Cray (CRAY) 10-K 15 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 13, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,017
Entity Registrant Name	CRAY INC
Entity Central Index Key	949,158
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		40,475,586
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	Yes
Entity Public Float			$ 730,642,233

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 137,326	$ 222,962
Restricted cash	1,964	0
Short-term investments	6,997	0
Accounts and other receivables, net	162,034	197,941
Inventory	186,307	88,254
Prepaid expenses and other current assets	25,015	20,006
Total current assets	519,643	529,163
Noncurrent Assets:
Long-term restricted cash	1,030	1,655
Long-term investment in sales-type lease, net	23,367	31,050
Property and equipment, net	36,623	30,620
Service inventory, net	2,551	3,023
Goodwill	14,182	14,182
Purchased intangible assets, net	4,345	1,637
Deferred tax asset	1,106	85,613
Other non-current assets	15,910	17,629
TOTAL ASSETS	618,757	714,572
Current liabilities:
Accounts payable	57,207	45,504
Accrued payroll and related expenses	18,546	17,199
Other accrued liabilities	9,471	10,303
Deferred revenue	80,119	83,129
Total current liabilities	165,343	156,135
Noncurrent Liabilities:
Long-term deferred revenue	38,622	27,258
Other non-current liabilities	14,495	5,703
TOTAL LIABILITIES	218,460	189,096
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	633,408	622,604
Accumulated other comprehensive income	915	2,782
Accumulated deficit	(234,026)	(99,910)
TOTAL SHAREHOLDERS’ EQUITY	400,297	525,476
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 618,757	$ 714,572

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
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	40,464,693	40,693,707
Common stock and additional paid-in capital, shares outstanding	40,464,693	40,693,707

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Product	$ 250,195	$ 499,432	$ 601,294
Service	142,314	130,377	123,395
Total revenue	392,509	629,809	724,689
Cost of revenue:
Cost of product revenue	188,830	332,016	426,821
Cost of service revenue	72,975	77,578	72,185
Total cost of revenue	261,805	409,594	499,006
Gross profit	130,704	220,215	225,683
Operating expenses:
Research and development, net	98,777	112,130	96,563
Sales and marketing	59,894	64,893	60,150
General and administrative	29,113	34,053	27,966
Restructuring	8,568	0	0
Total operating expenses	196,352	211,076	184,679
Income from operations	(65,648)	9,139	41,004
Other income (expense), net	5,002	(1,365)	365
Interest income (expense), net	3,276	2,147	1,408
Gain on strategic transaction	4,480	0	0
Income before income taxes	(52,890)	9,921	42,777
Income tax benefit (expense)	(80,939)	694	(15,240)
Net income	$ (133,829)	$ 10,615	$ 27,537
Basic net income (loss) per common share (dollars per share)	$ (3.33)	$ 0.27	$ 0.70
Diluted net income (loss) per common share (dollars per share)	$ (3.33)	$ 0.26	$ 0.68
Basic weighted average shares outstanding (shares)	40,139	39,833	39,257
Diluted weighted average shares outstanding (shares)	40,139	41,012	40,691

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ (133,829)	$ 10,615	$ 27,537
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Unrealized loss on available-for-sale investments	(7)	8	(20)
Foreign currency translation adjustments	(490)	426	(394)
Unrealized gain (loss) on cash flow hedges	(1,457)	8,030	5,251
Reclassification adjustments on cash flow hedges included in net income	87	(13,324)	(3,698)
Other comprehensive income (loss)	(1,867)	(4,860)	1,139
Comprehensive income (loss)	$ (135,696)	$ 5,755	$ 28,676

Consolidated Statements of Shar

Consolidated Statements of Shareholders’ Equity - USD ($) $ in Thousands	Total	Common Stock and Additional Paid In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	New Accounting Pronouncement, Early Adoption, Effect	New Accounting Pronouncement, Early Adoption, EffectAccumulated Deficit
Balance, shares at Dec. 31, 2014		40,822,000
Balance at Dec. 31, 2014	$ 453,854	$ 598,390	$ 6,503	$ (151,039)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under employee stock purchase plan, shares		27,000
Issuance of shares under employee stock purchase plan	$ 711	$ 711
Exercise of stock options, shares	229,118	229,000
Exercise of stock options	$ 2,289	$ 2,289
Restricted shares issued for compensation, net of forfeitures, shares		(384,000)
Restricted shares issued for compensation, net of forfeitures and taxes	(4,373)	$ (2,464)		(1,909)
Share-based compensation	11,353	$ 11,353
Other comprehensive income (loss)	1,139		1,139
Net income	27,537			27,537
Balance, shares at Dec. 31, 2015		40,694,000
Balance at Dec. 31, 2015	492,510	$ 610,279	7,642	(125,411)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	(5,013)
Balance, shares at Dec. 31, 2015		40,694,000
Balance at Dec. 31, 2015	492,510	$ 610,279	7,642	(125,411)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of shares under employee stock purchase plan, shares		27,000
Issuance of shares under employee stock purchase plan	$ 718	$ 718
Exercise of stock options, shares	168,825	169,000
Exercise of stock options	$ 2,121	$ 2,121
Restricted shares issued for compensation, net of forfeitures, shares		(133,000)
Restricted shares issued for compensation, net of forfeitures and taxes	(3,379)	$ (1,665)		(1,714)
Share-based compensation	11,151	$ 11,151
Other comprehensive income (loss)	(4,860)		(4,860)
Net income	$ 10,615			10,615
Balance, shares at Dec. 31, 2016	40,693,707	40,757,000
Balance at Dec. 31, 2016	$ 525,476	$ 622,604	2,782	(99,910)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative-effect adjustment resulting from adoption of ASU 2016-09 (Note 14) | Accounting Standards Update 2016-09						$ 16,600
Cumulative-effect adjustment resulting from adoption of ASU 2016-09 (Note 14) | Accounting Standards Update 2016-09					$ 16,600	$ 16,600
Issuance of shares under employee stock purchase plan, shares		20,000
Issuance of shares under employee stock purchase plan	$ 365	$ 365
Exercise of stock options, shares	157,257	157,000
Exercise of stock options	$ 1,342	$ 1,342
Restricted shares issued for compensation, net of forfeitures, shares		(469,000)
Restricted shares issued for compensation, net of forfeitures and taxes	(2,039)	$ (1,752)		(287)
Share-based compensation	10,849	$ 10,849
Other comprehensive income (loss)	(1,867)		(1,867)
Net income	$ (133,829)			(133,829)
Balance, shares at Dec. 31, 2017	40,464,693	40,465,000
Balance at Dec. 31, 2017	$ 400,297	$ 633,408	$ 915	$ (234,026)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Statement of Cash Flows [Abstract]
Interest Paid	$ 14	$ 31
Operating activities:
Net income	(133,829)	10,615	$ 27,537
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	16,760	14,684	17,017
Share-based compensation expense	10,849	11,151	11,353
Deferred income taxes	81,468	(1,861)	12,103
Gain on strategic transaction	(4,480)	0	0
Gain on sale of equity investment	(3,349)	0	0
Other	837	2,850	1,945
Cash (used in) provided by operations due to changes in operating assets and liabilities:
Accounts and other receivables	38,660	(78,396)	36,665
Long-term investment in sales-type lease, net	10,129	(17,224)	11,510
Inventory	(97,688)	15,343	21,292
Prepaid expenses and other assets	(5,306)	2,265	(3,972)
Accounts payable	11,527	16,903	(19,849)
Accrued payroll and related expenses and other accrued liabilities	7,572	(21,073)	23,841
Deferred revenue	(6,491)	(7,570)	8,314
Net cash (used in) provided by operating activities	(73,341)	(52,313)	147,756
Investing activities:
Sales/maturities of short-term investments	87,513	30,990	16,229
Purchases of available-for-sale investments	(94,902)	(16,159)	(14,991)
Cash received in strategic transaction	8,000	0	0
Proceeds from sale of equity investment	(4,481)	0	0
Decrease in restricted cash	(1,288)	1,670	13,445
Purchases of property and equipment	(17,467)	(7,503)	(7,467)
Net cash provided by (used in) investing activities	(13,663)	8,998	7,216
Financing activities:
Proceeds from issuance of common stock through employee stock purchase plan	365	718	711
Purchase of employee restricted shares to fund related statutory tax withholding	(2,039)	(3,379)	(4,373)
Proceeds from exercise of options	1,342	2,121	2,289
Net cash provided by financing activities	(332)	(540)	(1,373)
Effect of foreign exchange rate changes on cash and cash equivalents	1,700	157	428
Net increase (decrease) in cash and cash equivalents	(85,636)	(43,698)	154,027
Cash and cash equivalents:
Beginning of period	222,962	266,660	112,633
End of period	137,326	222,962	266,660
Supplemental disclosure of cash flow information:
Cash paid for interest			4
Cash paid for income taxes	930	2,441	3,890
Non-cash investing and financing activities:
Inventory transfers to fixed assets and service inventory	2,429	5,292	8,177
Receivable from Seagate	1,782	0	0
Inventory	4,120	0	0
Property and equipment	2,915	0	0
Intangible assets	3,350	0	0
Deferred revenue	12,168	0	0
Deferred tax liabilities	3,019	0	0
Other liabilities	$ 500	$ 0	$ 0

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	DESCRIPTION OF BUSINESS Cray Inc. (Cray or the Company) designs, develops, manufactures, markets and services products primarily at the high-end of the high performance computing (HPC) and data analytics and artificial intelligence (AI) markets. These products include compute systems commonly known as supercomputers, and storage, data analytics and AI solutions leveraging more than four decades of delivering the world’s most advanced computing systems. The Company also provides related software, system maintenance and support and engineering services. The Company’s customers include domestic and foreign government and government-funded entities, academic institutions and commercial entities.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
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 (GAAP). Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All material 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 (loss) 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, 2017 and 2016 , the Company had $3.0 million and $1.7 million , respectively, in restricted cash associated with certain letters of credit to secure customer prepayments and other customer related obligations. 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 foreign currency exchange contracts to hedge certain foreign currency exposures. Foreign currency exchange 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. Most of the Company’s foreign currency exchange contracts are designated as cash flow hedges for the purposes of hedge accounting treatment and any gains or losses on the effective portion of the foreign currency exchange 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 foreign currency exchange 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 foreign currency exchange contract and expected cash flows based on changes in the spot prices of the underlying currencies. Cash flows from foreign currency exchange contracts accounted for as cash flow hedges are classified in the same category as the cash flows from the items being hedged. Unrealized gains or losses related to foreign currency exchange contracts that are not designated as cash flow hedges for the purposes of hedge accounting treatment are recorded in other income (expense) in the Consolidated Statements of Operations and are generally offset by foreign currency adjustments on related receivables. 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 foreign currency exchange contracts. The Company maintains cash and cash equivalents, available-for-sale securities and foreign currency exchange 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 foreign currency exchange 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 the U.S. Government. See Note 18 — 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 8 — 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 4 — Fair Value Measurement for a further discussion on fair value of financial instruments. Inventories Inventories are valued at the lower of cost or net realizable value, with cost computed on a first-in, first-out basis (FIFO). 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 net realizable value. Prior to the adoption of ASU 2015-11 at the beginning of the first quarter of 2017, inventories were valued at the lower of cost or market. The adoption of ASU 2015-11 did not have a material impact on the Company’s consolidated financial statements. 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 or there is an expected scrap value 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 net realizable value 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 ). Prior to the adoption of ASU 2015-11 at the beginning of the first quarter of 2017, service spares were valued at the lower of cost or market. The adoption of ASU 2015-11 did not have a material impact on the Company’s consolidated financial statements. 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 and whenever events or changes in circumstances indicate that the fair value of a reporting unit may be less than its carrying amount (a triggering event). In the second quarter of 2017, the Company determined that declining revenues in recent years, coupled with the anticipated loss for 2017, should be construed as a triggering event for the purposes of impairment testing of goodwill in accordance with ASC 350. The Company performed a quantitative goodwill impairment test on June 30, 2017. Due to the proximity of the triggering event to the October 1 annual testing date, the Company has elected to change the date of its annual goodwill impairment test from the beginning of its fourth fiscal quarter to the beginning of its second fiscal quarter. 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 quantitative 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 quantitative goodwill 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 quantitative goodwill impairment test. In performing the quantitative goodwill impairment test, 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. If the carrying value of a reporting unit exceeds its fair value, the Company records an impairment loss equal to the difference. The Company performed a quantitative goodwill impairment test during the second fiscal quarter of 2017 and concluded that the fair values of its reporting units were greater than their carrying amounts. Business Combinations The Company accounts for business combinations using the purchase 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 excess of the purchase price over the fair value of the net assets acquired is recorded as goodwill. If the fair value of the net assets acquired exceeds the purchase price the Company records a bargain purchase gain. The Company uses estimates and assumptions to 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 in the period in which the adjustments are recognized. 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 (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 (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 (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 of the product 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 (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 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 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 $1.7 million and $1.6 million for 2017 and 2015 , respectively. Net transaction losses were $1.0 million for 2016 . 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. Amounts to be received under co-funding arrangements with the U.S. government or others 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 will not be realized through future operations. This assessment is based upon consideration of all available positive and negative evidence, which includes, among other things, the Company’s recent results of operations, forecasted domestic and international earnings over a number of years, all known business risks and industry trends, and applicable tax planning strategies that should, if implemented, enable the Company to utilize its deferred tax assets before they expire. 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 has significant difficulty projecting future results due to the nature of the business and the industry in which it operates. The Company provided a valuation allowance against its U.S. deferred tax assets and against the majority of its deferred tax assets arising in foreign jurisdictions at December 31, 2017 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 benefit in its Consolidated Statements of Operations when that occurs. 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 th

Strategic Transaction

Strategic Transaction	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Strategic Transaction	STRATEGIC TRANSACTION On September 25, 2017, the Company completed a strategic transaction with Seagate Cloud Systems Inc. (Seagate) centered around the transfer of Seagate’s ClusterStor high-performance storage business (ClusterStor) to Cray. The ClusterStor business consists of the ClusterStor L300, ClusterStor L300N and the ClusterStor SL220 storage solutions. The Company will sell, support, develop, manufacture, and test the ClusterStor storage solutions. The addition of ClusterStor will allow the Company to have more control over its storage products and to increase the value added in its solutions. It will also enhance the opportunity for the Company to sell its storage products through other resellers and to consolidate its service capability. The transaction was accounted for under the acquisition method of accounting. The assets acquired and liabilities assumed by the Company were primarily recognized at their fair value at the acquisition date using significant inputs that are not observable in the market (i.e., Level 3 inputs). The Company utilized a third-party appraisal in its determination of the fair value of the various intangible assets acquired and deferred revenue. The Company received assets valued at $20.2 million and assumed liabilities valued at $15.7 million . The excess of assets received over liabilities assumed of $4.5 million has been accounted for as a bargain purchase and recognized as a gain in the line item gain on strategic transaction in the Consolidated Statements of Operations for the year ended December 31, 2017. The bargain purchase gain was primarily the result of the seller’s planned exit from the business. Assets received included cash of $8.0 million . The Company expects to receive approximately $1.8 million in additional cash in the first half of 2018 as part of post-closing adjustments based on the final analysis of obligations to be assumed. The Company has assumed customer support obligations associated with the ClusterStor business and has added more than 125 employees and contractors. Because the fair value of the assets acquired exceeded the amount of liabilities assumed, resulting in a $4.5 million gain on the transaction, the Company reassessed and reaffirmed that the recognition and measurement of identifiable assets acquired and liabilities assumed were appropriate as required by the accounting standards applicable to bargain purchase transactions. The Company incurred approximately $0.5 million of legal and other transaction costs directly related to the transaction, all of which were expensed and included in general and administrative expenses in the Consolidated Statements of Operations for the year ended December 31, 2017. The Company estimated the fair value of the assets acquired and liabilities assumed as of the acquisition date based on information that is currently available. The Company may obtain additional information to assist it in determining the fair value of the net assets acquired at the acquisition date during the measurement period and, as such, additional purchase price adjustments may be recorded. The Company will record measurement period adjustments, if any, in the period in which the adjustments are recognized. Pro forma financial results are not presented as it is impractical to obtain the necessary information. The seller did not operate the acquired assets as a standalone business and, therefore, historical financial information is not available. It is impractical to determine the revenue or net income (loss) included in the Consolidated Statements of Operations related to ClusterStor since the date of acquisition because ClusterStor has been fully integrated into the Company’s storage and data management segment. The Company was also previously purchasing the same ClusterStor products from Seagate for resale that it acquired as part of the transaction. For these reasons, the operating results of ClusterStor cannot be separately identified. The following are the estimated values of the assets acquired and the liabilities assumed (in thousands): Cash $ 8,000 Receivable from Seagate 1,782 Inventory 4,120 Property and equipment 2,915 Deferred revenue (12,168 ) Deferred tax liabilities (3,019 ) Other liabilities (500 ) Net tangible assets 1,130 Trademarks 90 Developed technology 1,400 Customer relationships 260 Supply agreement 1,600 Total net assets acquired $ 4,480 The fair values of the major components of the intangible assets acquired and their estimated useful lives are as follows (in thousands): Intangible Asset Class Fair Value Useful Life (in Years) Trademarks $ 90 5 Developed technology $ 1,400 3 Customer relationships $ 260 10 Supply agreement $ 1,600 4 The carrying amount of the major components of intangible assets acquired are as follows as of December 31, 2017 (in thousands): Gross Carrying Amount Accumulated Amortization Net Carrying Amount Trademarks $ 90 $ 5 $ 85 Developed technology 1,400 117 1,283 Customer relationships 260 7 253 Supply agreement 1,600 100 1,500 Total $ 3,350 $ 229 $ 3,121 Aggregate amortization expense of these intangible assets expected for the years ending December 31 are as follows (in thousands): 2018 $ 911 2019 911 2020 794 2021 344 2022 40 Thereafter 121 Total $ 3,121

