Cray (CRAY) 10-K 19 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Feb. 13, 2015	Jun. 30, 2014
Document and Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2014
Entity Registrant Name	CRAY INC
Entity Central Index Key	949158
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		40,826,651
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Entity Public Float			$1,041,002,837

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$112,633	$192,633
Restricted cash	16,874	0
Short-term investments	16,289	14,048
Accounts and other receivables, net	165,113	182,527
Inventory	143,632	95,129
Deferred tax asset	36,073	9,195
Prepaid expenses and other current assets	17,948	11,804
Total current assets	508,562	505,336
Noncurrent Assets:
Long-term restricted cash	0	13,768
Long-term investment in sales-type lease, net	31,089	0
Property and equipment, net	34,793	30,278
Service inventory, net	1,868	1,828
Goodwill	14,182	14,182
Purchased intangible assets, net	3,895	6,362
Deferred tax asset	41,414	19,206
Other non-current assets	15,631	12,406
TOTAL ASSETS	651,434	603,366
Current liabilities:
Accounts payable	48,699	34,225
Accrued payroll and related expenses	16,054	22,470
Other accrued liabilities	16,285	22,225
Deferred revenue	65,910	91,488
Total current liabilities	146,948	170,408
Noncurrent Liabilities:
Long-term deferred revenue	47,588	50,477
Other non-current liabilities	3,044	6,894
TOTAL LIABILITIES	197,580	227,779
Shareholders’ equity:
Preferred stock — Authorized and undesignated, 5,000,000 shares; no shares issued or outstanding	0	0
Common stock and additional paid-in capital, par value $.01 per share — Authorized, 75,000,000 shares; issued and outstanding 39,435,215 and 36,763,379 shares, respectively	598,390	586,243
Accumulated other comprehensive income	6,503	853
Accumulated deficit	-151,039	-211,509
TOTAL SHAREHOLDERS’ EQUITY	453,854	375,587
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$651,434	$603,366

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (dollars per share)	$0.01	$0.01
Common stock, shares authorized	75,000,000	75,000,000
Common stock and additional paid-in capital, shares issued	40,822,377	40,469,854
Common stock and additional paid-in capital, shares outstanding	40,822,377	40,469,854

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue:
Product	$460,748	$436,330	$353,767
Service	100,858	89,419	67,291
Total revenue	561,606	525,749	421,058
Cost of revenue:
Cost of product revenue	321,554	298,244	231,237
Cost of service revenue	55,638	43,179	38,643
Total cost of revenue	377,192	341,423	269,880
Gross profit	184,414	184,326	151,178
Operating expenses:
Research and development, net	94,048	87,728	64,303
Sales and marketing	57,785	51,345	37,180
General and administrative	23,381	23,603	20,707
Total operating expenses	175,214	162,676	122,190
Net gain on sale of interconnect hardware development program	0	0	139,068
Income from operations	9,200	21,650	168,056
Other income (expense), net	-9	-1,378	472
Interest income (expense), net	506	757	204
Income before income taxes	9,697	21,029	168,732
Income tax benefit (expense)	52,626	11,194	-7,491
Net income	$62,323	$32,223	$161,241
Basic net income per common share (dollars per share)	$1.61	$0.85	$4.42
Diluted net income per common share (dollars per share)	$1.54	$0.81	$4.27
Basic weighted average shares outstanding (shares)	38,634	37,832	36,509
Diluted weighted average shares outstanding (shares)	40,435	39,776	37,789

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net income	$62,323	$32,223	$161,241
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Unrealized loss on available-for-sale investments	12	46	-46
Foreign currency translation adjustments	-1,188	-1,044	-43
Unrealized gain (loss) on cash flow hedges	8,475	-4,292	-824
Reclassification adjustments on cash flow hedges included in net income	-1,649	962	-386
Other comprehensive income (loss)	5,650	-4,328	-1,299
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest	$67,973	$27,895	$159,942

Consolidated_Statements_of_Sha

Consolidated Statements of Shareholders’ Equity (USD $)	Total	Common Stock and Additional Paid In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
In Thousands, except Share data, unless otherwise specified
Balance at Dec. 31, 2011	$166,814	$564,148	$6,480	($403,814)
Balance, shares at Dec. 31, 2011		36,763,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under employee stock purchase plan, shares		38,000
Issuance of shares under employee stock purchase plan	397	397
Exercise of stock options, shares	1,346,326	1,346,000
Exercise of stock options	7,430	7,430
Restricted shares issued for compensation, net of forfeitures, shares		1,288,000
Restricted shares issued for compensation, net of forfeitures and taxes	0	0
Share-based compensation	5,963	5,963
Other comprehensive income	-1,299		-1,299
Net income	161,241			161,241
Balance at Dec. 31, 2012	340,546	577,938	5,181	-242,573
Balance, shares at Dec. 31, 2012		39,435,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under employee stock purchase plan, shares		25,000
Issuance of shares under employee stock purchase plan	517	517
Exercise of stock options, shares	495,221	495,000
Exercise of stock options	3,161	3,161
Restricted shares issued for compensation, net of forfeitures, shares		515,000
Restricted shares issued for compensation, net of forfeitures and taxes	-3,771	-2,612		-1,159
Share-based compensation	7,239	7,239
Other comprehensive income	-4,328		-4,328
Net income	32,223			32,223
Balance at Dec. 31, 2013	375,587	586,243	853	-211,509
Balance, shares at Dec. 31, 2013	40,469,854	40,470,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under employee stock purchase plan, shares		21,000
Issuance of shares under employee stock purchase plan	611	611
Exercise of stock options, shares	411,352	411,000
Exercise of stock options	3,086	3,086
Restricted shares issued for compensation, net of forfeitures, shares		-80,000
Restricted shares issued for compensation, net of forfeitures and taxes	-3,767	-1,914		-1,853
Share-based compensation	10,364	10,364
Other comprehensive income	5,650		5,650
Net income	62,323			62,323
Balance at Dec. 31, 2014	$453,854	$598,390	$6,503	($151,039)
Balance, shares at Dec. 31, 2014	40,822,377	40,822,000

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities:
Net income	$62,323	$32,223	$161,241
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	16,324	14,242	8,652
Accretion and amortization on available for sale investments	235	1,977	0
Loss on disposal of fixed assets	1,594	42	128
Net gain on sale of interconnect hardware development program	0	0	-139,068
Share-based compensation expense	10,364	7,239	5,963
Inventory write-down	2,330	917	2,329
Deferred income taxes	-53,204	-13,175	3,020
Cash (used in) provided by operations due to changes in operating assets and liabilities:
Accounts and other receivables	17,450	-169,753	60,744
Long-term investment in sales-type lease, net	-32,889	0	0
Inventory	-54,147	-10,780	7,004
Prepaid expenses and other assets	-9,349	-2,670	1,763
Accounts payable	14,504	-509	-6,489
Accrued payroll and related expenses and other accrued liabilities	-1,395	4,721	15,202
Other non-current liabilities	-3,842	3,701	492
Deferred revenue	-28,407	44,475	35,911
Net cash (used in) provided by operating activities	-58,109	-87,350	156,892
Investing activities:
Sales/maturities of short-term investments	53,608	139,277	0
Purchases of available-for-sale investments	-56,064	-85,162	-70,218
Decrease in restricted cash	-3,106	-13,768	3,776
Proceeds from the sale of interconnect hardware development program, net	0	0	139,225
Cash used in acquisition, net of cash acquired	0	0	-24,246
Purchases of property and equipment	-17,193	-13,136	-10,843
Net cash provided by (used in) investing activities	-22,755	27,211	37,694
Financing activities:
Proceeds from issuance of common stock through employee stock purchase plan	611	517	397
Restricted shares issued for compensation, net of forfeitures and taxes	-3,767	-3,771	0
Proceeds from exercise of options	3,086	3,161	7,430
Net cash provided by financing activities	-70	-93	7,827
Effect of foreign exchange rate changes on cash and cash equivalents	934	-200	241
Net increase (decrease) in cash and cash equivalents	-80,000	-60,432	202,654
Cash and cash equivalents:
Beginning of period	192,633	253,065	50,411
End of period	112,633	192,633	253,065
Supplemental disclosure of cash flow information:
Cash paid for interest	5	3	90
Cash paid for income taxes	2,935	2,611	2,804
Non-cash investing and financing activities:
Inventory transfers to fixed assets and service inventory	$3,313	$4,530	$6,278

