TPI Composites (TPIC) 10-Q 3 May 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Trading Symbol	TPIC
Entity Registrant Name	TPI COMPOSITES, INC
Entity Central Index Key	1,455,684
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		34,097,048

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 138,841	$ 148,113
Restricted cash	3,251	3,849
Accounts receivable	117,950	121,576
Contract assets	130,015	105,619
Prepaid expenses and other current assets	35,718	27,507
Inventories	4,205	4,112
Total current assets	429,980	410,776
Property, plant, and equipment, net	126,860	123,480
Other noncurrent assets	23,024	22,306
Total assets	579,864	556,562
Current liabilities:
Accounts payable and accrued expenses	169,179	167,175
Accrued warranty	32,670	30,419
Current maturities of long-term debt	43,085	35,506
Contract liabilities	4,449	2,763
Total current liabilities	249,383	235,863
Long-term debt, net of debt issuance costs and current maturities	82,658	85,879
Other noncurrent liabilities	4,791	4,938
Total liabilities	336,832	326,680
Commitments and contingencies (Note 10)
Stockholders’ equity: (Note 4)
Common shares, $0.01 par value, 100,000 shares authorized and 34,128 shares issued and 34,097 shares outstanding at March 31, 2018 and 100,000 shares authorized and 34,049 shares issued and 34,021 shares outstanding at December 31, 2017	341	340
Paid-in capital	304,230	301,543
Accumulated other comprehensive income	1,332	(558)
Accumulated deficit	(62,284)	(70,932)
Treasury stock, at cost, 31 shares at March 31, 2018 and 28 shares at December 31, 2017	(587)	(511)
Total stockholders’ equity	243,032	229,882
Total liabilities and stockholders’ equity	$ 579,864	$ 556,562

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	34,128,000	34,049,000
Common stock, shares outstanding	34,097,000	34,021,000
Treasury stock, shares	31,000	28,000

Condensed Consolidated Income S

Condensed Consolidated Income Statements - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Net sales (Note 4)	$ 253,981	$ 208,615
Cost of sales	210,988	182,538
Startup and transition costs	14,735	6,159
Total cost of goods sold	225,723	188,697
Gross profit	28,258	19,918
General and administrative expenses	11,163	8,306
Income from operations	17,095	11,612
Other income (expense):
Interest income	41	19
Interest expense	(3,338)	(3,026)
Realized loss on foreign currency remeasurement	(4,011)	(1,381)
Miscellaneous income	818	320
Total other expense	(6,490)	(4,068)
Income before income taxes	10,605	7,544
Income tax provision	(1,957)	(2,331)
Net income	$ 8,648	$ 5,213
Weighted-average common shares outstanding:
Basic	34,049	33,737
Diluted	35,479	33,827
Net income per common share:
Basic	$ 0.25	$ 0.15
Diluted	$ 0.24	$ 0.15

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 8,648	$ 5,213
Other comprehensive income:
Foreign currency translation adjustments	1,890	277
Comprehensive income	$ 10,538	$ 5,490

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 8,648	$ 5,213
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	7,072	3,952
Share-based compensation expense	2,388	1,707
Amortization of debt issuance costs	181	143
Changes in assets and liabilities:
Accounts receivable	3,626	(28,722)
Contract assets and liabilities	(22,710)	6,848
Inventories	(93)	(68)
Prepaid expenses and other current assets	(8,211)	6,816
Other noncurrent assets	734	(156)
Accounts payable and accrued expenses	3,241	11,928
Accrued warranty	2,250	2,080
Other noncurrent liabilities	(158)	197
Net cash provided by (used in) operating activities	(3,032)	9,938
Cash flows from investing activities:
Purchase of property and equipment	(11,714)	(16,922)
Net cash used in investing activities	(11,714)	(16,922)
Cash flows from financing activities:
Repayments of term loan	(938)	(938)
Net proceeds from (repayments of) accounts receivable financing	8,093	(1,233)
Net proceeds from working capital loans		517
Net repayments of other debt	(2,978)	(1,155)
Proceeds from exercise of stock options	585
Repurchase of common stock including shares withheld in lieu of income taxes	(272)
Net cash provided by (used in) financing activities	4,490	(2,809)
Impact of foreign exchange rates on cash, cash equivalents and restricted cash	386	(63)
Net change in cash, cash equivalents and restricted cash	(9,870)	(9,856)
Cash, cash equivalents and restricted cash, beginning of year	152,437	129,863
Cash, cash equivalents and restricted cash, end of period	142,567	120,007
Supplemental disclosures of cash flow information:
Cash paid for interest	3,127	2,899
Cash paid for income taxes, net	1,434	4,146
Supplemental disclosures of noncash investing and financing activities:
Accrued capital expenditures in accounts payable	$ 4,425	$ 2,569