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
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, 2017 and 2016 , and indicates the fair value hierarchy of the valuation inputs utilized to determine such fair value (in thousands): Description Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Assets: Cash and cash equivalents and restricted cash $ 140,320 $ 140,320 $ — Available-for-sale investments (1) 6,997 6,997 — Foreign currency exchange contracts (2) 3,251 — 3,251 Assets measured at fair value at December 31, 2017 $ 150,568 $ 147,317 $ 3,251 Liabilities: Foreign currency exchange contracts (3) 2,431 — 2,431 Liabilities measured at fair value at December 31, 2017 $ 2,431 $ — $ 2,431 Description Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Assets: Cash and cash equivalents and restricted cash $ 224,617 $ 224,617 $ — Foreign currency exchange contracts (2) 11,250 — 11,250 Assets measured at fair value at December 31, 2016 $ 235,867 $ 224,617 $ 11,250 Liabilities: Foreign currency exchange contracts (3) 41 — 41 Liabilities measured at fair value at December 31, 2016 $ 41 $ — $ 41 _______________________________ (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, 2017 and 2016 , the Company had outstanding foreign currency exchange contracts that were designated and accounted for as cash flow hedges of anticipated future cash receipts on sales contracts payable in foreign currencies. The outstanding notional amounts were approximately (in millions): December 31, 2017 2016 Euros (EUR) 2.1 1.5 Swiss Francs (CHF) — 3.6 Japanese Yen (JPY) 4,345.6 — Canadian Dollars (CAD) 56.0 54.4 New Zealand Dollars (NZD) 16.2 — The Company had hedged foreign currency exposure related to these designated cash flow hedges of approximately $96.3 million and $46.9 million as of December 31, 2017 and 2016 , respectively. As of December 31, 2017 and 2016 , the Company had outstanding foreign currency exchange contracts that had been dedesignated for the purposes of hedge accounting treatment. The Company dedesignates cash flow hedges when the receivable related to the hedged cash flow is recorded. The outstanding notional amounts were approximately (in millions): December 31, 2017 2016 British Pounds (GBP) 26.1 33.8 Euros (EUR) 4.7 8.0 Japanese Yen (JPY) — 2,464.7 Canadian Dollars (CAD) 0.3 32.4 Swiss Francs (CHF) 2.6 — The foreign currency exposure related to these contracts was approximately $46.9 million as of December 31, 2017 and $107.5 million as of December 31, 2016 . Unrealized gains or losses related to these dedesignated contracts are recorded in other income (expense) in the Consolidated Statements of Operations and are generally offset by foreign currency adjustments on related receivables. These foreign currency exchange contracts are considered to be economic hedges. Cash receipts associated with the hedged contracts are expected to be received from 2018 through 2022, 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 in the case of receivables denominated in a foreign currency, each period during which hedged receivables denominated in a foreign currency are outstanding. As of December 31, 2017 and 2016 , the fair value of outstanding foreign currency exchange contracts totaled a net gain of $0.8 million and $11.2 million , respectively. Fair values of derivative instruments, consisting of foreign currency exchange contracts, designated as cash flow hedges (in thousands): December 31, Balance Sheet Location 2017 2016 Prepaid expenses and other current assets $ 546 $ 71 Other non-current assets — 367 Other accrued liabilities (129 ) (9 ) Other non-current liabilities (1,907 ) (5 ) Total fair value of derivative instruments designated as cash flow hedges $ (1,490 ) $ 424 As of December 31, 2017, unrecognized losses, net of tax, of $0.7 million were included in “Accumulated other comprehensive income” on the Company’s Consolidated Balance Sheets. As of December 31, 2016, unrecognized gains, net of tax, of $0.7 million , were included in “Accumulated other comprehensive income” on the Company’s Consolidated Balance Sheets. Fair values of derivative instruments, consisting of foreign currency exchange contracts, not designated as cash flow hedges (in thousands): December 31, Balance Sheet Location 2017 2016 Prepaid expenses and other current assets $ 1,252 $ 5,344 Other non-current assets 1,453 5,468 Other accrued liabilities (395 ) (27 ) Total fair value of derivative instruments not designated as cash flow hedges $ 2,310 $ 10,785

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	12 Months Ended
	Dec. 31, 2017
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income	ACCUMULATED OTHER COMPREHENSIVE INCOME The following table shows the impact on product revenue of reclassification adjustments from accumulated other comprehensive income resulting from hedged foreign currency transactions recorded by the Company for the years ended December 31, 2017, 2016 and 2015 (in thousands). The gross reclassification adjustments decreased product revenue for the year ended December 31, 2017 and increased product revenue for the years ended December 31, 2016 and 2015. Year Ended 2017 2016 2015 Gross of Tax Reclassifications $ (146 ) $ 22,207 $ 6,163 Net of Tax Reclassifications $ (87 ) $ 13,324 $ 3,698 The following tables show the changes in Accumulated Other Comprehensive Income by component for the years ended December 31, 2017 and 2016 (in thousands): Year Ended December 31, 2017 Unrealized Loss on Investments Foreign Currency Translation Adjustments Unrealized Gain (Loss) on Cash Flow Hedges Accumulated Other Comprehensive Income Beginning balance $ — $ 2,101 $ 681 $ 2,782 Current-period change, net of tax (7 ) (490 ) (1,370 ) (1,867 ) Ending balance $ (7 ) $ 1,611 $ (689 ) $ 915 Income tax expense (benefit) associated with current-period change $ (3 ) $ 1,110 $ (1,399 ) $ (292 ) Year Ended December 31, 2016 Unrealized Loss on Investments Foreign Currency Translation Adjustments Unrealized Gain on Cash Flow Hedges Accumulated Other Comprehensive Income Beginning balance $ (8 ) $ 1,675 $ 5,975 $ 7,642 Current-period change, net of tax 8 426 (5,294 ) (4,860 ) Ending balance $ — $ 2,101 $ 681 $ 2,782 Income tax expense (benefit) associated with current-period change $ 6 $ (152 ) $ (2,425 ) $ (2,571 )

Investments

Investments	12 Months Ended
	Dec. 31, 2017
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 (loss). The carrying amount of the Company’s investments in available-for-sale securities are shown in the table below (in thousands): December 31, 2017 Short-term available-for-sale securities cost $ 7,007 Short-term available-for-sale securities unrealized loss (10 ) Short-term available-for-sale securities fair value $ 6,997 The Company’s investments in 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, 2017
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, 2017 2016 Trade accounts receivable $ 131,151 $ 156,705 Unbilled receivables 9,321 17,264 Advance billings 3,569 1,915 Short-term investment in sales-type lease 10,684 8,683 Other receivables 7,337 13,395 162,062 197,962 Allowance for doubtful accounts (28 ) (21 ) Accounts and other receivables, net $ 162,034 $ 197,941 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 revenue has not been recognized. As of December 31, 2017 and 2016 , accounts receivable included $45.3 million and $104.6 million , respectively, due from the U.S. Government. Of these amounts, $2.1 million and $1.4 million were unbilled as of December 31, 2017 and 2016 , respectively, based upon contractual billing arrangements with these customers. As of December 31, 2017 , two non-U.S. Government customers accounted for 38% of total accounts and other receivables. As of December 31, 2016 , two non-U.S. Government customers accounted for 24% of total accounts and other receivables.

Sales-Type Lease

Sales-Type Lease	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Sales-Type Lease	SALES-TYPE LEASE The Company has a sales-type lease with one non-U.S. Government customer, under which it will receive quarterly payments over the term of the lease, which expires in September 2020. The lease is denominated in British Pounds and the Company has entered into certain foreign currency exchange contracts that act as an economic hedge for the foreign currency exposure associated with this arrangement. The following table shows the components of the net investment in the sales-type lease as of December 31, 2017 and 2016 (in thousands): December 31 2017 2016 Total minimum lease payments to be received $ 42,268 $ 52,224 Less: executory costs (6,831 ) (10,139 ) Net minimum lease payments receivable 35,437 42,085 Less: unearned income (1,386 ) (2,352 ) Net investment in sales-type lease 34,051 39,733 Less: long-term investment in sales-type lease (23,367 ) (31,050 ) Investment in sales-type lease included in accounts and other receivables $ 10,684 $ 8,683 As of December 31, 2017 , minimum lease payments for each of the succeeding three fiscal years were as follows (in thousands): 2018 $ 15,197 2019 15,478 2020 11,593 Total minimum lease payments to be received $ 42,268

Inventory

Inventory	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Inventory	INVENTORY A summary of inventory follows (in thousands): December 31 2017 2016 Components and subassemblies $ 37,219 $ 31,695 Work in process 59,456 39,894 Finished goods 89,632 16,665 $ 186,307 $ 88,254 As of December 31, 2017 and 2016 , $48.1 million and $10.5 million , respectively, of finished goods inventory was located at customer sites pending acceptance. At December 31, 2017 , two customers accounted for $67.7 million of finished goods inventory and at December 31, 2016 , two customers accounted for $11.9 million of finished goods inventory. The Company did no t write-off any inventory in 2017. During 2016 and 2015 , the Company wrote-off $4.8 million and $0.5 million , respectively, of excess and obsolete inventory.

Property and Equipment, Net

Property and Equipment, Net	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	PROPERTY AND EQUIPMENT, NET A summary of property and equipment follows (in thousands): December 31, 2017 2016 Land $ 203 $ 498 Buildings 20,480 20,679 Furniture and equipment 13,219 11,740 Computer equipment 58,358 54,541 Leasehold improvements 9,961 2,976 102,221 90,434 Accumulated depreciation and amortization (65,598 ) (59,814 ) Property and equipment, net $ 36,623 $ 30,620 Depreciation expense on property and equipment for 2017, 2016 and 2015 was $14.4 million , $12.5 million and $13.3 million , respectively.

Service Spares, Net

Service Spares, Net	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Service Spares, Net	SERVICE SPARES, NET A summary of service spares follows (in thousands): December 31, 2017 2016 Service spares $ 7,670 $ 6,503 Accumulated depreciation (5,119 ) (3,480 ) Service spares, net $ 2,551 $ 3,023 Depreciation expense on service spares for 2017, 2016 and 2015 was $1.6 million , $1.5 million and $1.1 million , respectively.