Description_of_Business

Description of Business	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	DESCRIPTION OF BUSINESS
	Cray Inc., or Cray, or the Company, designs, develops, manufactures, markets and services the high-end of the high-performance computing, or HPC, market, primarily categories of systems commonly known as supercomputers, and provides storage and analytics solutions. The Company also provides software, system maintenance and support services and engineering services related to supercomputer systems. Cray’s supercomputer systems address challenging scientific, engineering, commercial and national security computing problems. The Company’s customers include foreign and domestic government agencies, government-funded entities, academic institutions and commercial entities.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Accounting Principles
	The consolidated financial statements and accompanying notes are prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP.
	Principles of Consolidation
	The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. Intercompany balances and transactions have been eliminated.
	Reclassifications
	Certain prior year amounts have been reclassified to conform with the current year presentation. There has been no impact on previously reported net income or shareholders’ equity from such reclassifications.
	Use of Estimates
	The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the amounts reported in the Company’s consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates.
	Cash, Cash Equivalents and Restricted Cash
	Cash and cash equivalents consist of highly liquid financial instruments that are readily convertible to cash and have maturities of three months or less at the time of acquisition. The Company maintains cash and cash equivalent balances with financial institutions that exceed federally insured limits. As of December 31, 2014, the Company had $16.9 million in short-term restricted cash and as of December 31, 2013, $13.8 million in long-term restricted cash, associated with certain letters of credit outstanding to secure customer prepayments.
	Investments
	The Company’s investments consist primarily of commercial paper, corporate debt, and other debt securities. Debt securities are classified as available-for-sale and are reported at fair value with unrealized gains and losses, net of applicable taxes, recorded in accumulated other comprehensive income, a component of shareholders’ equity. The realized gains and losses for available-for-sale securities are included in other income and expense in the Consolidated Statements of Operations. Realized gains and losses are calculated based on the specific identification method.
	The Company monitors its investment portfolio for impairment on a periodic basis. When the carrying value of an investment in debt securities exceeds its fair value and the decline in value is determined to be an other-than-temporary decline, and when the Company does not intend to sell the debt security and it is not more likely than not that the Company will be required to sell the debt securities prior to recovery of its amortized cost basis, the Company records an impairment charge in the amount of the credit loss and the balance, if any, to other comprehensive income (loss).
	Investments that mature between three months and one year from the purchase date are initially classified as short-term investments in the Consolidated Balance Sheet. Investments that mature beyond one year from the purchase date are initially classified as long-term investments in the Consolidated Balance Sheet.
	Foreign Currency Derivatives
	The Company uses forward foreign currency exchange contracts to hedge certain foreign currency exposures. Forward contracts are cash flow hedges of the Company’s foreign currency exposures on certain revenue contracts and are recorded at the contract’s fair value. Any gains or losses on the effective portion of the forward contract is initially reported in “Accumulated other comprehensive income,” a component of shareholders’ equity, with a corresponding asset or liability recorded based on the fair value of the forward contract. When the hedged transaction is recognized, any unrecognized gains or losses on the hedged transaction are reclassified into results of operations in the same period. Any hedge ineffectiveness is recorded to operations in the current period. The Company measures hedge effectiveness by comparing changes in fair values of the forward contract and expected cash flows based on changes in the spot prices of the underlying currencies. Cash flows from forward contracts accounted for as cash flow hedges are classified in the same category as the cash flows from the items being hedged. The Company does not use derivative financial instruments for speculative purposes.
	Concentration of Credit Risk
	Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents, available-for-sale investments, accounts receivable, short-term and long-term restricted cash and forward foreign currency exchange contracts.
	The Company maintains cash and cash equivalents, available-for-sale securities and forward contracts with various financial institutions. As part of its risk management process, the Company performs periodic evaluations of the relative credit standing of the financial institutions. The Company has not sustained any credit losses from instruments held at financial institutions. The Company utilizes forward contracts to protect against the effects of foreign currency fluctuations. Such contracts involve the risk of non-performance by the counterparty, which could result in a material loss.
	The Company currently derives a significant portion of its revenue from sales of products and services to different agencies of the U.S. government or commercial customers primarily serving various agencies of the U.S. government. See Note 19 — Segment Information for additional information. Given the type of customers, the Company does not believe its accounts receivable represent significant credit risk.
	The Company currently has a long-term investment in a sales-type lease it entered into with one of its customers. See Note 9 — Sales-type Lease for additional information. Given the credit standing of the customer, the Company does not believe that this investment represents a significant credit risk.
	Other Concentration
	The Company obtains certain components from single source suppliers due to technology, availability, price, quality or other considerations. The loss of a single source supplier, the single source supplier’s inability to deliver the required components or intellectual property due to natural disaster or other reasons, the deterioration of the relationship with a single source supplier, or any unilateral modification of contract terms under which the Company is supplied components by a single source supplier could have a significant adverse effect on the Company’s revenue and gross margins.
	Accounts Receivable
	Accounts receivable are stated at principal amounts and are primarily comprised of amounts contractually due from customers for products and services and amounts due from government research and development contracts. The Company provides an allowance for doubtful accounts based on an evaluation of customer past due account balances. In determining whether to record an allowance for a specific customer, the Company considers a number of factors, including prior payment history and financial information for the customer.
	Fair Values of Financial Instruments
	The Company measures certain financial assets and liabilities at fair value based on the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants. The Company’s financial instruments primarily consist of debt securities, time deposits, money market funds, and foreign currency derivatives. See Note 5 — Fair Value Measurement for a further discussion on fair value of financial instruments.
	Inventories
	Inventories are valued at the lower of cost or market, with cost computed on a first-in, first-out basis. The Company regularly evaluates the technological usefulness and anticipated future demand for various inventory components and the expected use of the inventory. When the Company determines it is not likely the cost of inventory items will be recovered through future sales, the Company writes-down the related inventory to its estimated market value.
	In connection with certain of its sales agreements, the Company may receive used equipment from a customer. This inventory generally will be recorded at no value based on the expectation that the Company will not be able to resell or otherwise use the equipment. In the event that the Company has a specific contractual plan for resale at the date the inventory is acquired, the inventory is recorded at its estimated fair value.
	Property and Equipment and Intangible Assets, net
	Property and equipment are recorded at cost less accumulated depreciation and amortization. Additions and improvements are capitalized and maintenance and repairs are expensed as incurred. Depreciation is calculated on a straight-line basis over the estimated useful lives of the related assets, ranging from eighteen months to seven years for furniture and fixtures, three years for computer equipment, and eight to twenty-five years for buildings and land improvements. Leasehold improvements are depreciated over the life of the lease or asset, whichever is shorter.
	The Company amortizes purchased intangible assets with finite lives using the straight-line method over the estimated economic lives of the assets, ranging from two to ten years.
	Service Spares
	Service spares are valued at the lower of cost or market and represent inventory used to support service and maintenance agreements with customers. As inventory is utilized, replaced items are returned to the Company and are either repaired or scrapped. Costs incurred to repair inventory to a usable state are charged to expense as incurred. Service spares are recorded at cost and amortized over the estimated service life of the related product platform (generally four years).
	Impairment of Long-Lived Assets and Intangibles
	The Company evaluates property, plant and equipment and intangible assets with finite lives for impairment whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable. The Company assesses the recoverability of the assets based on the undiscounted future cash flow the assets are expected to generate and recognizes an impairment loss when estimated undiscounted future cash flow expected to result from the use of the asset plus net proceeds expected from disposition of the asset, if any, are less than the carrying value of the asset. When the Company identifies an impairment, the carrying value of the asset is reduced to its estimated fair value based on a discounted cash flow approach or, when available and appropriate, to comparable market values.
	Goodwill
	Goodwill is not amortized but is tested for impairment at least annually. The Company reviews goodwill for impairment annually at the beginning of its fourth fiscal quarter and whenever events or changes in circumstances indicate the carrying value of the asset may not be recoverable. The goodwill impairment test consists of a two-step process, if necessary. However, the Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test described in ASC Topic 350. The more likely than not threshold is defined as having a likelihood of more than 50 percent. If, after assessing the totality of events or circumstances, the Company determines that it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing the two-step impairment test is unnecessary and goodwill is considered to be unimpaired. However, if based on the qualitative assessment the Company concludes that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the Company will proceed with performing the two-step process.
	In step one, the Company determines the fair value of each reporting unit and compares it to its carrying value. If the fair value of the reporting unit exceeds the carrying value of the net assets assigned to that unit, goodwill is not impaired and no further testing is performed. If the carrying value of the net assets assigned to the reporting unit exceeds the fair value of the reporting unit, then the Company must perform the second step of the impairment test in order to determine the implied fair value of the reporting unit’s goodwill. If the carrying value of a reporting unit’s goodwill exceeds its implied fair value, the Company records an impairment loss equal to the difference.
	The Company performed its qualitative assessment during the fourth fiscal quarter of 2014 and concluded that it was more likely than not that the fair values of its reporting units were greater than their carrying amounts. After reaching this conclusion, the two-step impairment test was unnecessary and no further testing was performed. The qualitative factors that were considered included, but were not limited to, general economic conditions, outlook for the HPC and big data markets, recent and forecasted financial performance and the price of the Company’s common stock.
	Business Combinations
	The Company accounts for business combinations using the acquisition method of accounting and allocates the purchase price to the tangible and intangible assets acquired and the liabilities assumed based upon their estimated fair values at the acquisition date. The difference between the purchase price and the fair value of the net assets acquired is recorded as goodwill. The Company uses estimates and assumptions to accurately value assets acquired and liabilities assumed at the acquisition date. During the measurement period, which may be up to one year from the acquisition date, any refinements made to the fair value of the assets and liabilities assumed are recorded with retrospective effect.
	The fair values of intangible assets acquired are estimated using a discounted cash flow approach with Level 3 inputs. Under this method, an intangible asset’s fair value is equal to the present value of the incremental after-tax cash flows (excess earnings) attributable solely to the intangible asset over its remaining useful life. To calculate fair value, the Company uses risk-adjusted cash flows discounted at rates considered appropriate given the inherent risks associated with each type of asset. The Company believes the level and timing of cash flows appropriately reflects market participant assumptions.
	Revenue Recognition
	The Company recognizes revenue, including transactions under sales-type leases, when it is realized or realizable and earned. The Company considers revenue realized or realizable and earned when it has persuasive evidence of an arrangement, delivery has occurred, the sales price is fixed or determinable, and collectibility is reasonably assured. Delivery does not occur until the products have been shipped or services provided to the customer, risk of loss has transferred to the customer, and, where applicable, a customer acceptance has been obtained. The sales price is not considered to be fixed or determinable until all material contingencies related to the sales have been resolved. The Company records revenue in the Consolidated Statements of Operations net of any sales, use, value added or certain excise taxes imposed by governmental authorities on specific sales transactions. In addition to the aforementioned general policy, the following are the Company’s statements of policy with regard to multiple-element arrangements and specific revenue recognition policies for each major category of revenue.
	Multiple-Element Arrangements. The Company commonly enters into revenue arrangements that include multiple deliverables of its product and service offerings due to the needs of its customers. Products may be delivered in phases over time periods which can be as long as five years. Maintenance services generally begin upon acceptance of the first equipment delivery and future deliveries of equipment generally have an associated maintenance period. The Company considers the maintenance period to commence upon acceptance of the product or installation in situations where a formal acceptance is not required, which may include a warranty period and accordingly allocates a portion of the arrangement consideration as a separate deliverable which is recognized as service revenue over the entire service period. Other services such as training and engineering services can be delivered as a discrete delivery or over the term of the contract. A multiple-element arrangement is separated into more than one unit of accounting if the following criteria are met:
	•	The delivered item(s) has value to the customer on a standalone basis; and
	•	If the arrangement includes a general right of return relative to the delivered item(s), delivery or performance of the undelivered item(s) is considered probable and substantially in the control of the Company.
	If these criteria are met for each element, the arrangement consideration is allocated to the separate units of accounting based on each unit’s relative selling price. If these criteria are not met, the arrangement is accounted for as one unit of accounting which would result in revenue being recognized ratably over the contract term or being deferred until the earlier of when such criteria are met or when the last undelivered element is delivered.
	The Company follows a selling price hierarchy in determining the best estimate of the selling price of each deliverable. Certain products and services are sold separately in standalone arrangements for which the Company is sometimes able to determine vendor specific objective evidence, or VSOE. The Company determines VSOE based on normal pricing and discounting practices for the product or service when sold separately.
	When the Company is not able to establish VSOE for all deliverables in an arrangement with multiple elements, the Company attempts to establish the selling price of each remaining element based on third-party evidence, or TPE. The Company’s inability to establish VSOE is often due to a relatively small sample of customer contracts that differ in system size and contract terms which can be due to infrequently selling each element separately, not pricing products within a narrow range, or only having a limited sales history, such as in the case of certain advanced and emerging technologies. TPE is determined based on the Company’s prices or competitor prices for similar deliverables when sold separately. However, the Company is often unable to determine TPE, as the Company’s offerings usually contain a significant level of customization and differentiation from those of competitors and the Company is often unable to reliably determine what similar competitor products’ selling prices are on a standalone basis.
	When the Company is unable to establish selling price using VSOE or TPE, the Company uses estimated selling price, or ESP, in its allocation of arrangement consideration. The objective of ESP is to determine the price at which the Company would transact a sale if the product or service were sold on a standalone basis. In determining ESP, the Company uses the cost to provide the product or service plus a margin, or considers other factors. When using cost plus a margin, the Company considers the total cost of the product or service, including customer-specific and geographic factors. The Company also considers the historical margins of the product or service on previous contracts and several factors including any changes to pricing methodologies, competitiveness of products and services and cost drivers that would cause future margins to differ from historical margins.
	Products. The Company most often recognizes revenue from sales of products upon customer acceptance of the system. Where formal acceptance is not required, the Company recognizes revenue upon delivery or installation. When the product is part of a multiple element arrangement, the Company allocates a portion of the arrangement consideration to product revenue based on estimates of selling price.
	Services. Maintenance services are provided under separate maintenance contracts with customers. These contracts generally provide for maintenance services for one year, although some are for multi-year periods, often with prepayments for the term of the contract. The Company considers the maintenance period to commence upon acceptance of the product or installation in situations where a formal acceptance is not required, which may include a warranty period. When service is part of a multiple element arrangement, the Company allocates a portion of the arrangement consideration to maintenance service revenue based on estimates of selling price. Maintenance contracts that are billed in advance of revenue recognition are recorded as deferred revenue. Maintenance revenue is recognized ratably over the term of the maintenance contract.
	Revenue from engineering services is recognized as services are performed.
	Project Revenue. Revenue from design and build contracts is recognized under the percentage-of-completion (or POC method). Under the POC method, revenue is recognized based on the costs incurred to date as a percentage of the total estimated costs to fulfill the contract. If circumstances arise that change the original estimates of revenues, costs, or extent of progress toward completion, revisions to the estimates are made. These revisions may result in increases or decreases in estimated revenues or costs, and such revisions are recorded in income in the period in which the circumstances that gave rise to the revision become known by management. The Company performs ongoing profitability analyses of its contracts accounted for under the POC method in order to determine whether the latest estimates of revenue, costs and extent of progress require updating. If at any time these estimates indicate that the contract will be unprofitable, the entire estimated loss for the remainder of the contract is recorded immediately.
	The Company records revenue from certain research and development contracts which include milestones using the milestone method if the milestones are determined to be substantive. A milestone is considered to be substantive if management believes there is substantive uncertainty that it will be achieved and the milestone consideration meets all of the following criteria:
	•	It is commensurate with either of the following:
	•	The Company’s performance to achieve the milestone; or
	•	The enhancement of value of the delivered item or items as a result of a specific outcome resulting from the Company’s performance to achieve the milestone.
	•	It relates solely to past performance.
	•	It is reasonable relative to all of the deliverables and payment terms (including other potential milestone consideration) within the arrangement.
The individual milestones are determined to be substantive or non-substantive in their entirety and milestone consideration is not bifurcated.
Revenue from projects is classified as Product Revenue or Service Revenue, based on the nature of the work performed.
Nonmonetary Transactions. The Company values and records nonmonetary transactions at the fair value of the asset surrendered unless the fair value of the asset received is more clearly evident, in which case the fair value of the asset received is used.
Sales-type leases
When the Company leases a system to a customer, the accounting involves specific determinations, which often involve complex provisions and significant judgments. The four criteria of the accounting standard that the Company uses in the determination of whether a lease is a sales-type lease or an operating lease are: (a) a review of the lease term to determine if it is equal to or greater than 75% of the economic life of the system; (b) a review of the minimum lease payments to determine if they are equal to or greater than 90% of the fair value of the system; (c) a determination of whether or not the lease transfers ownership to the lessee at the end of the lease term; and (d) a determination of whether or not the lease contains a bargain purchase option. If the lease transaction meets one of the four criteria, then it is recorded as a sales-type lease; otherwise it is an operating lease. Additionally, the Company assesses whether collectibility of the lease payments is reasonably assured and whether there are any significant uncertainties related to costs that it has yet to incur with respect to the lease.
The Company considers the economic lives of most of its products to range from three to four years. There is no significant after-market for the Company’s used products and the Company believes that the economic lives are representative of the periods during which its products are expected to be economically usable, with normal service, for the purposes for which they were intended. Residual values are not significant.
The discount rate implicit in the sales-type lease is used to calculate the present value of minimum lease payments, which the Company records as a lease receivable. The minimum lease payment consists of the gross lease payments net of executory costs and contingencies, if any. While revenue is recognized at the inception of the lease, the cash flow from the sales-type lease occurs over the course of the lease, which results in interest income. Unearned interest income is recorded at the inception of the lease and amortized over the lease term using the effective interest method.
Foreign Currency Translation
The Company uses the U.S. dollar predominantly as its functional currency. Assets and liabilities of foreign subsidiaries that have a functional currency denominated in non-U.S. dollars are translated into U.S. dollars at year-end exchange rates, and revenue and expenses of these foreign subsidiaries are translated at average rates prevailing during the year. Translation adjustments are included in “Accumulated other comprehensive income,” a separate component of shareholders’ equity. Transaction gains and losses arising from transactions denominated in a currency other than the functional currency of the entity involved are included in “Other (income) expense, net” in the accompanying Consolidated Statements of Operations. Net transaction gains were $2.1 million for 2014 and net transactions losses were $1.3 million, and $0.1 million for 2013, and 2012, respectively.
Research and Development
Research and development expenses include costs incurred in the development and production of hardware and software, costs incurred to enhance and support existing product features, costs incurred to support and improve development processes, and costs related to future product development. Research and development costs are expensed as incurred, and may be offset by co-funding from third parties. The Company may also enter into arrangements whereby it makes advance, non-refundable payments to a vendor to perform certain research and development services. These payments are deferred and recognized over the vendor’s estimated performance period. During the third quarter of 2009, the Company amended a vendor agreement to settle outstanding performance issues. The Company had made advance payments of $16.2 million to the vendor. Due to the amendment, the Company received a refund of $10.0 million of amounts previously paid to the vendor and the right to receive rebates on future purchases. The Company estimated the fair value of this rebate right to be $6.2 million. The Company believes the rebate right is recoverable and it has been classified in “Other non-current assets” in the Consolidated Balance Sheets. No gain or loss was recorded as a result of this amendment. As of December 31, 2014, $0.1 million in rebates remain available for use.
Amounts to be received under co-funding arrangements with the U.S. government or other customers are based on either contractual milestones or costs incurred. These co-funding milestone payments are recognized in operations as performance is estimated to be completed and are measured as milestone achievements occur or as costs are incurred. These estimates are reviewed on a periodic basis and are subject to change, including in the near term. If an estimate is changed, net research and development expense could be impacted significantly.
The Company does not record a receivable from the U.S. government prior to completing the requirements necessary to bill for a milestone or cost reimbursement. Funding from the U.S. government is subject to certain budget restrictions and milestones may be subject to completion risk, and as a result, there may be periods in which research and development costs are expensed as incurred for which no reimbursement is recorded, as milestones have not been completed or the U.S. government has not funded an agreement. Accordingly, there can be substantial variability in the amount of net research and development expenses from quarter to quarter and year to year.
The Company classifies amounts to be received from funded research and development projects as either revenue or a reduction to research and development expense based on the specific facts and circumstances of the contractual arrangement, considering total costs expected to be incurred compared to total expected funding and the nature of the research and development contractual arrangement. In the event that a particular arrangement is determined to represent revenue, the corresponding research and development costs are classified as cost of revenue.
Income Taxes
Deferred tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities and operating loss and tax credit carryforwards and are measured using the enacted tax rates and laws that will be in effect when the differences and carryforwards are expected to be recovered or settled. A valuation allowance for deferred tax assets is provided when the Company estimates that it is more likely than not that all or a portion of the deferred tax assets may not be realized through future operations. This assessment is based upon consideration of available positive and negative evidence, which includes, among other things, recent results of operations and expected future profitability. The Company considers its actual historical results over several years to have stronger weight than other more subjective indicators, including forecasts, when considering whether to establish or reduce a valuation allowance on deferred tax assets.
The Company recognizes the income tax benefit from a tax position only if it is more likely than not that the tax position will be sustained on examination by the applicable taxing authorities, based on the technical merits of the Company’s position. The tax benefit recognized in the financial statements from such a position is measured based on the largest benefit that has a greater than fifty percent likelihood of being realized upon ultimate settlement.
Estimated interest and penalties are recorded as a component of interest expense and other expense, respectively.
As of December 31, 2014, the Company had approximately $87.6 million of net deferred tax assets, against which the Company provided a $10.1 million valuation allowance, resulting in a net deferred tax asset of $77.5 million. During the year ended December 31, 2014 the Company reduced substantially all of the remaining valuation allowance held against the Company’s U.S. deferred tax assets. The Company continues to provide a valuation allowance against specific U.S. deferred tax assets and a full valuation allowance against deferred tax assets arising in a limited number of foreign jurisdictions as the realization of such assets is not considered to be more likely than not at this time. In a future period the Company’s assessment of the realizability of its deferred tax assets and therefore the appropriateness of the valuation allowance could change based on an assessment of all available evidence, both positive and negative in that future period. If the Company’s conclusion about the realizability of its deferred tax assets and therefore the appropriateness of the valuation allowance changes in a future period, the Company could record a substantial tax provision or benefit in its Consolidated Statement of Operations when that occurs.
Share-Based Compensation
The Company measures compensation cost for share-based payment awards at fair value and recognizes it as compensation expense over the service period for awards expected to vest. Share-based compensation expense is recognized for all share-based payment awards, net of an estimated forfeiture rate. Compensation cost is only recognized for those shares expected to vest on a straight-line basis over the requisite service period of the award.
Determining the appropriate fair value model and calculating the fair value of share-based payment awards requires subjective assumptions, including the expected life of the share-based payment awards and stock price volatility. The Company utilizes the Black-Scholes options pricing model to value the stock options granted under its options plans. In this model, the assumptions utilized relate to stock price volatility, stock option term and forfeiture rates that are based upon both historical factors as well as management’s judgment.
The fair value of restricted stock and restricted stock units is determined based on the number of shares or units granted and the quoted price of the Company’s common stock at the date of grant.
The Company grants performance vesting restricted shares to executives as one of the ways to align compensation with shareholder interests. Vesting of these awards is contingent upon achievement of certain performance conditions. Compensation expense for these awards is only recorded when vesting is deemed to be probable.
Shipping and Handling Costs
Costs related to shipping and handling are included in “Cost of product revenue” and “Cost of service revenue” in the accompanying Consolidated Statements of Operations.
Advertising Costs
Sales and marketing expenses in the accompanying Consolidated Statements of Operations include advertising expenses of $2.9 million, $2.2 million, and $1.2 million in 2014, 2013, and 2012, respectively. The Company incurs advertising costs for representation at certain trade shows, promotional events and sales lead generation, as well as design and printing costs for promotional materials. The Company expenses all advertising costs as incurred.
Earnings Per Share, or EPS
Basic EPS is computed by dividing net income available to common shareholders by the weighted average number of common shares, excluding unvested restricted stock outstanding during the period. Diluted EPS is computed by dividing net income available to common shareholders by the weighted average number of common and potential common shares outstanding during the period, which includes the additional dilution related to conversion of stock options, unvested restricted stock and restricted stock units as computed under the treasury stock method. For the years ended December 31, 2014, 2013 and 2012, the added shares from these items included in the calculation of diluted shares and EPS totaled approximately 1.8 million, 1.9 million, and 1.3 million, respectively. Potentially dilutive shares of 0.6 million, 0.5 million, and 0.4 million, respectively, have been excluded from the denominator in the computation of diluted EPS for the years ended December 31, 2014, 2013 and 2012, respectively, because they are antidilutive. Performance vesting restricted stock totaling 0.8 million, 1.1 million and 0.7 million were excluded from the computation of diluted EPS for the years ended December 31, 2014, 2013 and 2012, respectively, because the conditions for vesting had not been met as of the balance sheet date.
Accumulated Other Comprehensive Income
Accumulated other comprehensive income, a component of Shareholders’ equity, consisted of the following at December 31 (in thousands):
		2014		2013			2012
Accumulated unrealized net gain (loss) on available-for-sale investments		$	12	$	—		$	(46	)
Accumulated currency translation adjustments		2,069		3,257			4,301
Accumulated unrealized net gain (loss) on cash flow hedges		4,422		(2,404		)	926
Accumulated other comprehensive income		$	6,503	$	853		$	5,181
Recent Accounting Pronouncements
In May 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers: Topic 606 (ASU 2014-09), to supersede nearly all existing revenue recognition guidance under GAAP. The core principle of ASU 2014-09 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. ASU 2014-09 defines a five step process to achieve this core principle and, in doing so, it is possible more judgment and estimates may be required within the revenue recognition process than required under existing U.S. GAAP including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. ASU 2014-09 is effective for the fiscal and interim reporting periods beginning after December 15, 2016 using either of two methods: (i) retrospective to each prior reporting period presented with the option to elect certain practical expedients as defined within ASU 2014-09; or (ii) retrospective with the cumulative effect of initially applying ASU 2014-09 recognized at the date of initial application and providing certain additional disclosures as defined per ASU 2014-09. The Company is currently evaluating the potential impact of the pending adoption of ASU 2014-09 on its consolidated financial statements.

Acquisition

Acquisition	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Acquisition	ACQUISITION
	On November 21, 2012, the Closing Date, the Company acquired all the outstanding shares of Appro International, Inc., or Appro, for cash consideration of $24.9 million. Appro is a provider of cluster solutions in the high performance computing market. The acquisition of Appro allowed the Company to expand its product offering in the high performance computing market. The Company reports the financial results of the Appro business in the supercomputing segment.
	The Company utilized a third-party appraisal in its determination of the fair value of the various assets acquired and liabilities assumed. The fair value of the acquired assets, net of assumed liabilities, equals the $24.9 million cash consideration paid by the Company. No measurement period adjustments were required.
	The following are the estimated fair values of the assets acquired and liabilities assumed (in thousands):
	Cash	$	635
	Inventories	7,526
	Other tangible assets	5,702
	Deferred revenue	(2,400		)
	Accounts payable	(2,918		)
	Deferred tax liabilities	(3,685		)
	Other liabilities assumed	(2,061		)
	Net tangible assets	2,799
	Trademarks	300
	Developed technology	5,400
	Customer relationships	1,800
	Non-compete agreements	400
	Goodwill	14,182
	Total net assets acquired	$	24,881
	The fair values of the major components of the intangible assets acquired and their estimated useful lives are as follows (in thousands):
							Useful Life
	Intangible Asset Class		Fair Value				(in Years)
	Trademarks		$	300			5
	Developed technology		$	5,400			3
	Customer relationships		$	1,800			10
	Non-compete agreements		$	400			2
	The revenue and net loss of Appro from the Closing Date to December 31, 2012 included in the accompanying consolidated statements of operations were $0.6 million and $1.3 million, respectively.
	The Company incurred acquisition-related costs (i.e., legal, accounting, valuation, and other costs) of $0.9 million during the year ended December 31, 2012. The acquisition-related costs were expensed in the accompanying Consolidated Statements of Operations for the year ended December 31, 2012.
	The following unaudited pro forma condensed financial information presents the combined results of operations of the Company and Appro for the year ended December 31, 2012 as if the acquisition had occurred on January 1, 2012 (in thousands):
		Year Ended December 31, 2012
	Revenue	$	494,369
	Net income	$	161,985
	The unaudited pro forma condensed financial information is not intended to represent or be indicative of the results of operations of the Company that would have been reported had the acquisition been completed as of the beginning of the period presented, and should not be taken as representative of the future consolidated results of operations of the Company.
	The goodwill recorded in connection with the acquisition of Appro is primarily related to the synergies expected to be achieved and the value of the assembled workforce. The goodwill balance is not deductible for tax purposes.
	The carrying amount of purchased intangibles at December 31, 2014 was as follows (in thousands):
		31-Dec-14
		Gross Carrying Amount			Accumulated Amortization			Net Carrying Amount
	Trademarks	$	300		$	127		$	173
	Developed technology	5,400			3,800			1,600
	Customer relationships	1,800			380			1,420
	Non-compete agreements	400			400			—
	Total	$	7,900		$	4,707		$	3,193
	The carrying amount of purchased intangibles at December 31, 2013 was as follows (in thousands):
		31-Dec-13
		Gross Carrying Amount			Accumulated Amortization			Net Carrying Amount
	Trademarks	$	300		$	67		$	233
	Developed technology	5,400			2,000			3,400
	Customer relationships	1,800			200			1,600
	Non-compete agreements	400			222			178
	Total	$	7,900		$	2,489		$	5,411
	Aggregate estimated amortization expense for the years ending December 31 are as follows (in thousands):
	2015	$	1,840
	2016	240
	2017	233
	2018	180
	2019	180
		$	2,673
	For the years ended December 31, 2014, 2013 and 2012, amortization expense related to purchased intangibles was $2.2 million, $2.2 million and $0.2 million, respectively.

Sale_of_Interconnect_Hardware_

Sale of Interconnect Hardware Development Program	12 Months Ended
	Dec. 31, 2014
Sale of Interconnect Hardware Development Program [Abstract]
Sale of Interconnect Hardware Development Program	SALE OF INTERCONNECT HARDWARE DEVELOPMENT PROGRAM
	On May 2, 2012, the Company sold its interconnect hardware development program to Intel Corporation (“Intel”) for cash consideration of $140 million. As part of the transaction, 73 of the Company’s employees joined Intel, and certain intellectual property and fixed assets were transferred to Intel. The Company retained certain rights to use the transferred assets and intellectual property. As a result of the sale, the Company recorded a gain of $139.1 million in “Net gain on sale of interconnect hardware development program” on the Consolidated Statements of Operations for the year ended December 31, 2012.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS
	Under FASB Accounting Standards Codification Topic 820, Fair Value Measurements and Disclosures, based on the observability of the inputs used in the valuation techniques used to determine the fair value of certain financial assets and liabilities, the Company is required to provide the following information according to the fair value hierarchy. The fair value hierarchy ranks the quality and reliability of the information used to determine fair values.
	In general, fair values determined by Level 1 inputs utilize quoted prices (unadjusted) in active markets for identical assets or liabilities. Fair values determined by Level 2 inputs utilize 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 related assets or liabilities. Fair values determined by Level 3 inputs are unobservable data points for the asset or liability, and include situations where there is little, if any, market activity for the asset or liability. The following table presents information about the Company’s financial assets and liabilities that have been measured at fair value on a recurring basis as of December 31, 2014 and 2013, and indicates the fair value hierarchy of the valuation inputs utilized to determine such fair value (in thousands):
	Description		Fair Value				Quoted				Significant
			as of				Prices in				Other
			December 31,				Active				Observable
			2014				Markets				Inputs
							(Level 1)				(Level 2)
	Assets:
	Cash and cash equivalents and restricted cash		$	129,507			$	129,507			$	—
	Available-for-sale investments (1)		16,289				16,289				—
	Foreign exchange forward contracts (2)		11,079				—				11,079
	Assets measured at fair value at December 31, 2014		$	156,875			$	145,796			$	11,079
	Liabilities:
	Foreign exchange forward contracts (3)		2,139				—				2,139
	Liabilities measured at fair value at December 31, 2014		$	2,139			$	—			$	2,139
	Description		Fair Value				Quoted				Significant
			as of				Prices in				Other
			December 31,				Active				Observable
			2013				Markets				Inputs
							(Level 1)				(Level 2)
	Assets:
	Cash and cash equivalents and restricted cash		$	206,401			$	206,401			$	—
	Available-for-sale investments (1)		14,048				14,048				—
	Foreign exchange forward contracts (2)		1,730				—				1,730
	Assets measured at fair value at December 31, 2013		$	222,179			$	220,449			$	1,730
	Liabilities:
	Foreign exchange forward contracts (3)		7,237				—				7,237
	Liabilities measured at fair value at December 31, 2013		$	7,237			$	—			$	7,237
	_______________________________
	-1	Included in “Short-term investments” on the Company’s Consolidated Balance Sheets.
	-2	Included in “Prepaid expenses and other current assets” and “Other non-current assets” on the Company’s Consolidated Balance Sheets.
	-3	Included in “Other accrued liabilities” and “Other non-current liabilities” on the Company’s Consolidated Balance Sheets.
	Foreign Currency Derivatives
	The Company may enter into foreign currency derivatives to hedge future cash receipts on certain sales transactions that are payable in foreign currencies.
	As of December 31, 2014 and 2013, the Company had outstanding forward contracts which were designated as cash flow hedges of anticipated future cash receipts on sales contracts payable in foreign currencies. The outstanding notional amounts were approximately (in millions):
		31-Dec-14			31-Dec-13
	British Pounds (GBP)	77.9			36.4
	Euros (EUR)	40.7			53
	Swiss Francs (CHF)	0.9			5.6
	Canadian Dollars (CAD)	—			3.9
	Japanese Yen (JPY)	—			1,239.80
	Singapore Dollars (SGD)	0.1			3.2
	Swedish Krona (SEK)	84.8			—
	The Company had hedged foreign currency exposure of approximately $192.5 million and $151.4 million as of December 31, 2014 and December 31, 2013, respectively. Cash receipts associated with the hedged contracts are expected to be received from 2015 through 2018, during which time the revenue on the associated sales contracts is expected to be recognized, or in the case of receivables denominated in a foreign currency, the receivables balances will be collected. Any gain or loss on hedged foreign currency will be recognized at the time of customer acceptance or over the period during which hedged receivables denominated in a foreign currency are outstanding.
	As of December 31, 2014, the Company had outstanding forward contracts which were not designated as cash flow hedges with notional amounts of 28.3 million British Pounds. The foreign currency exposure related to these contracts was approximately $43.4 million. The Company had no outstanding forward contracts which were not designated as cash flow hedges as of December 31, 2013.
	As of December 31, 2014 and 2013, the fair value of outstanding forward contracts totaled a net gain of $8.9 million and a net loss of $5.5 million, respectively. As of December 31, 2014 and 2013, unrecognized gains, net of tax, of $4.4 million and unrecognized losses, net of tax, of $2.4 million, respectively, were included in “Accumulated other comprehensive income” on the Company’s Consolidated Balance Sheets.
	Fair values of derivative instruments (in thousands):
	Hedge Classification	Balance Sheet Location		Fair Value				Fair Value
				as of				as of
				December 31,				December 31,
				2014				2013
	Foreign currency contracts	Prepaid expenses and other current assets		$	5,362			$	1,654
	Foreign currency contracts	Other non-current assets		5,717				76
	Foreign currency contracts	Other accrued liabilities		(1,454		)		(2,942		)
	Foreign currency contracts	Other non-current liabilities		(685		)		(4,295		)
	Total fair value of derivatives classified as hedging instruments			$	8,940			$	(5,507	)