Summary of Operations and Signi

Summary of Operations and Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Summary of Operations and Significant Accounting Policies	Note 1. Summary of Operations and Significant Accounting Policies Description of Business TPI Composites, Inc. is the holding company that conducts substantially all of its business operations through its direct and indirect subsidiaries (collectively, the Company). The Company was founded in 1968 and has been producing composite wind blades since 2001. The Company’s knowledge and experience of composite materials and manufacturing originates with its predecessor company, Tillotson Pearson Inc., a leading manufacturer of high-performance sail and powerboats along with a wide range of composite structures used in other industrial applications. Following the separation from the boat building business in 2004, the Company reorganized in Delaware as LCSI Holding, Inc. and then changed its corporate name to TPI Composites, Inc. in 2008. Today, the Company is headquartered in Scottsdale, Arizona and has expanded its global footprint to include domestic facilities in Newton, Iowa; Fall River, Massachusetts; Warren, Rhode Island and Santa Teresa, New Mexico and international facilities in Dafeng, China; Taicang Port, China; Taicang City, China; Yangzhou, China; Juárez, Mexico; Matamoros, Mexico; Izmir, Turkey and Kolding, Denmark. Public Offerings and Stock Split In July 2016, the Company completed an initial public offering (IPO) of 7,187,500 shares of the its common stock at a price of $11.00 per share, which included 937,500 shares issued pursuant to the underwriters’ over-allotment option. Certain of the Company’s existing shareholders, a non-employee director and executive officers purchased an aggregate of 1,250,000 shares of common stock in the IPO included in the total issuance above. The net proceeds from the IPO were $67.2 million after deducting underwriting discounts and offering expenses. Immediately prior to the closing of the IPO, all shares of the then-outstanding redeemable preferred shares converted into an aggregate of 21,110,204 shares of common stock and the redeemable preferred share warrants converted on a net issuance basis into 120,923 shares of common stock. In addition, concurrent with the closing of the IPO, certain subordinated convertible promissory notes in the aggregate principal and interest amount of $11.9 million were converted into 1,079,749 shares of common stock at the public offering price of $11.00 per share. Prior to the IPO, in July 2016 the Company amended its amended and restated certificate of incorporation to effect a 360-for-1 forward stock split of its common stock. As a result of the stock split, the Company has adjusted the share amounts authorized and issuable under the share-based compensation plans. All share and per share common stock information (including the share-based compensation plans) referenced throughout the unaudited condensed consolidated financial statements and notes thereto have been retroactively adjusted to reflect this stock split. The stock split did not cause an adjustment to the par value of the authorized shares of common stock. In May 2017, the Company completed a secondary public offering of 5,075,000 shares of its common stock at a price of $16.35 per share, which included 575,000 shares issued pursuant to the underwriters’ option to purchase additional shares. All of the shares were sold by existing shareholders and certain of the Company’s executive officers. The selling shareholders received all of the net proceeds of $78.8 million from the secondary public offering. The Company did not sell any shares and did not receive any of the proceeds from the offering and the costs paid by the Company in connection with the offering of $0.8 million were recorded in general and administrative costs in the accompanying condensed consolidated income statement. Basis of Presentation The Company divides its business operations into four geographic operating segments—the United States, Asia, Mexico and Europe, the Middle East and Africa (EMEA) as follows: • The U.S. segment includes (1) the manufacturing of wind blades at the Newton, Iowa plant, (2) the manufacturing of precision molding and assembly systems used for the manufacture of wind blades at the Warren, Rhode Island facility, (3) the manufacturing of composite solutions for the transportation industry, which the Company also conducts at its existing Rhode Island and Massachusetts facilities, (4) wind blade inspection and repair services, (5) our advanced engineering center in Kolding, Denmark, which provides technical and engineering resources to our manufacturing facilities and (6) our corporate headquarters, the costs of which are included in general and administrative expenses. In January 2018, the Company entered into a new lease agreement with a third party for a new manufacturing facility in Newton, Iowa and expects to commence operations at this facility in the second quarter of 2018. • The Asia segment includes (1) the manufacturing of wind blades at the facility in Taicang Port, China and at its two facilities in Dafeng, China, (2) the manufacturing of precision molding and assembly systems at the Taicang City, China facility and (3) wind blade inspection and repair services. In March 2018, the Company entered into a new binding agreement with a third party related to the lease of a new manufacturing facility in the Yangzhou Economic & Technical Development Zone in Yangzhou, China and we expect to commence operations at this facility in early 2019. • The Mexico segment manufactures wind blades from its three facilities in Juárez, Mexico, the most recent of which commenced operations in January 2017. In April 2017, the Company entered into a new lease agreement with a third party for a new manufacturing facility in Matamoros, Mexico and the Company expects to commence operations at this facility in the third quarter of 2018. • The EMEA segment manufactures wind blades from its two facilities in Izmir, Turkey, the most recent of which commenced operations in 2016. These two facilities also perform wind blade inspection and repair services. The accompanying condensed consolidated financial statements include the accounts of TPI Composites, Inc. and all majority owned subsidiaries. All significant intercompany transactions and balances have been eliminated. The condensed consolidated financial statements included herein have been prepared by the Company without audit, pursuant to the rules and regulations of the SEC and should be read in conjunction with the audited consolidated financial statements for the year ended December 31, 2017 included in the Company’s Annual Report on Form 10-K. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States (GAAP) have been condensed or omitted, as permitted by the SEC, although the Company believes the disclosures that are made are adequate to make the information presented herein not misleading. The accompanying condensed consolidated financial statements reflect, in the opinion of management, all normal recurring adjustments necessary to present fairly the Company’s financial position at March 31, 2018, and the results of the Company’s operations, comprehensive income and cash flows for the periods presented. The Company restated the December 31, 2017 condensed consolidated balance sheet and the March 31, 2017 condensed consolidated statements of income and cash flow data for the effect of the adoption of Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement, As previously announced, effective January 1, 2018, the Company adopted the requirements of Topic 606 using the full retrospective method as further described in Recently Issued Accounting Pronouncements - Revenue from Contracts with Customers Revenue from Contracts with Customers Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement Revenue Recognition The majority of our revenues are generated from long-term contracts associated with manufacturing of wind blades and related services. The Company accounts for a long-term contract when it has the approval from both parties, the rights of the parties are identified, payment terms are established, the contract has commercial substance and the collectability of consideration is probable. To determine the proper revenue recognition method for each long-term contract, the Company evaluates whether the original contract should be accounted for as one or more performance obligations. This evaluation requires judgment and the decisions reached could change the amount of revenue and gross profit recorded in a given period. As most of the Company’s contracts contain multiple performance obligations, the Company allocates the total transaction price to each performance obligation based on the estimated relative standalone selling prices of the promised goods or services underlying each performance obligation. The Company’s manufacturing services are customer specific and involve production of items that cannot be sold to other customers due to the customers’ protected intellectual property; therefore, the Company allocates the total transaction price under contracts with multiple performance obligations using the contractually stated prices, as these prices represent the relative standalone selling price based on an expected cost plus margin model. Revenue is primarily recognized over time as the Company has an enforceable right to payment upon termination and the Company may not use or sell the product to fulfill other customers’ contracts. In addition, the customer does not have return or refund rights for items produced that conform to the specifications included in the contract. Because control transfers over time, revenue is recognized based on the extent of progress towards the completion of the performance obligation. The Company uses the cost-to-cost input measure of progress for its contracts as this method provides the best representation of the production progress towards satisfaction of the performance obligation as the materials are distinct to the product being manufactured because of customer specifications provided for in the contract, the costs incurred are proportional to the progress towards completion of the product, and the products do not involve significant pre-fabricated component parts. Under the cost-to-cost method, progress and the related revenue recognition is determined by a ratio of direct costs incurred to date in fulfillment of the contract to the total estimated direct costs required to complete the performance obligation. Determining the revenue to be recognized for services performed under the Company’s manufacturing contracts involves significant judgments and estimates relating to the total consideration to be received and the expected total costs to complete the performance obligation. The judgments and estimates relating to the total consideration to be received include the amount of variable consideration as the Company’s contracts typically provide the customer with a range of production output options from guaranteed minimum volume obligations to the production capacity of the facility, and customers will provide periodic non-cancellable commitments for the number of wind blades to be produced over the term of the agreement. The Company uses historical experience, customer commitments and forecasted future production based on the capacity of the plant to estimate the total revenue to be received to complete the performance obligation. In addition, the amount of revenue per unit produced may vary based on the costs of production of the wind blades as the Company may be able to change the price per unit based on changes in the cost of production. Further, some contracts provide opportunities for the Company to share in labor and material cost savings as