Deferred Revenue

Deferred Revenue	12 Months Ended
	Dec. 31, 2017
Deferred Revenue Disclosure [Abstract]
Deferred Revenue	DEFERRED REVENUE A summary of deferred revenue follows (in thousands): December 31 2017 2016 Deferred product revenue $ 22,245 $ 14,274 Deferred service revenue 96,496 96,113 Total deferred revenue 118,741 110,387 Less long-term deferred revenue (38,622 ) (27,258 ) Deferred revenue in current liabilities $ 80,119 $ 83,129 As of December 31, 2017 and 2016 , the U.S. Government accounted for $32.5 million and $60.3 million , respectively, of total deferred revenue. As of December 31, 2017 and 2016 , 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, 2017
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 were accounted for as operating leases, in 2017, 2016 and 2015 of $8.7 million , $8.4 million , and $5.9 million , respectively. The 2016 rent expense includes a $2.3 million lease termination fee for the Company’s St. Paul facility. Minimum contractual commitments as of December 31, 2017 , were as follows (in thousands): Operating Leases Development Agreements 2018 $ 7,461 $ 19,930 2019 6,918 5,116 2020 6,232 15 2021 6,271 — 2022 6,342 — Thereafter 20,709 — Minimum contractual commitments $ 53,933 $ 25,061 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, 2017, 2016 and 2015 , the Company incurred $17.5 million , $15.6 million and $14.3 million , respectively, for such arrangements. Litigation From time to time, the Company is subject to various legal proceedings that arise in the ordinary course of business. Other than as outlined below, none of these legal proceedings are deemed to be material to the Company’s business. The Company is subject to patent lawsuits brought by Raytheon Company (Raytheon). The first suit was brought by Raytheon on September 25, 2015 in the Eastern District of Texas (Civil Action No. 2:15-cv-1554) asserting infringement of four patents owned by Raytheon. Two of the asserted patents relate to computer hardware alleged to be encompassed by Cray’s current and past products, and the two remaining asserted patents relate to features alleged to be performed by certain third-party software that Cray optionally includes as part of its product offerings. A second suit was brought by Raytheon on April 22, 2016 in the Eastern District of Texas (Civil Action No. 2:16-cv-423) asserting infringement of five patents owned by Raytheon. In this second suit, all five asserted patents relate to features alleged to be performed by certain third-party software that Cray optionally includes as part of its product offerings. As of July 18, 2017, trial in the first action has been stayed by the trial court until further notice from the court. The United States Court of Appeals for the Federal Circuit granted Cray’s petition for writ of mandamus and overturned the trial court’s determination that venue was proper in the Eastern District of Texas. The Federal Circuit also remanded so the district court could determine where the case should be transferred, but the trial court has not yet ruled on that issue. Trial in the second action is currently stayed pending resolution of the first action. The Company is vigorously defending these actions. The probable outcome of either litigation cannot be determined, nor can the Company estimate a range of potential loss. Based on its review of the matters to date, the Company believes that it has valid defenses and claims in each of the two lawsuits. As a result, the Company considers the likelihood of a material loss related to these matters to be remote.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
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. On December 22, 2017, the President of the United States signed into law H.R. 1, “An Act to Provide for Reconciliation Pursuant to Titles II and V of the Concurrent Resolution on the Budget for Fiscal Year 2018” (the “Tax Cuts and Jobs Act”). ASC Topic 740, Accounting for Income Taxes, requires companies to recognize the effect of tax law changes in the period of enactment. The Tax Cuts and Jobs Act made significant changes to existing U.S. tax law, including, but not limited to, a permanent reduction to the U.S. federal corporate income tax rate from 35% to 21%, imposition of a one-time tax on deferred foreign income (“Repatriation Transition Tax”), adoption of a participation exemption system with respect to the taxation of future dividends received from foreign corporations, and repeal of the corporate alternative minimum tax system. Other significant changes in the Tax Cuts and Jobs Act include taxing payments made to foreign related parties that are deemed to be excessive, imposing a minimum tax on certain foreign earnings, requiring (beginning after December 31, 2021) the capitalization and subsequent amortization of certain research and development related expenses, and placing additional limits on the use of net operating losses and the deductibility of certain executive compensation. Given the significance of the Tax Cuts and Jobs Act, the Securities and Exchange Commission (“SEC”) issued Staff Accounting Bulletin 118 (“SAB 118”) that expresses the views of the SEC regarding ASC Topic 740 in the reporting period that includes the date of enactment. The SEC staff issuing SAB 118 recognized that a company’s review of the income tax effects attributable to the enactment of the Tax Cuts and Jobs Act may be incomplete at the time financial statements are issued for the reporting period that included the date of enactment and allows a company to record provisional amounts during a one year measurement period similar to the principles adopted in ASC Topic 805, Business Combinations. During the measurement period, income tax effects attributable to the enactment of the Tax Cuts and Jobs Act are expected to be recorded at the time a reasonable estimate for all or a portion of the effects can be made, and provisional amounts can be adjusted and recognized, as a discreet item in the applicable reporting period, as information becomes available, prepared or analyzed. The measurement period is deemed to have ended when the company has obtained, prepared and analyzed the information necessary to finalize its accounting. SAB 118 summarizes a three-step process to be applied to each reporting period to account for and qualitatively disclose income tax effects attributable to the enactment of the Tax Cuts and Jobs Act: (1) the effects of the change in tax law for which accounting is complete; (2) provisional amounts (including subsequent adjustments to those amounts) for the effects of the tax law where accounting is not complete, but that a reasonable estimate has been determined; and (3) a reasonable estimate cannot yet be made and therefore taxes are reflected in accordance with the law prior to the enactment of the Tax Cuts and Jobs Act. Amounts recorded by the Company during the year ended December 31, 2017 where the accounting is considered to be complete relate to a reduction, in the amount of $28.9 million , in the carrying value of the Company’s U.S. deferred tax assets resulting from the Tax Cuts and Jobs Act’s reduction in the U.S. federal corporate income tax rate from 35% to 21%. The Tax Cuts and Jobs Act also includes a Repatriation Transaction Tax on the net accumulated and previously untaxed earnings and profits of a U.S. taxpayer’s foreign subsidiaries. As of December 31, 2017, the Company has recorded provisional tax expense, in the amount of $0.3 million , attributable to the Repatriation Transition Tax and provisional tax expense, in the amount of $0.3 million , as a result of the Company’s decision to no longer consider the undistributed earnings of its foreign subsidiaries to be permanently reinvested outside of the U.S. The Company has not had sufficient time to obtain, prepare and analyze historical tax returns, financial statements and related accounts that is required to finalize its accounting with respect to the items for which provisional tax expense has been recorded A majority of the Company’s deferred tax assets result from net operating loss carryforwards and research and development tax credits. As of December 31, 2017 , the Company had U.S. federal net operating loss carryforwards of approximately $72.6 million and U.S. federal research and development tax credit carryforwards of approximately $36.0 million . Upon the adoption of ASU 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting in March of 2016, the Company recognized $16.6 million in deferred tax benefits from approximately $47.4 million of federal net operating losses attributable to share-based income tax deductions that exceeded amounts that had been recognized for financial reporting purposes. These deferred tax benefits were recorded as a cumulative-effect adjustment to accumulated deficit. The federal net operating loss carryforwards will expire from 2019 through 2037, and the federal research and development tax credits will expire from 2021 through 2037 if not utilized. Utilization of $21.2 million of the Company’s federal net operating loss carryforwards generated prior to May 10, 2001 is limited under Section 382 of the Internal Revenue Code to $4.3 million per year. As of December 31, 2017 , the Company had approximately $7.1 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 2018 to 2027. Income (loss) before income taxes consisted of the following (in thousands): Year Ended December 31, 2017 2016 2015 United States $ (53,201 ) $ 2,648 $ 38,362 International 311 7,273 4,415 Total $ (52,890 ) $ 9,921 $ 42,777 The tax provision (benefit) for income taxes related to operations consisted of the following (in thousands): Year Ended December 31, 2017 2016 2015 Current provision (benefit): Federal $ 445 $ 3 $ 725 State 310 (279 ) 1,389 Foreign 1,735 1,443 1,023 Total current provision 2,490 1,167 3,137 Deferred provision (benefit): Federal 77,152 (2,127 ) 12,198 State 1,185 416 (52 ) Foreign 112 (150 ) (43 ) Total deferred provision (benefit) 78,449 (1,861 ) 12,103 Total provision (benefit) for income taxes $ 80,939 $ (694 ) $ 15,240 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, 2017 2016 2015 Income tax provision (benefit) at statutory rate $ (18,511 ) $ 3,472 $ 14,972 State taxes, net of federal benefit (1,066 ) 89 897 Foreign income taxes 135 (407 ) (12 ) Additional increases (deductions) from share-based compensation 1,036 (1,815 ) — Deemed dividends for U.S. income tax purposes — 329 407 Nondeductible expenses 222 231 283 Disallowed compensation 60 331 455 Audit accrual (settlement) 1,156 (297 ) — Research and development tax credit (3,827 ) (2,470 ) (1,733 ) Tax effect of repatriation transition tax on unremitted earnings 605 — — Gain on strategic transaction (1,568 ) — — Deferred tax impact from tax rate change 28,907 — — Effect of change in valuation allowance on deferred tax assets 73,790 (157 ) (29 ) Effective income tax provision (benefit) $ 80,939 $ (694 ) $ 15,240 Significant components of the Company’s deferred income tax assets and liabilities follow (in thousands): December 31, 2017 2016 Deferred Income Tax Assets Inventory $ 6,495 $ 4,127 Accrued compensation 262 511 Deferred revenue 8,285 14,742 Research and development credit carryforwards 32,218 28,241 Net operating loss carryforwards 22,775 38,348 Property and equipment 4,136 8,188 Goodwill 289 106 Research and development expenses 9,944 — Share-based compensation 4,124 7,016 Other 2,592 12,939 Gross deferred tax assets 91,120 114,218 Valuation allowance (82,875 ) (8,727 ) Deferred tax assets 8,245 105,491 Deferred Income Tax Liabilities Investment in sales-type lease, net (3,084 ) (13,728 ) Intangible assets (205 ) (421 ) Other (3,850 ) (5,729 ) Deferred tax liabilities (7,139 ) (19,878 ) Net deferred tax asset $ 1,106 $ 85,613 The Company recorded income tax expense of $80.9 million during the year ended December 31, 2017 , an income tax benefit of $0.7 million during the year ended December 31, 2016 and income tax expense of $15.2 million during the year ended December 31, 2015 . The difference between the income tax benefit at the statutory rate and the Company’s effective income tax expense for the year ended December 31, 2017 was primarily attributable to the reduction in the U.S. federal corporate income tax rate as a result of the Tax Cuts and Jobs Act and its impact on the carrying value of the Company’s U.S. deferred tax assets and the Company’s decision after the Tax Cuts and Jobs Act was enacted to increase the valuation allowance held against its U.S. deferred tax assets, offset, in part, by research and development tax credits. The difference between the income tax provision at the statutory rate and the Company’s effective income tax benefit for the year ended December 31, 2016 was the result of research and development tax credits and additional tax deductions from share-based compensation, sometimes referred to as excess tax benefits, partially offset by state taxes, non-deductible expenses and other permanent items. Excess tax benefits arise when tax deductions recognized by the Company with respect to share-based compensation exceed the compensation cost attributable to share-based compensation that was recognized in the Company’s consolidated financial statements. 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, 2015 was the result of state taxes, non-deductible expenses and other permanent items, partially offset by research and development tax credits. The valuation allowance on deferred tax assets increased by $74.1 million in 2017 and decreased by $0.8 million and $0.7 million in 2016 and 2015, respectively. Substantially all of the increase in the valuation allowance during 2017 was attributable to the Company’s decision to increase the valuation allowance held against its U.S. deferred tax assets on December 31, 2017. The Company’s assessment of its ability to utilize its U.S. deferred tax assets was based upon all available positive and negative evidence, which included, among other things, the Company’s recent results of operations, forecasted domestic and international earnings over a number of years, all known business risks and industry trends, and applicable tax planning strategies. 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 has significant difficulty projecting future results due to the nature of its business and the industry in which it operates. As of December 31, 2017, the Company had experienced a significant decline in revenue, gross profit, and operating income since 2015, had reported a cumulative pre-tax loss in recent years and is currently forecasting to a report a pre-tax loss for the year ending December 31, 2018. If the Company had determined that it was appropriate to increase the valuation allowance held against our U.S. deferred tax assets prior to enactment of the Tax Cuts and Jobs Act total tax expense for the year ended December 31, 2017 would not have changed. The decrease in the carrying value of our U.S. deferred tax assets as a result of the reduction in the U.S. federal corporate income tax rate would have been completely offset by a reduction in the valuation allowance that would have been previously established against those deferred tax assets. 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 benefit in the Consolidated Statements of Operations when that occurs. 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, 2017, 2016 and 2015 (in thousands): Balance at December 31, 2014 $ 5,630 Increase related to prior year income tax positions 151 Increase related to current year income tax positions 433 Balance at December 31, 2015 $ 6,214 Increase related to prior year income tax positions 53 Decrease related to prior year income tax positions (365 ) Increase related to current year income tax positions 565 Balance at December 31, 2016 $ 6,467 Increase related to prior year income tax positions 1,440 Increase related to current year income tax positions 673 Balance at December 31, 2017 $ 8,580 Included in the balance of unrecognized tax benefits as of December 31, 2017 was $1.2 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 United Kingdom and the United States. The Company is no longer subject to income tax examinations with respect to periods before 2016 in the United Kingdom and before 2014 in the United States, although in the United States 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 2017, 2016 and 2015 .

Lines of Credit

Lines of Credit	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Credit Facilities	CREDIT FACILITIES As of December 31, 2017 , the Company had a $50.0 million revolving line of credit (Credit Facility) with Wells Fargo Bank, National Association, designed to be used for general corporate purposes, including working capital requirements and capital expenditures. The Credit Facility also supports the issuance of letters of credit. The Credit Facility is secured by a first priority lien in all of the Company’s accounts receivable and other rights to payment, general intangibles, inventory and equipment. Any borrowings under the Credit Facility bear interest at either a fluctuating rate equal to the daily one month LIBOR rate plus a margin of 1.25% or a fixed interest rate for one, three or six months equal to the LIBOR rate for the applicable period plus a margin of 1.25% . The Company is also required to pay the lender customary letter of credit fees, and a commitment fee of 0.18% per annum in respect of the unutilized commitment amount under the Credit Facility. The Credit Facility requires that the Company maintain certain financial ratios and restricts its ability to incur additional indebtedness, pay dividends or distributions, create liens on assets, and engage in certain other activities. The Company was in compliance with all of its financial covenants as of the end of each quarter for the year ended December 31, 2017 . The Credit Facility matures in March 2018. The Company has begun discussions with the bank that may result in changes to the size and terms of this arrangement. The Company made no draws and had no outstanding cash borrowings on the credit facility as of December 31, 2017 . As of December 31, 2017 , the Company had $15.0 million in USD equivalent value in outstanding letters of credit and $3.0 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, 2017
Disclosure of Compensation Related Costs, Share-based Payments [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. Stock Plans: As of December 31, 2017 , the Company had one active equity incentive plan that provides shares available for option, restricted stock and restricted stock unit grants to employees, directors, executives and others. Stock Options: In determining the fair value of stock options, the Company uses the Black-Scholes option pricing model. The following key weighted average assumptions were employed in the calculation for the indicated years ended December 31: 2017 2016 2015 Risk-free interest rate 1.64 % 1.12 % 1.31 % Expected dividend yield — % — % — % Volatility 54.14 % 50.92 % 50.55 % Expected life (in years) 4.0 4.0 4.0 Weighted average Black-Scholes value of options granted $ 7.91 $ 13.16 $ 11.23 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 is 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 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 to the Company’s stock option grants for the years ended December 31, 2017, 2016 and 2015 was 8.0% . 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, which impact the fair value of the option calculated under the Black-Scholes methodology and, ultimately, the expense that will be recognized over the vesting period or requisite service period of the option. The Company typically issues stock options with a four -year vesting period (the requisite service period) and amortizes the fair value of stock options (share-based compensation cost) ratably over the requisite service period. Options to purchase shares expire no later than ten years after the date of grant. A summary of the Company’s stock option activity and related information follows: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Outstanding at January 1, 2015 1,930,990 $ 12.34 Granted 307,450 27.86 Exercised (229,118 ) 9.99 Canceled and forfeited (60,847 ) 20.00 Outstanding at December 31, 2015 1,948,475 14.83 Granted 240,075 32.65 Exercised (168,825 ) 12.57 Canceled and forfeited (30,588 ) 26.60 Outstanding at December 31, 2016 1,989,137 16.99 Granted 324,500 18.36 Exercised (157,257 ) 8.51 Canceled and forfeited (121,906 ) 27.02 Outstanding at December 31, 2017 2,034,474 17.26 5.2 Exercisable at December 31, 2017 1,532,691 15.39 4.0 Available for grant at December 31, 2017 3,107,064 Outstanding and exercisable options by price range as of December 31, 2017 , were as follows: Outstanding Options Exercisable Options Range of Exercise Prices per Share Number Outstanding Weighted Average Remaining Life (Years) Weighted Average Exercise Price Number Exercisable Weighted Average Exercise Price $ 0.00 - $ 10.00 673,584 1.9 $ 5.49 673,584 $ 5.49 $ 10.01 - $ 20.00 619,941 6.7 16.78 327,941 15.71 $ 20.01 - $ 30.00 507,844 6.6 26.30 411,552 26.15 $ 30.01 - $ 42.40 233,105 7.5 32.86 119,614 33.34 $ 0.00 - $ 42.40 2,034,474 5.2 17.26 1,532,691 15.39 As of December 31, 2017 , there was $17.4 million of aggregate intrinsic value of outstanding stock options, including $15.5 million of aggregate intrinsic value of exercisable stock options. Intrinsic value represents 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 2017 and the exercise price, multiplied by the number of shares of common stock underlying the stock options) that would have been received by the option holders if all option holders had exercised their options on December 31, 2017 . This amount changes, based on the fair market value of the Company’s stock. Total intrinsic value of options exercised was $1.8 million , $4.0 million , and $5.0 million for the years ended December 31, 2017, 2016 and 2015 , respectively. Restricted Stock: During 2017 , 2016 and 2015 , the Company issued an aggregate of 44,002 , 9,893 , and 45,175 shares of restricted stock, respectively, to certain directors, executives and other employees. The grant date fair value of these grants was approximately $0.8 million , $0.3 million , and $1.4 million for 2017 , 2016 and 2015 , respectively. Share-based compensation expense is recorded over the vesting period, which is generally one year for non-employee directors and four years for officers and employees of the Company. A summary of the Company’s unvested restricted stock grants and changes during the indicated years ended December 31 is as follows: Service Vesting Restricted Shares Performance Vesting Restricted Shares Total Restricted Shares Shares Weighted Average Grant Date Fair Value Shares Weighted Shares Weighted Average Grant Date Fair Value Outstanding at January 1, 2015 1,033,602 $ 19.48 817,000 $ 15.41 1,850,602 $ 17.68 Granted 45,175 30.44 — — 45,175 30.44 Forfeited (48,998 ) 24.00 (219,000 ) 15.60 (267,998 ) 17.14 Vested (513,336 ) 15.34 (12,500 ) 28.20 (525,836 ) 15.64 Outstanding at December 31, 2015 516,443 24.12 585,500 15.07 1,101,943 19.31 Granted 9,893 34.86 — — 9,893 34.86 Forfeited (18,685 ) 24.73 (72,000 ) 15.57 (90,685 ) 17.46 Vested (250,849 ) 22.14 — — (250,849 ) 22.14 Outstanding at December 31, 2016 256,802 26.43 513,500 15.00 770,302 18.81 Granted 44,002 17.55 — — 44,002 17.55 Forfeited (32,207 ) 28.15 (513,500 ) 15.00 (545,707 ) 15.78 Vested (156,272 ) 25.25 — — (156,272 ) 25.25 Outstanding at December 31, 2017 112,325 24.09 — — 112,325 24.09 The estimated forfeiture rates applied to the Company’s service vesting restricted stock grants during the years ended December 31, 2017 , 2016 and 2015 was 8.0% . The aggregate fair value of restricted shares vested during 2017 , 2016 and 2015 was $2.9 million , $7.7 million , and $14.2 million , respectively. There are no longer any performance vesting restricted shares outstanding. Restricted Stock Units: During 2017 , 2016 and 2015 , the Company issued an aggregate of 825,000 , 244,160 and 984,850 restricted stock and performance vesting restricted stock units, respectively, to certain executives and other employees. The grant date fair value of these grants was approximately $15.2 million , $8.0 million and $29.5 million for 2017 , 2016 and 2015 , respectively. 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 share-based compensation expense over the vesting period. At the time of vesting, a share of common stock representing each restricted stock unit vested will be issued by the Company. A summary of the Company’s unvested restricted stock unit grants and changes during the indicated years ended December 31 is as follows: Service Vesting Restricted Stock Units Performance Vesting Restricted Stock Units Total Restricted Stock Units Units Weighted Units Weighted Units Weighted Average Grant Date Fair Value Outstanding at January 1, 2015 — $ — — $ — — $ — Granted 285,550 29.78 699,300 30.04 984,850 29.97 Forfeited (12,500 ) 30.48 (66,600 ) 30.04 (79,100 ) 30.11 Vested — — — — — — Outstanding at December 31, 2015 273,050 29.75 632,700 30.04 905,750 29.95 Granted 220,575 31.89 23,585 42.65 244,160 32.93 Forfeited (7,700 ) 29.44 — — (7,700 ) 29.44 Vested (60,204 ) 29.57 — — (60,204 ) 29.57 Outstanding at December 31, 2016 425,721 30.89 656,285 30.49 1,082,006 30.65 Granted 799,000 18.40 26,000 20.25 825,000 18.46 Forfeited (95,001 ) 25.75 (199,800 ) 30.04 (294,801 ) 28.66 Vested (141,697 ) 30.91 — — (141,697 ) 30.91 Outstanding at December 31, 2017 988,023 21.29 482,485 30.13 1,470,508 24.19 The estimated forfeiture rates applied to the Company’s service vesting restricted stock unit grants during the years ended December 31, 2017 , 2016 and 2015 was 8.0% . The aggregate fair value of restricted stock units vested during 2017 and 2016 was $2.7 million and $1.9 million , respectively. The performance vesting restricted stock units are subject to performance measures that are currently not considered “probable” of attainment and as such, no compensation cost has been recorded for these units. The performance vesting restricted stock units are eligible to vest between 2018 and 2020 . Share-based Compensation Expense: Including performance-based equity awards, the Company had $33.0 million of total unrecognized compensation cost related to unvested stock options, unvested restricted stock and unvested restricted stock units as of December 31, 2017 . Excluding the $14.5 million of unrecognized compensation cost related to unvested restricted stock units that are subject to performance measures that are currently not considered “probable” of attainment, unrecognized compensation cost is $18.5 million . No compensation expense is recognized for unvested restricted stock or unvested restricted stock units subject to performance measures that are not considered “probable” of attainment. Unrecognized compensation cost related to unvested stock options, unvested non-performance-based restricted stock and unvested non-performance-based restricted stock units is expected to be recognized over a weighted average period of 2.9 years. The following table sets forth the gross share-based compensation cost resulting from stock options, unvested restricted stock and unvested restricted stock units that were recorded in the Company’s Consolidated Statements of Operations for the indicated years ended December 31 (in thousands): 2017 2016 2015 Cost of product revenue $ 294 $ 320 $ 254 Cost of service revenue 290 211 276 Research and development 3,759 3,113 3,770 Sales and marketing 2,432 3,710 3,047 General and administrative 4,074 3,797 4,006 Total share-based compensation expense $ 10,849 $ 11,151 $ 11,353 Employee Stock Purchase Plan (ESPP): The Company’s non-compensatory employee stock purchase plan was discontinued in the third quarter of 2017. The maximum number of shares of the Company’s common stock that employees could acquire under the ESPP was 1,750,000 shares. Eligible employees were 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 was 95% of the closing market price on the fourth business day after the end of each offering period. As of December 31, 2017, 2016 and 2015, an aggregate of 1,118,151 , 1,098,085 and 1,070,343 shares, respectively, had been issued under the ESPP.