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2014
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income	ACCUMULATED OTHER COMPREHENSIVE INCOME
	The following table shows the gross and net of tax reclassification adjustments from accumulated other comprehensive income resulting from hedged foreign currency transactions recorded by the Company for the years ended December 31, 2014, 2013 and 2012 (in thousands). The gross reclassification adjustments increased product revenue for the years ended December 31, 2014 and 2012 and decreased product revenue for the year ended December 31, 2013.
			Year Ended
			December 31,
			2014			2013				2012
	Gross of Tax Reclassifications		$	2,748		$	(1,604	)		$	643
	Net of Tax Reclassifications		$	1,649		$	(962	)		$	386
	The following tables show the changes in Accumulated Other Comprehensive Income by component for the years ended December 31, 2014 and 2013 (in thousands):
	Year Ended December 31, 2014
		Unrealized Gain on Investments			Foreign Currency Translation Adjustments				Unrealized Gain/(Loss) on Cash Flow Hedges			Accumulated Other Comprehensive Income
	Beginning balance	$	—		$	3,257			$	(2,404	)	$	853
	Current-period change, net of tax	$	12		$	(1,188	)		$	6,826		$	5,650
	Ending balance	$	12		$	2,069			$	4,422		$	6,503
	Income tax expense (benefit) associated with current-period change	$	8		$	(229	)		$	4,593		$	4,372
	Year Ended December 31, 2013
		Unrealized Gain/(Loss) on Investments			Foreign Currency Translation Adjustments				Unrealized Gain/(Loss) on Cash Flow Hedges			Accumulated Other Comprehensive Income
	Beginning balance	$	(46	)	$	4,301			$	926		$	5,181
	Current-period change, net of tax	$	46		$	(1,044	)		$	(3,330	)	$	(4,328	)
	Ending balance	$	—		$	3,257			$	(2,404	)	$	853
	Income tax expense (benefit) associated with current-period change	$	31		$	27			$	(2,390	)	$	(2,332	)

Investments

Investments	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Investments	INVESTMENTS
	The Company’s investments in debt securities with maturities at purchase greater than three months are classified as “available-for-sale.”  Changes in fair value are reflected in other comprehensive income. The carrying amount of the Company’s investments in available-for-sale securities as of December 31, 2014 and December 31, 2013 are shown in the table below (in thousands):
		31-Dec-14		31-Dec-13
	Short-term available-for-sale securities cost	$	16,269	$	14,048
	Short-term available-for-sale securities unrealized gains	20		—
	Short-term available-for-sale securities fair value	$	16,289	$	14,048
	As of December 31, 2014, the Company’s debt securities were investment grade and carried a long-term rating of A2/A or higher.

Accounts_and_Other_Receivables

Accounts and Other Receivables, Net	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Accounts and Other Receivables, Net	ACCOUNTS AND OTHER RECEIVABLES, NET
	A summary of net accounts and other receivables follows (in thousands):
		December 31,
		2014			2013
	Trade accounts receivable	$	126,874		$	169,417
	Unbilled receivables	20,788			9,075
	Advance billings	4,960			2,141
	Short-term investment in sales-type lease	10,187			—
	Other receivables	2,401			2,051
		165,210			182,684
	Allowance for doubtful accounts	(97		)	(157		)
	Accounts and other receivables, net	$	165,113		$	182,527
	Unbilled receivables represent amounts where the Company has recognized revenue in advance of the contractual billing terms. Advance billings represent billings made based on contractual terms for which no revenue has yet been recognized.
	As of December 31, 2014 and 2013, accounts receivable included $87.0 million and $111.9 million, respectively, due from the U.S. Government. Of these amounts, $2.1 million and $0.3 million, respectively, were unbilled, based upon contractual billing arrangements with these customers. As of December 31, 2014 and 2013, no non-U.S. Government customers accounted for more than 10% of total accounts and other receivables.

Salestype_lease

Sales-type lease	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Sales-type lease	NOTE 9    SALES-TYPE LEASE
	As of December 31, 2014, the Company has a sales-type lease with one of its customers. Under the terms of the arrangement, the Company has agreed to provide a high performance computing solution to the customer for a term of four years, beginning at the customer’s acceptance of the system.
	The following table shows the components of the net investment in the sales-type lease as of December 31, 2014 (in thousands):
	Total minimum lease payments to be received	$	53,134
	Less: executory costs	(10,717		)
	Net minimum lease payments receivable	42,417
	Estimated residual value of leased property (unguaranteed)	1,253
	Less: unearned income	(2,394		)
	Net investment in sales-type lease	41,276
	Less: long-term investment in sales-type lease	(31,089		)
	Investment in sales-type lease included in accounts and other receivables	$	10,187
	As of December 31, 2014, minimum lease payments for each of the succeeding four fiscal years are as follows (in thousands):
	2015	$	14,169
	2016	14,169
	2017	14,169
	2018	10,627
	Total minimum lease payments to be received	$	53,134

Inventory

Inventory	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventory	INVENTORY
	A summary of inventory follows (in thousands):
		31-Dec
		2014		2013
	Components and subassemblies	$	60,851	$	46,339
	Work in process	46,954		23,618
	Finished goods	35,827		25,172
		$	143,632	$	95,129
	As of December 31, 2014 and 2013, $35.3 million and $24.8 million, respectively, of finished goods inventory was located at customer sites pending acceptance. At December 31, 2014, two customers accounted for $31.2 million of finished goods inventory. At December 31, 2013, one customer accounted for $18.0 million of finished goods inventory.
	During 2014, 2013 and 2012, the Company wrote-off $2.3 million, $0.9 million and $2.3 million related to various product lines.

Property_and_Equipment_Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	PROPERTY AND EQUIPMENT, NET
	A summary of property and equipment follows (in thousands):
		December 31,
		2014			2013
	Land	$	275		$	203
	Buildings	20,409			17,022
	Furniture and equipment	13,198			14,443
	Computer equipment	59,785			91,475
	Leasehold improvements	446			1,276
		94,113			124,419
	Accumulated depreciation and amortization	(59,320		)	(94,141		)
	Property and equipment, net	$	34,793		$	30,278
	Depreciation expense on property and equipment for 2014, 2013 and 2012 was $12.8 million, $10.9 million and $7.4 million, respectively.

Service_Spares_Net

Service Spares, Net	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Service Spares, Net	SERVICE SPARES, NET
	A summary of service spares follows (in thousands):
		December 31,
		2014			2013
	Service spares	$	13,114		$	16,613
	Accumulated depreciation	(11,246		)	(14,785		)
	Service spares, net	$	1,868		$	1,828
	Depreciation expense on service spares for 2014, 2013 and 2012 was $1.0 million, $0.9 million and $0.9 million, respectively.

Deferred_Revenue

Deferred Revenue	12 Months Ended
	Dec. 31, 2014
Deferred Revenue Disclosure [Abstract]
Deferred Revenue	DEFERRED REVENUE
	Deferred revenue consisted of the following (in thousands):
		31-Dec
		2014			2013
	Deferred product revenue	$	21,152		$	54,065
	Deferred service revenue	92,346			87,900
	Total deferred revenue	113,498			141,965
	Less long-term deferred revenue	(47,588		)	(50,477		)
	Deferred revenue in current liabilities	$	65,910		$	91,488
	As of December 31, 2014 and 2013 the U.S. Government accounted for $63.8 million and $49.2 million of total deferred revenue. As of December 31, 2013, two non-U.S. Government customers accounted for $52.0 million of total deferred revenue. As of December 31, 2014, no non-U.S. Government customers accounted for more than 10% of total deferred revenue.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES
	The Company has recorded rent expense under leases for buildings or office space, which are accounted for as operating leases, in 2014, 2013 and 2012 of $5.2 million, $5.3 million, and $4.6 million, respectively.
	Minimum contractual commitments as of December 31, 2014, were as follows (in thousands):
		Operating		Development
		Leases		Agreements
	2015	$	5,097	$	6,856
	2016	4,762		25
	2017	4,563		25
	2018	4,373		25
	2019	4,266		25
	Thereafter	14,563		—
	Minimum contractual commitments	$	37,624	$	6,956
	In its normal course of operations, the Company engages in development arrangements under which it hires outside engineering resources to augment its existing internal staff in order to complete research and development projects, or parts thereof. For the years ended December 31, 2014, 2013 and 2012, the Company incurred $12.2 million, $9.3 million and $4.9 million for such arrangements, respectively.
	Litigation
	From time to time, the Company is subject to various legal proceedings that arise in the ordinary course of business, none of which are currently material to the Company’s business.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES
	Income taxes are recognized for the amount of taxes payable for the current year and for the impact of deferred tax assets and liabilities, which represent consequences of events that have been recognized differently in the financial statements under GAAP than for tax purposes.
	Most of the Company’s deferred tax assets result from net operating loss carryforwards and research and development tax credits. As of December 31, 2014, the Company had U.S. federal net operating loss carryforwards of approximately $115.4 million, of which approximately $37.9 million was related to stock-based income tax deductions in excess of amounts that have been recognized for financial reporting purposes. Any reduction of taxes payable for stock-based income tax deductions in excess of amounts that have been recognized for financial reporting purposes will be directly credited to shareholders’ equity. As of December 31, 2014, the Company had federal research and development tax credit carryforwards of approximately $21.3 million. The federal net operating loss carryforwards will expire from 2019 through 2031, and the research and development tax credits will expire from 2021 through 2034 if not utilized. Utilization of the Company’s federal net operating loss and research and development tax credit carryforwards generated prior to May 10, 2001 are limited under Section 382 of the Internal Revenue Code. As of December 31, 2014, the Company had approximately $7.0 million of foreign net operating loss carryforwards in various jurisdictions. Most of the Company’s foreign net operating losses can be carried forward indefinitely, with certain amounts expiring from 2016 to 2022.
	Income before income taxes consisted of the following (in thousands):
			Year Ended December 31,
			2014			2013			2012
	United States		$	5,710		$	17,467		$	161,592
	International		3,987			3,562			7,140
	Total		$	9,697		$	21,029		$	168,732
	The tax provision (benefit) for income taxes related to operations consisted of the following (in thousands):
			Year Ended December 31,
			2014			2013			2012
	Current provision (benefit):
	Federal		$	230		$	484		$	1,162
	State		(392		)	696			2,768
	Foreign		740			801			541
	Total current provision		578			1,981			4,471
	Deferred (benefit) provision:
	Federal		(53,242		)	(13,160		)	1,362
	State		(885		)	(327		)	1,415
	Foreign		923			312			243
	Total deferred (benefit) provision		(53,204		)	(13,175		)	3,020
	Total (benefit) provision for income taxes		$	(52,626	)	$	(11,194	)	$	7,491
	The tax provision (benefit) differs from the amount computed by applying the federal statutory income tax rate as follows (in thousands):
			Year Ended December 31,
			2014			2013			2012
	Income tax provision at statutory rate		$	3,394		$	7,360		$	59,056
	State taxes, net of federal benefit		(217		)	369			4,183
	Foreign income taxes		284			(749		)	(518		)
	Stock compensation adjustment		—			(8,419		)	—
	Deemed dividends for U.S. income tax purposes		492			477			2,352
	Nondeductible expenses		337			208			549
	Liquidation of subsidiary		—			—			(30,704		)
	Disallowed compensation		(116		)	19			492
	Research and development tax credit		(1,140		)	(5,736		)	—
	Effect of change in valuation allowance on deferred tax assets		(55,660		)	(4,723		)	(27,919		)
	Effective income tax provision (benefit)		$	(52,626	)	$	(11,194	)	$	7,491
	Significant components of the Company’s deferred income tax assets and liabilities follow (in thousands):
			December 31,
			2014			2013
	Current:
	Deferred Income Tax Assets
	Inventory		$	5,840		$	3,388
	Accrued compensation		681			460
	Deferred revenue		18,186			12,100
	Net operating loss carryforwards		12,981			5,922
	Other		1,261			8,120
	Gross current deferred tax assets		38,949			29,990
	Valuation allowance		(2,039		)	(20,107		)
	Current deferred tax assets		36,910			9,883
	Deferred Income Tax Liabilities
	Other		(837		)	(688		)
	Current deferred tax liabilities		(837		)	(688		)
	Net current deferred tax assets		$	36,073		$	9,195
	Long-Term:
	Deferred Income Tax Assets
	Property and equipment		$	11,555		$	328
	Research and experimentation credit carryforwards		24,596			23,941
	Net operating loss carryforwards		21,511			47,154
	Goodwill		203			628
	Other		9,967			10,161
	Gross long-term deferred tax assets		67,832			82,212
	Valuation allowance		(8,099		)	(57,687		)
	Long-term deferred tax assets		59,733			24,525
Deferred Income Tax Liabilities
Property and equipment		—			(1,905		)
Investment in sales-type lease, net		(14,321		)	—
Intangible assets		(1,215		)	(2,059		)
Other		(2,783		)	(1,355		)
Long-term deferred tax liabilities		(18,319		)	(5,319		)
Net long-term deferred tax asset		$	41,414		$	19,206
The Company recorded an income tax benefit of $52.6 million and $11.2 million for the years ended December 31, 2014 and 2013, respectively, and income tax expense of $7.5 million during the year ended December 31, 2012. The tax benefit recorded by the Company during the year ended December 31, 2014 was primarily attributable to a partial reduction, in the amount of $55.7 million, of the remaining valuation allowance that was held against the Company’s U.S. deferred tax assets. The tax benefit recorded by the Company during the year ended December 31, 2013 was primarily attributable to a partial reduction, in the amount of $13.5 million, of the valuation allowance held against the Company’s U.S. deferred tax assets. The primary reason for the difference between the income tax provision at the statutory rate and the Company’s effective income tax provision for the year ended December 31, 2012 is that the gain from the sale of the Company’s interconnect hardware development program did not result in significant income tax expense. The Company had existing deferred tax assets that were subject to valuation allowances and deductible temporary differences that were previously unrecognized. The sale of the interconnect hardware development program was never anticipated in previous evaluations of the realizability of the Company’s deferred tax assets and consequently the sale, together with a tax benefit that was recognized as a result of a restructuring of a subsidiary, resulted in the Company’s ability to experience a relatively small tax consequence from the sale.
The Company’s decision to partially reduce, in the amount of $55.7 million, the valuation allowance held against the Company’s U.S. deferred tax assets during the year ended December 31, 2014 was based upon an evaluation of all available positive and negative evidence, known business risks and industry trends. The Company considers its actual results over several years to have stronger weight than other more subjective indicators, including forecasts, when considering whether or not to establish or reduce a valuation allowance on deferred tax assets and believes that its ability to forecast results significantly into the future is severely limited due to the rapid rate of technological and competitive change in the industry in which it operates. As of December 31, 2014 the Company had generated U.S. pre-tax income in each of the last three years and cumulative U.S. pre-tax income of $184.8 million ($51.1 million excluding the impact of the sale of the Company’s interconnect hardware development program) over the last three years. In addition to the Company’s cumulative income position, the assessment of the Company’s ability to utilize its U.S. deferred tax assets included an assessment of forecasted domestic and international earnings over a number of years, which included the impact of several major contracts that were finalized during the fourth quarter of 2014.
The partial reduction, in the amount of $13.5 million, of the valuation allowance held against the Company’s U.S. deferred tax assets during the year ended December 31, 2013 was due to actual income from operations during the year ended December 31, 2013 exceeding amounts previously used in the evaluation of the realizability of the Company’s deferred tax assets at the beginning of the year and based upon an assessment of all positive and negative evidence relating to future years.
During the year ended December 31, 2012 the Company reduced the valuation allowance held against its deferred tax assets by $18.4 million as a result of the sale of the Company’s interconnect hardware development program. The Company further reduced the valuation allowance held against its U.S. deferred tax assets by $10.7 million during the year ended December 31, 2012 due to actual income from operations during the year ended December 31, 2012 exceeding amounts previously used in the evaluation of the realizability of the Company’s deferred tax assets at the beginning of the year and based upon an assessment of all positive and negative evidence relating to future years.
The Company’s conclusion about the realizability of its deferred tax assets, and therefore the appropriateness of the valuation allowance, is reviewed quarterly and could change in future periods depending on the Company’s future assessment of all available evidence in support of the likelihood of realization of its deferred tax assets. If the Company’s conclusion about the realizability of its deferred tax assets and therefore the appropriateness of its valuation allowance changes in a future period it could record a substantial tax provision or benefit in the Consolidated Statement of Operations when that occurs.
The valuation allowance on deferred tax assets decreased by $67.7 million, $4.7 million and $27.9 million in 2014, 2013 and 2012, respectively. The decrease in the valuation allowance for the year ended December 31, 2014 included a reduction, in the amount of $55.7 million, of the valuation allowance held against the Company’s U.S. deferred tax assets based upon an assessment of all positive and negative evidence relating to future years. The decrease in the valuation allowance for the year ended December 31, 2013 was comprised of the partial reduction of the valuation allowance of $13.5 million which was principally offset by a stock compensation related adjustment of $8.4 million.
Undistributed earnings relating to the Company’s foreign subsidiaries are considered to be permanently reinvested; accordingly, no provision for U.S. federal and state income taxes has been provided thereon. Upon repatriation of those earnings, in the form of dividends or otherwise, the Company would be subject to both U.S. income taxes (subject to an adjustment for foreign tax credits) and withholding taxes payable to the various foreign countries. Determination of the amount of unrecognized deferred U.S. income tax liability is not practicable due to the complexities associated with this hypothetical calculation. As of December 31, 2014, the Company’s foreign subsidiaries held cash in the amount of $42.2 million.
The following table summarizes changes in the amount of the Company’s unrecognized tax benefits for uncertain tax positions for the three years ended December 31, 2014, 2013 and 2012 (in thousands):
Balance at December 31, 2011	$	—
Increase related to current year income tax positions	470
Balance at December 31, 2012	$	470
Decrease related to prior year income tax positions	(268		)
Balance at December 31, 2013	$	202
Increase related to prior year income tax positions	5,059
Increase related to current year income tax positions	369
Balance at December 31, 2014	$	5,630
The balance of unrecognized tax benefits as of December 31, 2014 was $5.6 million of tax benefits that, if recognized, would affect the effective tax rate. It is not anticipated that the balance of unrecognized tax benefits will significantly change over the next twelve months.
The Company or its subsidiaries file income tax returns in the U.S. federal jurisdiction and various state and foreign jurisdictions. The Company defines its major tax jurisdictions to include Australia, Germany, the United Kingdom and the United States. The Company is no longer subject to income tax examinations with respect to Australia for periods before 2009 and for periods before 2013 in Germany and the United Kingdom, respectively. With respect to the U.S. federal and various state jurisdictions the Company is no longer subject to income tax examinations with respect to periods before 2011, although in such jurisdictions net operating loss and tax credit carryforwards generated in a year are subject to examination and adjustment for at least three years following the year in which such losses or credits are actually used to offset taxable income.
Estimated interest and penalties are recorded as a component of interest expense and other expense, respectively. Such amounts were not material for 2014, 2013 and 2012.

Lines_of_Credit

Lines of Credit	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Credit Facilities	CREDIT FACILITIES
	As of December 31, 2014, the Company had a $10.0 million unsecured line of credit with Wells Fargo Bank, National Association and an $11.0 million letter of credit facility with Silicon Valley Bank. Both facilities are designed to support the issuance of letters of credit and foreign exchange hedging transactions. The Wells Fargo Bank, National Association credit facility matures in October 2015 and the Silicon Valley Bank credit facility matures in December 2015. The Company made no draws and had no outstanding cash borrowings on any credit facilities as of December 31, 2014.
	As of December 31, 2014, the Company had $13.5 million in outstanding letters of credit and $16.9 million in restricted cash associated with certain letters of credit to secure customer prepayments and other customer related obligations.