well as absorb some additional costs as an incentive for more efficient production, both of which impact the margin realized on the contract and ultimately the total amount of revenue to be recognized. Additionally, certain customer contracts provide for concessions by the Company for missed production deadlines. The Company estimates variable consideration at the most likely amount to which it expects to be entitled. The Company includes estimated amounts in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. The Company’s estimates of variable consideration and determination of whether to include estimated amounts in the transaction price are based largely on an assessment of the Company’s anticipated performance and all information available to the Company at the time of the estimate and may materially change as additional information becomes known. Contracts may be modified to account for changes in specifications of products and changing requirements. If the contract modifications are for goods or services that are not distinct from the existing contract, they are accounted for as if they were part of the original contract. The effect of a contract modification on the transaction price and the measure of progress for the performance obligation to which it relates is recognized as an adjustment to revenue on a cumulative catch-up basis. If contract modifications are for goods and services that are distinct from the existing contract and increases the amount of consideration reflecting the standalone sale price of the additional goods or services, then the contract modification is accounted for as a separate contract and is evaluated for one or more performance obligations. Each reporting period, the Company evaluates the progress towards satisfaction of each performance obligation based on any contract modifications that have occurred, cost incurred to date, and an estimate of the expected future revenue and costs to be incurred to complete the performance obligation. Based on this analysis, any changes in estimates of revenue, cost of sales, contract assets and liabilities and the related impact to operating income are recognized on a cumulative catch-up basis, which recognizes in the current period the cumulative effect of the changes on current and prior periods based on a performance obligation's percentage of completion. Wind blade pricing is based on annual commitments of volume as established in the customer’s contract and orders less than committed volume may result in a higher price per wind blade to customers. Orders in excess of annual commitments may result in discounts to customers from the contracted price for the committed volume. Customers typically provide periodic purchase orders with the price per wind blade given the current cost of the bill of materials, labor requirements and volume desired. The Company records an allowance for expected utilization of early payment discounts which are reported as a reduction of the related revenue. Precision molding and assembly systems included in a customer’s contract are based upon the specific engineering requirements and design determined by the customer and are specific to the wind blade design and function desired. From the customer’s engineering specifications, a job cost estimate is developed along with a production plan, and the desired margin is applied based on the location the work is to be performed and complexity of the customer’s design. Precision molding and assembly systems are generally built to produce wind blades which may be manufactured by the Company in production runs specified in the customer contract. Contract assets primarily relate to the Company’s rights to consideration for work completed but not billed at the reporting date on manufacturing services contracts. The contract assets are transferred to accounts receivable when the rights become unconditional, which generally occurs when customers are invoiced upon the determination that a product conforms to the contract specifications and invoices are due based on each customers negotiated payment terms, which range from 30 to 65 days. The Company applies the practical expedient that allows it to exclude payment terms under one year from the transfer of a promised good or service from consideration of a significant financing component in its contracts. With regards to the production of precision molding and assembly systems, the Company’s contracts generally call for progress payments to be made in advance of production. Generally, payment is made at certain percentage of completion milestones with the final payment due upon delivery to the manufacturing facility. These progress payments are recorded within contract liabilities as current liabilities in the condensed consolidated balance sheets and are reduced as the Company records revenue over time. The Company’s customers may request, in situations where they do not have space available to receive products or do not want to take possession of products immediately for other reasons, that their finished products be stored by the Company in one of its facilities. Most contracts provide for a limited number of wind blades to be stored during the period of the contract with any additional wind blades stored subject to additional storage fees, which are included in the wind blade performance obligation revenue. Revenue related to non-recurring engineering and freight services provided under customer contracts is recognized at a point in time following the transfer of control of the promised services to the customer. Customers usually pay the carrier directly for the cost of shipping associated with items produced. When the Company pays the shipping costs, the Company applies the practical expedient that allows it to account for shipping and handling as a fulfillment costs and include the revenue in the associated performance obligation and the costs are included in cost of goods sold. Taxes assessed by a governmental authority that are both imposed on and concurrent with specific revenue-producing transactions, that are collected by the Company from a customer, are excluded from revenue. Warranty Expense The Company provides a limited warranty for its mold and wind blade products, including parts and labor, with terms and conditions that vary depending on the product sold, generally for periods that range from two to five years. Warranty expense is recorded based upon estimates of future repairs using a probability-based methodology that considers previous warranty claims, identified quality issues and industry practices. Once the warranty period has expired, any remaining unused warranty accrual for the specific products is reversed against the current year warranty expense amount. Warranty accrual at March 31 consisted of the following: 2018 (in thousands) Warranty accrual at beginning of year $ 30,419 Accrual during the period 3,621 Cost of warranty services provided during the period (306 ) Reversal of reserves upon warranty expiration (1,064 ) Warranty accrual at end of period $ 32,670 Treasury Stock Common stock purchased for treasury is recorded at historical cost. Transactions in treasury shares relate to share-based compensation plans and are recorded at weighted-average cost. Net Income Per Common Share Calculation The basic net income per common share is computed by dividing the net income by the weighted-average number of common shares outstanding during a period. Diluted net income per common share is computed by dividing the net income by the weighted-average number of common shares outstanding plus potentially dilutive securities using the treasury stock method. The table below reflects the calculation of the weighted-average number of common shares outstanding, using the treasury stock method, used in computing basic and diluted earnings per common share: Three Months Ended March 31, 2018 2017 (in thousands) Basic weighted-average shares outstanding 34,049 33,737 Effect of dilutive stock options and warrants 1,430 90 Diluted weighted-average shares outstanding 35,479 33,827 Share-based compensation awards of 175,000 shares were excluded from the computation of diluted net income per share for the three months ended March 31, 2018 because the effect would be anti-dilutive. In addition, PSUs have been excluded from the computation of diluted net income per share for the three months ended March 31, 2018 as the performance conditions have not yet been met. The Company did not have any potential dilutive securities which were excluded from the computation of diluted net income per share for the three months ended March 31, 2017. Use of Estimates The preparation of these condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Recently Issued Accounting Pronouncements Accounting Pronouncements Adopted in 2018 Revenue from Contracts with Customers In May 2014, the Financial Accounting Standards Board (FASB) issued Topic 606, which provides new recognition and disclosure requirements for revenue from contracts with customers that supersedes the existing revenue recognition guidance. The new recognition requirements focus on when the customer obtains control of the goods or services, rather than the current risks and rewards model of recognition. The core principle of the new standard is that an entity will recognize revenue when it transfers goods or services to its customers in an amount that reflects the consideration an entity expects to be entitled to for those goods or services. The new disclosure requirements included in these financial statements contain information intended to communicate the nature, amount, timing and any uncertainty of revenue and cash flows from the applicable contracts, including any significant judgments and changes in judgments and assets recognized from the costs to obtain or fulfill a contract. The Company adopted Topic 606 as of January 1, 2018 with retrospective application to January 1, 2016 through December 31, 2017. See Note 2, Revenue from Contracts with Customers Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement, Cash Flow Presentation In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments Restricted Cash The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets which total the same such amounts in the condensed consolidated statements of cash flows: March 31, December 31, March 31, December 31, 2018 2017 2017 2016 (in thousands) Cash and cash equivalents $ 138,841 $ 148,113 $ 115,541 $ 119,066 Restricted cash 3,251 3,849 1,928 2,259 Restricted cash included within other noncurrent assets 475 475 2,538 8,538 Total cash, cash equivalents and restricted cash shown in the condensed consolidated statements of cash flows $ 142,567 $ 152,437 $ 120,007 $ 129,863 See Note 13, Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement, Income Taxes In December 2017, the SEC staff issued Staff Accounting Bulletin 118 (SAB 118), which provides relief for companies that have not completed their accounting for the effects of The Tax Cuts and Jobs Act (Tax Reform Act) but can determine a reasonable estimate of those effects to allow them to include a provisional amount based on their reasonable estimate in their financial statements. The guidance in SAB 118 also allows companies to adjust the provisional amounts during a one-year “measurement period” which is similar to the measurement period used when accounting for business combinations. In the accompanying consolidated financial statements, the Company has not completed its accounting for all the tax effects associated with the enactment of the Tax Reform Act. However, the Company has, in certain cases made a reasonable estimate of the effects on its existing deferred tax balances and the one-time transition tax. See Note 9, Income Taxes, Accounting Pronouncements Not Yet Adopted Leases In February 2016, the FASB issued ASU 2016-02, Leases