Benefit Plans

Benefit Plans	12 Months Ended
	Dec. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Benefit Plans	BENEFIT PLANS 401(k) Plan For the three years ended December 31, 2017 , 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 2017, 2016 and 2015 Company match expense was $3.0 million , $2.9 million and $2.6 million , respectively. Pension Plan The Company’s German subsidiary maintains a defined benefit pension plan. At December 31, 2017 , the excess of plan assets over the projected benefit obligation of $2.0 million was $0.2 million . At December 31, 2016 , the excess of plan assets over the projected benefit obligation of $2.0 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, 2017
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION The Company has the following reportable segments: Supercomputing, Storage and Data Management, Maintenance and Support, and Engineering Services and Other. 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, tightly integrated and cluster supercomputer systems which are used by 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 Cray DataWarp and ClusterStor, 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 are the Company’s analytics and artificial intelligence businesses and Custom Engineering. The following table presents revenues and gross margin for the Company’s operating segments for the indicated years ended December 31 (in thousands): 2017 2016 2015 Revenue: Supercomputing $ 282,217 $ 510,403 $ 581,733 Storage and Data Management 63,620 89,438 112,862 Maintenance and Support 124,840 107,795 97,091 Engineering Services and Other 46,672 29,968 30,094 Elimination of inter-segment revenue (124,840 ) (107,795 ) (97,091 ) Total revenue $ 392,509 $ 629,809 $ 724,689 Gross Profit: Supercomputing $ 93,272 $ 173,245 $ 177,048 Storage and Data Management 20,288 34,125 37,181 Maintenance and Support 61,305 43,147 41,487 Engineering Services and Other 17,144 12,845 11,454 Elimination of inter-segment gross profit (61,305 ) (43,147 ) (41,487 ) Total gross profit $ 130,704 $ 220,215 $ 225,683 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 Europe and the Middle East, South America, Asia Pacific and Canada. The following data represents the Company’s revenue and long-lived assets for the United States and all other countries (in thousands): United States All Other Countries Total For the year ended December 31, 2017: Product revenue $ 159,279 $ 90,916 $ 250,195 Service revenue $ 96,406 $ 45,908 $ 142,314 Long-lived assets $ 48,989 $ 28,009 $ 76,998 For the year ended December 31, 2016: Product revenue $ 251,317 $ 248,115 $ 499,432 Service revenue $ 88,208 $ 42,169 $ 130,377 Long-lived assets $ 39,933 $ 36,555 $ 76,488 For the year ended December 31, 2015: Product revenue $ 373,494 $ 227,800 $ 601,294 Service revenue $ 88,956 $ 34,439 $ 123,395 Long-lived assets $ 39,014 $ 23,238 $ 62,252 Long-lived assets as of December 31, 2017, 2016 and 2015 , included $23.4 million , $31.1 million and $18.3 million , respectively, of long-term investment in sales-type lease which was held by the Company’s United Kingdom subsidiary. Revenue derived from the U.S. Government totaled approximately $206.1 million , $296.9 million and $338.5 million in 2017, 2016 and 2015 , respectively. In 2017 , one non-U.S. Government customer accounted for 11% of total revenue. In 2016 , one non-U.S. Government customer accounted for 10% of total revenue. In 2015 , no non-U.S. Government customers accounted for more than 10% of total revenue. Revenue attributed to foreign countries is derived from sales to customers located outside the United States. In general, concentrations of revenue by customer encompass all segments. In 2017 , revenue in India accounted for 11% of total revenue. In 2016 , revenue in the United Kingdom accounted for 17% of total revenue. In 2015 , no foreign countries accounted for more than 10% of total revenue.

Research and Development

Research and Development	12 Months Ended
	Dec. 31, 2017
Research and Development [Abstract]
Research and Development	RESEARCH AND DEVELOPMENT Details for the Company’s net research and development expenses for the indicated years ended December 31 follows (in thousands): 2017 2016 2015 Gross research and development expenses $ 141,289 $ 130,006 $ 126,060 Less: Amounts included in cost of revenue (9,473 ) (12,621 ) (16,515 ) Less: Reimbursed research and development (excludes amounts in revenue) (33,039 ) (5,255 ) (12,982 ) Net research and development expenses $ 98,777 $ 112,130 $ 96,563

Interest Income (Expense)

Interest Income (Expense)	12 Months Ended
	Dec. 31, 2017
Other Income and Expenses [Abstract]
Interest Income (Expense)	INTEREST INCOME (EXPENSE) The detail of interest income (expense) for the indicated years ended December 31 follows (in thousands): 2017 2016 2015 Interest income $ 3,386 $ 2,120 $ 1,465 Interest expense (110 ) 27 (57 ) Net interest income $ 3,276 $ 2,147 $ 1,408 Interest income is earned by the Company on cash and cash equivalents, investment balances and the investment in sales-type lease.

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Restructuring	RESTRUCTURING In the third quarter of 2017, the Company implemented a restructuring plan intended to reduce the Company’s operating costs and better align its workforce with long-term business strategies. The restructuring plan involved reducing the Company’s workforce by approximately 190 employees, with the vast majority of such terminations effective in July 2017. For the year ended December 31, 2017, the Company recorded $8.6 million in expense in connection with the restructuring plan, primarily related to employee severance. The majority of the cash payments related to the restructuring charges were paid in 2017. The actions associated with the restructuring plan are expected to be completed by the end of the first half of 2018. Restructuring charges associated with the restructuring plan were included in restructuring on the company’s Consolidated Statements of Operations.

Quarterly Data (Unaudited)

Quarterly Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
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, 2017 . 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) 2017 2016 For the Quarter Ended 3/31 6/30 9/30 12/31 3/31 6/30 9/30 12/31 Revenue $ 59,031 $ 87,135 $ 79,700 $ 166,643 $ 105,549 $ 100,235 $ 77,451 $ 346,574 Cost of revenue 35,222 58,792 51,208 116,583 65,587 64,074 53,850 226,083 Gross profit 23,809 28,343 28,492 50,060 39,962 36,161 23,601 120,491 Research and development, net 32,640 17,325 26,626 22,186 25,840 27,399 29,084 29,807 Sales and marketing 14,653 15,247 13,392 16,602 16,001 15,380 15,010 18,502 General and administrative 8,797 7,205 7,022 6,089 7,338 9,019 7,968 9,728 Restructuring — — 7,653 915 — — — — Net income (loss) (19,215 ) (6,840 ) (10,232 ) (97,542 ) (5,013 ) (13,126 ) (23,021 ) 51,775 Net income (loss) per common share, basic $ (0.48 ) $ (0.17 ) $ (0.25 ) $ (2.42 ) $ (0.13 ) $ (0.33 ) $ (0.58 ) $ 1.30 Net income (loss) per common share, diluted $ (0.48 ) $ (0.17 ) $ (0.25 ) $ (2.42 ) $ (0.13 ) $ (0.33 ) $ (0.58 ) $ 1.27

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2017
Valuation and Qualifying Accounts [Abstract]
Schedule of Valuation and Qualifying Accounts	Schedule II — Valuation and Qualifying Accounts(1) December 31, 2017 (In thousands) Description Balance at Beginning of Period Charge to Expense Deductions (2) Balance at End of Period Year ended December 31, 2015: Allowance for doubtful accounts $ 97 $ — $ (78 ) $ 19 Year ended December 31, 2016: Allowance for doubtful accounts $ 19 $ 2 $ — $ 21 Year ended December 31, 2017: Allowance for doubtful accounts $ 21 $ 7 $ — $ 28 (1) The Company does not have any warranty liabilities. (2) Deductions represent uncollectible accounts written off, net of recoveries.

Summary of Significant Accoun31

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All material 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 (loss) 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, 2017 and 2016 , the Company had $3.0 million and $1.7 million , respectively, in restricted cash associated with certain letters of credit to secure customer prepayments and other customer related obligations.
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 (loss).
Foreign Currency Derivatives	Foreign Currency Derivatives The Company uses foreign currency exchange contracts to hedge certain foreign currency exposures. Foreign currency exchange 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. Most of the Company’s foreign currency exchange contracts are designated as cash flow hedges for the purposes of hedge accounting treatment and any gains or losses on the effective portion of the foreign currency exchange 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 foreign currency exchange 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 foreign currency exchange contract and expected cash flows based on changes in the spot prices of the underlying currencies. Cash flows from foreign currency exchange contracts accounted for as cash flow hedges are classified in the same category as the cash flows from the items being hedged. Unrealized gains or losses related to foreign currency exchange contracts that are not designated as cash flow hedges for the purposes of hedge accounting treatment are recorded in other income (expense) in the Consolidated Statements of Operations and are generally offset by foreign currency adjustments on related receivables. 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 foreign currency exchange contracts. The Company maintains cash and cash equivalents, available-for-sale securities and foreign currency exchange 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 foreign currency exchange 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 the U.S. Government. See Note 18 — 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 8 — 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	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 4 — Fair Value Measurement for a further discussion on fair value of financial instruments.
Inventories	Inventories Inventories are valued at the lower of cost or net realizable value, with cost computed on a first-in, first-out basis (FIFO). 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 net realizable value. Prior to the adoption of ASU 2015-11 at the beginning of the first quarter of 2017, inventories were valued at the lower of cost or market. The adoption of ASU 2015-11 did not have a material impact on the Company’s consolidated financial statements. 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 or there is an expected scrap value 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 net realizable value 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 ). Prior to the adoption of ASU 2015-11 at the beginning of the first quarter of 2017, service spares were valued at the lower of cost or market. The adoption of ASU 2015-11 did not have a material impact on the Company’s consolidated financial statements.
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 and whenever events or changes in circumstances indicate that the fair value of a reporting unit may be less than its carrying amount (a triggering event). In the second quarter of 2017, the Company determined that declining revenues in recent years, coupled with the anticipated loss for 2017, should be construed as a triggering event for the purposes of impairment testing of goodwill in accordance with ASC 350. The Company performed a quantitative goodwill impairment test on June 30, 2017. Due to the proximity of the triggering event to the October 1 annual testing date, the Company has elected to change the date of its annual goodwill impairment test from the beginning of its fourth fiscal quarter to the beginning of its second fiscal quarter. 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 quantitative 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 quantitative goodwill 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 quantitative goodwill impairment test. In performing the quantitative goodwill impairment test, 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. If the carrying value of a reporting unit exceeds its fair value, the Company records an impairment loss equal to the difference. The Company performed a quantitative goodwill impairment test during the second fiscal quarter of 2017 and concluded that the fair values of its reporting units were greater than their carrying amounts.
Business Combinations	Business Combinations The Company accounts for business combinations using the purchase 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 excess of the purchase price over the fair value of the net assets acquired is recorded as goodwill. If the fair value of the net assets acquired exceeds the purchase price the Company records a bargain purchase gain. The Company uses estimates and assumptions to 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 in the period in which the adjustments are recognized. 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 (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 (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 (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 of the product 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 (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 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 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 $1.7 million and $1.6 million for 2017 and 2015 , respectively. Net transaction losses were $1.0 million for 2016 .
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. Amounts to be received under co-funding arrangements with the U.S. government or others 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 will not be realized through future operations. This assessment is based upon consideration of all available positive and negative evidence, which includes, among other things, the Company’s recent results of operations, forecasted domestic and international earnings over a number of years, all known business risks and industry trends, and applicable tax planning strategies that should, if implemented, enable the Company to utilize its deferred tax assets before they expire. 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 has significant difficulty projecting future results due to the nature of the business and the industry in which it operates. The Company provided a valuation allowance against its U.S. deferred tax assets and against the majority of its deferred tax assets arising in foreign jurisdictions at December 31, 2017 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 benefit in its Consolidated Statements of Operations when that occurs. 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.
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 has granted performance vesting restricted stock and performance vesting restricted stock units 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.” Awards are evaluated for probability of vesting each reporting period.
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 included advertising expenses of $3.4 million , $3.2 million , and $2.3 million in 2017 , 2016 , and 2015 , 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 (EPS) Basic EPS is computed by dividing net income (loss) 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 (loss) 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 unvested restricted stock units as computed under the treasury stock method. For the year ended December 31, 2017 , outstanding stock options, unvested restricted stock and unvested restricted stock units were antidilutive because of the net loss and, as such, their effect has not been included in the calculation of basic or diluted net loss per share. For the years ended December 31, 2016 and 2015, the added shares from these items included in the calculation of diluted shares and EPS totaled approximately 1.2 million , and 1.4 million , respectively. Potentially dilutive shares of 3.1 million , 1.2 million , and 0.9 million , respectively, have been excluded from the denominator in the computation of diluted EPS for the years ended December 31, 2017, 2016 and 2015 , respectively, because they were antidilutive. An additional 0.5 million , 1.2 million and 1.2 million performance vesting restricted stock and performance vesting restricted stock units were excluded from the computation of diluted EPS for the years ended December 31, 2017, 2016 and 2015 , respectively, because the conditions for vesting had not been met as of the balance sheet date.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (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 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. Adoption of ASU 2014-09 was initially required for 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 (full retrospective method); 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 (modified retrospective method). In August 2015, FASB issued Accounting Standards Update No. 2015-14, Revenue from Contracts with Customers - Deferral of the Effective Date: Topic 606 (ASU 2015-14) that deferred the effective date of ASU 2014-09 by one year. Application of the new revenue standard is permitted for fiscal and interim reporting periods beginning after December 15, 2016 and required for fiscal and interim reporting periods beginning after December 15, 2017. The Company believes the impact of adopting the new guidance will be immaterial to its annual and interim financial statements. The Company believes that the impact will be limited to the identification of a significant financing component in a small number of its contracts with customers. The Company will also be required to make additional disclosures under the new guidance. The Company plans to adopt this standard in the first quarter of 2018 using the modified retrospective method. In July 2015, FASB issued Accounting Standards Update No. 2015-11, Simplifying the Measurement of Inventory: Topic 330 (ASU 2015-11). Topic 330 previously required an entity to measure inventory at the lower of cost or market. Market could be replacement cost, net realizable value, or net realizable value less an approximately normal profit margin. ASU 2015-11 requires that inventory measured using either the first-in-first-out (FIFO) or average cost method now be measured at the lower of cost and net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. The Company adopted ASU 2015-11 at the beginning of the first quarter of 2017. Adoption of ASU 2015-11 did not have a material impact on the Company’s consolidated financial statements. In November 2015, FASB issued Accounting Standards Update No. 2015-17, Balance Sheet Classification of Deferred Taxes: Topic 740 (ASU 2015-17). Current GAAP requires the deferred taxes for each jurisdiction to be presented as a net current asset or liability and net noncurrent asset or liability. This requires a jurisdiction-by-jurisdiction analysis based on the classification of the assets and liabilities to which the underlying temporary differences relate, or, in the case of loss or credit carryforwards, based on the period in which the attribute is expected to be realized. Any valuation allowance is then required to be allocated on a pro rata basis, by jurisdiction, between current and noncurrent deferred tax assets. The new guidance requires that all deferred tax assets and liabilities, along with any related valuation allowance, be classified as noncurrent on the balance sheet. As a result, each jurisdiction will now only have one net noncurrent deferred tax asset or liability. The guidance does not change the existing requirement that only permits offsetting within a jurisdiction. The Company adopted ASU 2015-17 at the beginning of the first quarter of 2017. At the time of adoption, all of the Company’s deferred tax assets and liabilities, along with any related valuation allowance, were classified as noncurrent on its Consolidated Balance Sheet. The Company adopted ASU 2015-17 on a retrospective basis. As such, prior period amounts have been adjusted to reflect the retrospective application of ASU 2015-17. This resulted in $19.1 million of current net deferred tax assets being reclassified as noncurrent on the Company’s December 31, 2016 Consolidated Balance Sheet. In January 2016, FASB issued Accounting Standards Update No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities: Topic 825 (ASU 2016-01). The updated guidance enhances the reporting model for financial instruments, which includes amendments to address aspects of recognition, measurement, presentation and disclosure. Adoption of ASU 2016-01 is required for fiscal reporting periods beginning after December 15, 2017, including interim reporting periods within those fiscal years. The Company does not expect the adoption of ASU 2016-01 to have a material impact on its consolidated financial statements. In February 2016, FASB issued Accounting Standards Update No. 2016-02, Leases: Topic 842 (ASU 2016-02), that replaces existing lease guidance. The new standard is intended to provide enhanced transparency and comparability by requiring lessees to record right-of-use assets and corresponding lease liabilities on the balance sheet. Under the new guidance, leases will continue to be classified as either finance or operating, with classification affecting the pattern of expense recognition in the Consolidated Statements of Operations. Lessor accounting is largely unchanged under ASU 2016-02. Adoption of ASU 2016-02 is required for fiscal reporting periods beginning after December 15, 2018, including interim reporting periods within those fiscal years with early adoption being permitted. As of December 31, 2017, the new standard requires application with a modified retrospective approach to each prior reporting period presented with various optional practical expedients. While the Company expects adoption to lead to a material increase in the assets and liabilities recorded on its Consolidated Balance Sheet, the Company is still evaluating the overall impact on its consolidated financial statements. In August 2016, FASB issued Accounting Standards Update No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments (ASU 2016-15). The updated guidance clarifies how companies present and classify certain cash receipts and cash payments in the statement of cash flows. Adoption of ASU 2016-15 is required for fiscal reporting periods beginning after December 15, 2017, including interim reporting periods within those fiscal years with early adoption being permitted. The Company does not expect the adoption of ASU 2016-15 to have a material impact on its consolidated financial statements. In November 2016, FASB issued Accounting Standards Update No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash (ASU 2016-18) which amends ASC 230 to add or clarify guidance on the classification and presentation of restricted cash in the statement of cash flows. The amended guidance requires that amounts that are deemed to be restricted cash and restricted cash equivalents be included in the cash and cash-equivalent balances in the statement of cash flows. A reconciliation between the consolidated balance sheet and the statement of cash flows must be disclosed when the consolidated balance sheet includes more than one line item for cash, cash equivalents, restricted cash, and restricted cash equivalents. The guidance also requires that changes in restricted cash and restricted cash equivalents that result from transfers between cash, cash equivalents, and restricted cash and restricted cash equivalents should not be presented as cash flow activities in the statement of cash flows. An entity with a material balance of amounts generally described as restricted cash and restricted cash equivalents must disclose information about the nature of the restrictions. Adoption of ASU 2016-18 is required for fiscal reporting periods beginning after December 15, 2017, including interim reporting periods within those fiscal years with early adoption being permitted. The Company does not expect the adoption of ASU 2016-18 to have a material impact on its consolidated financial statements. In January 2017, FASB issued Accounting Standards Update No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment (ASU 2017-04) which eliminates Step 2 from the goodwill impairment test. ASU 2017-04 also eliminates the requirements for any reporting unit with a zero or negative carrying amount to perform a qualitative assessment and, if it fails that qualitative test, to perform Step 2 of the goodwill impairment test. An entity still has the option to perform the qualitative assessment for a reporting unit to determine if the quantitative impairment test is necessary. Adoption of ASU 2017-04 is required for annual or interim goodwill impairment tests in fiscal years beginning after December 15, 2019 with early adoption being permitted for annual or interim goodwill impairment tests performed on testing dates after January 1, 2017. The Company adopted ASU 2017-04 at the beginning of the second quarter of 2017. Adoption of ASU 2017-04 did not have a material impact on the Company’s consolidated financial statements. In August 2017, FASB issued Accounting Standards Update No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities (ASU 2017-12). The new standard simplifies and expands the eligible hedging strategies for financial and nonfinancial risks. It also enhances the transparency of how hedging results are presented and disclosed. Further, the new standard provides partial relief on the timing of certain aspects of hedge documentation and eliminates the requirement to recognize hedge ineffectiveness separately in earnings. Adoption of ASU 2017-12 is required for fiscal reporting periods beginning after December 15, 2018, including interim reporting periods within those fiscal years with early adoption being permitted. The Company is currently evaluating the potential impact of the pending adoption of ASU 2017-12 on its consolidated financial statements.