Shareholders_Equity

Shareholders' Equity	12 Months Ended
	Dec. 31, 2014
Share-based Compensation [Abstract]
Shareholders' Equity	SHAREHOLDERS’ EQUITY
	Preferred Stock:    The Company has 5,000,000 shares of undesignated preferred stock authorized, and no shares of preferred stock outstanding.
	Common Stock:    The Company has 75,000,000 authorized shares of common stock with a par value of $0.01 per share.
	Restricted Stock and Restricted Stock Units:    During 2014, 2013 and 2012, respectively, the Company issued an aggregate of 463,734, 755,979, and 1,316,447 shares of restricted stock, respectively, to certain directors, executives and other employees. The grant date fair value of these grants was approximately $13.3 million, $15.8 million, and $15.8 million for 2014, 2013 and 2012, respectively. Stock compensation expense is recorded over the vesting period, which has generally been two years for non-employee directors and four years for officers and employees of the Company. As of December 31, 2014, $24.0 million remains to be expensed over the remaining vesting periods of these grants. This includes $12.4 million for performance vesting restricted stock subject to performance measures which are currently not considered probable to vest and $0.2 million for performance vesting restricted stock subject to performance measures which currently are considered probable to vest. No compensation expense is recognized for performance vesting restricted stock subject to performance measures that are not yet considered probable of attainment.
	As of December 31, 2012, the Company had issued and outstanding 12,500 restricted stock units. There were no restricted stock units issued and outstanding as of December 31, 2014 and 2013. Restricted stock units have similar vesting characteristics as restricted stock but are not outstanding shares and do not have any voting or dividend rights. The Company records stock-based compensation expense over the vesting period. Once a restricted stock unit vests, a share of common stock of the Company will be issued.
	Stock Option Plans:    As of December 31, 2014, the Company had one active equity incentive plan that provides shares available for option grants to employees, directors, executives and others. Options granted to employees under the Company’s equity incentive plan typically vest over four years or as otherwise determined by the plan administrator. Options to purchase shares expire no later than ten years after the date of grant.
	In determining the fair value of stock options, the Company used the Black-Scholes option pricing model that employed the following key weighted average assumptions:
			2014				2013				2012
	Risk-free interest rate		1.22		%		0.98		%		0.56		%
	Expected dividend yield		—		%		—		%		—		%
	Volatility		52.43		%		50.45		%		74.84		%
	Expected life (in years)		4				4				4
	Weighted average Black-Scholes value of options granted		$	11.16			$	8.22			$	6.56
	The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant. The Company does not anticipate declaring dividends in the foreseeable future. Volatility is based on historical data. The expected life of an option was based on the assumption that options will be exercised, on average, about two years after vesting occurs. The Company recognizes compensation expense for only the portion of options or stock units that are expected to vest. Therefore, management applies an estimated forfeiture rate that is derived from historical employee termination data and adjusted for expected future employee turnover rates. The estimated forfeiture rates applied for the years ended December 31, 2014, 2013 and 2012 were 8.3%, 10.0%, and 6.6%, respectively. If the actual number of forfeitures differs from those estimated by management, additional adjustments to compensation expense may be required in future periods. The Company’s stock price volatility, option lives and expected forfeiture rates involve management’s best estimates at the time of such determination, all of which impact the fair value of the option calculated under the Black-Scholes methodology and, ultimately, the expense that will be recognized over the life of the option.
	A summary of the Company’s stock option activity and related information follows:
			Options			Weighted				Weighted Average Remaining
						Average				Contractual
						Exercise				Term (Years)
						Price
	Outstanding at January 1, 2012		3,417,920			$	6.28
	Granted		359,500			11.9
	Exercised		(1,346,326	)		5.52
	Canceled and forfeited		(137,589	)		11.35
	Outstanding at December 31, 2012		2,293,505			7.31
	Granted		346,360			20.65
	Exercised		(495,221	)		6.38
	Canceled and forfeited		(66,575	)		21.97
	Outstanding at December 31, 2013		2,078,069			9.29
	Granted		323,900			26.92
	Exercised		(411,352	)		7.5
	Canceled and forfeited		(59,627	)		18.45
	Outstanding at December 31, 2014		1,930,990			12.34				6.6
	Exercisable at December 31, 2014		1,251,080			8.18				5.6
	Available for grant at December 31, 2014		3,079,888
	As of December 31, 2014, there was $42.8 million of aggregate intrinsic value of outstanding stock options, including $32.9 million of aggregate intrinsic value of exercisable stock options. Intrinsic value is the total pretax intrinsic value for all “in-the-money” options (i.e., the difference between the Company’s closing stock price on the last trading day of 2014 and the exercise price, multiplied by the number of shares) that would have been received by the option holders had all option holders exercised their options as of December 31, 2014. This amount changes, based on the fair market value of the Company’s stock. Total intrinsic value of options exercised was $10.2 million, $7.9 million, and $7.6 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	A summary of the Company’s unvested restricted stock and restricted stock unit grants and changes during the years ended December 31 was as follows:
		Service Vesting Restricted Shares							Performance Vesting Restricted Shares						Total Restricted Shares
		Shares			Weighted				Shares			Weighted			Shares		Weighted Average Grant Date Fair Value
					Average							Average
					Grant Date							Grant Date
					Fair Value							Fair Value
	Outstanding at January 1, 2012	1,302,414			$	5.47			—			$	—		1,302,414		$	5.47
	Granted	579,447			10.84				737,000			12.9			1,316,447		11.99
	Forfeited	(31,771	)		7.64				—			—			(31,771	)	7.64
	Vested	(384,352	)		5.86				—			—			(384,352	)	5.86
	Outstanding at December 31, 2012	1,465,738			7.44				737,000			12.9			2,202,738		9.27
	Granted	326,979			20.83				429,000			21			755,979		20.93
	Forfeited	(3,437	)		5.92				(72,000	)		14.88			(75,437	)	14.48
	Vested	(661,580	)		6.22				—			—			(661,580	)	6.22
	Outstanding at December 31, 2013	1,127,700			12.05				1,094,000			15.94			2,221,700		13.97
	Granted	463,734			28.74				—			—			463,734		28.74
	Forfeited	(134,653	)		15.39				(277,000	)		17.49			(411,653	)	16.8
	Vested	(423,179	)		11.14				—			—			(423,179	)	11.14
	Outstanding at December 31, 2014	1,033,602			19.48				817,000			15.41			1,850,602		17.68
	The estimated forfeiture rate applied to the Company’s restricted stock grants during the year ended December 31, 2014 was 6.3%. The total number of restricted shares outstanding as of December 31, 2014, 2013 and 2012 included 804,500, 1,081,500 and 737,000 performance vesting restricted shares subject to performance conditions that are currently not considered probable of vesting, respectively.
	The aggregate fair value of restricted shares vested during 2014, 2013 and 2012 was $11.9 million, $14.0 million, and $4.2 million, respectively.
	As of December 31, 2014, the Company had $29.4 million of total unrecognized compensation cost related to unvested stock options and unvested restricted stock grants. Excluding the $12.4 million for performance vesting restricted stock subject to performance measures which are currently not considered probable to vest, unrecognized compensation cost was $17.0 million. No compensation expense is recorded for performance vesting restricted stock subject to performance measures which are not yet considered probable of attainment. Unrecognized compensation cost related to unvested stock options and unvested restricted stock grants considered probable of vesting is expected to be recognized over a weighted average period of 2.9 years.
	Outstanding and exercisable options by price range as of December 31, 2014, were as follows:
			Outstanding Options									Exercisable Options
	Range of Exercise		Number			Weighted		Weighted				Number		Weighted
	Prices per Share		Outstanding			Average		Average				Exercisable		Average
						Remaining		Exercise						Exercise
						Life (Years)		Price						Price
	$ 0.00 - $ 4.00		265,142			4.3		$	3.71			265,142		$	3.71
$ 4.01 - $ 6.00		240,647			5.1		$	5.49			240,647		$	5.49
$ 6.01 - $ 8.00		438,159			5.7		$	6.29			360,553		$	6.33
$ 8.01 - $ 34.15		987,042			8.1		$	19.01			384,738		$	14.68
$ 0.00 - $ 34.15		1,930,990			6.6		$	12.34			1,251,080		$	8.18
The following table (in thousands) sets forth the share-based compensation cost resulting from stock options and stock grants recorded in the Company’s Consolidated Statements of Operations for the years ended December 31, 2014, 2013 and 2012.
		2014				2013				2012
Cost of product revenue		$	229			$	135			$	57
Cost of service revenue		255				229				258
Research and development		2,721				1,480				1,327
Sales and marketing		3,152				2,230				1,717
General and administrative		4,007				3,165				2,604
Total share-based compensation expense		$	10,364			$	7,239			$	5,963
Employee Stock Purchase Plan (ESPP):    Under the Company’s non-compensatory employee stock purchase plan, the maximum number of shares of the Company’s common stock that employees could acquire under the ESPP is 1,750,000 shares. Eligible employees are permitted to acquire shares of the Company’s common stock through payroll deductions not exceeding 15% of base wages. The purchase price per share under the ESPP is 95% of the closing market price on the fourth business day after the end of each offering period. As of December 31, 2014, 2013 and 2012, 1,043,228, 1,022,610 and 998,118 shares, respectively, had been issued under the ESPP.

Benefit_Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Benefit Plans	BENEFIT PLANS
	401(k) Plan
	For the three years ended December 31, 2014, the Company’s retirement plan covered substantially all U.S. employees and provided for voluntary salary deferral contributions on a pre-tax basis in accordance with Section 401(k) of the Internal Revenue Code of 1986, as amended. The Company matches a portion of employee contributions. The 2014, 2013 and 2012 Company match expense was $1.6 million, $1.2 million and $1.0 million, respectively.
	Pension Plan
	The Company’s German subsidiary maintains a defined benefit pension plan. At December 31, 2014, the excess of plan assets over the projected benefit obligation of $2.3 million was $0.2 million. At December 31, 2013, the excess of plan assets over the projected benefit obligation of $2.6 million was $0.2 million. Plan assets are invested in insurance policies payable to employees. Net pension expense was not material for any period. Contributions to the plan are not expected to be significant to the financial position of the Company.

Segment_Information

Segment Information	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION
	The Company has the following reportable segments: Supercomputing (formerly HPC Systems), Storage and Data Management, Maintenance and Support and Engineering Services and Other. The Company’s segment presentation changed beginning January 1, 2014 to be consistent with information now provided to its Chief Executive Officer, who is the Company’s Chief Operating Decision Maker. This information has been modified to include inter-segment revenue and gross profit from Maintenance and Support services in Supercomputing and Storage and Data Management resulting from the sales of products in these segments. The prior period financial information has been reclassified to conform to the current period’s presentation.
	The Company’s reportable segments represent components of the Company for which separate financial information is available that is utilized on a regular basis by the Chief Executive Officer, who is the Chief Operating Decision Maker, in determining how to allocate the Company’s resources and evaluate performance. The segments are determined based on several factors, including the Company’s internal operating structure, the manner in which the Company’s operations are managed, client base, similar economic characteristics and the availability of separate financial information.
	Supercomputing
	Supercomputing includes a suite of highly advanced supercomputers and cluster systems which are used by single users all the way up through large research and engineering centers in universities, government laboratories, and commercial institutions. Supercomputing also includes the ongoing maintenance of these systems as well as system analysts.
	Storage and Data Management
	Storage and Data Management offers the Cray Sonexion and Tiered Adaptive Storage solution as well as other third-party storage products and their ongoing maintenance as well as system analysts.
	Maintenance and Support
	Maintenance and Support provides ongoing maintenance of Cray supercomputers, big data storage and analytics systems, as well as system analysts.
	Engineering Services and Other
	Included within Engineering Services and Other is the Company’s analytics business and Custom Engineering.
	The following table presents revenues and gross margin for the Company’s operating segments for the years ended December 31 (in thousands):
		2014			2013			2012
	Revenue:
	Supercomputing	$	459,729		$	434,133		$	355,736
	Storage and Data Management	84,412			76,955			55,009
	Maintenance and Support	86,573			77,817			62,245
	Engineering Services and Other	17,465			14,661			10,313
	Elimination of inter-segment revenue	(86,573		)	(77,817		)	(62,245		)
	Total revenue	$	561,606		$	525,749		$	421,058
	Gross Profit:
	Supercomputing	$	146,565		$	143,440		$	128,723
	Storage and Data Management	31,572			31,403			16,574
	Maintenance and Support	38,819			38,476			25,735
	Engineering Services and Other	6,277			9,483			5,881
	Elimination of inter-segment gross profit	(38,819		)	(38,476		)	(25,735		)
	Total gross profit	$	184,414		$	184,326		$	151,178
	Revenue and cost of revenue is the only discrete financial information the Company prepares for its segments. Other financial results or assets are not separated by segment.
	The Company’s geographic operations outside the United States include sales and service offices in Canada, Brazil, Europe, Japan, Australia, India, South Korea, the United Arab Emirates, China, Singapore and Taiwan. Product and service revenue and long-lived assets classified by significant country were as follows (in thousands):
		United			All			Total
		States			Other
					Countries
	For the year ended December 31, 2014:
	Product revenue	$	253,930		$	206,818		$	460,748
	Service revenue	$	72,434		$	28,424		$	100,858
	Long-lived assets	$	58,868		$	36,792		$	95,660
	For the year ended December 31, 2013:
	Product revenue	$	297,583		$	138,747		$	436,330
	Service revenue	$	62,072		$	27,347		$	89,419
	Long-lived assets	$	58,910		$	6,146		$	65,056
	For the year ended December 31, 2012:
	Product revenue	$	301,162		$	52,605		$	353,767
	Service revenue	$	42,359		$	24,932		$	67,291
	Long-lived assets	$	57,549		$	4,460		$	62,009
	Long-lived assets as of December 31, 2014 included the $31.1 million long-term investment in sales-type lease which was held by the Company’s UK subsidiary.
	Revenue attributed to foreign countries is derived from sales to customers located outside the United States. Revenue derived from the U.S. Government totaled approximately $272.0 million, $266.1 million and $286.9 million in 2014, 2013 and 2012, respectively. In 2014, no non-U.S. Government customers accounted for more than 10% of total revenue. In 2013, one non-U.S. Government customer accounted for an aggregate of approximately 11% of total revenue. In 2012, one non-U.S. Government customer accounted for an aggregate of approximately 13% of total revenue. In general, concentrations of revenue by customer encompass all segments. In 2014, the UK and Germany accounted for a combined 23% of total revenue. In 2013 and 2012 no foreign country accounted for more than 10% of total revenue.

Research_and_Development

Research and Development	12 Months Ended
	Dec. 31, 2014
Research and Development [Abstract]
Research and Development	RESEARCH AND DEVELOPMENT
	The detail for the Company’s net research and development costs for the years ended December 31 follows (in thousands):
		2014			2013			2012
	Gross research and development expenses	$	104,797		$	92,469		$	86,305
	Less: Amounts included in cost of revenue	(7,713		)	(3,741		)	(1,080		)
	Less: Reimbursed research and development (excludes amounts in revenue)	(3,036		)	(1,000		)	(20,922		)
	Net research and development expenses	$	94,048		$	87,728		$	64,303

Interest_Income_Expense

Interest Income (Expense)	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
Interest Income (Expense)	INTEREST INCOME (EXPENSE)
	The detail of interest income (expense) for the years ended December 31 follows (in thousands):
		2014			2013			2012
	Interest income	$	643		$	894		$	397
	Interest expense	(137		)	(137		)	(193		)
	Net interest income	$	506		$	757		$	204
	Interest income is earned by the Company on cash and cash equivalent, investment balances and the investment in sales-type lease.

Quarterly_Data_Unaudited

Quarterly Data (Unaudited)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Quarterly Data (Unaudited)	QUARTERLY DATA (UNAUDITED)
	The following table presents unaudited quarterly financial information for the two years ended December 31, 2014. In the opinion of management, this information contains all adjustments, consisting only of normal recurring adjustments, necessary for a fair presentation thereof.
	The operating results are not necessarily indicative of results for any future periods. Quarter-to-quarter comparisons should not be relied upon as indicators of future performance. The Company’s business is driven by a few significant contracts and, as a result, the Company’s operating results are subject to very large quarterly fluctuations. The Company’s earnings per share for the full year may not equal the sum of the four quarterly earnings per share amounts because of common share activity during the year.
	(In thousands, except per share data)
			2014										2013
	For the Quarter Ended		31-Mar			30-Jun			30-Sep		31-Dec		31-Mar			30-Jun			30-Sep			31-Dec
	Revenue		$	55,110		$	85,147		$	159,406	$	261,943	$	79,547		$	84,467		$	54,366		$	307,369
	Cost of revenue		37,173			56,143			110,876		173,000		55,397			57,666			33,940			194,420
	Gross profit		17,937			29,004			48,530		88,943		24,150			26,801			20,426			112,949
	Research and development, net		22,621			24,189			22,503		24,735		20,226			19,968			21,555			25,979
	Sales and marketing		11,776			13,259			14,808		17,942		11,143			11,550			11,480			17,172
	General and administrative		5,413			5,316			5,813		6,839		5,485			5,085			4,970			8,063
	Net income (loss) (1)		(12,938		)	(6,748		)	7,371		74,638		(7,609		)	(150		)	(11,025		)	51,007
	Net income (loss) per common share, basic		$	(0.34	)	$	(0.18	)	$	0.19	$	1.92	$	(0.20	)	$	—		$	(0.29	)	$	1.33
	Net income (loss) per common share, diluted		$	(0.34	)	$	(0.18	)	$	0.18	$	1.84	$	(0.20	)	$	—		$	(0.29	)	$	1.27
	-1	The fourth quarter of 2014 includes the impact of the reduction of substantially all of the valuation allowance held against the Company’s U.S. deferred tax assets.