Revenue From Contracts with Cus

Revenue From Contracts with Customers	3 Months Ended
	Mar. 31, 2018
Revenue From Contract With Customer [Abstract]
Revenue From Contracts with Customers	Note 2. Revenue From Contracts with Customers The following tables represents the disaggregation of revenue by contract type for each of our reportable segments: Three Months Ended March 31, 2018 U.S. Asia Mexico EMEA Total (in thousands) Wind blade sales $ 38,945 $ 68,171 $ 56,043 $ 71,021 $ 234,180 Precision molding and assembly systems sales 1,863 8,179 764 — 10,806 Transportation sales 4,053 — — — 4,053 Other sales 1,263 1,320 1,157 1,202 4,942 Total net sales: $ 46,124 $ 77,670 $ 57,964 $ 72,223 $ 253,981 Three Months Ended March 31, 2017 U.S. Asia Mexico EMEA Total (in thousands) Wind blade sales $ 41,970 $ 65,266 $ 45,199 $ 43,270 $ 195,705 Precision molding and assembly systems sales 3,336 3,664 655 — 7,655 Transportation sales 2,578 — — — 2,578 Other sales 83 567 1,094 933 2,677 Total net sales: $ 47,967 $ 69,497 $ 46,948 $ 44,203 $ 208,615 In addition, all of the Company’s net sales are made directly to the consumer, primarily wind turbine manufacturers, under long-term contracts which are typically five years in length. Contract Assets and Liabilities: Contract assets consist of unbilled amounts typically resulting from revenue recognized over time for products in production and the revenue recognized exceeds the amount billed to the customer. The contract assets are recorded as current assets in the condensed consolidated balance sheets. Contract liabilities consist of advance payments in excess of costs incurred. These amounts were historically recorded as customer deposits which primarily related to progress payments received as precision molding and assembly systems were being manufactured. The contract liabilities are recorded as current liabilities in the condensed consolidated balance sheets and are reduced as the Company records revenue over time. These contract assets and liabilities are reported on the condensed consolidated balance sheets on a contract-by-contract basis at the end of each reporting period. The following table reflects the changes in the Company’s contract assets and contract liabilities for the three months ended March 31, 2018: March 31, December 31, 2018 2017 $ Change (in thousands) Contract assets $ 130,015 $ 105,619 $ 24,396 March 31, December 31, 2018 2017 $ Change (in thousands) Contract liabilities $ 4,449 $ 2,763 $ 1,686 For the three months ended March 31, 2018, contracts assets increased by $24.4 million primarily due to $28.2 million of incremental unbilled production. For the three months ended March 31, 2018, contracts liabilities increased by $1.7 million primarily due to progress billings being received as precision molding and assembly systems are being manufactured. The time it takes to produce a single blade is typically between 24 to 36 hours. The time it takes to produce a mold is typically between 3 to 6 months. For the three months ended March 31, 2018, the Company recognized revenue of $2.7 million that was included in the corresponding contract liability balance at the beginning of the period. Performance Obligations: Remaining performance obligations represent the transaction price of firm orders for which work has not been performed and excludes any unexercised contract options. For the three months ended March 31, 2018, net revenue recognized from our performance obligations satisfied in previous periods decreased by $4.9 million. This primarily relates to changes in certain of the Company’s estimated total contract values and related percentage of completion estimates. As of March 31, 2018, the aggregate amount of the transaction price allocated to the remaining performance obligations was approximately $4.3 billion. The Company expects to recognize the remaining performance obligations as revenue as follows: 16 percent in the remainder of 2018, 24 percent in 2019, 26 percent in 2020, 17 percent in 2021, 12 percent in 2022 and the remaining 5 percent in 2023. Pre-Production Investments: The Company recognizes an asset from the costs incurred to fulfill a contract when those costs meet all of the following criteria: (a) the costs relate directly to a contract or to an anticipated contract that the Company can specifically identify; (b) the costs generate or enhance resources of the Company that will be used in satisfying performance obligations in the future; and, (c) the costs are expected to be recovered. The Company capitalizes the costs related to training its workforce to execute the manufacturing services and other facility set-up costs related to preparing for production. The Company factors these costs into its estimated cost analysis for the overall contract. Costs capitalized are amortized over the number of units produced during the contract term. As of March 31, 2018, the cost and accumulated amortization of such assets totaled $2.8 million and $1.6 million, respectively. As of December 31, 2017, the cost and accumulated amortization of such assets totaled $2.4 million and $1.4 million, respectively. Applying the practical expedient, the Company recognizes the incremental costs of obtaining contracts as an expense when incurred if the amortization period of the asset that the Company otherwise would have recognized is one year or less. These costs are included in cost of goods sold.