Summary of Significant Accoun32

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
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): 2017 2016 Accumulated unrealized net loss on available-for-sale investments $ (7 ) $ — Accumulated currency translation adjustments 1,611 2,101 Accumulated unrealized net gain (loss) on cash flow hedges (689 ) 681 Accumulated other comprehensive income $ 915 $ 2,782 The following tables show the changes in Accumulated Other Comprehensive Income by component for the years ended December 31, 2017 and 2016 (in thousands): Year Ended December 31, 2017 Unrealized Loss on Investments Foreign Currency Translation Adjustments Unrealized Gain (Loss) on Cash Flow Hedges Accumulated Other Comprehensive Income Beginning balance $ — $ 2,101 $ 681 $ 2,782 Current-period change, net of tax (7 ) (490 ) (1,370 ) (1,867 ) Ending balance $ (7 ) $ 1,611 $ (689 ) $ 915 Income tax expense (benefit) associated with current-period change $ (3 ) $ 1,110 $ (1,399 ) $ (292 ) Year Ended December 31, 2016 Unrealized Loss on Investments Foreign Currency Translation Adjustments Unrealized Gain on Cash Flow Hedges Accumulated Other Comprehensive Income Beginning balance $ (8 ) $ 1,675 $ 5,975 $ 7,642 Current-period change, net of tax 8 426 (5,294 ) (4,860 ) Ending balance $ — $ 2,101 $ 681 $ 2,782 Income tax expense (benefit) associated with current-period change $ 6 $ (152 ) $ (2,425 ) $ (2,571 )

Strategic Transaction (Tables)

Strategic Transaction (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	The following are the estimated values of the assets acquired and the liabilities assumed (in thousands): Cash $ 8,000 Receivable from Seagate 1,782 Inventory 4,120 Property and equipment 2,915 Deferred revenue (12,168 ) Deferred tax liabilities (3,019 ) Other liabilities (500 ) Net tangible assets 1,130 Trademarks 90 Developed technology 1,400 Customer relationships 260 Supply agreement 1,600 Total net assets acquired $ 4,480
Schedule of Indefinite-Lived Intangible Assets [Table Text Block]	The fair values of the major components of the intangible assets acquired and their estimated useful lives are as follows (in thousands): Intangible Asset Class Fair Value Useful Life (in Years) Trademarks $ 90 5 Developed technology $ 1,400 3 Customer relationships $ 260 10 Supply agreement $ 1,600 4 The carrying amount of the major components of intangible assets acquired are as follows as of December 31, 2017 (in thousands): Gross Carrying Amount Accumulated Amortization Net Carrying Amount Trademarks $ 90 $ 5 $ 85 Developed technology 1,400 117 1,283 Customer relationships 260 7 253 Supply agreement 1,600 100 1,500 Total $ 3,350 $ 229 $ 3,121
Finite-lived Intangible Assets Amortization Expense [Table Text Block]	Aggregate amortization expense of these intangible assets expected for the years ending December 31 are as follows (in thousands): 2018 $ 911 2019 911 2020 794 2021 344 2022 40 Thereafter 121 Total $ 3,121

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	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, 2017 and 2016 , and indicates the fair value hierarchy of the valuation inputs utilized to determine such fair value (in thousands): Description Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Assets: Cash and cash equivalents and restricted cash $ 140,320 $ 140,320 $ — Available-for-sale investments (1) 6,997 6,997 — Foreign currency exchange contracts (2) 3,251 — 3,251 Assets measured at fair value at December 31, 2017 $ 150,568 $ 147,317 $ 3,251 Liabilities: Foreign currency exchange contracts (3) 2,431 — 2,431 Liabilities measured at fair value at December 31, 2017 $ 2,431 $ — $ 2,431 Description Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Assets: Cash and cash equivalents and restricted cash $ 224,617 $ 224,617 $ — Foreign currency exchange contracts (2) 11,250 — 11,250 Assets measured at fair value at December 31, 2016 $ 235,867 $ 224,617 $ 11,250 Liabilities: Foreign currency exchange contracts (3) 41 — 41 Liabilities measured at fair value at December 31, 2016 $ 41 $ — $ 41 _______________________________ (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, 2017 and 2016 , the Company had outstanding foreign currency exchange contracts that had been dedesignated for the purposes of hedge accounting treatment. The Company dedesignates cash flow hedges when the receivable related to the hedged cash flow is recorded. The outstanding notional amounts were approximately (in millions): December 31, 2017 2016 British Pounds (GBP) 26.1 33.8 Euros (EUR) 4.7 8.0 Japanese Yen (JPY) — 2,464.7 Canadian Dollars (CAD) 0.3 32.4 Swiss Francs (CHF) 2.6 — As of December 31, 2017 and 2016 , the Company had outstanding foreign currency exchange contracts that were designated and accounted for as cash flow hedges of anticipated future cash receipts on sales contracts payable in foreign currencies. The outstanding notional amounts were approximately (in millions): December 31, 2017 2016 Euros (EUR) 2.1 1.5 Swiss Francs (CHF) — 3.6 Japanese Yen (JPY) 4,345.6 — Canadian Dollars (CAD) 56.0 54.4 New Zealand Dollars (NZD) 16.2 —
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	Fair values of derivative instruments, consisting of foreign currency exchange contracts, designated as cash flow hedges (in thousands): December 31, Balance Sheet Location 2017 2016 Prepaid expenses and other current assets $ 546 $ 71 Other non-current assets — 367 Other accrued liabilities (129 ) (9 ) Other non-current liabilities (1,907 ) (5 ) Total fair value of derivative instruments designated as cash flow hedges $ (1,490 ) $ 424 Fair values of derivative instruments, consisting of foreign currency exchange contracts, not designated as cash flow hedges (in thousands): December 31, Balance Sheet Location 2017 2016 Prepaid expenses and other current assets $ 1,252 $ 5,344 Other non-current assets 1,453 5,468 Other accrued liabilities (395 ) (27 ) Total fair value of derivative instruments not designated as cash flow hedges $ 2,310 $ 10,785

Accumulated Other Comprehensi35

Accumulated Other Comprehensive Income Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2017
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Reclassification from Accumulated Other Comprehensive Income	The following table shows the impact on product revenue of reclassification adjustments from accumulated other comprehensive income resulting from hedged foreign currency transactions recorded by the Company for the years ended December 31, 2017, 2016 and 2015 (in thousands). The gross reclassification adjustments decreased product revenue for the year ended December 31, 2017 and increased product revenue for the years ended December 31, 2016 and 2015. Year Ended 2017 2016 2015 Gross of Tax Reclassifications $ (146 ) $ 22,207 $ 6,163 Net of Tax Reclassifications $ (87 ) $ 13,324 $ 3,698
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): 2017 2016 Accumulated unrealized net loss on available-for-sale investments $ (7 ) $ — Accumulated currency translation adjustments 1,611 2,101 Accumulated unrealized net gain (loss) on cash flow hedges (689 ) 681 Accumulated other comprehensive income $ 915 $ 2,782 The following tables show the changes in Accumulated Other Comprehensive Income by component for the years ended December 31, 2017 and 2016 (in thousands): Year Ended December 31, 2017 Unrealized Loss on Investments Foreign Currency Translation Adjustments Unrealized Gain (Loss) on Cash Flow Hedges Accumulated Other Comprehensive Income Beginning balance $ — $ 2,101 $ 681 $ 2,782 Current-period change, net of tax (7 ) (490 ) (1,370 ) (1,867 ) Ending balance $ (7 ) $ 1,611 $ (689 ) $ 915 Income tax expense (benefit) associated with current-period change $ (3 ) $ 1,110 $ (1,399 ) $ (292 ) Year Ended December 31, 2016 Unrealized Loss on Investments Foreign Currency Translation Adjustments Unrealized Gain on Cash Flow Hedges Accumulated Other Comprehensive Income Beginning balance $ (8 ) $ 1,675 $ 5,975 $ 7,642 Current-period change, net of tax 8 426 (5,294 ) (4,860 ) Ending balance $ — $ 2,101 $ 681 $ 2,782 Income tax expense (benefit) associated with current-period change $ 6 $ (152 ) $ (2,425 ) $ (2,571 )

Investments Investments (Tables

Investments Investments (Tables)	12 Months Ended
	Dec. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities	The carrying amount of the Company’s investments in available-for-sale securities are shown in the table below (in thousands): December 31, 2017 Short-term available-for-sale securities cost $ 7,007 Short-term available-for-sale securities unrealized loss (10 ) Short-term available-for-sale securities fair value $ 6,997

Accounts and Other Receivable37

Accounts and Other Receivables, Net Accounts and Other Receivables, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Schedule of Accounts, Notes, Loans and Financing Receivable	A summary of net accounts and other receivables follows (in thousands): December 31, 2017 2016 Trade accounts receivable $ 131,151 $ 156,705 Unbilled receivables 9,321 17,264 Advance billings 3,569 1,915 Short-term investment in sales-type lease 10,684 8,683 Other receivables 7,337 13,395 162,062 197,962 Allowance for doubtful accounts (28 ) (21 ) Accounts and other receivables, net $ 162,034 $ 197,941

Sales-Type Lease Sales-Type Lea

Sales-Type Lease Sales-Type Lease (Tables)	12 Months Ended
	Dec. 31, 2017
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, 2017 and 2016 (in thousands): December 31 2017 2016 Total minimum lease payments to be received $ 42,268 $ 52,224 Less: executory costs (6,831 ) (10,139 ) Net minimum lease payments receivable 35,437 42,085 Less: unearned income (1,386 ) (2,352 ) Net investment in sales-type lease 34,051 39,733 Less: long-term investment in sales-type lease (23,367 ) (31,050 ) Investment in sales-type lease included in accounts and other receivables $ 10,684 $ 8,683
Schedule of Future Minimum Lease Payments for Capital Leases	As of December 31, 2017 , minimum lease payments for each of the succeeding three fiscal years were as follows (in thousands): 2018 $ 15,197 2019 15,478 2020 11,593 Total minimum lease payments to be received $ 42,268

Inventory Inventory (Tables)

Inventory Inventory (Tables)	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Schedule of Inventory, Current	A summary of inventory follows (in thousands): December 31 2017 2016 Components and subassemblies $ 37,219 $ 31,695 Work in process 59,456 39,894 Finished goods 89,632 16,665 $ 186,307 $ 88,254

Property and Equipment, Net Pro

Property and Equipment, Net Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	A summary of property and equipment follows (in thousands): December 31, 2017 2016 Land $ 203 $ 498 Buildings 20,480 20,679 Furniture and equipment 13,219 11,740 Computer equipment 58,358 54,541 Leasehold improvements 9,961 2,976 102,221 90,434 Accumulated depreciation and amortization (65,598 ) (59,814 ) Property and equipment, net $ 36,623 $ 30,620

Service Spares, Net Service Spa

Service Spares, Net Service Spares, Net (Tables)	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Schedule of Inventory, Noncurrent	A summary of service spares follows (in thousands): December 31, 2017 2016 Service spares $ 7,670 $ 6,503 Accumulated depreciation (5,119 ) (3,480 ) Service spares, net $ 2,551 $ 3,023

Deferred Revenue Deferred Reven

Deferred Revenue Deferred Revenue (Tables)	12 Months Ended
	Dec. 31, 2017
Deferred Revenue Disclosure [Abstract]
Deferred Revenue, by Arrangement, Disclosure	A summary of deferred revenue follows (in thousands): December 31 2017 2016 Deferred product revenue $ 22,245 $ 14,274 Deferred service revenue 96,496 96,113 Total deferred revenue 118,741 110,387 Less long-term deferred revenue (38,622 ) (27,258 ) Deferred revenue in current liabilities $ 80,119 $ 83,129