Schedule_II_Valuation_and_Qual

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2014
Valuation and Qualifying Accounts [Abstract]
Schedule of Valuation and Qualifying Accounts	Schedule II — Valuation and Qualifying Accounts(1)
	December 31, 2014
	(In Thousands)
	Description		Balance at		Charge/(Benefit)			Deductions (2)			Balance at
			Beginning		to Expense						End of
			of Period								Period
	Year ended December 31, 2012:
	Allowance for doubtful accounts		$	110	$	(62	)	$	(43	)	$	5
	Year ended December 31, 2013:
	Allowance for doubtful accounts		$	5	$	179		$	(27	)	$	157
	Year ended December 31, 2014:
	Allowance for doubtful accounts		$	157	$	22		$	(82	)	$	97
	-1	The Company does not have any warranty liabilities.
	-2	Deductions represent uncollectible accounts written off, net of recoveries.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation
	The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. Intercompany balances and transactions have been eliminated.
Reclassifications	Reclassifications
	Certain prior year amounts have been reclassified to conform with the current year presentation. There has been no impact on previously reported net income or shareholders’ equity from such reclassifications.
Use of Estimates	Use of Estimates
	The preparation of financial statements in accordance with GAAP requires management to make estimates and assumptions that affect the amounts reported in the Company’s consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates.
Cash, Cash Equivalents and Restricted Cash	Cash, Cash Equivalents and Restricted Cash
	Cash and cash equivalents consist of highly liquid financial instruments that are readily convertible to cash and have maturities of three months or less at the time of acquisition. The Company maintains cash and cash equivalent balances with financial institutions that exceed federally insured limits. As of December 31, 2014, the Company had $16.9 million in short-term restricted cash and as of December 31, 2013, $13.8 million in long-term restricted cash, associated with certain letters of credit outstanding to secure customer prepayments.
Investments	Investments
	The Company’s investments consist primarily of commercial paper, corporate debt, and other debt securities. Debt securities are classified as available-for-sale and are reported at fair value with unrealized gains and losses, net of applicable taxes, recorded in accumulated other comprehensive income, a component of shareholders’ equity. The realized gains and losses for available-for-sale securities are included in other income and expense in the Consolidated Statements of Operations. Realized gains and losses are calculated based on the specific identification method.
	The Company monitors its investment portfolio for impairment on a periodic basis. When the carrying value of an investment in debt securities exceeds its fair value and the decline in value is determined to be an other-than-temporary decline, and when the Company does not intend to sell the debt security and it is not more likely than not that the Company will be required to sell the debt securities prior to recovery of its amortized cost basis, the Company records an impairment charge in the amount of the credit loss and the balance, if any, to other comprehensive income (loss).
	Investments that mature between three months and one year from the purchase date are initially classified as short-term investments in the Consolidated Balance Sheet. Investments that mature beyond one year from the purchase date are initially classified as long-term investments in the Consolidated Balance Sheet.
	The Company’s investments in debt securities with maturities at purchase greater than three months are classified as “available-for-sale.”  Changes in fair value are reflected in other comprehensive income.
Foreign Currency Derivatives	Foreign Currency Derivatives
	The Company uses forward foreign currency exchange contracts to hedge certain foreign currency exposures. Forward contracts are cash flow hedges of the Company’s foreign currency exposures on certain revenue contracts and are recorded at the contract’s fair value. Any gains or losses on the effective portion of the forward contract is initially reported in “Accumulated other comprehensive income,” a component of shareholders’ equity, with a corresponding asset or liability recorded based on the fair value of the forward contract. When the hedged transaction is recognized, any unrecognized gains or losses on the hedged transaction are reclassified into results of operations in the same period. Any hedge ineffectiveness is recorded to operations in the current period. The Company measures hedge effectiveness by comparing changes in fair values of the forward contract and expected cash flows based on changes in the spot prices of the underlying currencies. Cash flows from forward contracts accounted for as cash flow hedges are classified in the same category as the cash flows from the items being hedged. The Company does not use derivative financial instruments for speculative purposes.
Concentration of Credit Risk	Concentration of Credit Risk
	Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents, available-for-sale investments, accounts receivable, short-term and long-term restricted cash and forward foreign currency exchange contracts.
	The Company maintains cash and cash equivalents, available-for-sale securities and forward contracts with various financial institutions. As part of its risk management process, the Company performs periodic evaluations of the relative credit standing of the financial institutions. The Company has not sustained any credit losses from instruments held at financial institutions. The Company utilizes forward contracts to protect against the effects of foreign currency fluctuations. Such contracts involve the risk of non-performance by the counterparty, which could result in a material loss.
	The Company currently derives a significant portion of its revenue from sales of products and services to different agencies of the U.S. government or commercial customers primarily serving various agencies of the U.S. government. See Note 19 — Segment Information for additional information. Given the type of customers, the Company does not believe its accounts receivable represent significant credit risk.
Other Concentration	Other Concentration
	The Company obtains certain components from single source suppliers due to technology, availability, price, quality or other considerations. The loss of a single source supplier, the single source supplier’s inability to deliver the required components or intellectual property due to natural disaster or other reasons, the deterioration of the relationship with a single source supplier, or any unilateral modification of contract terms under which the Company is supplied components by a single source supplier could have a significant adverse effect on the Company’s revenue and gross margins.
Accounts Receivable	Accounts Receivable
	Accounts receivable are stated at principal amounts and are primarily comprised of amounts contractually due from customers for products and services and amounts due from government research and development contracts. The Company provides an allowance for doubtful accounts based on an evaluation of customer past due account balances. In determining whether to record an allowance for a specific customer, the Company considers a number of factors, including prior payment history and financial information for the customer.
Fair Values of Financial Instruments	Fair Values of Financial Instruments
	The Company measures certain financial assets and liabilities at fair value based on the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants. The Company’s financial instruments primarily consist of debt securities, time deposits, money market funds, and foreign currency derivatives. See Note 5 — Fair Value Measurement for a further discussion on fair value of financial instruments.
Inventories	Inventories
	Inventories are valued at the lower of cost or market, with cost computed on a first-in, first-out basis. The Company regularly evaluates the technological usefulness and anticipated future demand for various inventory components and the expected use of the inventory. When the Company determines it is not likely the cost of inventory items will be recovered through future sales, the Company writes-down the related inventory to its estimated market value.
	In connection with certain of its sales agreements, the Company may receive used equipment from a customer. This inventory generally will be recorded at no value based on the expectation that the Company will not be able to resell or otherwise use the equipment. In the event that the Company has a specific contractual plan for resale at the date the inventory is acquired, the inventory is recorded at its estimated fair value.
Property and Equipment and Intangible Assets	Property and Equipment and Intangible Assets, net
	Property and equipment are recorded at cost less accumulated depreciation and amortization. Additions and improvements are capitalized and maintenance and repairs are expensed as incurred. Depreciation is calculated on a straight-line basis over the estimated useful lives of the related assets, ranging from eighteen months to seven years for furniture and fixtures, three years for computer equipment, and eight to twenty-five years for buildings and land improvements. Leasehold improvements are depreciated over the life of the lease or asset, whichever is shorter.
	The Company amortizes purchased intangible assets with finite lives using the straight-line method over the estimated economic lives of the assets, ranging from two to ten years.
Service Spares	Service Spares
	Service spares are valued at the lower of cost or market and represent inventory used to support service and maintenance agreements with customers. As inventory is utilized, replaced items are returned to the Company and are either repaired or scrapped. Costs incurred to repair inventory to a usable state are charged to expense as incurred. Service spares are recorded at cost and amortized over the estimated service life of the related product platform (generally four years).
Impairment of Long-Lived Assets and Intangibles	Impairment of Long-Lived Assets and Intangibles
	The Company evaluates property, plant and equipment and intangible assets with finite lives for impairment whenever events or changes in circumstances indicate the carrying value of an asset may not be recoverable. The Company assesses the recoverability of the assets based on the undiscounted future cash flow the assets are expected to generate and recognizes an impairment loss when estimated undiscounted future cash flow expected to result from the use of the asset plus net proceeds expected from disposition of the asset, if any, are less than the carrying value of the asset. When the Company identifies an impairment, the carrying value of the asset is reduced to its estimated fair value based on a discounted cash flow approach or, when available and appropriate, to comparable market values.
Goodwill	Goodwill
	Goodwill is not amortized but is tested for impairment at least annually. The Company reviews goodwill for impairment annually at the beginning of its fourth fiscal quarter and whenever events or changes in circumstances indicate the carrying value of the asset may not be recoverable. The goodwill impairment test consists of a two-step process, if necessary. However, the Company first assesses qualitative factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test described in ASC Topic 350. The more likely than not threshold is defined as having a likelihood of more than 50 percent. If, after assessing the totality of events or circumstances, the Company determines that it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing the two-step impairment test is unnecessary and goodwill is considered to be unimpaired. However, if based on the qualitative assessment the Company concludes that it is more likely than not that the fair value of a reporting unit is less than its carrying amount, the Company will proceed with performing the two-step process.
	In step one, the Company determines the fair value of each reporting unit and compares it to its carrying value. If the fair value of the reporting unit exceeds the carrying value of the net assets assigned to that unit, goodwill is not impaired and no further testing is performed. If the carrying value of the net assets assigned to the reporting unit exceeds the fair value of the reporting unit, then the Company must perform the second step of the impairment test in order to determine the implied fair value of the reporting unit’s goodwill. If the carrying value of a reporting unit’s goodwill exceeds its implied fair value, the Company records an impairment loss equal to the difference.
	The Company performed its qualitative assessment during the fourth fiscal quarter of 2014 and concluded that it was more likely than not that the fair values of its reporting units were greater than their carrying amounts. After reaching this conclusion, the two-step impairment test was unnecessary and no further testing was performed. The qualitative factors that were considered included, but were not limited to, general economic conditions, outlook for the HPC and big data markets, recent and forecasted financial performance and the price of the Company’s common stock.
Business Combinations	Business Combinations
	The Company accounts for business combinations using the acquisition method of accounting and allocates the purchase price to the tangible and intangible assets acquired and the liabilities assumed based upon their estimated fair values at the acquisition date. The difference between the purchase price and the fair value of the net assets acquired is recorded as goodwill. The Company uses estimates and assumptions to accurately value assets acquired and liabilities assumed at the acquisition date. During the measurement period, which may be up to one year from the acquisition date, any refinements made to the fair value of the assets and liabilities assumed are recorded with retrospective effect.
	The fair values of intangible assets acquired are estimated using a discounted cash flow approach with Level 3 inputs. Under this method, an intangible asset’s fair value is equal to the present value of the incremental after-tax cash flows (excess earnings) attributable solely to the intangible asset over its remaining useful life. To calculate fair value, the Company uses risk-adjusted cash flows discounted at rates considered appropriate given the inherent risks associated with each type of asset. The Company believes the level and timing of cash flows appropriately reflects market participant assumptions.
Revenue Recognition	Revenue Recognition
	The Company recognizes revenue, including transactions under sales-type leases, when it is realized or realizable and earned. The Company considers revenue realized or realizable and earned when it has persuasive evidence of an arrangement, delivery has occurred, the sales price is fixed or determinable, and collectibility is reasonably assured. Delivery does not occur until the products have been shipped or services provided to the customer, risk of loss has transferred to the customer, and, where applicable, a customer acceptance has been obtained. The sales price is not considered to be fixed or determinable until all material contingencies related to the sales have been resolved. The Company records revenue in the Consolidated Statements of Operations net of any sales, use, value added or certain excise taxes imposed by governmental authorities on specific sales transactions. In addition to the aforementioned general policy, the following are the Company’s statements of policy with regard to multiple-element arrangements and specific revenue recognition policies for each major category of revenue.
	Multiple-Element Arrangements. The Company commonly enters into revenue arrangements that include multiple deliverables of its product and service offerings due to the needs of its customers. Products may be delivered in phases over time periods which can be as long as five years. Maintenance services generally begin upon acceptance of the first equipment delivery and future deliveries of equipment generally have an associated maintenance period. The Company considers the maintenance period to commence upon acceptance of the product or installation in situations where a formal acceptance is not required, which may include a warranty period and accordingly allocates a portion of the arrangement consideration as a separate deliverable which is recognized as service revenue over the entire service period. Other services such as training and engineering services can be delivered as a discrete delivery or over the term of the contract. A multiple-element arrangement is separated into more than one unit of accounting if the following criteria are met:
	•	The delivered item(s) has value to the customer on a standalone basis; and
	•	If the arrangement includes a general right of return relative to the delivered item(s), delivery or performance of the undelivered item(s) is considered probable and substantially in the control of the Company.
	If these criteria are met for each element, the arrangement consideration is allocated to the separate units of accounting based on each unit’s relative selling price. If these criteria are not met, the arrangement is accounted for as one unit of accounting which would result in revenue being recognized ratably over the contract term or being deferred until the earlier of when such criteria are met or when the last undelivered element is delivered.
	The Company follows a selling price hierarchy in determining the best estimate of the selling price of each deliverable. Certain products and services are sold separately in standalone arrangements for which the Company is sometimes able to determine vendor specific objective evidence, or VSOE. The Company determines VSOE based on normal pricing and discounting practices for the product or service when sold separately.
	When the Company is not able to establish VSOE for all deliverables in an arrangement with multiple elements, the Company attempts to establish the selling price of each remaining element based on third-party evidence, or TPE. The Company’s inability to establish VSOE is often due to a relatively small sample of customer contracts that differ in system size and contract terms which can be due to infrequently selling each element separately, not pricing products within a narrow range, or only having a limited sales history, such as in the case of certain advanced and emerging technologies. TPE is determined based on the Company’s prices or competitor prices for similar deliverables when sold separately. However, the Company is often unable to determine TPE, as the Company’s offerings usually contain a significant level of customization and differentiation from those of competitors and the Company is often unable to reliably determine what similar competitor products’ selling prices are on a standalone basis.
	When the Company is unable to establish selling price using VSOE or TPE, the Company uses estimated selling price, or ESP, in its allocation of arrangement consideration. The objective of ESP is to determine the price at which the Company would transact a sale if the product or service were sold on a standalone basis. In determining ESP, the Company uses the cost to provide the product or service plus a margin, or considers other factors. When using cost plus a margin, the Company considers the total cost of the product or service, including customer-specific and geographic factors. The Company also considers the historical margins of the product or service on previous contracts and several factors including any changes to pricing methodologies, competitiveness of products and services and cost drivers that would cause future margins to differ from historical margins.
	Products. The Company most often recognizes revenue from sales of products upon customer acceptance of the system. Where formal acceptance is not required, the Company recognizes revenue upon delivery or installation. When the product is part of a multiple element arrangement, the Company allocates a portion of the arrangement consideration to product revenue based on estimates of selling price.
	Services. Maintenance services are provided under separate maintenance contracts with customers. These contracts generally provide for maintenance services for one year, although some are for multi-year periods, often with prepayments for the term of the contract. The Company considers the maintenance period to commence upon acceptance of the product or installation in situations where a formal acceptance is not required, which may include a warranty period. When service is part of a multiple element arrangement, the Company allocates a portion of the arrangement consideration to maintenance service revenue based on estimates of selling price. Maintenance contracts that are billed in advance of revenue recognition are recorded as deferred revenue. Maintenance revenue is recognized ratably over the term of the maintenance contract.
	Revenue from engineering services is recognized as services are performed.
	Project Revenue. Revenue from design and build contracts is recognized under the percentage-of-completion (or POC method). Under the POC method, revenue is recognized based on the costs incurred to date as a percentage of the total estimated costs to fulfill the contract. If circumstances arise that change the original estimates of revenues, costs, or extent of progress toward completion, revisions to the estimates are made. These revisions may result in increases or decreases in estimated revenues or costs, and such revisions are recorded in income in the period in which the circumstances that gave rise to the revision become known by management. The Company performs ongoing profitability analyses of its contracts accounted for under the POC method in order to determine whether the latest estimates of revenue, costs and extent of progress require updating. If at any time these estimates indicate that the contract will be unprofitable, the entire estimated loss for the remainder of the contract is recorded immediately.
	The Company records revenue from certain research and development contracts which include milestones using the milestone method if the milestones are determined to be substantive. A milestone is considered to be substantive if management believes there is substantive uncertainty that it will be achieved and the milestone consideration meets all of the following criteria:
	•	It is commensurate with either of the following:
	•	The Company’s performance to achieve the milestone; or
	•	The enhancement of value of the delivered item or items as a result of a specific outcome resulting from the Company’s performance to achieve the milestone.
	•	It relates solely to past performance.
	•	It is reasonable relative to all of the deliverables and payment terms (including other potential milestone consideration) within the arrangement.
	The individual milestones are determined to be substantive or non-substantive in their entirety and milestone consideration is not bifurcated.
	Revenue from projects is classified as Product Revenue or Service Revenue, based on the nature of the work performed.
	Nonmonetary Transactions. The Company values and records nonmonetary transactions at the fair value of the asset surrendered unless the fair value of the asset received is more clearly evident, in which case the fair value of the asset received is used.
Sales-type lease	Sales-type leases
	When the Company leases a system to a customer, the accounting involves specific determinations, which often involve complex provisions and significant judgments. The four criteria of the accounting standard that the Company uses in the determination of whether a lease is a sales-type lease or an operating lease are: (a) a review of the lease term to determine if it is equal to or greater than 75% of the economic life of the system; (b) a review of the minimum lease payments to determine if they are equal to or greater than 90% of the fair value of the system; (c) a determination of whether or not the lease transfers ownership to the lessee at the end of the lease term; and (d) a determination of whether or not the lease contains a bargain purchase option. If the lease transaction meets one of the four criteria, then it is recorded as a sales-type lease; otherwise it is an operating lease. Additionally, the Company assesses whether collectibility of the lease payments is reasonably assured and whether there are any significant uncertainties related to costs that it has yet to incur with respect to the lease.
	The Company considers the economic lives of most of its products to range from three to four years. There is no significant after-market for the Company’s used products and the Company believes that the economic lives are representative of the periods during which its products are expected to be economically usable, with normal service, for the purposes for which they were intended. Residual values are not significant.
	The discount rate implicit in the sales-type lease is used to calculate the present value of minimum lease payments, which the Company records as a lease receivable. The minimum lease payment consists of the gross lease payments net of executory costs and contingencies, if any. While revenue is recognized at the inception of the lease, the cash flow from the sales-type lease occurs over the course of the lease, which results in interest income. Unearned interest income is recorded at the inception of the lease and amortized over the lease term using the effective interest method.
Foreign Currency Transaction	Foreign Currency Translation
	The Company uses the U.S. dollar predominantly as its functional currency. Assets and liabilities of foreign subsidiaries that have a functional currency denominated in non-U.S. dollars are translated into U.S. dollars at year-end exchange rates, and revenue and expenses of these foreign subsidiaries are translated at average rates prevailing during the year. Translation adjustments are included in “Accumulated other comprehensive income,” a separate component of shareholders’ equity. Transaction gains and losses arising from transactions denominated in a currency other than the functional currency of the entity involved are included in “Other (income) expense, net” in the accompanying Consolidated Statements of Operations. Net transaction gains were $2.1 million for 2014 and net transactions losses were $1.3 million, and $0.1 million for 2013, and 2012, respectively.
Research and Development	Research and Development
	Research and development expenses include costs incurred in the development and production of hardware and software, costs incurred to enhance and support existing product features, costs incurred to support and improve development processes, and costs related to future product development. Research and development costs are expensed as incurred, and may be offset by co-funding from third parties. The Company may also enter into arrangements whereby it makes advance, non-refundable payments to a vendor to perform certain research and development services. These payments are deferred and recognized over the vendor’s estimated performance period. During the third quarter of 2009, the Company amended a vendor agreement to settle outstanding performance issues. The Company had made advance payments of $16.2 million to the vendor. Due to the amendment, the Company received a refund of $10.0 million of amounts previously paid to the vendor and the right to receive rebates on future purchases. The Company estimated the fair value of this rebate right to be $6.2 million. The Company believes the rebate right is recoverable and it has been classified in “Other non-current assets” in the Consolidated Balance Sheets. No gain or loss was recorded as a result of this amendment. As of December 31, 2014, $0.1 million in rebates remain available for use.
	Amounts to be received under co-funding arrangements with the U.S. government or other customers are based on either contractual milestones or costs incurred. These co-funding milestone payments are recognized in operations as performance is estimated to be completed and are measured as milestone achievements occur or as costs are incurred. These estimates are reviewed on a periodic basis and are subject to change, including in the near term. If an estimate is changed, net research and development expense could be impacted significantly.
	The Company does not record a receivable from the U.S. government prior to completing the requirements necessary to bill for a milestone or cost reimbursement. Funding from the U.S. government is subject to certain budget restrictions and milestones may be subject to completion risk, and as a result, there may be periods in which research and development costs are expensed as incurred for which no reimbursement is recorded, as milestones have not been completed or the U.S. government has not funded an agreement. Accordingly, there can be substantial variability in the amount of net research and development expenses from quarter to quarter and year to year.
	The Company classifies amounts to be received from funded research and development projects as either revenue or a reduction to research and development expense based on the specific facts and circumstances of the contractual arrangement, considering total costs expected to be incurred compared to total expected funding and the nature of the research and development contractual arrangement. In the event that a particular arrangement is determined to represent revenue, the corresponding research and development costs are classified as cost of revenue.
Income Taxes	Income Taxes
	Deferred tax assets and liabilities are determined based on differences between financial reporting and tax bases of assets and liabilities and operating loss and tax credit carryforwards and are measured using the enacted tax rates and laws that will be in effect when the differences and carryforwards are expected to be recovered or settled. A valuation allowance for deferred tax assets is provided when the Company estimates that it is more likely than not that all or a portion of the deferred tax assets may not be realized through future operations. This assessment is based upon consideration of available positive and negative evidence, which includes, among other things, recent results of operations and expected future profitability. The Company considers its actual historical results over several years to have stronger weight than other more subjective indicators, including forecasts, when considering whether to establish or reduce a valuation allowance on deferred tax assets.
	The Company recognizes the income tax benefit from a tax position only if it is more likely than not that the tax position will be sustained on examination by the applicable taxing authorities, based on the technical merits of the Company’s position. The tax benefit recognized in the financial statements from such a position is measured based on the largest benefit that has a greater than fifty percent likelihood of being realized upon ultimate settlement.
	Estimated interest and penalties are recorded as a component of interest expense and other expense, respectively.
	As of December 31, 2014, the Company had approximately $87.6 million of net deferred tax assets, against which the Company provided a $10.1 million valuation allowance, resulting in a net deferred tax asset of $77.5 million. During the year ended December 31, 2014 the Company reduced substantially all of the remaining valuation allowance held against the Company’s U.S. deferred tax assets. The Company continues to provide a valuation allowance against specific U.S. deferred tax assets and a full valuation allowance against deferred tax assets arising in a limited number of foreign jurisdictions as the realization of such assets is not considered to be more likely than not at this time. In a future period the Company’s assessment of the realizability of its deferred tax assets and therefore the appropriateness of the valuation allowance could change based on an assessment of all available evidence, both positive and negative in that future period. If the Company’s conclusion about the realizability of its deferred tax assets and therefore the appropriateness of the valuation allowance changes in a future period, the Company could record a substantial tax provision or benefit in its Consolidated Statement of Operations when that occurs.
Share-based Compensation	Share-Based Compensation
	The Company measures compensation cost for share-based payment awards at fair value and recognizes it as compensation expense over the service period for awards expected to vest. Share-based compensation expense is recognized for all share-based payment awards, net of an estimated forfeiture rate. Compensation cost is only recognized for those shares expected to vest on a straight-line basis over the requisite service period of the award.
	Determining the appropriate fair value model and calculating the fair value of share-based payment awards requires subjective assumptions, including the expected life of the share-based payment awards and stock price volatility. The Company utilizes the Black-Scholes options pricing model to value the stock options granted under its options plans. In this model, the assumptions utilized relate to stock price volatility, stock option term and forfeiture rates that are based upon both historical factors as well as management’s judgment.
	The fair value of restricted stock and restricted stock units is determined based on the number of shares or units granted and the quoted price of the Company’s common stock at the date of grant.
	The Company grants performance vesting restricted shares to executives as one of the ways to align compensation with shareholder interests. Vesting of these awards is contingent upon achievement of certain performance conditions. Compensation expense for these awards is only recorded when vesting is deemed to be probable.
Shipping and Handling Costs	Shipping and Handling Costs
	Costs related to shipping and handling are included in “Cost of product revenue” and “Cost of service revenue” in the accompanying Consolidated Statements of Operations.
Advertising Costs	Advertising Costs
	Sales and marketing expenses in the accompanying Consolidated Statements of Operations include advertising expenses of $2.9 million, $2.2 million, and $1.2 million in 2014, 2013, and 2012, respectively. The Company incurs advertising costs for representation at certain trade shows, promotional events and sales lead generation, as well as design and printing costs for promotional materials. The Company expenses all advertising costs as incurred.
Earnings Per Share	Earnings Per Share, or EPS
	Basic EPS is computed by dividing net income available to common shareholders by the weighted average number of common shares, excluding unvested restricted stock outstanding during the period. Diluted EPS is computed by dividing net income available to common shareholders by the weighted average number of common and potential common shares outstanding during the period, which includes the additional dilution related to conversion of stock options, unvested restricted stock and restricted stock units as computed under the treasury stock method. For the years ended December 31, 2014, 2013 and 2012, the added shares from these items included in the calculation of diluted shares and EPS totaled approximately 1.8 million, 1.9 million, and 1.3 million, respectively. Potentially dilutive shares of 0.6 million, 0.5 million, and 0.4 million, respectively, have been excluded from the denominator in the computation of diluted EPS for the years ended December 31, 2014, 2013 and 2012, respectively, because they are antidilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board, or FASB, issued Accounting Standards Update No. 2014-09, Revenue from Contracts with Customers: Topic 606 (ASU 2014-09), to supersede nearly all existing revenue recognition guidance under GAAP. The core principle of ASU 2014-09 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. ASU 2014-09 defines a five step process to achieve this core principle and, in doing so, it is possible more judgment and estimates may be required within the revenue recognition process than required under existing U.S. GAAP including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. ASU 2014-09 is effective for the fiscal and interim reporting periods beginning after December 15, 2016 using either of two methods: (i) retrospective to each prior reporting period presented with the option to elect certain practical expedients as defined within ASU 2014-09; or (ii) retrospective with the cumulative effect of initially applying ASU 2014-09 recognized at the date of initial application and providing certain additional disclosures as defined per ASU 2014-09. The Company is currently evaluating the potential impact of the pending adoption of ASU 2014-09 on its consolidated financial statements.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income
	Accumulated other comprehensive income, a component of Shareholders’ equity, consisted of the following at December 31 (in thousands):
			2014			2013				2012
	Accumulated unrealized net gain (loss) on available-for-sale investments		$	12		$	—			$	(46	)
	Accumulated currency translation adjustments		2,069			3,257				4,301
	Accumulated unrealized net gain (loss) on cash flow hedges		4,422			(2,404		)		926
	Accumulated other comprehensive income		$	6,503		$	853			$	5,181
	The following tables show the changes in Accumulated Other Comprehensive Income by component for the years ended December 31, 2014 and 2013 (in thousands):
	Year Ended December 31, 2014
		Unrealized Gain on Investments			Foreign Currency Translation Adjustments				Unrealized Gain/(Loss) on Cash Flow Hedges				Accumulated Other Comprehensive Income
	Beginning balance	$	—		$	3,257			$	(2,404	)		$	853
	Current-period change, net of tax	$	12		$	(1,188	)		$	6,826			$	5,650
	Ending balance	$	12		$	2,069			$	4,422			$	6,503
	Income tax expense (benefit) associated with current-period change	$	8		$	(229	)		$	4,593			$	4,372