Significant Risks and Uncertain

Significant Risks and Uncertainties	3 Months Ended
	Mar. 31, 2018
Risks And Uncertainties [Abstract]
Significant Risks and Uncertainties	Note 3. Significant Risks and Uncertainties The Company’s revenues and receivables are from a small number of customers. As such, the Company’s production levels are dependent on these customers’ orders. See Note 11, Concentration of Customers. The Company maintains its U.S. cash in bank deposit accounts that, at times, exceed U.S. federally insured limits. U.S. bank accounts are guaranteed by the Federal Deposit Insurance Corporation (FDIC) in an amount up to $250,000 during 2018 and 2017. At March 31, 2018 and December 31, 2017, the Company had $103.4 million and $98.9 million, respectively, of cash in deposit accounts in high quality U.S. banks, which was in excess of FDIC limits. The Company has not experienced losses in any such accounts. The Company also maintains cash in bank deposit accounts outside the U.S. with no insurance. At March 31, 2018, this includes $29.2 million in China, $1.1 million in Turkey and $5.1 million in Mexico. The Company has not experienced losses in these accounts. In addition, at March 31, 2018, the Company has short-term deposits in interest bearing accounts of $3.3 million in China, which are reported as restricted cash in the Company’s condensed consolidated balance sheets. The Company also has long-term deposits in interest bearing accounts of $0.5 million in Iowa which are reported as restricted cash within the caption other noncurrent assets in the Company’s condensed consolidated balance sheets.

Related-Party Transactions

Related-Party Transactions	3 Months Ended
	Mar. 31, 2018
Related Party Transactions [Abstract]
Related-Party Transactions	Note 4. Related-Party Transactions Related party transactions include transactions between the Company and certain of its affiliates. The following transactions were in the normal course of operations and were measured at the exchange amount, which is the amount of consideration established and agreed to by the parties. The Company has entered into several agreements with subsidiaries of General Electric Company and its consolidated affiliates (GE) relating to the operation of its business. As a result of these agreements, GE has been a debtor, creditor and holder of both preferred and common shares. During the second quarter of 2017, GE reduced its holdings of the Company’s common shares to less than five percent of the total shares outstanding and then completely divested of the Company’s common shares during the third quarter of 2017. The Company has entered into five separate supply agreements with GE to manufacture wind blades in Newton, Iowa; Taicang Port, China; Juárez, Mexico (2) and Izmir, Turkey. The supply agreements in Taicang Port, China and Izmir, Turkey expired on December 31, 2017 and GE decided not to renew or extend these two contracts. As a result of the supply agreements, GE is the Company’s largest customer. For the six months ended June 30, 2017, the Company recorded related-party sales with GE of $187.3 million. As disclosed in Note 11, Concentration of Customers Certain of the Company’s existing stockholders, consisting of entities associated with Element Partners, Angeleno Group and Landmark Partners, each of which is an affiliate of a member of the board of directors, as well as certain executive officers and a director, purchased an aggregate of 1,250,000 shares of common stock in the IPO. In addition, all outstanding obligations and accrued interest under the Company’s subordinated convertible promissory notes held by certain existing stockholders, including Element Partners, Angeleno Group and Landmark Partners, were converted into an aggregate of 1,079,749 shares of common stock concurrent with the closing of the IPO at the public offering price of $11.00 per share. In connection with the Company’s secondary offering in May 2017, certain entities associated with Element Partners, Angeleno Group, Landmark Partners and NGP Energy Technology Partners, L.P, as well as certain executive officers of the Company sold an aggregate of 5,075,000 shares of common stock at the public offering price of $16.35 per share.

Accounts Receivable

Accounts Receivable	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Accounts Receivable	Note 5. Accounts Receivable Accounts receivable consisted of the following: March 31, December 31, 2018 2017 (in thousands) Trade accounts receivable $ 114,411 $ 117,794 Other accounts receivable 3,539 3,782 Total accounts receivable $ 117,950 $ 121,576

Property, Plant, and Equipment,

Property, Plant, and Equipment, Net	3 Months Ended
	Mar. 31, 2018
Property Plant And Equipment [Abstract]
Property, Plant, and Equipment, Net	Note 6. Property, Plant and Equipment, Net Property, plant and equipment, net consisted of the following: March 31, December 31, 2018 2017 (in thousands) Machinery and equipment $ 100,974 $ 100,681 Buildings 14,385 14,711 Leasehold improvements 22,135 21,853 Office equipment and software 20,665 18,664 Furniture 19,831 19,017 Vehicles 277 294 Construction in progress 14,521 10,687 Total 192,788 185,907 Accumulated depreciation (65,928 ) (62,427 ) Property, plant and equipment, net $ 126,860 $ 123,480 Total depreciation expense for the three months ended March 31, 2018 and 2017 was $6.8 million and $3.8 million, respectively.

Long-Term Debt, Net of Debt Iss

Long-Term Debt, Net of Debt Issuance Costs and Current Maturities	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Long-Term Debt, Net of Debt Issuance Costs and Current Maturities	Note 7. Long-Term Debt, Net of Debt Issuance Costs and Current Maturities Long-term debt, net of debt issuance costs and current maturities, consisted of the following: March 31, December 31, 2018 2017 (in thousands) Senior term loan—U.S. $ 70,313 $ 71,250 Senior revolving loan—U.S. 2,820 2,820 Accounts receivable financing—EMEA 22,192 14,100 Equipment financing—EMEA 16,313 16,901 Equipment capital lease—U.S. 188 536 Equipment capital lease—EMEA 5,045 5,058 Equipment capital lease—Mexico 10,815 12,844 Equipment loan—Mexico 47 47 Total long-term debt 127,733 123,556 Less: Debt issuance costs (1,990 ) (2,171 ) Total long-term debt, net of debt issuance costs 125,743 121,385 Less: Current maturities of long-term debt (43,085 ) (35,506 ) Long-term debt, net of debt issuance costs and current maturities $ 82,658 $ 85,879