Commitments and Contingencies C

Commitments and Contingencies Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Contractual Obligation, Fiscal Year Maturity Schedule	Minimum contractual commitments as of December 31, 2017 , were as follows (in thousands): Operating Leases Development Agreements 2018 $ 7,461 $ 19,930 2019 6,918 5,116 2020 6,232 15 2021 6,271 — 2022 6,342 — Thereafter 20,709 — Minimum contractual commitments $ 53,933 $ 25,061

Income Taxes Income Taxes (Tabl

Income Taxes Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Income before Income Tax, Domestic and Foreign	Income (loss) before income taxes consisted of the following (in thousands): Year Ended December 31, 2017 2016 2015 United States $ (53,201 ) $ 2,648 $ 38,362 International 311 7,273 4,415 Total $ (52,890 ) $ 9,921 $ 42,777
Schedule of Components of Income Tax Expense (Benefit)	The tax provision (benefit) for income taxes related to operations consisted of the following (in thousands): Year Ended December 31, 2017 2016 2015 Current provision (benefit): Federal $ 445 $ 3 $ 725 State 310 (279 ) 1,389 Foreign 1,735 1,443 1,023 Total current provision 2,490 1,167 3,137 Deferred provision (benefit): Federal 77,152 (2,127 ) 12,198 State 1,185 416 (52 ) Foreign 112 (150 ) (43 ) Total deferred provision (benefit) 78,449 (1,861 ) 12,103 Total provision (benefit) for income taxes $ 80,939 $ (694 ) $ 15,240
Schedule of Effective Income Tax Rate Reconciliation	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, 2017 2016 2015 Income tax provision (benefit) at statutory rate $ (18,511 ) $ 3,472 $ 14,972 State taxes, net of federal benefit (1,066 ) 89 897 Foreign income taxes 135 (407 ) (12 ) Additional increases (deductions) from share-based compensation 1,036 (1,815 ) — Deemed dividends for U.S. income tax purposes — 329 407 Nondeductible expenses 222 231 283 Disallowed compensation 60 331 455 Audit accrual (settlement) 1,156 (297 ) — Research and development tax credit (3,827 ) (2,470 ) (1,733 ) Tax effect of repatriation transition tax on unremitted earnings 605 — — Gain on strategic transaction (1,568 ) — — Deferred tax impact from tax rate change 28,907 — — Effect of change in valuation allowance on deferred tax assets 73,790 (157 ) (29 ) Effective income tax provision (benefit) $ 80,939 $ (694 ) $ 15,240
Schedule of Deferred Tax Assets and Liabilities	Significant components of the Company’s deferred income tax assets and liabilities follow (in thousands): December 31, 2017 2016 Deferred Income Tax Assets Inventory $ 6,495 $ 4,127 Accrued compensation 262 511 Deferred revenue 8,285 14,742 Research and development credit carryforwards 32,218 28,241 Net operating loss carryforwards 22,775 38,348 Property and equipment 4,136 8,188 Goodwill 289 106 Research and development expenses 9,944 — Share-based compensation 4,124 7,016 Other 2,592 12,939 Gross deferred tax assets 91,120 114,218 Valuation allowance (82,875 ) (8,727 ) Deferred tax assets 8,245 105,491 Deferred Income Tax Liabilities Investment in sales-type lease, net (3,084 ) (13,728 ) Intangible assets (205 ) (421 ) Other (3,850 ) (5,729 ) Deferred tax liabilities (7,139 ) (19,878 ) Net deferred tax asset $ 1,106 $ 85,613
Schedule of Unrecognized Tax Benefits Roll Forward	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, 2017, 2016 and 2015 (in thousands): Balance at December 31, 2014 $ 5,630 Increase related to prior year income tax positions 151 Increase related to current year income tax positions 433 Balance at December 31, 2015 $ 6,214 Increase related to prior year income tax positions 53 Decrease related to prior year income tax positions (365 ) Increase related to current year income tax positions 565 Balance at December 31, 2016 $ 6,467 Increase related to prior year income tax positions 1,440 Increase related to current year income tax positions 673 Balance at December 31, 2017 $ 8,580

Shareholders' Equity Shareholde

Shareholders' Equity Shareholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The following key weighted average assumptions were employed in the calculation for the indicated years ended December 31: 2017 2016 2015 Risk-free interest rate 1.64 % 1.12 % 1.31 % Expected dividend yield — % — % — % Volatility 54.14 % 50.92 % 50.55 % Expected life (in years) 4.0 4.0 4.0 Weighted average Black-Scholes value of options granted $ 7.91 $ 13.16 $ 11.23
Schedule of Share-based Compensation, Stock Options, Activity	A summary of the Company’s stock option activity and related information follows: Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term (Years) Outstanding at January 1, 2015 1,930,990 $ 12.34 Granted 307,450 27.86 Exercised (229,118 ) 9.99 Canceled and forfeited (60,847 ) 20.00 Outstanding at December 31, 2015 1,948,475 14.83 Granted 240,075 32.65 Exercised (168,825 ) 12.57 Canceled and forfeited (30,588 ) 26.60 Outstanding at December 31, 2016 1,989,137 16.99 Granted 324,500 18.36 Exercised (157,257 ) 8.51 Canceled and forfeited (121,906 ) 27.02 Outstanding at December 31, 2017 2,034,474 17.26 5.2 Exercisable at December 31, 2017 1,532,691 15.39 4.0 Available for grant at December 31, 2017 3,107,064
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range	Outstanding and exercisable options by price range as of December 31, 2017 , were as follows: Outstanding Options Exercisable Options Range of Exercise Prices per Share Number Outstanding Weighted Average Remaining Life (Years) Weighted Average Exercise Price Number Exercisable Weighted Average Exercise Price $ 0.00 - $ 10.00 673,584 1.9 $ 5.49 673,584 $ 5.49 $ 10.01 - $ 20.00 619,941 6.7 16.78 327,941 15.71 $ 20.01 - $ 30.00 507,844 6.6 26.30 411,552 26.15 $ 30.01 - $ 42.40 233,105 7.5 32.86 119,614 33.34 $ 0.00 - $ 42.40 2,034,474 5.2 17.26 1,532,691 15.39
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	A summary of the Company’s unvested restricted stock grants and changes during the indicated years ended December 31 is as follows: Service Vesting Restricted Shares Performance Vesting Restricted Shares Total Restricted Shares Shares Weighted Average Grant Date Fair Value Shares Weighted Shares Weighted Average Grant Date Fair Value Outstanding at January 1, 2015 1,033,602 $ 19.48 817,000 $ 15.41 1,850,602 $ 17.68 Granted 45,175 30.44 — — 45,175 30.44 Forfeited (48,998 ) 24.00 (219,000 ) 15.60 (267,998 ) 17.14 Vested (513,336 ) 15.34 (12,500 ) 28.20 (525,836 ) 15.64 Outstanding at December 31, 2015 516,443 24.12 585,500 15.07 1,101,943 19.31 Granted 9,893 34.86 — — 9,893 34.86 Forfeited (18,685 ) 24.73 (72,000 ) 15.57 (90,685 ) 17.46 Vested (250,849 ) 22.14 — — (250,849 ) 22.14 Outstanding at December 31, 2016 256,802 26.43 513,500 15.00 770,302 18.81 Granted 44,002 17.55 — — 44,002 17.55 Forfeited (32,207 ) 28.15 (513,500 ) 15.00 (545,707 ) 15.78 Vested (156,272 ) 25.25 — — (156,272 ) 25.25 Outstanding at December 31, 2017 112,325 24.09 — — 112,325 24.09 A summary of the Company’s unvested restricted stock unit grants and changes during the indicated years ended December 31 is as follows: Service Vesting Restricted Stock Units Performance Vesting Restricted Stock Units Total Restricted Stock Units Units Weighted Units Weighted Units Weighted Average Grant Date Fair Value Outstanding at January 1, 2015 — $ — — $ — — $ — Granted 285,550 29.78 699,300 30.04 984,850 29.97 Forfeited (12,500 ) 30.48 (66,600 ) 30.04 (79,100 ) 30.11 Vested — — — — — — Outstanding at December 31, 2015 273,050 29.75 632,700 30.04 905,750 29.95 Granted 220,575 31.89 23,585 42.65 244,160 32.93 Forfeited (7,700 ) 29.44 — — (7,700 ) 29.44 Vested (60,204 ) 29.57 — — (60,204 ) 29.57 Outstanding at December 31, 2016 425,721 30.89 656,285 30.49 1,082,006 30.65 Granted 799,000 18.40 26,000 20.25 825,000 18.46 Forfeited (95,001 ) 25.75 (199,800 ) 30.04 (294,801 ) 28.66 Vested (141,697 ) 30.91 — — (141,697 ) 30.91 Outstanding at December 31, 2017 988,023 21.29 482,485 30.13 1,470,508 24.19
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs	The following table sets forth the gross share-based compensation cost resulting from stock options, unvested restricted stock and unvested restricted stock units that were recorded in the Company’s Consolidated Statements of Operations for the indicated years ended December 31 (in thousands): 2017 2016 2015 Cost of product revenue $ 294 $ 320 $ 254 Cost of service revenue 290 211 276 Research and development 3,759 3,113 3,770 Sales and marketing 2,432 3,710 3,047 General and administrative 4,074 3,797 4,006 Total share-based compensation expense $ 10,849 $ 11,151 $ 11,353

Segment Information Segment Inf

Segment Information Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The following table presents revenues and gross margin for the Company’s operating segments for the indicated years ended December 31 (in thousands): 2017 2016 2015 Revenue: Supercomputing $ 282,217 $ 510,403 $ 581,733 Storage and Data Management 63,620 89,438 112,862 Maintenance and Support 124,840 107,795 97,091 Engineering Services and Other 46,672 29,968 30,094 Elimination of inter-segment revenue (124,840 ) (107,795 ) (97,091 ) Total revenue $ 392,509 $ 629,809 $ 724,689 Gross Profit: Supercomputing $ 93,272 $ 173,245 $ 177,048 Storage and Data Management 20,288 34,125 37,181 Maintenance and Support 61,305 43,147 41,487 Engineering Services and Other 17,144 12,845 11,454 Elimination of inter-segment gross profit (61,305 ) (43,147 ) (41,487 ) Total gross profit $ 130,704 $ 220,215 $ 225,683
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area	The following data represents the Company’s revenue and long-lived assets for the United States and all other countries (in thousands): United States All Other Countries Total For the year ended December 31, 2017: Product revenue $ 159,279 $ 90,916 $ 250,195 Service revenue $ 96,406 $ 45,908 $ 142,314 Long-lived assets $ 48,989 $ 28,009 $ 76,998 For the year ended December 31, 2016: Product revenue $ 251,317 $ 248,115 $ 499,432 Service revenue $ 88,208 $ 42,169 $ 130,377 Long-lived assets $ 39,933 $ 36,555 $ 76,488 For the year ended December 31, 2015: Product revenue $ 373,494 $ 227,800 $ 601,294 Service revenue $ 88,956 $ 34,439 $ 123,395 Long-lived assets $ 39,014 $ 23,238 $ 62,252

Research and Development Resear

Research and Development Research and Development (Tables)	12 Months Ended
	Dec. 31, 2017
Research and Development [Abstract]
Research and Development Arrangement, Contract to Perform for Others	Details for the Company’s net research and development expenses for the indicated years ended December 31 follows (in thousands): 2017 2016 2015 Gross research and development expenses $ 141,289 $ 130,006 $ 126,060 Less: Amounts included in cost of revenue (9,473 ) (12,621 ) (16,515 ) Less: Reimbursed research and development (excludes amounts in revenue) (33,039 ) (5,255 ) (12,982 ) Net research and development expenses $ 98,777 $ 112,130 $ 96,563

Interest Income (Expense) (Tabl

Interest Income (Expense) (Tables)	12 Months Ended
	Dec. 31, 2017
Other Income and Expenses [Abstract]
Schedule of Other Nonoperating Income (Expense)	The detail of interest income (expense) for the indicated years ended December 31 follows (in thousands): 2017 2016 2015 Interest income $ 3,386 $ 2,120 $ 1,465 Interest expense (110 ) 27 (57 ) Net interest income $ 3,276 $ 2,147 $ 1,408

Quarterly Data (Unaudited) (Tab

Quarterly Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The following table presents unaudited quarterly financial information for the two years ended December 31, 2017 . 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) 2017 2016 For the Quarter Ended 3/31 6/30 9/30 12/31 3/31 6/30 9/30 12/31 Revenue $ 59,031 $ 87,135 $ 79,700 $ 166,643 $ 105,549 $ 100,235 $ 77,451 $ 346,574 Cost of revenue 35,222 58,792 51,208 116,583 65,587 64,074 53,850 226,083 Gross profit 23,809 28,343 28,492 50,060 39,962 36,161 23,601 120,491 Research and development, net 32,640 17,325 26,626 22,186 25,840 27,399 29,084 29,807 Sales and marketing 14,653 15,247 13,392 16,602 16,001 15,380 15,010 18,502 General and administrative 8,797 7,205 7,022 6,089 7,338 9,019 7,968 9,728 Restructuring — — 7,653 915 — — — — Net income (loss) (19,215 ) (6,840 ) (10,232 ) (97,542 ) (5,013 ) (13,126 ) (23,021 ) 51,775 Net income (loss) per common share, basic $ (0.48 ) $ (0.17 ) $ (0.25 ) $ (2.42 ) $ (0.13 ) $ (0.33 ) $ (0.58 ) $ 1.30 Net income (loss) per common share, diluted $ (0.48 ) $ (0.17 ) $ (0.25 ) $ (2.42 ) $ (0.13 ) $ (0.33 ) $ (0.58 ) $ 1.27

Summary of Significant Accoun50

Summary of Significant Accounting Policies Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	$ 3	$ 1.7
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 Accoun51

Summary of Significant Accounting Policies Property and Equipment and Intangible Assets (Details)	12 Months Ended
	Dec. 31, 2017
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 Accoun52

Summary of Significant Accounting Policies Service Spares (Details)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Service spares, useful life	4 years

Summary of Significant Accoun53

Summary of Significant Accounting Policies Revenue Recognition (Details)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Product delivery period	5 years
Maintenance services period	1 year

Summary of Significant Accoun54

Summary of Significant Accounting Policies Sales-type leases (Details)	12 Months Ended
	Dec. 31, 2017
Minimum
Capital Leased Assets [Line Items]
Economic life of product	3 years
Maximum
Capital Leased Assets [Line Items]
Economic life of product	4 years

Summary of Significant Accoun55

Summary of Significant Accounting Policies Foreign Currency Translation and Transaction (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other (Income) Expense, Net
Foreign Currency Translations and Transactions [Line Items]
Net transaction gains (losses)	$ (1.7)	$ 1	$ (1.6)

Summary of Significant Accoun56

Summary of Significant Accounting Policies Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Net deferred tax assets	$ 91,120	$ 114,218
Valuation allowance amount	(82,875)	(8,727)
Net deferred tax assets of valuation allowance	$ 8,245	105,491
Accounting Standards Update 2016-09 | New Accounting Pronouncement, Early Adoption, Effect
Cumulative-effect adjustment resulting from adoption of ASU 2016-09 (Note 14)		16,600
Accounting Standards Update 2016-09 | Retained Earnings | New Accounting Pronouncement, Early Adoption, Effect
Cumulative-effect adjustment resulting from adoption of ASU 2016-09 (Note 14)		$ 16,600	$ 16,600

Summary of Significant Accoun57

Summary of Significant Accounting Policies Advertising Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Advertising expenses	$ 3.4	$ 3.2	$ 2.3

Summary of Significant Accoun58

Summary of Significant Accounting Policies EPS (Details) - shares shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental common shares attributable to dilutive effect of share-based payment arrangements		1.2	1.4
Time-vesting Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	3.1	1.2	0.9
Performance Shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	0.5	1.2	1.2

Summary of Significant Accoun59

Summary of Significant Accounting Policies Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	$ 915	$ 2,782	$ 7,642
Accumulated unrealized net loss on available-for-sale investments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	(7)	0	(8)
Accumulated currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	1,611	2,101	1,675
Accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	$ (689)	$ 681	$ 5,975

Summary of Significant Accoun60

Summary of Significant Accounting Policies New Accounting Pronouncements (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Mar. 31, 2016
Accounting Standards Update 2015-17
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred tax assets, net, current	$ (19,100)
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment resulting from adoption of ASU 2016-09 (Note 14)	16,600
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2016-09 | Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment resulting from adoption of ASU 2016-09 (Note 14)	$ 16,600	$ 16,600