Acquisition_Tables

Acquisition (Tables)	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Schedule of estimated fair values of assets acquired and liabilities assumed	The following are the estimated fair values of the assets acquired and liabilities assumed (in thousands):
	Cash	$	635
	Inventories	7,526
	Other tangible assets	5,702
	Deferred revenue	(2,400		)
	Accounts payable	(2,918		)
	Deferred tax liabilities	(3,685		)
	Other liabilities assumed	(2,061		)
	Net tangible assets	2,799
	Trademarks	300
	Developed technology	5,400
	Customer relationships	1,800
	Non-compete agreements	400
	Goodwill	14,182
	Total net assets acquired	$	24,881
Schedule of fair value of major components of intangible assets acquired and estimated useful lives	The fair values of the major components of the intangible assets acquired and their estimated useful lives are as follows (in thousands):
							Useful Life
	Intangible Asset Class		Fair Value				(in Years)
	Trademarks		$	300			5
	Developed technology		$	5,400			3
	Customer relationships		$	1,800			10
	Non-compete agreements		$	400			2
Schedule of unaudited pro forma condensed financial information	The following unaudited pro forma condensed financial information presents the combined results of operations of the Company and Appro for the year ended December 31, 2012 as if the acquisition had occurred on January 1, 2012 (in thousands):
		Year Ended December 31, 2012
	Revenue	$	494,369
	Net income	$	161,985
Schedule of carrying amount of purchased intangibles	The carrying amount of purchased intangibles at December 31, 2014 was as follows (in thousands):
		31-Dec-14
		Gross Carrying Amount			Accumulated Amortization			Net Carrying Amount
	Trademarks	$	300		$	127		$	173
	Developed technology	5,400			3,800			1,600
	Customer relationships	1,800			380			1,420
	Non-compete agreements	400			400			—
	Total	$	7,900		$	4,707		$	3,193
	The carrying amount of purchased intangibles at December 31, 2013 was as follows (in thousands):
		31-Dec-13
		Gross Carrying Amount			Accumulated Amortization			Net Carrying Amount
	Trademarks	$	300		$	67		$	233
	Developed technology	5,400			2,000			3,400
	Customer relationships	1,800			200			1,600
	Non-compete agreements	400			222			178
	Total	$	7,900		$	2,489		$	5,411
Schedule of amortization expense	Aggregate estimated amortization expense for the years ending December 31 are as follows (in thousands):
	2015	$	1,840
	2016	240
	2017	233
	2018	180
	2019	180
		$	2,673

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Company's financial assets and liabilities measured at fair value and the hierarchy of the valuation inputs	The following table presents information about the Company’s financial assets and liabilities that have been measured at fair value on a recurring basis as of December 31, 2014 and 2013, and indicates the fair value hierarchy of the valuation inputs utilized to determine such fair value (in thousands):
	Description		Fair Value				Quoted				Significant
			as of				Prices in				Other
			December 31,				Active				Observable
			2014				Markets				Inputs
							(Level 1)				(Level 2)
	Assets:
	Cash and cash equivalents and restricted cash		$	129,507			$	129,507			$	—
	Available-for-sale investments (1)		16,289				16,289				—
	Foreign exchange forward contracts (2)		11,079				—				11,079
	Assets measured at fair value at December 31, 2014		$	156,875			$	145,796			$	11,079
	Liabilities:
	Foreign exchange forward contracts (3)		2,139				—				2,139
	Liabilities measured at fair value at December 31, 2014		$	2,139			$	—			$	2,139
	Description		Fair Value				Quoted				Significant
			as of				Prices in				Other
			December 31,				Active				Observable
			2013				Markets				Inputs
							(Level 1)				(Level 2)
	Assets:
	Cash and cash equivalents and restricted cash		$	206,401			$	206,401			$	—
	Available-for-sale investments (1)		14,048				14,048				—
	Foreign exchange forward contracts (2)		1,730				—				1,730
	Assets measured at fair value at December 31, 2013		$	222,179			$	220,449			$	1,730
	Liabilities:
	Foreign exchange forward contracts (3)		7,237				—				7,237
	Liabilities measured at fair value at December 31, 2013		$	7,237			$	—			$	7,237
	_______________________________
	-1	Included in “Short-term investments” on the Company’s Consolidated Balance Sheets.
	-2	Included in “Prepaid expenses and other current assets” and “Other non-current assets” on the Company’s Consolidated Balance Sheets.
	-3	Included in “Other accrued liabilities” and “Other non-current liabilities” on the Company’s Consolidated Balance Sheets.
Schedule of notional amounts of outstanding derivative positions	As of December 31, 2014 and 2013, the Company had outstanding forward contracts which were designated as cash flow hedges of anticipated future cash receipts on sales contracts payable in foreign currencies. The outstanding notional amounts were approximately (in millions):
		31-Dec-14			31-Dec-13
	British Pounds (GBP)	77.9			36.4
	Euros (EUR)	40.7			53
	Swiss Francs (CHF)	0.9			5.6
	Canadian Dollars (CAD)	—			3.9
	Japanese Yen (JPY)	—			1,239.80
	Singapore Dollars (SGD)	0.1			3.2
	Swedish Krona (SEK)	84.8			—
Fair values of derivative instruments	Fair values of derivative instruments (in thousands):
	Hedge Classification	Balance Sheet Location		Fair Value				Fair Value
				as of				as of
				December 31,				December 31,
				2014				2013
	Foreign currency contracts	Prepaid expenses and other current assets		$	5,362			$	1,654
	Foreign currency contracts	Other non-current assets		5,717				76
	Foreign currency contracts	Other accrued liabilities		(1,454		)		(2,942		)
	Foreign currency contracts	Other non-current liabilities		(685		)		(4,295		)
	Total fair value of derivatives classified as hedging instruments			$	8,940			$	(5,507	)

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2014
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Reclassification from Accumulated Other Comprehensive Income	The following table shows the gross and net of tax reclassification adjustments from accumulated other comprehensive income resulting from hedged foreign currency transactions recorded by the Company for the years ended December 31, 2014, 2013 and 2012 (in thousands). The gross reclassification adjustments increased product revenue for the years ended December 31, 2014 and 2012 and decreased product revenue for the year ended December 31, 2013.
			Year Ended
			December 31,
			2014			2013				2012
	Gross of Tax Reclassifications		$	2,748		$	(1,604	)		$	643
	Net of Tax Reclassifications		$	1,649		$	(962	)		$	386
Schedule of Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income
	Accumulated other comprehensive income, a component of Shareholders’ equity, consisted of the following at December 31 (in thousands):
			2014			2013				2012
	Accumulated unrealized net gain (loss) on available-for-sale investments		$	12		$	—			$	(46	)
	Accumulated currency translation adjustments		2,069			3,257				4,301
	Accumulated unrealized net gain (loss) on cash flow hedges		4,422			(2,404		)		926
	Accumulated other comprehensive income		$	6,503		$	853			$	5,181
	The following tables show the changes in Accumulated Other Comprehensive Income by component for the years ended December 31, 2014 and 2013 (in thousands):
	Year Ended December 31, 2014
		Unrealized Gain on Investments			Foreign Currency Translation Adjustments				Unrealized Gain/(Loss) on Cash Flow Hedges				Accumulated Other Comprehensive Income
	Beginning balance	$	—		$	3,257			$	(2,404	)		$	853
	Current-period change, net of tax	$	12		$	(1,188	)		$	6,826			$	5,650
	Ending balance	$	12		$	2,069			$	4,422			$	6,503
	Income tax expense (benefit) associated with current-period change	$	8		$	(229	)		$	4,593			$	4,372

Investments_Tables

Investments (Tables)	12 Months Ended
	Dec. 31, 2014
Investments, Debt and Equity Securities [Abstract]
Investments	The carrying amount of the Company’s investments in available-for-sale securities as of December 31, 2014 and December 31, 2013 are shown in the table below (in thousands):
		31-Dec-14		31-Dec-13
	Short-term available-for-sale securities cost	$	16,269	$	14,048
	Short-term available-for-sale securities unrealized gains	20		—
	Short-term available-for-sale securities fair value	$	16,289	$	14,048

Accounts_and_Other_Receivables1

Accounts and Other Receivables, Net (Tables)	12 Months Ended
	Dec. 31, 2014
Receivables [Abstract]
Accounts and Other Receivables, Net	A summary of net accounts and other receivables follows (in thousands):
		December 31,
		2014			2013
	Trade accounts receivable	$	126,874		$	169,417
	Unbilled receivables	20,788			9,075
	Advance billings	4,960			2,141
	Short-term investment in sales-type lease	10,187			—
	Other receivables	2,401			2,051
		165,210			182,684
	Allowance for doubtful accounts	(97		)	(157		)
	Accounts and other receivables, net	$	165,113		$	182,527

Salestype_lease_Tables

Sales-type lease (Tables)	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Components of the Net Investment in the Sales-type Lease	The following table shows the components of the net investment in the sales-type lease as of December 31, 2014 (in thousands):
	Total minimum lease payments to be received	$	53,134
	Less: executory costs	(10,717		)
	Net minimum lease payments receivable	42,417
	Estimated residual value of leased property (unguaranteed)	1,253
	Less: unearned income	(2,394		)
	Net investment in sales-type lease	41,276
	Less: long-term investment in sales-type lease	(31,089		)
	Investment in sales-type lease included in accounts and other receivables	$	10,187
Minimum Lease Payments to be Received for Each of the Next Five Fiscal Years	As of December 31, 2014, minimum lease payments for each of the succeeding four fiscal years are as follows (in thousands):
	2015	$	14,169
	2016	14,169
	2017	14,169
	2018	10,627
	Total minimum lease payments to be received	$	53,134

Inventory_Tables

Inventory (Tables)	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventory	A summary of inventory follows (in thousands):
		31-Dec
		2014		2013
	Components and subassemblies	$	60,851	$	46,339
	Work in process	46,954		23,618
	Finished goods	35,827		25,172
		$	143,632	$	95,129

Property_and_Equipment_Net_Tab

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	A summary of property and equipment follows (in thousands):
		December 31,
		2014			2013
	Land	$	275		$	203
	Buildings	20,409			17,022
	Furniture and equipment	13,198			14,443
	Computer equipment	59,785			91,475
	Leasehold improvements	446			1,276
		94,113			124,419
	Accumulated depreciation and amortization	(59,320		)	(94,141		)
	Property and equipment, net	$	34,793		$	30,278

Service_Spares_Net_Tables

Service Spares, Net (Tables)	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Service Spares, Net	A summary of service spares follows (in thousands):
		December 31,
		2014			2013
	Service spares	$	13,114		$	16,613
	Accumulated depreciation	(11,246		)	(14,785		)
	Service spares, net	$	1,868		$	1,828

Deferred_Revenue_Tables

Deferred Revenue (Tables)	12 Months Ended
	Dec. 31, 2014
Deferred Revenue Disclosure [Abstract]
Deferred revenue	Deferred revenue consisted of the following (in thousands):
		31-Dec
		2014			2013
	Deferred product revenue	$	21,152		$	54,065
	Deferred service revenue	92,346			87,900
	Total deferred revenue	113,498			141,965
	Less long-term deferred revenue	(47,588		)	(50,477		)
	Deferred revenue in current liabilities	$	65,910		$	91,488

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Minimum contractual commitments as of December 31, 2014, were as follows (in thousands):
		Operating		Development
		Leases		Agreements
	2015	$	5,097	$	6,856
	2016	4,762		25
	2017	4,563		25
	2018	4,373		25
	2019	4,266		25
	Thereafter	14,563		—
	Minimum contractual commitments	$	37,624	$	6,956

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income (loss) before income taxes	Income before income taxes consisted of the following (in thousands):
			Year Ended December 31,
			2014			2013			2012
	United States		$	5,710		$	17,467		$	161,592
	International		3,987			3,562			7,140
	Total		$	9,697		$	21,029		$	168,732
Tax provision (benefit) for income taxes related to operations	The tax provision (benefit) for income taxes related to operations consisted of the following (in thousands):
			Year Ended December 31,
			2014			2013			2012
	Current provision (benefit):
	Federal		$	230		$	484		$	1,162
	State		(392		)	696			2,768
	Foreign		740			801			541
	Total current provision		578			1,981			4,471
	Deferred (benefit) provision:
	Federal		(53,242		)	(13,160		)	1,362
	State		(885		)	(327		)	1,415
	Foreign		923			312			243
	Total deferred (benefit) provision		(53,204		)	(13,175		)	3,020
	Total (benefit) provision for income taxes		$	(52,626	)	$	(11,194	)	$	7,491
Tax provision (benefit) differs from the amount computed by applying the federal statutory income tax rate	The tax provision (benefit) differs from the amount computed by applying the federal statutory income tax rate as follows (in thousands):
			Year Ended December 31,
			2014			2013			2012
	Income tax provision at statutory rate		$	3,394		$	7,360		$	59,056
	State taxes, net of federal benefit		(217		)	369			4,183
	Foreign income taxes		284			(749		)	(518		)
	Stock compensation adjustment		—			(8,419		)	—
	Deemed dividends for U.S. income tax purposes		492			477			2,352
	Nondeductible expenses		337			208			549
	Liquidation of subsidiary		—			—			(30,704		)
	Disallowed compensation		(116		)	19			492
	Research and development tax credit		(1,140		)	(5,736		)	—
	Effect of change in valuation allowance on deferred tax assets		(55,660		)	(4,723		)	(27,919		)
	Effective income tax provision (benefit)		$	(52,626	)	$	(11,194	)	$	7,491
Significant components of the Company's deferred income tax assets and liabilities	Significant components of the Company’s deferred income tax assets and liabilities follow (in thousands):
			December 31,
			2014			2013
	Current:
	Deferred Income Tax Assets
	Inventory		$	5,840		$	3,388
	Accrued compensation		681			460
	Deferred revenue		18,186			12,100
	Net operating loss carryforwards		12,981			5,922
	Other		1,261			8,120
	Gross current deferred tax assets		38,949			29,990
	Valuation allowance		(2,039		)	(20,107		)
	Current deferred tax assets		36,910			9,883
	Deferred Income Tax Liabilities
	Other		(837		)	(688		)
	Current deferred tax liabilities		(837		)	(688		)
	Net current deferred tax assets		$	36,073		$	9,195
	Long-Term:
	Deferred Income Tax Assets
	Property and equipment		$	11,555		$	328
	Research and experimentation credit carryforwards		24,596			23,941
	Net operating loss carryforwards		21,511			47,154
	Goodwill		203			628
	Other		9,967			10,161
	Gross long-term deferred tax assets		67,832			82,212
	Valuation allowance		(8,099		)	(57,687		)
	Long-term deferred tax assets		59,733			24,525
	Deferred Income Tax Liabilities
	Property and equipment		—			(1,905		)
	Investment in sales-type lease, net		(14,321		)	—
	Intangible assets		(1,215		)	(2,059		)
	Other		(2,783		)	(1,355		)
	Long-term deferred tax liabilities		(18,319		)	(5,319		)
	Net long-term deferred tax asset		$	41,414		$	19,206
Unrecognized tax benefits for uncertain tax positions	The following table summarizes changes in the amount of the Company’s unrecognized tax benefits for uncertain tax positions for the three years ended December 31, 2014, 2013 and 2012 (in thousands):
	Balance at December 31, 2011	$	—
	Increase related to current year income tax positions	470
	Balance at December 31, 2012	$	470
	Decrease related to prior year income tax positions	(268		)
	Balance at December 31, 2013	$	202
	Increase related to prior year income tax positions	5,059
	Increase related to current year income tax positions	369
	Balance at December 31, 2014	$	5,630

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation [Abstract]
Key weighted average assumptions used in determining fair value	In determining the fair value of stock options, the Company used the Black-Scholes option pricing model that employed the following key weighted average assumptions:
			2014				2013				2012
	Risk-free interest rate		1.22		%		0.98		%		0.56		%
	Expected dividend yield		—		%		—		%		—		%
	Volatility		52.43		%		50.45		%		74.84		%
	Expected life (in years)		4				4				4
	Weighted average Black-Scholes value of options granted		$	11.16			$	8.22			$	6.56
Stock option activity	A summary of the Company’s stock option activity and related information follows:
			Options			Weighted				Weighted Average Remaining
						Average				Contractual
						Exercise				Term (Years)
						Price
	Outstanding at January 1, 2012		3,417,920			$	6.28
	Granted		359,500			11.9
	Exercised		(1,346,326	)		5.52
	Canceled and forfeited		(137,589	)		11.35
	Outstanding at December 31, 2012		2,293,505			7.31
	Granted		346,360			20.65
	Exercised		(495,221	)		6.38
	Canceled and forfeited		(66,575	)		21.97
	Outstanding at December 31, 2013		2,078,069			9.29
	Granted		323,900			26.92
	Exercised		(411,352	)		7.5
	Canceled and forfeited		(59,627	)		18.45
	Outstanding at December 31, 2014		1,930,990			12.34				6.6
	Exercisable at December 31, 2014		1,251,080			8.18				5.6
	Available for grant at December 31, 2014		3,079,888
Restricted stock activity	A summary of the Company’s unvested restricted stock and restricted stock unit grants and changes during the years ended December 31 was as follows:
		Service Vesting Restricted Shares							Performance Vesting Restricted Shares						Total Restricted Shares
		Shares			Weighted				Shares			Weighted			Shares		Weighted Average Grant Date Fair Value
					Average							Average
					Grant Date							Grant Date
					Fair Value							Fair Value
	Outstanding at January 1, 2012	1,302,414			$	5.47			—			$	—		1,302,414		$	5.47
	Granted	579,447			10.84				737,000			12.9			1,316,447		11.99
	Forfeited	(31,771	)		7.64				—			—			(31,771	)	7.64
	Vested	(384,352	)		5.86				—			—			(384,352	)	5.86
	Outstanding at December 31, 2012	1,465,738			7.44				737,000			12.9			2,202,738		9.27
	Granted	326,979			20.83				429,000			21			755,979		20.93
	Forfeited	(3,437	)		5.92				(72,000	)		14.88			(75,437	)	14.48
	Vested	(661,580	)		6.22				—			—			(661,580	)	6.22
	Outstanding at December 31, 2013	1,127,700			12.05				1,094,000			15.94			2,221,700		13.97
	Granted	463,734			28.74				—			—			463,734		28.74
	Forfeited	(134,653	)		15.39				(277,000	)		17.49			(411,653	)	16.8
	Vested	(423,179	)		11.14				—			—			(423,179	)	11.14
	Outstanding at December 31, 2014	1,033,602			19.48				817,000			15.41			1,850,602		17.68
Outstanding and exercisable options by price range	Outstanding and exercisable options by price range as of December 31, 2014, were as follows:
			Outstanding Options									Exercisable Options
	Range of Exercise		Number			Weighted		Weighted				Number		Weighted
	Prices per Share		Outstanding			Average		Average				Exercisable		Average
						Remaining		Exercise						Exercise
						Life (Years)		Price						Price
	$ 0.00 - $ 4.00		265,142			4.3		$	3.71			265,142		$	3.71
	$ 4.01 - $ 6.00		240,647			5.1		$	5.49			240,647		$	5.49
	$ 6.01 - $ 8.00		438,159			5.7		$	6.29			360,553		$	6.33
	$ 8.01 - $ 34.15		987,042			8.1		$	19.01			384,738		$	14.68
	$ 0.00 - $ 34.15		1,930,990			6.6		$	12.34			1,251,080		$	8.18
Gross share-based compensation cost recorded in the condensed consolidated statements of operations	The following table (in thousands) sets forth the share-based compensation cost resulting from stock options and stock grants recorded in the Company’s Consolidated Statements of Operations for the years ended December 31, 2014, 2013 and 2012.
			2014				2013				2012
	Cost of product revenue		$	229			$	135			$	57
	Cost of service revenue		255				229				258
	Research and development		2,721				1,480				1,327
	Sales and marketing		3,152				2,230				1,717
	General and administrative		4,007				3,165				2,604
	Total share-based compensation expense		$	10,364			$	7,239			$	5,963