Share-Based Compensation Plans

Share-Based Compensation Plans	3 Months Ended
	Mar. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation Plans	Note 8. Share-Based Compensation Plans The Company’s Amended and Restated 2015 Stock Option and Incentive Plan (the 2015 Plan) provides for the issuance of incentive stock options, non-qualified stock options, stock appreciation rights, restricted stock units, restricted stock awards, unrestricted stock awards, cash-based awards, performance share awards and dividend equivalent rights to certain employees, non-employee directors and consultants. Under the 2015 Plan, the Company has granted awards of stock options, restricted stock units (RSUs) and performance-based restricted stock units (PSUs) to certain employees and non-employee directors. In March 2018, the Company issued to certain employees of the Company an aggregate of 121,386 timed-based restricted stock units, 121,386 performance-based restricted stock units that vest upon achievement of a cumulative, three-year Adjusted EBITDA target measured from January 1, 2018 through December 31, 2020, and 170,712 performance-based restricted stock units that vest upon achievement of certain stock price hurdles for the period of the grant date through December 31, 2020. 100% of the time-based restricted stock units vest on the third anniversary date of the grant date. Each of the time-based restricted stock unit awards and performance-based restricted stock unit awards are subject to the employee’s continued service with the Company, the terms and conditions of the 2015 Plan and the applicable award agreement. The share-based compensation expense recognized in the condensed consolidated income statements was as follows: Three Months Ended March 31, 2018 2017 (in thousands) Cost of goods sold $ 412 $ 213 General and administrative expenses 1,976 1,494 Total share-based compensation expense $ 2,388 $ 1,707 The share-based compensation expense recognized by award type was as follows: Three Months Ended March 31, 2018 2017 (in thousands) RSUs $ 1,318 $ 535 Stock options 990 1,172 PSUs 80 - Total share-based compensation expense $ 2,388 $ 1,707 As of March 31, 2018, the unamortized cost of the outstanding RSUs and PSUs was $6.4 million and $4.8 million, respectively, which the Company expects to recognize in the condensed consolidated financial statements over weighted-average periods of approximately 2.1 years and 3.0 years, respectively. Additionally, the total unrecognized cost related to non-vested stock option awards was $4.0 million, which the Company expects to recognize in the condensed consolidated financial statements over a weighted-average period of approximately 1.7 years. The summary of activity for the Company’s incentive plans is as follows: Stock Options RSUs PSUs Shares Available for Grant Shares Weighted- Average Exercise Price Options Exercisable Units Weighted- Average Grant Date Fair Value Units Weighted- Average Grant Date Fair Value Balance as of December 31, 2017 4,731,117 3,203,290 $ 13.34 890,433 613,380 $ 15.02 — $ — Increase in shares authorized 1,360,826 — — — — — — Granted (423,136 ) 9,652 22.67 121,386 22.67 292,098 22.67 Exercised/vested — (53,250 ) 10.87 (38,196 ) 23.29 — — Forfeited/cancelled 576 — — (576 ) 23.29 — — Balance as of March 31, 2018 5,669,383 3,159,692 13.41 1,028,241 695,994 15.90 292,098 22.67 The fair value of RSUs which vested during the three months ended March 31, 2018 was $0.8 million. In addition, during the three months ended March 31, 2018, the Company repurchased 13,441 shares for $0.3 million related to tax withholding requirements on vested RSU awards. The following table summarizes the outstanding and exercisable stock option awards as of March 31, 2018: Options Outstanding Options Exercisable Range of Exercise Prices: Shares Weighted- Average Remaining Contractual Life ( in years Weighted- Average Exercise Price Shares Weighted- Average Exercise Price $8.49 22,728 1.8 $ 8.49 22,728 $ 8.49 $ 10.87 1,920,099 7.2 10.87 637,599 10.87 $11.00 to $16.53 656,523 7.8 16.12 239,872 16.23 $17.68 to $18.70 342,790 8.2 18.68 128,042 18.68 $18.77 to $22.34 217,552 9.5 19.92 — — $8.49 to $22.34 3,159,692 7.6 13.41 1,028,241 13.04

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Note 9. Income Taxes The effective tax rate for the three months ended March 31, 2018 was lower than for the three months ended March 31, 2017 primarily due to earnings mix by jurisdiction. The Company continues to maintain a full U.S. valuation allowance on its net deferred tax assets. Management will continue to reevaluate the positive and negative evidence at each reporting period. The Company expects to continue to record a full valuation allowance on its U.S. net deferred tax assets until the Company sustains an appropriate level of taxable income through an increase in overall pre-tax income to be recognized in the U.S. and the finalization of its analysis of The Tax Cuts and Jobs Act (Tax Reform Act) impact as discussed below. In December 2017, President Trump signed into law the Tax Reform Act, which significantly revised U.S. tax law by, among other things, lowering the statutory federal corporate income tax rate from 35% to 21% for tax years beginning after December 31, 2017, eliminating certain deductions, imposing a mandatory one-time transition tax, introducing new tax regimes, and changing how foreign earnings are subject to U.S. tax. The Tax Reform Act also includes many new provisions, such as changes to bonus depreciation, changes to deductions for executive compensation, interest expense limitations, net operating loss deduction limitations, a tax on global intangible low-taxed income (GILTI) earned by foreign corporate subsidiaries, a base erosion anti-abuse tax (BEAT) and a deduction for foreign-derived intangible income (FDII). Many of these provisions, including the tax on GILTI, the BEAT, and the deduction for FDII, just became applicable to the Company at the beginning of 2018, and the Company continues to evaluate the impact of such provisions of the Tax Reform Act. Under U.S. GAAP, the Company is permitted to make an accounting policy election to either recognize deferred taxes for temporary basis differences expected to reverse as GILTI in future years or provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. Given the complexity of the GILTI provision, the Company is still evaluating the effects of the GILTI provisions and has not yet made its accounting policy election. The impact of the provisional calculations of GILTI and other provisions of the Tax Reform Act resulted in no incremental tax expense for the three months ended March 31, 2018 due to the net operating loss carryforwards, foreign tax credits and a full valuation allowance on U.S. net deferred tax assets. The Company will continue to refine its calculations, which may result in changes to the expected impact for 2018. The Company continues to not record a deferred tax liability related to unremitted foreign earnings as it maintains its assertion to permanently reinvest its unremitted foreign earnings. No other changes in tax law since December 31, 2017 have had a material impact on the Company’s income tax provision.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 10. Commitments and Contingencies Legal Proceedings From time to time, the Company may be involved in disputes or litigation relating to claims arising out of its operations. In March 2015, a complaint was filed against the Company in the Superior Court of the State of Arizona (Maricopa County) by a former employee of the Company, alleging that the Company had agreed to make certain cash payments to such employee upon any future sale of the Company. The Company filed a motion to dismiss the complaint in April 2015, which was denied. The Company subsequently filed an answer to the complaint in July 2015 denying the substantive allegations of the complaint. The parties completed court-ordered mediation in December 2015 but were not able to reach a settlement. The Company filed a motion for summary judgment to dismiss the complaint in April 2016 and the court denied our motion in August 2016. The court set a trial date for September 2017. In May 2017, the Company filed a motion for continuance to change the trial date and the court granted its motion. The court has set a trial date in August 2018. The Company continues to deny the substantive allegations of the complaint and intends to vigorously defend this lawsuit; however, the Company is currently unable to determine the ultimate outcome of this case. In August 2015, the Company entered into a transition agreement with its former Senior Vice President – Asia (SVP–Asia), pursuant to which he transitioned out of this role at the end of 2015 and was to serve in a consulting capacity in 2016 and 2017. In January 2016, following our discovery that he had materially violated the terms of his transition agreement, the Company terminated his consultancy for cause. In April 2016, he filed an arbitration claim in China with the Taicang Labor and Personnel Dispute Arbitration Committee alleging that the Company improperly terminated his transition agreement. He is demanding that the Company continue to honor the terms of the transition agreement and pay him compensation and fees owed to him under the transition agreement, which in the aggregate totals approximately $2.6 million. In addition, he is also challenging the validity of the Company’s termination of his option to purchase 164,880 shares of the Company’s common stock and 77,760 restricted stock units under the 2015 Plan, which were canceled in January 2016 when the Company terminated his consultancy. The Company is awaiting a final decision on this matter. The Company previously established a reserve for these matters and does not believe the award, if upheld on appeal, will have a material impact on its operating results or financial condition. From time to time, the Company is party to various lawsuits, claims, and other legal proceedings that arise in the ordinary course of business, some of which are covered by insurance. Upon resolution of any pending legal matters, the Company may incur charges in excess of presently established reserves. Management does not believe that any such charges would, individually or in the aggregate, have a material adverse effect on the Company’s financial condition, results of operations or cash flows.

Concentration of Customers

Concentration of Customers	3 Months Ended
	Mar. 31, 2018
Risks And Uncertainties [Abstract]
Concentration of Customers	Note 11. Concentration of Customers Revenues from certain customers in excess of 10 percent of total consolidated Company revenues (dollars in thousands) are as follows: Three Months Ended March 31, 2018 2017 Customer Revenues % of Total Revenues % of Total GE $ 87,828 34.6 % $ 91,528 43.9 % Vestas 85,269 33.6 48,263 23.1 Nordex Acciona 48,201 19.0 40,632 19.5 Siemens Gamesa 24,291 9.5 25,642 12.3 Other 8,392 3.3 2,550 1.2 Total $ 253,981 100.0 % $ 208,615 100.0 % Trade accounts receivable from certain customers in excess of 10 percent of total consolidated Company trade accounts receivable are as follows: March 31, December 31, 2018 2017 Customer % of Total % of Total GE 18.8 % 18.9 % Vestas 40.3 % 52.4 % Nordex Acciona 30.4 % 19.5 %