Strategic Transaction - Narrat

Strategic Transaction - Narrative (Details) $ in Thousands	Sep. 25, 2017USD ($)Employee	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Jul. 31, 2017Employee
Business Acquisition [Line Items]
Gain on strategic transaction		$ 4,480	$ 0	$ 0
Number of employees | Employee					190
Seagate Cloud Systems, Inc
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	$ 20,200	$ 1,130
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	15,700
Gain on strategic transaction	4,500
Payments to Acquire Businesses, Gross	$ 8,000
Number of employees | Employee	125
Gain (Loss) on Disposition of Business	$ 4,500
Business Acquisition, Transaction Costs	500
Post-closing adjustments [Member] | Seagate Cloud Systems, Inc
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 1,800

Strategic Transaction - Schedul

Strategic Transaction - Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Sep. 25, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Inventory	$ 4,120		$ 0	$ 0
Property and equipment	2,915		0	0
Deferred revenue	(12,168)		0	0
Other liabilities	(500)		$ 0	$ 0
Seagate Cloud Systems, Inc
Business Acquisition [Line Items]
Cash	8,000
Receivable from Seagate	1,782
Inventory	4,120
Property and equipment	2,915
Deferred revenue	(12,168)
Deferred tax liabilities	(3,019)
Other liabilities	(500)
Net tangible assets	1,130	$ 20,200
Total net assets acquired	4,480
Trademarks | Seagate Cloud Systems, Inc
Business Acquisition [Line Items]
Indefinite-Lived Intangible Assets	90
Developed technology | Seagate Cloud Systems, Inc
Business Acquisition [Line Items]
Indefinite-Lived Intangible Assets	1,400
Customer relationships | Seagate Cloud Systems, Inc
Business Acquisition [Line Items]
Indefinite-Lived Intangible Assets	260
Supply agreement | Seagate Cloud Systems, Inc
Business Acquisition [Line Items]
Indefinite-Lived Intangible Assets	$ 1,600

Strategic Transaction Strategic

Strategic Transaction Strategic Transaction - schedule of Intangible Assets (Details) - Seagate Cloud Systems, Inc $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)
Trademarks
Business Acquisition [Line Items]
Fair Value	$ 90
Useful Life (in Years)	5 years
Developed technology
Business Acquisition [Line Items]
Fair Value	$ 1,400
Useful Life (in Years)	3 years
Customer relationships
Business Acquisition [Line Items]
Fair Value	$ 260
Useful Life (in Years)	10 years
Supply agreement
Business Acquisition [Line Items]
Fair Value	$ 1,600
Useful Life (in Years)	4 years

Strategic Transaction - Sched64

Strategic Transaction - Schedule of Major Componets of Intangible Assets (Details) $ in Thousands	Dec. 31, 2017USD ($)
Business Acquisition [Line Items]
Gross Carrying Amount	$ 3,350
Accumulated Amortization	229
Total	3,121
Trademarks
Business Acquisition [Line Items]
Gross Carrying Amount	90
Accumulated Amortization	5
Total	85
Developed technology
Business Acquisition [Line Items]
Gross Carrying Amount	1,400
Accumulated Amortization	117
Total	1,283
Customer relationships
Business Acquisition [Line Items]
Gross Carrying Amount	260
Accumulated Amortization	7
Total	253
Supply agreement
Business Acquisition [Line Items]
Gross Carrying Amount	1,600
Accumulated Amortization	100
Total	$ 1,500

Strategic Transaction - Sched65

Strategic Transaction - Schedule of Amortization of Intangible Assets (Details) $ in Thousands	Dec. 31, 2017USD ($)
Business Combinations [Abstract]
2,018	$ 911
2,019	911
2,020	794
2,021	344
2,022	40
Thereafter	121
Total	$ 3,121

Fair Value Measurements Fair Va

Fair Value Measurements Fair Value Measurement (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents and restricted cash		$ 140,320	$ 224,617
Available-for-sale investments		6,997
Foreign currency exchange contracts	[1]	3,251	11,250
Assets measured at fair value		150,568	235,867
Foreign currency exchange contracts	[2]	2,431	41
Liabilities measured at fair value		2,431	41
Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents and restricted cash		140,320	224,617
Available-for-sale investments		6,997
Foreign currency exchange contracts		0	0	[1]
Assets measured at fair value		147,317	224,617
Foreign currency exchange contracts		0	0	[2]
Liabilities measured at fair value		0	0
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents and restricted cash		0	0
Available-for-sale investments		0
Foreign currency exchange contracts		3,251	11,250	[1]
Assets measured at fair value		3,251	11,250
Foreign currency exchange contracts		2,431	41	[2]
Liabilities measured at fair value		$ 2,431	$ 41
[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.

Fair Value Measurements Derivat

Fair Value Measurements Derivative Instruments and Hedging Activities Disclosure (Details) $ in Thousands, € in Millions, ¥ in Millions, £ in Millions, SFr in Millions, NZD in Millions, CAD in Millions

12 Months Ended

Dec. 31, 2017USD ($)

Dec. 31, 2016USD ($)

Dec. 31, 2017EUR (€)

Dec. 31, 2017USD ($)

Dec. 31, 2017JPY (¥)

Dec. 31, 2017CAD

Dec. 31, 2017CHF (SFr)

Dec. 31, 2017NZD

Dec. 31, 2017GBP (£)

Dec. 31, 2016EUR (€)

Dec. 31, 2016USD ($)

Dec. 31, 2016JPY (¥)

Dec. 31, 2016CAD

Dec. 31, 2016CHF (SFr)

Dec. 31, 2016NZD

Dec. 31, 2016GBP (£)

Dec. 31, 2015USD ($)

Derivative [Line Items]

Hedged foreign currency exposure

$ 96,300

$ 46,900

Foreign currency exposure on dedesignated foreign currency contracts

46,900

107,500

Accumulated other comprehensive income

915

2,782

$ 7,642

Designated as Hedging Instrument

Derivative [Line Items]

Derivative, notional amount

€ 2.1

¥ 4,345.6

CAD 56

SFr 0

NZD 16.2

€ 1.5

¥ 0

CAD 54.4

SFr 3.6

NZD 0

Total fair value of derivative instruments

(1,490)

424

Not Designated as Hedging Instrument

Derivative [Line Items]

Derivative, notional amount

€ 4.7

¥ 0

CAD 0.3

SFr 2.6

£ 26.1

€ 8

¥ 2,464.7

CAD 32.4

SFr 0

£ 33.8

Total fair value of derivative instruments

2,310

10,785

Prepaid Expenses and Other Current Assets | Designated as Hedging Instrument

Derivative [Line Items]

Prepaid expenses and other current assets

546

71

Prepaid Expenses and Other Current Assets | Not Designated as Hedging Instrument

Derivative [Line Items]

Prepaid expenses and other current assets

1,252

5,344

Other Noncurrent Assets | Designated as Hedging Instrument

Derivative [Line Items]

Other non-current assets

0

367

Other Noncurrent Assets | Not Designated as Hedging Instrument

Derivative [Line Items]

Other non-current assets

1,453

5,468

Other Current Liabilities | Designated as Hedging Instrument

Derivative [Line Items]

Other accrued liabilities

(129)

(9)

Other Current Liabilities | Not Designated as Hedging Instrument

Derivative [Line Items]

Other accrued liabilities

(395)

(27)

Other Noncurrent Liabilities | Designated as Hedging Instrument

Derivative [Line Items]

Other non-current liabilities

(1,907)

(5)

Foreign Exchange Forward

Derivative [Line Items]

Derivative, gain (loss) on derivative, net

$ 800

$ 11,200

Accumulated other comprehensive income

$ (700)

$ 700

Accumulated Other Comprehensi68

Accumulated Other Comprehensive Income Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Gross of Tax Reclassifications	$ (146)	$ 22,207	$ 6,163
Net of Tax Reclassifications	(87)	13,324	3,698
Accumulated other comprehensive income	915	2,782	7,642
Current-period change, net of tax	(1,867)	(4,860)	1,139
Income tax expense (benefit) associated with current-period change	(292)	(2,571)
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	(7)	0	(8)
Current-period change, net of tax	(7)	8
Income tax expense (benefit) associated with current-period change	(3)	6
Accumulated Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	1,611	2,101	1,675
Current-period change, net of tax	(490)	426
Income tax expense (benefit) associated with current-period change	1,110	(152)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income	(689)	681	$ 5,975
Current-period change, net of tax	(1,370)	(5,294)
Income tax expense (benefit) associated with current-period change	$ (1,399)	$ (2,425)

Investments Investments (Detail

Investments Investments (Details) $ in Thousands	Dec. 31, 2017USD ($)
Investments, Debt and Equity Securities [Abstract]
Short-term available-for-sale securities cost	$ 7,007
Short-term available-for-sale securities unrealized loss	(10)
Short-term available-for-sale securities fair value	$ 6,997

Accounts and Other Receivable70

Accounts and Other Receivables, Net Accounts and Other Receivables, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, gross	$ 162,062	$ 197,962
Allowance for doubtful accounts	(28)	(21)
Accounts and other receivables, net	162,034	197,941
Trade Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, gross	131,151	156,705
Unbilled Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, gross	9,321	17,264
Advance Billings
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, gross	3,569	1,915
Financing Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, gross	10,684	8,683
Other Receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, gross	$ 7,337	$ 13,395
Non-US Government Customers | Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk, percent	38.00%	24.00%
Government Contracts Concentration Risk
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, net	$ 45,300	$ 104,600
Government Contracts Concentration Risk | Unbilled Revenues
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts and other receivables, net	$ 2,100	$ 1,400

Sales-Type Lease Sales-Type L71

Sales-Type Lease Sales-Type Lease (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Leases [Abstract]
Total minimum lease payments to be received	$ 42,268	$ 52,224
Less: executory costs	(6,831)	(10,139)
Net minimum lease payments receivable	35,437	42,085
Less: unearned income	(1,386)	(2,352)
Net investment in sales-type lease	34,051	39,733
Less: long-term investment in sales-type lease	(23,367)	(31,050)	$ (18,300)
Investment in sales-type lease included in accounts and other receivables	10,684	$ 8,683
2,018	15,197
2,019	15,478
2,020	11,593
Total minimum lease payments to be received	$ 42,268

Inventory Inventory (Details)

Inventory Inventory (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Inventory [Line Items]
Components and subassemblies	$ 37,219	$ 31,695
Work in process	59,456	39,894
Finished goods	89,632	16,665
Inventory	186,307	88,254
Inventory write-down	0	4,800	$ 500
Located at Customer Sites
Inventory [Line Items]
Finished goods	48,100	10,500
Finished Goods Inventory
Inventory [Line Items]
Finished goods	$ 67,700	$ 11,900

Property and Equipment, Net P73

Property and Equipment, Net Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 102,221	$ 90,434
Accumulated depreciation and amortization	(65,598)	(59,814)
Property and equipment, net	36,623	30,620
Depreciation	14,400	12,500	$ 13,300
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	203	498
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	20,480	20,679
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	13,219	11,740
Computer equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	58,358	54,541
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 9,961	$ 2,976

Service Spares, Net Service S74

Service Spares, Net Service Spares, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Inventory Disclosure [Abstract]
Service spares	$ 7,670	$ 6,503
Accumulated depreciation	5,119	3,480
Service spares, net	2,551	3,023
Service spares depreciation and amortization	$ 1,600	$ 1,500	$ 1,100

Deferred Revenue Deferred Rev75

Deferred Revenue Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 118,741	$ 110,387
Less long-term deferred revenue	(38,622)	(27,258)
Deferred revenue in current liabilities	80,119	83,129
Product
Deferred Revenue Arrangement [Line Items]
Deferred revenue	22,245	14,274
Service
Deferred Revenue Arrangement [Line Items]
Deferred revenue	96,496	96,113
Government Contracts Concentration Risk
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 32,500	$ 60,300
Deferred Revenue | Non-US Government Customers
Deferred Revenue Arrangement [Line Items]
Concentration risk, percent	10.00%	10.00%

Commitments and Contingencies76

Commitments and Contingencies Commitments and Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Long-term Purchase Commitment [Line Items]
Operating Leases, Rent Expense, Net									$ 8,700	$ 8,400	$ 5,900
Research and development, net	$ 22,186	$ 26,626	$ 17,325	$ 32,640	$ 29,807	$ 29,084	$ 27,399	$ 25,840	98,777	112,130	96,563
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating leases due in 2018	7,461								7,461
Operating leases due in 2019	6,918								6,918
Operating leases due in 2020	6,232								6,232
Operating leases due in 2021	6,271								6,271
Operating leases due in 2022	6,342								6,342
Operating leases due thereafter	20,709								20,709
Total operating leases	53,933								53,933
Research and Development Arrangement
Long-term Purchase Commitment [Line Items]
Research and development, net									17,500	15,600	$ 14,300
Other Commitment, Fiscal Year Maturity [Abstract]
Development agreements due in 2018	19,930								19,930
Development agreements due in 2019	5,116								5,116
Development agreements due in 2020	15								15
Development agreements due in 2021	0								0
Development agreements due in 2022	0								0
Development agreements due thereafter	0								0
Total development agreement	$ 25,061								$ 25,061
Facility Closing [Member]
Long-term Purchase Commitment [Line Items]
Operating Leases, Rent Expense, Net										$ 2,300

Commitments and Contingencies L

Commitments and Contingencies Loss Contingencies (Details)	Apr. 22, 2016patent	Sep. 25, 2015patent	Dec. 31, 2017lawsuit
Loss Contingencies [Line Items]
Loss Contingency, Pending Lawsuit, Number | lawsuit			2
Civil Action No. 2:15-cv-1554 [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Patents Allegedly Infringed, Number		4
Civil Action No. 2:15-cv-1554 [Member] | Pending Litigation [Member] | Patents Related to Company's Computer Hardware [Member]
Loss Contingencies [Line Items]
Loss Contingency, Patents Allegedly Infringed, Number		2
Civil Action No. 2:15-cv-1554 [Member] | Pending Litigation [Member] | Patents Related to Third Party's Computer Software [Member]
Loss Contingencies [Line Items]
Loss Contingency, Patents Allegedly Infringed, Number		2
Civil Action No. 2:16-cv-423 [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Patents Allegedly Infringed, Number	5
Civil Action No. 2:16-cv-423 [Member] | Pending Litigation [Member] | Patents Related to Third Party's Computer Software [Member]
Loss Contingencies [Line Items]
Loss Contingency, Patents Allegedly Infringed, Number	5

Income Taxes Narrative (Details

Income Taxes Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest [Abstract]
United States		$ (53,201)	$ 2,648	$ 38,362
International		311	7,273	4,415
Income before income taxes		(52,890)	9,921	42,777
Operating Loss Carryforwards [Line Items]
Deferred tax asset related to TCJA		28,900
Provisional income tax expense		300
Repatriation transition tax and provisional tax expense		300
Income tax benefit (expense)		(80,939)	694	(15,240)
Change in amount of deferred tax assets		74,100	(800)	$ (700)
Research Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards		36,000
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		72,600
Domestic Tax Authority | Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		21,200
Income Tax Effects Allocated Directly to Equity, Employee Stock Options	$ 47,400
Maximum utilization per year, of net operating loss carryforward		4,300
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		$ 7,100
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2016-09
Operating Loss Carryforwards [Line Items]
Cumulative-effect adjustment resulting from adoption of ASU 2016-09 (Note 14)			16,600
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2016-09 | Retained Earnings
Operating Loss Carryforwards [Line Items]
Cumulative-effect adjustment resulting from adoption of ASU 2016-09 (Note 14)	$ 16,600		$ 16,600

Income Taxes Tax Provision (Det

Income Taxes Tax Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current provision (benefit):
Federal	$ 445	$ 3	$ 725
State	310	(279)	1,389
Foreign	1,735	1,443	1,023
Total current provision	2,490	1,167	3,137
Deferred provision (benefit):
Federal	77,152	(2,127)	12,198
State	1,185	416	(52)
Foreign	112	(150)	(43)
Total deferred provision (benefit)	78,449	(1,861)	12,103
Total provision (benefit) for income taxes	$ 80,939	$ (694)	$ 15,240

Income Taxes Reconciliation of

Income Taxes Reconciliation of Statutory Federal Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Income tax provision at statutory rate	$ (18,511)	$ 3,472	$ 14,972
State taxes, net of federal benefit	(1,066)	89	897
Foreign income taxes	135	(407)	(12)
Additional increases (deductions) from share-based compensation	1,036	(1,815)	0
Deemed dividends for U.S. income tax purposes	0	329	407
Nondeductible expenses	222	231	283
Disallowed compensation	60	331	455
Audit accrual (settlement)	1,156	(297)	0
Research and development tax credit	(3,827)	(2,470)	(1,733)
Tax effect of repatriation transition tax on unremitted earnings	605	0	0
Gain on strategic transaction	(1,568)	0	0
Deferred tax impact from tax rate change	28,907	0	0
Effect of change in valuation allowance on deferred tax assets	73,790	(157)	(29)
Total provision (benefit) for income taxes	$ 80,939	$ (694)	$ 15,240