Segment_Information_Tables

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Information on operating segments	The following table presents revenues and gross margin for the Company’s operating segments for the years ended December 31 (in thousands):
		2014			2013			2012
	Revenue:
	Supercomputing	$	459,729		$	434,133		$	355,736
	Storage and Data Management	84,412			76,955			55,009
	Maintenance and Support	86,573			77,817			62,245
	Engineering Services and Other	17,465			14,661			10,313
	Elimination of inter-segment revenue	(86,573		)	(77,817		)	(62,245		)
	Total revenue	$	561,606		$	525,749		$	421,058
	Gross Profit:
	Supercomputing	$	146,565		$	143,440		$	128,723
	Storage and Data Management	31,572			31,403			16,574
	Maintenance and Support	38,819			38,476			25,735
	Engineering Services and Other	6,277			9,483			5,881
	Elimination of inter-segment gross profit	(38,819		)	(38,476		)	(25,735		)
	Total gross profit	$	184,414		$	184,326		$	151,178
Revenue by geographic location	Product and service revenue and long-lived assets classified by significant country were as follows (in thousands):
		United			All			Total
		States			Other
					Countries
	For the year ended December 31, 2014:
	Product revenue	$	253,930		$	206,818		$	460,748
	Service revenue	$	72,434		$	28,424		$	100,858
	Long-lived assets	$	58,868		$	36,792		$	95,660
	For the year ended December 31, 2013:
	Product revenue	$	297,583		$	138,747		$	436,330
	Service revenue	$	62,072		$	27,347		$	89,419
	Long-lived assets	$	58,910		$	6,146		$	65,056
	For the year ended December 31, 2012:
	Product revenue	$	301,162		$	52,605		$	353,767
	Service revenue	$	42,359		$	24,932		$	67,291
	Long-lived assets	$	57,549		$	4,460		$	62,009

Research_and_Development_Table

Research and Development (Tables)	12 Months Ended
	Dec. 31, 2014
Research and Development [Abstract]
Company's Net Research and Development Cost	The detail for the Company’s net research and development costs for the years ended December 31 follows (in thousands):
		2014			2013			2012
	Gross research and development expenses	$	104,797		$	92,469		$	86,305
	Less: Amounts included in cost of revenue	(7,713		)	(3,741		)	(1,080		)
	Less: Reimbursed research and development (excludes amounts in revenue)	(3,036		)	(1,000		)	(20,922		)
	Net research and development expenses	$	94,048		$	87,728		$	64,303

Interest_Income_Expense_Tables

Interest Income (Expense) (Tables)	12 Months Ended
	Dec. 31, 2014
Other Income and Expenses [Abstract]
The detail of interest income (expense) for the years ended	The detail of interest income (expense) for the years ended December 31 follows (in thousands):
		2014			2013			2012
	Interest income	$	643		$	894		$	397
	Interest expense	(137		)	(137		)	(193		)
	Net interest income	$	506		$	757		$	204

Quarterly_Data_Unaudited_Table

Quarterly Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information
		2014										2013
	For the Quarter Ended	31-Mar			30-Jun			30-Sep		31-Dec		31-Mar			30-Jun			30-Sep			31-Dec
	Revenue	$	55,110		$	85,147		$	159,406	$	261,943	$	79,547		$	84,467		$	54,366		$	307,369
	Cost of revenue	37,173			56,143			110,876		173,000		55,397			57,666			33,940			194,420
	Gross profit	17,937			29,004			48,530		88,943		24,150			26,801			20,426			112,949
	Research and development, net	22,621			24,189			22,503		24,735		20,226			19,968			21,555			25,979
	Sales and marketing	11,776			13,259			14,808		17,942		11,143			11,550			11,480			17,172
	General and administrative	5,413			5,316			5,813		6,839		5,485			5,085			4,970			8,063
	Net income (loss) (1)	(12,938		)	(6,748		)	7,371		74,638		(7,609		)	(150		)	(11,025		)	51,007
	Net income (loss) per common share, basic	$	(0.34	)	$	(0.18	)	$	0.19	$	1.92	$	(0.20	)	$	—		$	(0.29	)	$	1.33
	Net income (loss) per common share, diluted	$	(0.34	)	$	(0.18	)	$	0.18	$	1.84	$	(0.20	)	$	—		$	(0.29	)	$	1.27

Summary_of_Significant_Account3

Summary of Significant Accounting Policies Cash, Cash Equivalents and Restricted Cash (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Restricted Cash and Cash Equivalents Items [Line Items]
Short-term restricted cash	$16,874	$0
Long-term restricted cash	$0	$13,768
Long-term investments, expected term	1 year
Minimum
Restricted Cash and Cash Equivalents Items [Line Items]
Short term investments, expected term	3 months
Maximum
Restricted Cash and Cash Equivalents Items [Line Items]
Short term investments, expected term	1 year

Summary_of_Significant_Account4

Summary of Significant Accounting Policies Property and Equipment and Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2014
Minimum
Property, Plant and Equpment and Intangible Assets [Line Items]
Intangible assets, useful lives (years)	2 years
Maximum
Property, Plant and Equpment and Intangible Assets [Line Items]
Intangible assets, useful lives (years)	10 years
Furniture and Fixtures | Minimum
Property, Plant and Equpment and Intangible Assets [Line Items]
Property and equipment, useful lives (years)	18 months
Furniture and Fixtures | Maximum
Property, Plant and Equpment and Intangible Assets [Line Items]
Property and equipment, useful lives (years)	7 years
Computer equipment
Property, Plant and Equpment and Intangible Assets [Line Items]
Property and equipment, useful lives (years)	3 years
Building and Building Improvements | Minimum
Property, Plant and Equpment and Intangible Assets [Line Items]
Property and equipment, useful lives (years)	8 years
Building and Building Improvements | Maximum
Property, Plant and Equpment and Intangible Assets [Line Items]
Property and equipment, useful lives (years)	25 years

Summary_of_Significant_Account5

Summary of Significant Accounting Policies Service Spares (Details)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Service spares, useful life	4 years

Summary_of_Significant_Account6

Summary of Significant Accounting Policies Revenue Recognition (Details)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Product Delivery Period	5 years
Maintenance Services Period	1 year

Summary_of_Significant_Account7

Summary of Significant Accounting Policies Foreign Currency Translation and Transaction (Details) (Other (Income) Expense, Net, USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other (Income) Expense, Net
Foreign Currency Translations and Transactions [Line Items]
Net transaction losses	($2.10)	($1.30)	($0.10)

Summary_of_Significant_Account8

Summary of Significant Accounting Policies Research and Development (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2009	Dec. 31, 2014
Accounting Policies [Abstract]
Advance payments	$16.20
Amount of refund	10
Estimated fair value of rebate right	6.2
Amount of rebates that remain available for use		$0.10

Summary_of_Significant_Account9

Summary of Significant Accounting Policies Income Taxes (Details) (USD $)	Dec. 31, 2014
In Millions, unless otherwise specified
Valuation Allowance [Line Items]
Net deferred tax assets	$87.60
Valuation allowance amount	-10.1
Net deferred tax assets of valuation allowance	$77.50

Recovered_Sheet1

Summary of Significant Accounting Policies Advertising Costs (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounting Policies [Abstract]
Advertising expenses	$2.90	$2.20	$1.20

Recovered_Sheet2

Summary of Significant Accounting Policies EPS (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares added from these items included in the calculation of diluted shares and EPS	1,800,000	1,900,000	1,300,000
Potentially dilutive shares excluded from the denominator in the computation of diluted EPS	600,000	500,000	400,000
Issued and outstanding restricted stock units (In Shares)	1,850,602	2,221,700	2,202,738	1,302,414
Performance Vesting Restricted Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issued and outstanding restricted stock units (In Shares)	817,000	1,094,000	737,000	0

Recovered_Sheet3

Summary of Significant Accounting Policies Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$6,503	$853	$5,181
Accumulated unrealized net loss on available-for-sale investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	12	0	-46
Accumulated currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	2,069	3,257	4,301
Accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$4,422	($2,404)	$926

Acquisition_Details

Acquisition (Details) (USD $)	0 Months Ended
	Nov. 21, 2012	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill		$14,182,000	$14,182,000
Appro International, Inc.
Business Acquisition [Line Items]
Consideration transferred	24,900,000
Cash	635,000
Inventories	7,526,000
Other tangible assets	5,702,000
Deferred revenue	-2,400,000
Accounts payable	-2,918,000
Deferred tax liabilities	-3,685,000
Other liabilities assumed	-2,061,000
Net tangible assets	2,799,000
Goodwill	14,182,000
Total net assets acquired	24,881,000
Developed technology | Appro International, Inc.
Business Acquisition [Line Items]
Fair Value	5,400,000
Customer relationships | Appro International, Inc.
Business Acquisition [Line Items]
Fair Value	1,800,000
Non-compete agreements | Appro International, Inc.
Business Acquisition [Line Items]
Fair Value	400,000
Trademarks | Appro International, Inc.
Business Acquisition [Line Items]
Fair Value	$300,000

Acquisition_Intangible_Assets_

Acquisition Intangible Assets by Class (Details) (Appro International, Inc., USD $)	0 Months Ended
In Thousands, unless otherwise specified	Nov. 21, 2012
Developed technology
Finite-Lived and Indefinite-Lived Assets Acquired as Part of Business Combination [Line Items]
Fair Value	$5,400
Useful Life (Years)	3 years
Customer relationships
Finite-Lived and Indefinite-Lived Assets Acquired as Part of Business Combination [Line Items]
Fair Value	1,800
Useful Life (Years)	10 years
Non-compete agreements
Finite-Lived and Indefinite-Lived Assets Acquired as Part of Business Combination [Line Items]
Fair Value	400
Useful Life (Years)	2 years
Trademarks
Finite-Lived and Indefinite-Lived Assets Acquired as Part of Business Combination [Line Items]
Fair Value	$300
Useful Life (Years)	5 years

Acquisition_Acquisition_Pro_Fo

Acquisition Acquisition, Pro Forma Information (Details) (Appro International, Inc., USD $)	1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012
Appro International, Inc.
Business Acquisition [Line Items]
Revenue since Acquisition Date, Actual	$600,000
Loss since Acquisition Date, Actual	1,300,000
Acquisition related costs	900,000
Revenue		494,369,000
Net income		$161,985,000

Acquisition_Carrying_Amount_Ne

Acquisition Carrying Amount, Net, of Amortizable Intangible Assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Acquired Finite-Lived Intangible Assets [Line Items]
Net Carrying Amount	$3,895	$6,362
Appro International, Inc.
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	7,900	7,900
Accumulated Amortization	4,707	2,489
Net Carrying Amount	3,193	5,411
Developed technology | Appro International, Inc.
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,400	5,400
Accumulated Amortization	3,800	2,000
Net Carrying Amount	1,600	3,400
Customer relationships | Appro International, Inc.
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,800	1,800
Accumulated Amortization	380	200
Net Carrying Amount	1,420	1,600
Non-compete agreements | Appro International, Inc.
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	400	400
Accumulated Amortization	400	222
Net Carrying Amount	0	178
Trademarks | Appro International, Inc.
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	300	300
Accumulated Amortization	127	67
Net Carrying Amount	$173	$233

Acquisition_Future_Amortizatio

Acquisition Future Amortization Expense (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Business Acquisition [Line Items]
2015	$1,840,000
2016	240,000
2017	233,000
2018	180,000
2019	180,000
Finite-Lived Intangible Assets, Net	2,673,000
Appro International, Inc.
Business Acquisition [Line Items]
Amortization expense related to purchased intangibles	$2,200,000	$2,200,000	$200,000

Sale_of_Interconnect_Hardware_1

Sale of Interconnect Hardware Development Program (Details) (USD $)	0 Months Ended	12 Months Ended
	2-May-12	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Employee
Sale of Interconnect Hardware Development Program [Abstract]
Sale of interconnect hardware development program	$140,000,000
Number of employees joined Intel as part of transaction	73
Net Gain on sale of Interconnect Hardware Development Program	$139,100,000	$0	$0	$139,068,000

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets:
Cash and cash equivalents and restricted cash	$129,507	$206,401
Short-term available-for-sale securities fair value	16,289	14,048
Foreign currency contracts	11,079	1,730
Assets measured at fair value at December 31	156,875	222,179
Liabilities:
Foreign currency contracts	-2,139	-7,237
Liabilities measured at fair value at December 31	2,139	7,237
Quoted Prices in Active Markets (Level 1)
Assets:
Cash and cash equivalents and restricted cash	129,507	206,401
Short-term available-for-sale securities fair value	16,289	14,048
Foreign currency contracts	0	0
Assets measured at fair value at December 31	145,796	220,449
Liabilities:
Foreign currency contracts	0	0
Liabilities measured at fair value at December 31	0	0
Significant Other Observable Inputs (Level 2)
Assets:
Cash and cash equivalents and restricted cash	0	0
Short-term available-for-sale securities fair value	0	0
Foreign currency contracts	11,079	1,730
Assets measured at fair value at December 31	11,079	1,730
Liabilities:
Foreign currency contracts	-2,139	-7,237
Liabilities measured at fair value at December 31	$2,139	$7,237

Fair_Value_Measurements_Outsta

Fair Value Measurements Outstanding notional amounts of forward contracts designated as cash flow hedges (Details) (Designated as Hedging Instrument [Member])

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

Dec. 31, 2013

In Millions, unless otherwise specified

CAD

CHF

EUR (€)

GBP (£)

JPY (¥)

SEK

SGD

CAD

CHF

EUR (€)

GBP (£)

JPY (¥)

SEK

SGD

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Derivative, Notional Amount

0

0.9

€ 40.70

£ 77.9

¥ 0

84.8

0.1

3.9

5.6

€ 53

£ 36.4

¥ 1,239.8

0

3.2

Fair_Value_Measurements_Narrat

Fair Value Measurements Narrative (Details)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014
	USD ($)	USD ($)	USD ($)	Foreign Exchange Forward	Foreign Exchange Forward	Designated as Hedging Instrument [Member]
				USD ($)	USD ($)	GBP (£)
Fair Value Measurement [Abstract]
Hedged foreign currency exposure	$192,500,000	$151,400,000
Derivative, Notional Amount						28,300,000
Foreign Currency Exposure	43,400,000
Fair value of outstanding forward contracts				8,900,000	-5,500,000
Foreign currency gains	$2,069,000	$3,257,000	$4,301,000	$4,400,000	($2,400,000)

Fair_Value_Measurements_Deriva

Fair Value Measurements Derivatives (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]
Foreign currency contracts	$11,079	$1,730
Foreign currency contracts	-2,139	-7,237
Total fair value of derivatives classified as hedging instruments	8,940	-5,507
Foreign currency contracts | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Foreign currency contracts	5,362	1,654
Foreign currency contracts | Other non-current assets
Derivatives, Fair Value [Line Items]
Foreign currency contracts	5,717	76
Foreign currency contracts | Other accrued liabilities
Derivatives, Fair Value [Line Items]
Foreign currency contracts	-1,454	-2,942
Foreign currency contracts | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Foreign currency contracts	($685)	($4,295)

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Gross of Tax Reclassifications	$2,748	($1,604)	$643
Net of Tax Reclassifications	1,649	-962	386
Unrealized Gain on Investments
Beginning balance	0	-46
Current-period change, net of tax	12	46
Ending balance	12	0	-46
Income tax expense (benefit) associated with current-period change	8	31
Foreign Currency Translation Adjustments
Beginning balance	3,257	4,301
Current-period change, net of tax	-1,188	-1,044
Ending balance	2,069	3,257	4,301
Income tax expense (benefit) associated with current-period change	-229	27
Unrealized Gain/(Loss) on Cash Flow Hedges
Beginning balance	-2,404	926
Current-period change, net of tax	6,826	-3,330
Ending balance	4,422	-2,404	926
Income tax expense (benefit) associated with current-period change	4,593	-2,390
Accumulated Other Comprehensive Income
Beginning balance	853	5,181
Current-period change, net of tax	5,650	-4,328
Ending balance	6,503	853	5,181
Income tax expense (benefit) associated with current-period change	$4,372	($2,332)

Investments_Details

Investments (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Short-term available-for-sale securities cost	$16,269	$14,048
Short-term available-for-sale securities unrealized gains	20	0
Short-term available-for-sale securities fair value	$16,289	$14,048

Accounts_and_Other_Receivables2

Accounts and Other Receivables, Net (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$165,210	$182,684
Net accounts and other receivables
Allowance for doubtful accounts	-97	-157
Accounts and other receivables, net	165,113	182,527
Trade accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	126,874	169,417
Advance billings
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	4,960	2,141
Short-term investment in sales-type lease
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	10,187	0
Other receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	2,401	2,051
Unbilled receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$20,788	$9,075

Accounts_and_Other_Receivables3

Accounts and Other Receivables, Net Narrative (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$165,210	$182,684
US. government agencies and customers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	87,000	111,900
Accounts Receivable | Non US government customers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of non-U.S. customers that individually accounted for more than 10% of total accounts and other receivables	0
Non-U.S. government customers that accounted for total accounts and other receivables, percentage		10.00%
Unbilled receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	20,788	9,075
Unbilled receivables | US. government agencies and customers
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$2,100	$300

Salestype_lease_Details

Sales-type lease (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Leases [Abstract]
Total minimum lease payments to be received	$53,134
Less: executory costs	-10,717
Net minimum lease payments receivable	42,417
Estimated residual value of leased property (unguaranteed)	1,253
Less: unearned income	-2,394
Net investment in sales-type lease	41,276
Long-term investment in sales-type lease, net	-31,089	0
Investment in sales-type lease included in accounts and other receivables	10,187
Capital Leases, Future Minimum Payments Receivable, Fiscal Year Maturity [Abstract]
2015	14,169
2016	14,169
2017	14,169
2018	10,627
Total minimum lease payments to be received	$53,134

Inventory_Details

Inventory (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Components and subassemblies	$60,851	$46,339
Work in process	46,954	23,618
Finished goods	35,827	25,172
Total	$143,632	$95,129

Inventory_Narrative_Details

Inventory Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Inventory [Line Items]
Finished goods inventory located at customer sites pending acceptance	$35,300,000	$24,800,000
Inventory write-down	2,330,000	917,000	2,329,000
Finished Goods Inventory
Inventory [Line Items]
Number of customer that individually accounted for more than 10% of finished goods inventory	2	1
Amount of total finished goods inventory from customers that individually accounted for more than 10% of total finished goods inventory	$31,200,000	$18,000,000

Property_and_Equipment_Net_Det

Property and Equipment, Net (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$94,113,000	$124,419,000
Accumulated depreciation and amortization	-59,320,000	-94,141,000
Property and equipment, net	34,793,000	30,278,000
Depreciation, Depletion and Amortization [Abstract]
Depreciation	12,800,000	10,900,000	7,400,000
Land
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	275,000	203,000
Buildings
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	20,409,000	17,022,000
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	13,198,000	14,443,000
Computer equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	59,785,000	91,475,000
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$446,000	$1,276,000