Segment Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Segment Reporting	Note 12. Segment Reporting The Company’s operating segments are defined geographically as the United States, Asia, Mexico and EMEA. Financial results are aggregated into four reportable segments based on quantitative thresholds. All of the Company’s segments operate in their local currency, however a portion of the revenue attributable to our China and Mexico segments is derived in U.S. dollars because certain of the Company’s domestic subsidiaries are the contracting parties to the associated customer supply agreements. The following tables set forth certain information regarding each of the Company’s segments: Three Months Ended March 31, 2018 2017 (in thousands) Revenues by segment: U.S. $ 46,124 $ 47,967 Asia 77,670 69,497 Mexico 57,964 46,948 EMEA 72,223 44,203 Total revenues $ 253,981 $ 208,615 Revenues by geographic location (1): U.S. $ 46,124 $ 47,967 China 77,670 69,497 Mexico 57,964 46,948 Turkey 72,223 44,203 Total revenues $ 253,981 $ 208,615 Income (loss) from operations: U.S. (2) $ (9,050 ) $ (7,326 ) Asia 6,417 12,794 Mexico 4,258 2,844 EMEA 15,470 3,300 Total income from operations $ 17,095 $ 11,612 March 31, December 31, 2018 2017 (in thousands) Property, plant and equipment, net: U.S. $ 27,528 $ 24,575 Asia (China) 30,881 28,887 Mexico 38,466 39,756 EMEA (Turkey) 29,985 30,262 Total property, plant and equipment, net $ 126,860 $ 123,480 (1) Revenues are attributable to countries based on the location where the product is manufactured or the services are performed. (2) The losses from operations in the U.S. segment includes corporate general and administrative costs of $11.2 million and $8.3 million for the three months ended March 31, 2018 and 2017, respectively.

Adjustments to Previously Repor

Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement	3 Months Ended
	Mar. 31, 2018
New Accounting Pronouncements And Changes In Accounting Principles [Abstract]
Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement	Note 13. Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement As discussed in Note 1, Summary of Operations and Significant Accounting Policies Topic 606 and ASU’s 2016-15 and 2016-18 were adopted by the The following tables summarize the effects of adopting Topic 606 and ASU 2016-18 had on our previously reported financial statements. Condensed Consolidated Balance Sheet (In thousands, except par value data) December 31, 2017 As Reported Adoption of Topic 606 As Adjusted (Unaudited) Assets Current assets: Cash and cash equivalents $ 148,113 $ — $ 148,113 Restricted cash 3,849 — 3,849 Accounts receivable 121,576 — 121,576 Contract assets — 105,619 105,619 Inventories 67,064 (62,952 ) 4,112 Inventories held for customer orders 64,858 (64,858 ) — Prepaid expenses and other current assets 27,507 — 27,507 Total current assets 432,967 (22,191 ) 410,776 Property, plant, and equipment, net 123,480 — 123,480 Goodwill 2,807 — 2,807 Intangible assets, net 150 958 1,108 Other noncurrent assets 14,130 4,261 18,391 Total assets $ 573,534 $ (16,972 ) $ 556,562 Liabilities and Stockholders’ Equity Current liabilities: Accounts payable and accrued expenses $ 166,743 $ — $ 166,743 Accrued warranty 29,163 1,256 30,419 Deferred revenue 81,048 (81,048 ) — Customer deposits 10,134 (9,702 ) 432 Current maturities of long-term debt 35,506 — 35,506 Contract liabilities — 2,763 2,763 Total current liabilities 322,594 (86,731 ) 235,863 Long-term debt, net of debt issuance costs and current maturities 85,879 — 85,879 Other noncurrent liabilities 4,444 494 4,938 Total liabilities 412,917 (86,237 ) 326,680 Commitments and contingencies Stockholders’ equity: Common shares, $0.01 par value, 100,000 shares authorized and 34,049 shares issued and 34,021 shares outstanding at December 31, 2017 340 — 340 Paid-in capital 301,543 — 301,543 Accumulated other comprehensive loss (558 ) — (558 ) Accumulated deficit (140,197 ) 69,265 (70,932 ) Treasury stock, at cost, 28 shares at December 31, 2017 (511 ) — (511 ) Total stockholders’ equity 160,617 69,265 229,882 Total liabilities and stockholders’ equity $ 573,534 $ (16,972 ) $ 556,562 The primary effects of the adoption of Topic 606 on the Company’s balance sheet include 1) amounts being recognized as revenue for work performed as production takes place over time as contract assets, which differs from the prior practice of including the balances in inventory; 2) no longer reporting inventory held for customer orders or deferred revenue since revenue is now being recognized over the course of the production process, and before the product is delivered to the customer; 3) that contract liabilities are reported for amounts collected from customers in advance of the production of products, similar to our prior practice of recording customer deposits; and 4) the cumulative amount of the effect to prior periods’ net income related to the adoption of Topic 606 through December 31, 2017 is reflected in retained earnings. Condensed Consolidated Income Statement (In thousands, except per share data) Three Months Ended March 31, 2017 As Reported Adoption of Topic 606 As Adjusted (Unaudited) Net sales $ 191,602 $ 17,013 $ 208,615 Cost of sales 167,423 15,115 182,538 Startup and transition costs 6,159 — 6,159 Total cost of goods sold 173,582 15,115 188,697 Gross profit 18,020 1,898 19,918 General and administrative expenses 8,306 — 8,306 Income from operations 9,714 1,898 11,612 Other income (expense): Interest income 19 — 19 Interest expense (3,026 ) — (3,026 ) Realized loss on foreign currency remeasurement (1,381 ) — (1,381 ) Miscellaneous income 320 — 320 Total other expense (4,068 ) — (4,068 ) Income before income taxes 5,646 1,898 7,544 Income tax provision (2,101 ) (230 ) (2,331 ) Net income $ 3,545 $ 1,668 $ 5,213 Weighted-average common shares outstanding: Basic 33,737 33,737 33,737 Diluted 33,827 33,827 33,827 Net income per common share: Basic $ 0.11 $ 0.05 $ 0.15 Diluted $ 0.10 $ 0.05 $ 0.15 The primary effects of the adoption of Topic 606 on the Company’s condensed consolidated income statement relate to amounts being recognized as revenue for work performed as production takes place over time, which differs from the prior practice of recognizing revenue when the product was delivered to the customer. Condensed Consolidated Statement of Comprehensive Income (In thousands) Three Months Ended March 31, 2017 As Reported Adoption of Topic 606 As Adjusted (Unaudited) Net income $ 3,545 $ 1,668 $ 5,213 Other comprehensive income: Foreign currency translation adjustments 277 — 277 Comprehensive income $ 3,822 $ 1,668 $ 5,490 Condensed Consolidated Statements of Changes in Stockholders’ Equity (In thousands) Common Paid-in Accumulated other comprehensive Accumulated Treasury stock, Total stockholders' Shares Amount capital loss deficit at cost equity (Unaudited) Balance at December 31, 2017 - as reported 34,049 $ 340 $ 301,543 $ (558 ) $ (140,197 ) $ (511 ) $ 160,617 Cumulative effect of the adoption of Topic 606 — — — — 69,265 — 69,265 Balance at December 31, 2017 - as adjusted 34,049 $ 340 $ 301,543 $ (558 ) $ (70,932 ) $ (511 ) $ 229,882 The adoption of Topic 606 increased total stockholders’ equity in 2015 and 2016 by $61.2 million and $12.3 million, respectively and decreased total stockholders’ equity in 2017 by $4.2 million. Condensed Consolidated Statements of Cash Flows (In thousands) Three Months Ended March 31, 2017 As Reported Adoption of Topic 606 Adoption of ASU 2016-18 As Adjusted (Unaudited) Cash flows from operating activities: Net income $ 3,545 $ 1,668 $ — $ 5,213 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 3,829 123 — 3,952 Share-based compensation expense 1,707 — — 1,707 Amortization of debt issuance costs 143 — — 143 Changes in assets and liabilities: — — Accounts receivable (28,722 ) — — (28,722 ) Contract assets — 2,738 — 2,738 Inventories (15,220 ) 15,152 — (68 ) Prepaid expenses and other current assets 6,816 — — 6,816 Other noncurrent assets 5,871 (27 ) (6,000 ) (156 ) Accounts payable and accrued expenses 11,211 — — 11,211 Accrued warranty 1,983 97 — 2,080 Customer deposits 4,827 (4,110 ) — 717 Deferred revenue 19,751 (19,751 ) — — Contract liabilities — 4,110 — 4,110 Other noncurrent liabilities 197 — — 197 Net cash provided by (used in) operating activities 15,938 — (6,000 ) 9,938 Cash flows from investing activities: Purchase of property and equipment (16,922 ) — — (16,922 ) Net cash used in investing activities (16,922 ) — — (16,922 ) Cash flows from financing activities: Repayments of term loan (938 ) — — (938 ) Net repayments of accounts receivable financing (1,233 ) — — (1,233 ) Net proceeds from working capital loans 517 — — 517 Net repayments of other debt (1,155 ) — — (1,155 ) Restricted cash 331 — (331 ) — Net cash used in financing activities (2,478 ) — (331 ) (2,809 ) Impact of foreign exchange rates on cash and cash equivalents (63 ) — (63 ) Net change in cash and cash equivalents (3,525 ) — (6,331 ) (9,856 ) Cash, cash equivalents and restricted cash, beginning of year 119,066 10,797 129,863 Cash, cash equivalents and restricted cash, end of period $ 115,541 $ — $ 4,466 $ 120,007 The primary effects of the adoption of Topic 606 on the Company’s condensed consolidated statement of cash flows include 1) the establishment of contract assets and liabilities; 2) the reduction of inventory and elimination of inventory held for customer orders; and 3) the elimination of deferred revenue. For more details on these items, see the disclosure related to the effect of the adoption of Topic 606 on the Company’s condensed consolidated balance sheet. As part of our adoption of Topic 606, the Company has elected to use the following practical expedients: - for completed contracts that have variable consideration, the Company used the transaction price at the date on which the contract was completed, rather than estimating amounts for variable consideration in each comparative reporting period. - for modified contracts, the Company did not separately evaluate the effects of the contract modifications before the beginning of the earliest period presented. Instead, the Company reflected the aggregate effect of all of the modifications that occur before the beginning of the earliest period presented in determining the transaction price, identifying the satisfied and unsatisfied performance obligations, and allocating the transaction price to the performance obligations. - for all periods presented before the date of initial application, the Company did not disclose the amount of the transaction price allocated to remaining performance obligations, nor an explanation of when they expect to recognize that amount as revenue. The impact of applying the above practical expedients may change the period of revenue recognition but not the total amount to be recognized under the contract; therefore, the Company believes application of the practical expedients is not material to the comparability of the information presented above and the accounting and financial reporting related to the adoption of Topic 606.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2018
Subsequent Events [Abstract]
Subsequent Events	Note 14. Subsequent Events In April 2018, the Company entered into a new credit agreement (the Credit Agreement) with four lenders consisting of a multi-currency, revolving credit facility in an aggregate principal amount of $150.0 million, including a $25.0 million letter of credit sub-facility. The Company drew down $75.4 million on the revolving credit facility in connection with the closing of the transactions contemplated by the Credit Agreement and used the proceeds to pay all outstanding amounts due and payable under the Company’s senior secured credit facility. All borrowings and amounts outstanding under the Credit Agreement are scheduled to mature on April 6, 2023. Interest accrues at a variable rate equal to LIBOR plus an initial margin of 1.5%, which may vary based on the Company’s total net leverage ratio as defined in the Credit Agreement. Interest is payable monthly and the Company is not obligated to make any principal repayments prior to the maturity date so long as the Company is not in default under the Credit Agreement. The Company may prepay borrowings without penalty under the Credit Agreement. In April 2018, the Company also entered into an interest rate swap arrangement to fix a notional amount of $75.0 million under the Credit Agreement at an effective interest rate of 4.19% for a period of five years.