Income Taxes Deferred Tax Asset

Income Taxes Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Income Tax Assets
Inventory	$ 6,495	$ 4,127
Accrued compensation	262	511
Deferred revenue	8,285	14,742
Research and development credit carryforwards	32,218	28,241
Net operating loss carryforwards	22,775	38,348
Property and equipment	4,136	8,188
Goodwill	289	106
Research and development expenses	9,944	0
Share-based compensation	4,124	7,016
Other	2,592	12,939
Gross deferred tax assets	91,120	114,218
Valuation allowance	(82,875)	(8,727)
Deferred tax assets	8,245	105,491
Deferred Income Tax Liabilities
Investment in sales-type lease, net	(3,084)	(13,728)
Intangible assets	(205)	(421)
Other	(3,850)	(5,729)
Deferred tax liabilities	7,139	19,878
Net deferred tax asset	$ 1,106	$ 85,613

Income Taxes Unrecognized Tax B

Income Taxes Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Balance of unrecognized tax benefits that if recognized would affect the effective tax rate	$ 1,200
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at December 31,	6,467	$ 6,214	$ 5,630
Increase related to prior year income tax positions	1,440	53	151
Increase related to current year income tax positions	673	565	433
Decrease related to prior year income tax positions		(365)
Balance at December 31,	$ 8,580	$ 6,467	$ 6,214

Credit Facilities Lines of Cred

Credit Facilities Lines of Credit (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Letters of credit outstanding, amount	$ 15,000,000
Restricted cash and cash equivalents	3,000,000	$ 1,700,000
Wells Fargo Bank
Line of Credit Facility [Line Items]
Draws on line of credit	0
Line of credit, amount outstanding	$ 0
Revolving Credit Facility
Line of Credit Facility [Line Items]
Commitment fee percentage	0.18%
Revolving Credit Facility | Wells Fargo Bank
Line of Credit Facility [Line Items]
Amount of credit facility	$ 50,000,000
London Interbank Offered Rate (LIBOR) | Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.25%

Shareholders' Equity Narrative

Shareholders' Equity Narrative (Details)	Dec. 31, 2017equity_incentive_plan$ / sharesshares	Dec. 31, 2016$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Preferred stock, shares Authorized	5,000,000	5,000,000
Preferred stock, shares outstanding	0	0
Common stock, shares authorized	75,000,000	75,000,000
Common stock, par value (dollars per share) | $ / shares	$ 0.01	$ 0.01
Number of equity incentive plans (equity_incentive_plan) | equity_incentive_plan	1

Shareholders' Equity Assumption

Shareholders' Equity Assumptions (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.64%	1.12%	1.31%
Expected dividend yield	0.00%	0.00%	0.00%
Volatility	54.14%	50.92%	50.55%
Expected life (in years)	4 years	4 years	4 years
Weighted average Black-Scholes value of options granted	$ 7.91	$ 13.16	$ 11.23
Expected average period options will be exercised after vesting (in years)	2 years
Vesting period (in years)	4 years
Expiration period (in years)	10 years
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated forfeiture rate (as a percent)	8.00%
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated forfeiture rate (as a percent)	8.00%
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Estimated forfeiture rate (as a percent)	8.00%	190000000.00%

Shareholders' Equity Option Act

Shareholders' Equity Option Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at December 31	1,989,137	1,948,475	1,930,990
Granted	324,500	240,075	307,450
Exercised	(157,257)	(168,825)	(229,118)
Canceled and forfeited	(121,906)	(30,588)	(60,847)
Outstanding at December 31	2,034,474	1,989,137	1,948,475
Exercisable at December 31, 2017	1,532,691
Available for grant at December 31, 2017	3,107,064
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Outstanding at December 31	$ 16.99	$ 14.83	$ 12.34
Granted	18.36	32.65	27.86
Exercised	8.51	12.57	9.99
Canceled and forfeited	27.02	26.60	20
Outstanding at December 31	17.26	$ 16.99	$ 14.83
Exercisable at December 31, 2017	$ 15.39
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	2,034,474
Weighted Average Remaining Life (Years)	5 years 2 months 12 days
Weighted Average Exercise Price	$ 17.26
Number Exercisable	1,532,691
Weighted Average Exercise Price	$ 15.39
Lower Range	0
Upper Range	$ 42.40
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	5 years 2 months 12 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	4 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 17.4
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value	15.5
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 1.8	$ 4	$ 5
Range of Exercise Prices, Range One
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	673,584
Weighted Average Remaining Life (Years)	1 year 10 months 24 days
Weighted Average Exercise Price	$ 5.49
Number Exercisable	673,584
Weighted Average Exercise Price	$ 5.49
Lower Range	0
Upper Range	$ 10
Range of Exercise Prices, Range Two
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	619,941
Weighted Average Remaining Life (Years)	6 years 8 months 12 days
Weighted Average Exercise Price	$ 16.78
Number Exercisable	327,941
Weighted Average Exercise Price	$ 15.71
Lower Range	10.01
Upper Range	$ 20
Range of Exercise Prices, Range Three
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	507,844
Weighted Average Remaining Life (Years)	6 years 7 months 6 days
Weighted Average Exercise Price	$ 26.30
Number Exercisable	411,552
Weighted Average Exercise Price	$ 26.15
Lower Range	20.01
Upper Range	$ 30
Range of Exercise Prices, Range Four
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number Outstanding	233,105
Weighted Average Remaining Life (Years)	7 years 6 months
Weighted Average Exercise Price	$ 32.86
Number Exercisable	119,614
Weighted Average Exercise Price	$ 33.34
Lower Range	30.01
Upper Range	$ 42.40

Shareholders' Equity Restricted

Shareholders' Equity Restricted Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Exercise of stock options	$ 1,342	$ 2,121	$ 2,289
Vesting period (in years)	4 years
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at December 31	770,302	1,101,943	1,850,602
Granted	44,002	9,893	45,175
Forfeited	(545,707)	(90,685)	(267,998)
Vested	(156,272)	(250,849)	(525,836)
Outstanding at December 31	112,325	770,302	1,101,943
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at December 31	$ 18.81	$ 19.31	$ 17.68
Granted	17.55	34.86	30.44
Forfeited	15.78	17.46	17.14
Vested	$ 25.25	22.14	15.64
Outstanding at December 31		$ 18.81	$ 19.31
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Vested in period, fair value	$ 2,900	$ 7,700	$ 14,200
Restricted stock award, gross (in shares)	44,002	9,893	45,175
Exercise of stock options	$ 800	$ 300	$ 1,400
Restricted Stock | Time-vesting Shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at December 31	256,802	516,443	1,033,602
Granted	44,002	9,893	45,175
Forfeited	(32,207)	(18,685)	(48,998)
Vested	(156,272)	(250,849)	(513,336)
Outstanding at December 31	112,325	256,802	516,443
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at December 31	$ 26.43	$ 24.12	$ 19.48
Granted	17.55	34.86	30.44
Forfeited	28.15	24.73	24
Vested	$ 25.25	22.14	15.34
Outstanding at December 31		$ 26.43	$ 24.12
Restricted Stock | Performance-based Vesting
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at December 31	513,500	585,500	817,000
Granted	0	0	0
Forfeited	(513,500)	(72,000)	(219,000)
Vested	0	0	(12,500)
Outstanding at December 31	0	513,500	585,500
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at December 31	$ 15	$ 15.07	$ 15.41
Granted	0	0	0
Forfeited	15	15.57	15.60
Vested	$ 0	0	28.20
Outstanding at December 31		$ 15	$ 15.07
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at December 31	1,082,006	905,750	0
Granted	825,000	244,160	984,850
Forfeited	(294,801)	(7,700)	(79,100)
Vested	(141,697)	(60,204)	0
Outstanding at December 31	1,470,508	1,082,006	905,750
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at December 31	$ 30.65	$ 29.95	$ 0
Granted	18.46	32.93	29.97
Forfeited	28.66	29.44	30.11
Vested	30.91	29.57	0
Outstanding at December 31	$ 24.19	$ 30.65	$ 29.95
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Vested in period, fair value	$ 2,700
Restricted stock award, gross (in shares)	825,000	244,160	984,850
Exercise of stock options	$ 15,200	$ 8,000	$ 29,500
Restricted Stock Units (RSUs) | Time-vesting Shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at December 31	425,721	273,050	0
Granted	799,000	220,575	285,550
Forfeited	(95,001)	(7,700)	(12,500)
Vested	(141,697)	(60,204)	0
Outstanding at December 31	988,023	425,721	273,050
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at December 31	$ 30.89	$ 29.75	$ 0
Granted	18.40	31.89	29.78
Forfeited	25.75	29.44	30.48
Vested	30.91	29.57	0
Outstanding at December 31	$ 21.29	$ 30.89	$ 29.75
Restricted Stock Units (RSUs) | Performance-based Vesting
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at December 31	656,285	632,700	0
Granted	26,000	23,585	699,300
Forfeited	(199,800)	0	(66,600)
Vested	0	0	0
Outstanding at December 31	482,485	656,285	632,700
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding at December 31	$ 30.49	$ 30.04	$ 0
Granted	20.25	42.65	30.04
Forfeited	30.04	0	30.04
Vested	0	0	0
Outstanding at December 31	$ 30.13	$ 30.49	$ 30.04
NonEmployee Director | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Vesting period (in years)	1 year
Officers and Key Employees | Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Vesting period (in years)	4 years

Shareholders' Equity Expense (D

Shareholders' Equity Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Nonvested awards, compensation cost not yet recognized	$ 33,000
Nonvested awards, compensation cost not yet recognized, period for recognition (in years)	2 years 10 months 24 days
Allocated share-based compensation expense	$ 10,849	$ 11,151	$ 11,353
Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	3,759	3,113	3,770
Selling and Marketing Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	2,432	3,710	3,047
General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	4,074	3,797	4,006
Product | Cost of Sales
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	294	320	254
Service | Cost of Sales
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	290	$ 211	$ 276
Performance-based Vesting
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Nonvested awards, compensation cost not yet recognized	14,500
Time-vesting Shares
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Nonvested awards, compensation cost not yet recognized	$ 18,500

Shareholders' Equity ESPP (Deta

Shareholders' Equity ESPP (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued under employee stock purchase plan	1,118,151	1,098,085	1,070,343
Employee Stock Purchase Plan (ESPP)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	1,750,000
Maximum employee subscription rate	15.00%
Percentage of market price	95.00%

Benefit Plans (Details)

Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
United States Pension Plan of US Entity
Defered Compensation Arrangement with Individual [Line Items]
Company match expense	$ 3	$ 2.9	$ 2.6
Foreign Pension Plans, Defined Benefit
Defered Compensation Arrangement with Individual [Line Items]
Projected benefit	2	2
Funded status of plan	$ 0.2	$ 0.2

Segment Information Business Se

Segment Information Business Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Revenue	$ 166,643	$ 79,700	$ 87,135	$ 59,031	$ 346,574	$ 77,451	$ 100,235	$ 105,549	$ 392,509	$ 629,809	$ 724,689
Gross Profit	$ 50,060	$ 28,492	$ 28,343	$ 23,809	$ 120,491	$ 23,601	$ 36,161	$ 39,962	130,704	220,215	225,683
Supercomputing
Segment Reporting Information [Line Items]
Revenue									282,217	510,403	581,733
Gross Profit									93,272	173,245	177,048
Storage and Data Management
Segment Reporting Information [Line Items]
Revenue									63,620	89,438	112,862
Gross Profit									20,288	34,125	37,181
Maintenance and Support
Segment Reporting Information [Line Items]
Revenue									124,840	107,795	97,091
Gross Profit									61,305	43,147	41,487
Other Segments
Segment Reporting Information [Line Items]
Revenue									46,672	29,968	30,094
Gross Profit									17,144	12,845	11,454
Intersegment Eliminations
Segment Reporting Information [Line Items]
Revenue									124,840	107,795	(97,091)
Gross Profit									$ 61,305	$ 43,147	$ (41,487)

Segment Information Geographic

Segment Information Geographic Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Product revenue	$ 250,195	$ 499,432	$ 601,294
Service revenue	142,314	130,377	123,395
Long-lived assets	76,998	76,488	62,252
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Product revenue	159,279	251,317	373,494
Service revenue	96,406	88,208	88,956
Long-lived assets	48,989	39,933	39,014
Non-US
Revenues from External Customers and Long-Lived Assets [Line Items]
Product revenue	90,916	248,115	227,800
Service revenue	45,908	42,169	34,439
Long-lived assets	$ 28,009	$ 36,555	$ 23,238

Segment Information Narrative (

Segment Information Narrative (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017USD ($)Customers	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)Customers	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)Customers	Dec. 31, 2016USD ($)Customers	Dec. 31, 2015USD ($)Customers
Segment Reporting Information [Line Items]
Long-term investment in sales-type lease, net	$ 23,367				$ 31,050				$ 23,367	$ 31,050	$ 18,300
Revenue	$ 166,643	$ 79,700	$ 87,135	$ 59,031	$ 346,574	$ 77,451	$ 100,235	$ 105,549	392,509	629,809	724,689
Government Contracts Concentration Risk
Segment Reporting Information [Line Items]
Revenue									$ 206,100	$ 296,900	$ 338,500
Revenue
Segment Reporting Information [Line Items]
Concentration Risk, Number of Customers | Customers	1				1				1	1	0
Percentage of total revenue									11.00%		10.00%
INDIA | Revenue
Segment Reporting Information [Line Items]
Percentage of total revenue									11.00%

Research and Development Rese94

Research and Development Research and Development (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Research and Development [Abstract]
Gross research and development expenses									$ 141,289	$ 130,006	$ 126,060
Less: Amounts included in cost of revenue									(9,473)	(12,621)	(16,515)
Less: Reimbursed research and development (excludes amounts in revenue)									(33,039)	(5,255)	(12,982)
Net research and development expenses	$ 22,186	$ 26,626	$ 17,325	$ 32,640	$ 29,807	$ 29,084	$ 27,399	$ 25,840	$ 98,777	$ 112,130	$ 96,563

Interest Income (Expense) (Deta

Interest Income (Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Income and Expenses [Abstract]
Interest income	$ 3,386	$ 2,120	$ 1,465
Interest expense	110	27	57
Net interest income	$ 3,276	$ 2,147	$ 1,408

Restructuring - Narrative (Deta

Restructuring - Narrative (Details)	Jul. 31, 2017Employee
Restructuring Cost and Reserve [Line Items]
Number of employees	190

Quarterly Data (Unaudited) (Det

Quarterly Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Selected Quarterly Financial Information [Abstract]
Revenue	$ 166,643	$ 79,700	$ 87,135	$ 59,031	$ 346,574	$ 77,451	$ 100,235	$ 105,549	$ 392,509	$ 629,809	$ 724,689
Cost of revenue	116,583	51,208	58,792	35,222	226,083	53,850	64,074	65,587	261,805	409,594	499,006
Gross profit	50,060	28,492	28,343	23,809	120,491	23,601	36,161	39,962	130,704	220,215	225,683
Research and development, net	22,186	26,626	17,325	32,640	29,807	29,084	27,399	25,840	98,777	112,130	96,563
Sales and marketing	16,602	13,392	15,247	14,653	18,502	15,010	15,380	16,001	59,894	64,893	60,150
General and administrative	6,089	7,022	7,205	8,797	9,728	7,968	9,019	7,338	29,113	34,053	27,966
Restructuring		7,653	0	0	0	0	0	0	8,568	0	0
Net income (loss)	$ (97,542)	$ (10,232)	$ (6,840)	$ (19,215)	$ 51,775	$ (23,021)	$ (13,126)	$ (5,013)	$ (133,829)	$ 10,615	$ 27,537
Net income (loss) per common share, basic	$ (2.42)	$ (0.25)	$ (0.17)	$ (0.48)	$ 1.30	$ (0.58)	$ (0.33)	$ (0.13)	$ (3.33)	$ 0.27	$ 0.70
Net income (loss) per common share, diluted	$ (2.42)	$ (0.25)	$ (0.17)	$ (0.48)	$ 1.27	$ (0.58)	$ (0.33)	$ (0.13)	$ (3.33)	$ 0.26	$ 0.68

Schedule II - Valuation and Q98

Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for Trade Receivables - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		$ 21	$ 19	$ 97
Charge to Expense		7	2	0
Deductions	[1]	0	0	(78)
Balance at End of Period		$ 28	$ 21	$ 19
[1]	Deductions represent uncollectible accounts written off, net of recoveries.