Service_Spares_Net_Details

Service Spares, Net (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Service spares	$13,114	$16,613
Accumulated depreciation	-11,246	-14,785
Service spares, net	$1,868	$1,828

Service_Spares_Net_Narrative_D

Service Spares, Net Narrative (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Inventory Disclosure [Abstract]
Other Depreciation and Amortization	$1	$0.90	$0.90

Deferred_Revenue_Details

Deferred Revenue (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	$113,498,000	$141,965,000
Less long-term deferred revenue	-47,588,000	-50,477,000
Deferred revenue in current liabilities	65,910,000	91,488,000
Deferred product revenue
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	21,152,000	54,065,000
Deferred service revenue
Deferred Revenue Arrangement [Line Items]
Total deferred revenue	$92,346,000	$87,900,000

Deferred_Revenue_Narrative_Det

Deferred Revenue Narrative (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Deferred Revenue Arrangement [Line Items]
Deferred Revenue	$113,498,000	$141,965,000
US. government agencies and customers
Deferred Revenue Arrangement [Line Items]
Deferred Revenue	63,800,000	49,200,000
Non US government customers
Deferred Revenue Arrangement [Line Items]
Deferred Revenue		52,000,000
Deferred Revenue Maximum Percentage	10.00%
Non US government customers | Number of Customers [Member]
Deferred Revenue Arrangement [Line Items]
Deferred Revenue	$0	$2

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Commitments [Line Items]
Rent expense	$5,200,000	$5,300,000	$4,600,000
Research and development, net	94,048,000	87,728,000	64,303,000
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating Leases, 2015	5,097,000
Operating Leases, 2016	4,762,000
Operating Leases, 2017	4,563,000
Operating Leases, 2018	4,373,000
Operating Leases, 2019	4,266,000
Operating Leases, Thereafter	14,563,000
Minimum contractual commitments	37,624,000
Other Commitment, Fiscal Year Maturity [Abstract]
Minimum contractual commitments	6,956,000
Development Agreements
Other Commitments [Line Items]
Research and development, net	12,200,000	9,300,000	4,900,000
Other Commitment, Fiscal Year Maturity [Abstract]
Development Agreements, 2015	6,856,000
Development Agreements, 2016	25,000
Development Agreements, 2017	25,000
Development Agreements, 2018	25,000
Development Agreements, 2019	25,000
Development Agreements, Thereafter	$0

Income_Taxes_Narrative_Details

Income Taxes Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest [Abstract]
United States	$5,710,000	$17,467,000	$161,592,000
International	3,987,000	3,562,000	7,140,000
Income before income taxes	9,697,000	21,029,000	168,732,000
Operating Loss Carryforwards [Line Items]
Income tax benefit (expense)	-52,626,000	-11,194,000	7,491,000
Change in amount of deferred tax assets	67,700,000	4,700,000	27,900,000
Three year cumulative U.S. pre-tax income	184,800,000
Three year cumulative U.S. pre-tax income, excluding impact of sale of interconnect hardware development program	51,100,000
Stock compensation adjustment	0	-8,419,000	0
Cash and cash equivalents	112,633,000	192,633,000	253,065,000	50,411,000
Foreign Subsidiaries
Operating Loss Carryforwards [Line Items]
Cash and cash equivalents	42,200,000
Interconnect Hardware Development Program
Operating Loss Carryforwards [Line Items]
Change in amount of deferred tax assets			18,400,000
Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	21,300,000
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	115,400,000
Stock based income tax deductions in excess of amounts recognized	37,900,000
Change in amount of deferred tax assets	55,700,000	13,500,000	10,700,000
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$7,000,000

Income_Taxes_Tax_Provision_Det

Income Taxes Tax Provision (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current provision (benefit):
Federal	$230	$484	$1,162
State	-392	696	2,768
Foreign	740	801	541
Total current provision	578	1,981	4,471
Deferred provision (benefit):
Federal	-53,242	-13,160	1,362
State	-885	-327	1,415
Foreign	923	312	243
Total deferred provision (benefit)	-53,204	-13,175	3,020
Total provision (benefit) for income taxes	($52,626)	($11,194)	$7,491

Income_Taxes_Reconciliation_of

Income Taxes Reconciliation of Statutory Federal Tax Rate (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Income tax provision at statutory rate	$3,394	$7,360	$59,056
State taxes, net of federal benefit	-217	369	4,183
Foreign income taxes	284	-749	-518
Stock compensation adjustment	0	-8,419	0
Deemed dividends for U.S. income tax purposes	492	477	2,352
Nondeductible expenses	337	208	549
Liquidation of subsidiary	0	0	-30,704
Disallowed compensation	-116	19	492
Research and development tax credit	-1,140	-5,736	0
Effect of change in valuation allowance on deferred tax assets	-55,660	-4,723	-27,919
Total provision (benefit) for income taxes	($52,626)	($11,194)	$7,491

Income_Taxes_Deferred_Tax_Asse

Income Taxes Deferred Tax Assets and Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred Tax Assets, Net [Abstract]
Inventory	$5,840	$3,388
Accrued compensation	681	460
Deferred revenue	18,186	12,100
Net operating loss carryforwards	12,981	5,922
Other	1,261	8,120
Gross current deferred tax assets	38,949	29,990
Valuation allowance	-2,039	-20,107
Current deferred tax assets	36,910	9,883
Other	-837	-688
Current deferred tax liabilities	-837	-688
Net current deferred tax assets	36,073	9,195
Property and equipment	11,555	328
Research and experimentation credit carryforwards	24,596	23,941
Net operating loss carryforwards	21,511	47,154
Goodwill	203	628
Other	9,967	10,161
Gross long-term deferred tax assets	67,832	82,212
Valuation allowance	-8,099	-57,687
Long-term deferred tax assets	59,733	24,525
Property and equipment	0	-1,905
Investment in sales-type lease, net	-14,321	0
Intangible assets	-1,215	-2,059
Other	-2,783	-1,355
Long-term deferred tax liabilities	-18,319	-5,319
Net long-term deferred tax asset	$41,414	$19,206

Income_Taxes_Unrecognized_Tax_

Income Taxes Unrecognized Tax Benefits (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	$5,059,000
Balance of unrecognized tax benefits that if recognized would affect the effective tax rate	5,600,000
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at December 31,	202,000	470,000	0
Increase related to current year income tax positions	369,000		470,000
Decrease related to prior year income tax positions		-268,000
Balance at December 31,	$5,630,000	$202,000	$470,000

Credit_Facilities_Details

Credit Facilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Line of Credit Facility [Line Items]
Letters of Credit Outstanding, Amount	$13,500,000
Restricted cash	16,874,000	0
Wells Fargo Bank
Line of Credit Facility [Line Items]
Amount of credit facility	10,000,000
Silicon Valley Bank
Line of Credit Facility [Line Items]
Amount of credit facility	$11,000,000

Shareholders_Equity_Assumption

Shareholders' Equity Assumptions (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Key weighted average assumptions used in determining fair value
Risk-free interest rate (percent)	1.22%	0.98%	0.56%
Expected dividend yield (percent)	0.00%	0.00%	0.00%
Volatility (percent)	52.43%	50.45%	74.84%
Expected life (in years)	4 years	4 years	4 years
Weighted average Black-Scholes value of options granted (usd per share)	$11.16	$8.22	$6.56
Estimated forfeiture rates (percent)	8.30%	10.00%	6.60%

Option_Activity_Details

Option Activity (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock option activity
Outstanding beginning balance (In Shares)	2,078,069	2,293,505	3,417,920
Grants (In Shares)	323,900	346,360	359,500
Exercises (In Shares)	-411,352	-495,221	-1,346,326
Cancellations (In Shares)	-59,627	-66,575	-137,589
Outstanding ending balance (In Shares)	1,930,990	2,078,069	2,293,505
Exercisable ending balance (In Shares)	1,251,080
Available for grant ending balance (In Shares)	3,079,888
Weighted Average Exercise Price
Outstanding beginning balance (Per Share)	$9.29	$7.31	$6.28
Grants (Per Share)	$26.92	$20.65	$11.90
Exercises (Per Share)	$7.50	$6.38	$5.52
Cancellations (Per Share)	$18.45	$21.97	$11.35
Outstanding ending balance (Per Share)	$12.34	$9.29	$7.31
Exercisable ending balance (Per Share)	$8.18
Weighted Average Remaining Contractual Term
Outstanding ending balance	6 years 7 months 6 days
Exercisable ending balance	5 years 7 months 6 days

Restricted_Stock_Details

Restricted Stock (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding beginning balance (In Shares)	2,221,700	2,202,738	1,302,414
Granted (In Shares)	463,734	755,979	1,316,447
Forfeited (In Shares)	-411,653	-75,437	-31,771
Vested (In Shares)	-423,179	-661,580	-384,352
Outstanding ending balance (In Shares)	1,850,602	2,221,700	2,202,738
Unvested restricted stock grants and restricted stock units changes
Outstanding beginning balance (Per Share)	$13.97	$9.27	$5.47
Granted (Per Share)	$28.74	$20.93	$11.99
Forfeited (Per Share)	$16.80	$14.48	$7.64
Vested (Per Share)	$11.14	$6.22	$5.86
Outstanding ending balance (Per Share)	$17.68	$13.97	$9.27
Service Vesting Restricted Shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding beginning balance (In Shares)	1,127,700	1,465,738	1,302,414
Granted (In Shares)	463,734	326,979	579,447
Forfeited (In Shares)	-134,653	-3,437	-31,771
Vested (In Shares)	-423,179	-661,580	-384,352
Outstanding ending balance (In Shares)	1,033,602	1,127,700	1,465,738
Unvested restricted stock grants and restricted stock units changes
Outstanding beginning balance (Per Share)	$12.05	$7.44	$5.47
Granted (Per Share)	$28.74	$20.83	$10.84
Forfeited (Per Share)	$15.39	$5.92	$7.64
Vested (Per Share)	$11.14	$6.22	$5.86
Outstanding ending balance (Per Share)	$19.48	$12.05	$7.44
Performance Vesting Restricted Shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding beginning balance (In Shares)	1,094,000	737,000	0
Granted (In Shares)	0	429,000	737,000
Forfeited (In Shares)	-277,000	-72,000	0
Vested (In Shares)	0	0	0
Outstanding ending balance (In Shares)	817,000	1,094,000	737,000
Unvested restricted stock grants and restricted stock units changes
Outstanding beginning balance (Per Share)	$15.94	$12.90	$0
Granted (Per Share)	$0	$21	$12.90
Forfeited (Per Share)	$17.49	$14.88	$0
Vested (Per Share)	$0	$0	$0
Outstanding ending balance (Per Share)	$15.41	$15.94	$12.90

Shareholders_Equity_Exercise_P

Shareholders' Equity Exercise Price Range (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower Range		$0
Upper Range		$34.15
Number Outstanding (In Shares)	1,930,990
Weighted Average Remaining Life (Years)	6 years 7 months 6 days
Weighted Average Exercise Price (USD Per Share)	$12.34
Number Exercisable (In Shares)	1,251,080
Weighted Average Exercise Price (In USD Per Share)	$8.18
$ 0.00 - $ 4.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower Range		$0
Upper Range		$4
Number Outstanding (In Shares)	265,142
Weighted Average Remaining Life (Years)	4 years 3 months 18 days
Weighted Average Exercise Price (USD Per Share)	$3.71
Number Exercisable (In Shares)	265,142
Weighted Average Exercise Price (In USD Per Share)	$3.71
$ 4.01 - $ 6.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower Range		$4.01
Upper Range		$6
Number Outstanding (In Shares)	240,647
Weighted Average Remaining Life (Years)	5 years 1 month 6 days
Weighted Average Exercise Price (USD Per Share)	$5.49
Number Exercisable (In Shares)	240,647
Weighted Average Exercise Price (In USD Per Share)	$5.49
$ 6.01 - $ 8.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower Range		$6.01
Upper Range		$8
Number Outstanding (In Shares)	438,159
Weighted Average Remaining Life (Years)	5 years 8 months 12 days
Weighted Average Exercise Price (USD Per Share)	$6.29
Number Exercisable (In Shares)	360,553
Weighted Average Exercise Price (In USD Per Share)	$6.33
$ 8.01 - $ 34.15
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Lower Range		$8.01
Upper Range		$34.15
Number Outstanding (In Shares)	987,042
Weighted Average Remaining Life (Years)	8 years 1 month 6 days
Weighted Average Exercise Price (USD Per Share)	$19.01
Number Exercisable (In Shares)	384,738
Weighted Average Exercise Price (In USD Per Share)	$14.68

Expense_Details

Expense (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Gross share-based compensation cost recorded in the condensed consolidated statements of operations
Gross share-based compensation, total	$10,364	$7,239	$5,963
Cost of product revenue
Gross share-based compensation cost recorded in the condensed consolidated statements of operations
Gross share-based compensation, total	229	135	57
Cost of service revenue
Gross share-based compensation cost recorded in the condensed consolidated statements of operations
Gross share-based compensation, total	255	229	258
Research and development
Gross share-based compensation cost recorded in the condensed consolidated statements of operations
Gross share-based compensation, total	2,721	1,480	1,327
Sales and marketing
Gross share-based compensation cost recorded in the condensed consolidated statements of operations
Gross share-based compensation, total	3,152	2,230	1,717
General and administrative
Gross share-based compensation cost recorded in the condensed consolidated statements of operations
Gross share-based compensation, total	$4,007	$3,165	$2,604

Narrative_Details

Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, shares authorized	5,000,000	5,000,000
Common stock, shares authorized	75,000,000	75,000,000
Common stock, par value	$0.01	$0.01
Restricted stock issued (In Shares)	463,734	755,979	1,316,447
Grant date fair value of restricted stock issued (In USD)	$3,086,000	$3,161,000	$7,430,000
Amount remaining to be expensed (In USD)	24,000,000
Unrecognized compensation cost for performance vesting restricted stock subject to performance measures which are not considered probable to vest (In USD)	12,400,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Excluding Performance Vesting Restricted Stock	17,000,000
Unrecognized compensation cost for performance vesting restricted stock subject to performance measures which are considered probable to vest (In USD)	200,000
Issued and outstanding restricted stock units (In Shares)	1,850,602	2,221,700	2,202,738	1,302,414
Expected average period options will be exercised after vesting (In Years)	2 years
Aggregate intrinsic value of outstanding stock options (In USD)	42,800,000
Aggregate intrinsic value of exercisable stock options (In USD)	32,900,000
Total intrinsic value of shares exercised (In USD)	10,200,000	7,900,000	7,600,000
Estimated Forfeiture Rate for Restricted Stock (Percentage)	6.30%
Performance Vesting Restricted Stock Subject To Performance Measures Which Are Currently Not Considered Probable To Vest (In Shares)	804,500	1,081,500	737,000
Unrecognized compensation cost, weighted average recognition period (In Years)	2 years 10 months 24 days
Shares issued under ESPP	1,043,228	1,022,610	998,118
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for grant (In Shares)	1,750,000
Percentage of pay permitted to acquire shares of common stock	15.00%
Percentage of closing market price for purchase price	95.00%
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issued and outstanding restricted stock units (In Shares)	0	0	12,500
Restricted Stock and Restricted Stock Units (RSU's)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value of restricted stock issued (In USD)	13,300,000	15,800,000	15,800,000
Aggregate fair value of restricted stock vested (In USD)	11,900,000	14,000,000	4,200,000
Unrecognized compensation cost (In USD)	$29,400,000
NonEmployee Director | Restricted Stock and Restricted Stock Units (RSU's)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock options (In Years)	2 years
Officers and Key Employees | Restricted Stock and Restricted Stock Units (RSU's)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of stock options (In Years)	4 years

Benefit_Plans_Details

Benefit Plans (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
United States Pension Plan of US Entity
Defered Compensation Arrangement with Individual [Line Items]
Company match expense	$1.60	$1.20	$1
Foreign Pension Plans, Defined Benefit
Defered Compensation Arrangement with Individual [Line Items]
Projected benefit	2.3	2.6
Funded status of plan	$0.20	$0.20

Business_Segment_Details

Business Segment (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Information of Operating Segments
Revenue:	$261,943	$159,406	$85,147	$55,110	$307,369	$54,366	$84,467	$79,547	$561,606	$525,749	$421,058
Gross Profit:	88,943	48,530	29,004	17,937	112,949	20,426	26,801	24,150	184,414	184,326	151,178
Supercomputing
Information of Operating Segments
Revenue:									459,729	434,133	355,736
Gross Profit:									146,565	143,440	128,723
Storage and Data Management
Information of Operating Segments
Revenue:									84,412	76,955	55,009
Gross Profit:									31,572	31,403	16,574
Maintenance & Support
Information of Operating Segments
Revenue:									86,573	77,817	62,245
Gross Profit:									38,819	38,476	25,735
Engineering Services and Other
Information of Operating Segments
Revenue:									17,465	14,661	10,313
Gross Profit:									6,277	9,483	5,881
Elimination of inter-segment revenue
Information of Operating Segments
Revenue:									-86,573	-77,817	-62,245
Gross Profit:									($38,819)	($38,476)	($25,735)

Geographic_Segment_Details

Geographic Segment (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Product revenue	$460,748	$436,330	$353,767
Service revenue	100,858	89,419	67,291
Long-lived assets	95,660	65,056	62,009
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Product revenue	253,930	297,583	301,162
Service revenue	72,434	62,072	42,359
Long-lived assets	58,868	58,910	57,549
All Other Countries
Revenues from External Customers and Long-Lived Assets [Line Items]
Product revenue	206,818	138,747	52,605
Service revenue	28,424	27,347	24,932
Long-lived assets	$36,792	$6,146	$4,460

Segment_Information_Narrative_

Segment Information Narrative (Details) (USD $)	3 Months Ended								12 Months Ended			9 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014
Revenue, Major Customer [Line Items]
Long-term investment in sales-type lease, net	($31,089)				$0				($31,089)	$0
Revenue	261,943	159,406	85,147	55,110	307,369	54,366	84,467	79,547	561,606	525,749	421,058
US. government agencies and customers
Revenue, Major Customer [Line Items]
Revenue									$272,000	$266,100	$286,900
Non US government customers
Revenue, Major Customer [Line Items]
Revenue Maximum Percentage									10.00%
Percentage of total revenue from customers that individually accounted for more than 10% of total revenue										11.00%	13.00%
Revenue
Revenue, Major Customer [Line Items]
Number of foreign countries that individually accounted for more than 10% of total revenue	0				1				0	1	1
UK and Germany [Member]
Revenue, Major Customer [Line Items]
Percentage of total revenue from customers that individually accounted for more than 10% of total revenue												23.00%
All Other Countries
Revenue, Major Customer [Line Items]
Percentage of total revenue from customers that individually accounted for more than 10% of total revenue									10.00%
All Other Countries | Revenue
Revenue, Major Customer [Line Items]
Number of foreign countries that individually accounted for more than 10% of total revenue	0								0

Segment_Information_Longlived_

Segment Information Long-lived assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-term investment in sales-type lease, net	$31,089	$0

Research_and_Development_Detai

Research and Development (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Research and Development [Abstract]
Gross research and development expenses	$104,797	$92,469	$86,305
Less: Amounts included in cost of revenue	-7,713	-3,741	-1,080
Less: Reimbursed research and development (excludes amounts in revenue)	-3,036	-1,000	-20,922
Net research and development expenses	$94,048	$87,728	$64,303

Interest_Income_Expense_Detail

Interest Income (Expense) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Income and Expenses [Abstract]
Interest income	$643	$894	$397
Interest expense	-137	-137	-193
Interest Income (Expense), Net	$506	$757	$204

Quarterly_Data_Unaudited_Detai

Quarterly Data (Unaudited) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Selected Quarterly Financial Information [Abstract]
Revenue	$261,943	$159,406	$85,147	$55,110	$307,369	$54,366	$84,467	$79,547	$561,606	$525,749	$421,058
Cost of revenue	173,000	110,876	56,143	37,173	194,420	33,940	57,666	55,397	377,192	341,423	269,880
Gross profit	88,943	48,530	29,004	17,937	112,949	20,426	26,801	24,150	184,414	184,326	151,178
Research and development, net	24,735	22,503	24,189	22,621	25,979	21,555	19,968	20,226
Sales and marketing	17,942	14,808	13,259	11,776	17,172	11,480	11,550	11,143	57,785	51,345	37,180
General and administrative	6,839	5,813	5,316	5,413	8,063	4,970	5,085	5,485	23,381	23,603	20,707
Net income	$74,638	$7,371	($6,748)	($12,938)	$51,007	($11,025)	($150)	($7,609)	$62,323	$32,223	$161,241
Net income (loss) per common share, basic	$1.92	$0.19	($0.18)	($0.34)	$1.33	($0.29)	$0	($0.20)	$1.61	$0.85	$4.42
Net income (loss) per common share, diluted	$1.84	$0.18	($0.18)	($0.34)	$1.27	($0.29)	$0	($0.20)	$1.54	$0.81	$4.27

Schedule_II_Valuation_and_Qual1

Schedule II - Valuation and Qualifying Accounts (Details) (Allowance for Trade Receivables, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for Trade Receivables
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$157	$5	$110
Charge/(Benefit) to Expense	22	179	-62
Deductions (2)	-82	-27	-43
Balance at End of Period	$97	$157	$5