Reporting Information [Line Items]
Gross profit	9,603	8,397
Operating Segments [Member] | Asia Region Sales [Member]
Segment Reporting Information [Line Items]
Gross profit	6,920	9,077
Operating Segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Gross profit	6,843	6,747
Corporate and Eliminations [Member]
Segment Reporting Information [Line Items]
Gross profit	($5,008)	($1,956)

Business_Segment_Geographic_Ar5

Business Segment, Geographic Area, Product and Significant Customer Information - Schedule of Capital Expenditures, Depreciation and Amortization Expense by Reportable Segment (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Capital expenditures	$2,504	$3,098
Depreciation and amortization	5,532	4,150
Operating Segments [Member] | Advanced Manufacturing Capital Equipment [Member]
Segment Reporting Information [Line Items]
Capital expenditures	1,522	2,574
Depreciation and amortization	4,247	2,926
Operating Segments [Member] | Global Service [Member]
Segment Reporting Information [Line Items]
Capital expenditures	122	170
Depreciation and amortization	256	272
Operating Segments [Member] | Asia Region Sales [Member]
Segment Reporting Information [Line Items]
Capital expenditures	42	41
Depreciation and amortization	85	99
Operating Segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Capital expenditures	74	75
Depreciation and amortization	310	208
Corporate and Eliminations [Member]
Segment Reporting Information [Line Items]
Capital expenditures	744	238
Depreciation and amortization	$634	$645

Business_Segment_Geographic_Ar6

Business Segment, Geographic Area, Product and Significant Customer Information - Goodwill Associated with Reportable Segments (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Segment Reporting Information [Line Items]
Goodwill	$199,330	$192,381	$150,909
Operating Segments [Member] | Advanced Manufacturing Capital Equipment [Member]
Segment Reporting Information [Line Items]
Goodwill	173,510	166,946
Operating Segments [Member] | Global Service [Member]
Segment Reporting Information [Line Items]
Goodwill	19,728	19,728
Operating Segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Goodwill	6,228	6,228
Foreign Currency Translation [Member] | Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Goodwill	($136)	($521)

Business_Segment_Geographic_Ar7

Business Segment, Geographic Area, Product and Significant Customer Information - Worldwide Net Revenue for Each Group of Products (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenue from External Customer [Line Items]
Net sales from product groups	$213,839	$206,353
Instruments, Control and Vacuum Products [Member]
Revenue from External Customer [Line Items]
Net sales from product groups	110,436	101,657
Power and Reactive Gas Products [Member]
Revenue from External Customer [Line Items]
Net sales from product groups	88,499	90,602
Analytical Solutions Group Products [Member]
Revenue from External Customer [Line Items]
Net sales from product groups	$14,904	$14,094

Business_Segment_Geographic_Ar8

Business Segment, Geographic Area, Product and Significant Customer Information - Schedule of Net Revenues and Long-Lived Assets by Geographic Regions (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$213,839	$206,353
Long-lived assets	73,030		74,687
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	120,181	117,377
Long-lived assets	57,337		57,701
Korea [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	32,072	27,591
Japan [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	17,256	16,928
Asia (Excluding Korea and Japan) [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	23,683	24,902
Long-lived assets	10,162		10,887
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	20,647	19,555
Long-lived assets	$5,531		$6,099

Business_Segment_Geographic_Ar9

Business Segment, Geographic Area, Product and Significant Customer Information - Customers with Net Revenues Greater than 10% of Total Net Revenues (Detail) (Customer Concentration Risk [Member], Sales Revenue, Net [Member])	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Customer A [Member]
Revenue, Major Customer [Line Items]
Percentage of total net revenues	17.40%	20.30%
Customer B [Member]
Revenue, Major Customer [Line Items]
Percentage of total net revenues	12.10%	13.10%

Restructuring_Additional_Infor

Restructuring - Additional Information (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
	People
Reorganizations [Abstract]
Restructuring charges	$788	$747
Approximate number of workforce reduction from the company's headcount	120

Restructuring_Schedule_of_Comp

Restructuring - Schedule of Company's Restructuring Activity (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Restructuring and Related Activities [Abstract]
Balance at December 31	$92
Charged to expense	788	747
Payments	-348
Balance at March 31	$532