Summary of Operations and Sig21

Summary of Operations and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Description of Business	Description of Business TPI Composites, Inc. is the holding company that conducts substantially all of its business operations through its direct and indirect subsidiaries (collectively, the Company). The Company was founded in 1968 and has been producing composite wind blades since 2001. The Company’s knowledge and experience of composite materials and manufacturing originates with its predecessor company, Tillotson Pearson Inc., a leading manufacturer of high-performance sail and powerboats along with a wide range of composite structures used in other industrial applications. Following the separation from the boat building business in 2004, the Company reorganized in Delaware as LCSI Holding, Inc. and then changed its corporate name to TPI Composites, Inc. in 2008. Today, the Company is headquartered in Scottsdale, Arizona and has expanded its global footprint to include domestic facilities in Newton, Iowa; Fall River, Massachusetts; Warren, Rhode Island and Santa Teresa, New Mexico and international facilities in Dafeng, China; Taicang Port, China; Taicang City, China; Yangzhou, China; Juárez, Mexico; Matamoros, Mexico; Izmir, Turkey and Kolding, Denmark.
Public Offerings and Stock Split	Public Offerings and Stock Split In July 2016, the Company completed an initial public offering (IPO) of 7,187,500 shares of the its common stock at a price of $11.00 per share, which included 937,500 shares issued pursuant to the underwriters’ over-allotment option. Certain of the Company’s existing shareholders, a non-employee director and executive officers purchased an aggregate of 1,250,000 shares of common stock in the IPO included in the total issuance above. The net proceeds from the IPO were $67.2 million after deducting underwriting discounts and offering expenses. Immediately prior to the closing of the IPO, all shares of the then-outstanding redeemable preferred shares converted into an aggregate of 21,110,204 shares of common stock and the redeemable preferred share warrants converted on a net issuance basis into 120,923 shares of common stock. In addition, concurrent with the closing of the IPO, certain subordinated convertible promissory notes in the aggregate principal and interest amount of $11.9 million were converted into 1,079,749 shares of common stock at the public offering price of $11.00 per share. Prior to the IPO, in July 2016 the Company amended its amended and restated certificate of incorporation to effect a 360-for-1 forward stock split of its common stock. As a result of the stock split, the Company has adjusted the share amounts authorized and issuable under the share-based compensation plans. All share and per share common stock information (including the share-based compensation plans) referenced throughout the unaudited condensed consolidated financial statements and notes thereto have been retroactively adjusted to reflect this stock split. The stock split did not cause an adjustment to the par value of the authorized shares of common stock. In May 2017, the Company completed a secondary public offering of 5,075,000 shares of its common stock at a price of $16.35 per share, which included 575,000 shares issued pursuant to the underwriters’ option to purchase additional shares. All of the shares were sold by existing shareholders and certain of the Company’s executive officers. The selling shareholders received all of the net proceeds of $78.8 million from the secondary public offering. The Company did not sell any shares and did not receive any of the proceeds from the offering and the costs paid by the Company in connection with the offering of $0.8 million were recorded in general and administrative costs in the accompanying condensed consolidated income statement.
Basis of Presentation	Basis of Presentation The Company divides its business operations into four geographic operating segments—the United States, Asia, Mexico and Europe, the Middle East and Africa (EMEA) as follows: • The U.S. segment includes (1) the manufacturing of wind blades at the Newton, Iowa plant, (2) the manufacturing of precision molding and assembly systems used for the manufacture of wind blades at the Warren, Rhode Island facility, (3) the manufacturing of composite solutions for the transportation industry, which the Company also conducts at its existing Rhode Island and Massachusetts facilities, (4) wind blade inspection and repair services, (5) our advanced engineering center in Kolding, Denmark, which provides technical and engineering resources to our manufacturing facilities and (6) our corporate headquarters, the costs of which are included in general and administrative expenses. In January 2018, the Company entered into a new lease agreement with a third party for a new manufacturing facility in Newton, Iowa and expects to commence operations at this facility in the second quarter of 2018. • The Asia segment includes (1) the manufacturing of wind blades at the facility in Taicang Port, China and at its two facilities in Dafeng, China, (2) the manufacturing of precision molding and assembly systems at the Taicang City, China facility and (3) wind blade inspection and repair services. In March 2018, the Company entered into a new binding agreement with a third party related to the lease of a new manufacturing facility in the Yangzhou Economic & Technical Development Zone in Yangzhou, China and we expect to commence operations at this facility in early 2019. • The Mexico segment manufactures wind blades from its three facilities in Juárez, Mexico, the most recent of which commenced operations in January 2017. In April 2017, the Company entered into a new lease agreement with a third party for a new manufacturing facility in Matamoros, Mexico and the Company expects to commence operations at this facility in the third quarter of 2018. • The EMEA segment manufactures wind blades from its two facilities in Izmir, Turkey, the most recent of which commenced operations in 2016. These two facilities also perform wind blade inspection and repair services. The accompanying condensed consolidated financial statements include the accounts of TPI Composites, Inc. and all majority owned subsidiaries. All significant intercompany transactions and balances have been eliminated. The condensed consolidated financial statements included herein have been prepared by the Company without audit, pursuant to the rules and regulations of the SEC and should be read in conjunction with the audited consolidated financial statements for the year ended December 31, 2017 included in the Company’s Annual Report on Form 10-K. Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States (GAAP) have been condensed or omitted, as permitted by the SEC, although the Company believes the disclosures that are made are adequate to make the information presented herein not misleading. The accompanying condensed consolidated financial statements reflect, in the opinion of management, all normal recurring adjustments necessary to present fairly the Company’s financial position at March 31, 2018, and the results of the Company’s operations, comprehensive income and cash flows for the periods presented. The Company restated the December 31, 2017 condensed consolidated balance sheet and the March 31, 2017 condensed consolidated statements of income and cash flow data for the effect of the adoption of Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement, As previously announced, effective January 1, 2018, the Company adopted the requirements of Topic 606 using the full retrospective method as further described in Recently Issued Accounting Pronouncements - Revenue from Contracts with Customers Revenue from Contracts with Customers Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement
Revenue Recognition	Revenue Recognition The majority of our revenues are generated from long-term contracts associated with manufacturing of wind blades and related services. The Company accounts for a long-term contract when it has the approval from both parties, the rights of the parties are identified, payment terms are established, the contract has commercial substance and the collectability of consideration is probable. To determine the proper revenue recognition method for each long-term contract, the Company evaluates whether the original contract should be accounted for as one or more performance obligations. This evaluation requires judgment and the decisions reached could change the amount of revenue and gross profit recorded in a given period. As most of the Company’s contracts contain multiple performance obligations, the Company allocates the total transaction price to each performance obligation based on the estimated relative standalone selling prices of the promised goods or services underlying each performance obligation. The Company’s manufacturing services are customer specific and involve production of items that cannot be sold to other customers due to the customers’ protected intellectual property; therefore, the Company allocates the total transaction price under contracts with multiple performance obligations using the contractually stated prices, as these prices represent the relative standalone selling price based on an expected cost plus margin model. Revenue is primarily recognized over time as the Company has an enforceable right to payment upon termination and the Company may not use or sell the product to fulfill other customers’ contracts. In addition, the customer does not have return or refund rights for items produced that conform to the specifications included in the contract. Because control transfers over time, revenue is recognized based on the extent of progress towards the completion of the performance obligation. The Company uses the cost-to-cost input measure of progress for its contracts as this method provides the best representation of the production progress towards satisfaction of the performance obligation as the materials are distinct to the product being manufactured because of customer specifications provided for in the contract, the costs incurred are proportional to the progress towards completion of the product, and the products do not involve significant pre-fabricated component parts. Under the cost-to-cost method, progress and the related revenue recognition is determined by a ratio of direct costs incurred to date in fulfillment of the contract to the total estimated direct costs required to complete the performance obligation. Determining the revenue to be recognized for services performed under the Company’s manufacturing contracts involves significant judgments and estimates relating to the total consideration to be received and the expected total costs to complete the performance obligation. The judgments and estimates relating to the total consideration to be received include the amount of variable consideration as the Company’s contracts typically provide the customer with a range of production output options from guaranteed minimum volume obligations to the production capacity of the facility, and customers will provide periodic non-cancellable commitments for the number of wind blades to be produced over the term of the agreement. The Company uses historical experience, customer commitments and forecasted future production based on the capacity of the plant to estimate the total revenue to be received to complete the performance obligation. In addition, the amount of revenue per unit produced may vary based on the costs of production of the wind blades as the Company may be able to change the price per unit based on changes in the cost of production. Further, some contracts provide opportunities for the Company to share in labor and material cost savings as well as absorb some additional costs as an incentive for more efficient production, both of which impact the margin realized on the contract and ultimately the total amount of revenue to be recognized. Additionally, certain customer contracts provide for concessions by the Company for missed production deadlines. The Company estimates variable consideration at the most likely amount to which it expects to be entitled. The Company includes estimated amounts in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. The Company’s estimates of variable consideration and determination of whether to include estimated amounts in the transaction price are based largely on an assessment of the Company’s anticipated performance and all information available to the Company at the time of the estimate and may materially change as additional information becomes known. Contracts may be modified to account for changes in specifications of products and changing requirements. If the contract modifications are for goods or services that are not distinct from the existing contract, they are accounted for as if they were part of the original contract. The effect of a contract modification on the transaction price and the measure of progress for the performance obligation to which it relates is recognized as an adjustment to revenue on a cumulative catch-up basis. If contract modifications are for goods and services that are distinct from the existing contract and increases the amount of consideration reflecting the standalone sale price of the additional goods or services, then the contract modification is accounted for as a separate contract and is evaluated for one or more performance obligations. Each reporting period, the Company evaluates the progress towards satisfaction of each performance obligation based on any contract modifications that have occurred, cost incurred to date, and an estimate of the expected future revenue and costs to be incurred to complete the performance obligation. Based on this analysis, any changes in estimates of revenue, cost of sales, contract assets and liabilities and the related impact to operating income are recognized on a cumulative catch-up basis, which recognizes in the current period the cumulative effect of the changes on current and prior periods based on a performance obligation's percentage of completion. Wind blade pricing is based on annual commitments of volume as established in the customer’s contract and orders less than committed volume may result in a higher price per wind blade to customers. Orders in excess of annual commitments may result in discounts to customers from the contracted price for the committed volume. Customers typically provide periodic purchase orders with the price per wind blade given the current cost of the bill of materials, labor requirements and volume desired. The Company records an allowance for expected utilization of early payment discounts which are reported as a reduction of the related revenue. Precision molding and assembly systems included in a customer’s contract are based upon the specific engineering requirements and design determined by the customer and are specific to the wind blade design and function desired. From the customer’s engineering specifications, a job cost estimate is developed along with a production plan, and the desired margin is applied based on the location the work is to be performed and complexity of the customer’s design. Precision molding and assembly systems are generally built to produce wind blades which may be manufactured by the Company in production runs specified in the customer contract. Contract assets primarily relate to the Company’s rights to consideration for work completed but not billed at the reporting date on manufacturing services contracts. The contract assets are transferred to accounts receivable when the rights become unconditional, which generally occurs when customers are invoiced upon the determination that a product conforms to the contract specifications and invoices are due based on each customers negotiated payment terms, which range from 30 to 65 days. The Company applies the practical expedient that allows it to exclude payment terms under one year from the transfer of a promised good or service from consideration of a significant financing component in its contracts. With regards to the production of precision molding and assembly systems, the Company’s contracts generally call for progress payments to be made in advance of production. Generally, payment is made at certain percentage of completion milestones with the final payment due upon delivery to the manufacturing facility. These progress payments are recorded within contract liabilities as current liabilities in the condensed consolidated balance sheets and are reduced as the Company records revenue over time. The Company’s customers may request, in situations where they do not have space available to receive products or do not want to take possession of products immediately for other reasons, that their finished products be stored by the Company in one of its facilities. Most contracts provide for a limited number of wind blades to be stored during the period of the contract with any additional wind blades stored subject to additional storage fees, which are included in the wind blade performance obligation revenue. Revenue related to non-recurring engineering and freight services provided under customer contracts is recognized at a point in time following the transfer of control of the promised services to the customer. Customers usually pay the carrier directly for the cost of shipping associated with items produced. When the Company pays the shipping costs, the Company applies the practical expedient that allows it to account for shipping and handling as a fulfillment costs and include the revenue in the associated performance obligation and the costs are included in cost of goods sold. Taxes assessed by a governmental authority that are both imposed on and concurrent with specific revenue-producing transactions, that are collected by the Company from a customer, are excluded from revenue.
Warranty Expense	Warranty Expense The Company provides a limited warranty for its mold and wind blade products, including parts and labor, with terms and conditions that vary depending on the product sold, generally for periods that range from two to five years. Warranty expense is recorded based upon estimates of future repairs using a probability-based methodology that considers previous warranty claims, identified quality issues and industry practices. Once the warranty period has expired, any remaining unused warranty accrual for the specific products is reversed against the current year warranty expense amount. Warranty accrual at March 31 consisted of the following: 2018 (in thousands) Warranty accrual at beginning of year $ 30,419 Accrual during the period 3,621 Cost of warranty services provided during the period (306 ) Reversal of reserves upon warranty expiration (1,064 ) Warranty accrual at end of period $ 32,670
Treasury Stock	Treasury Stock Common stock purchased for treasury is recorded at historical cost. Transactions in treasury shares relate to share-based compensation plans and are recorded at weighted-average cost.
Net Income Per Common Share Calculation	Net Income Per Common Share Calculation The basic net income per common share is computed by dividing the net income by the weighted-average number of common shares outstanding during a period. Diluted net income per common share is computed by dividing the net income by the weighted-average number of common shares outstanding plus potentially dilutive securities using the treasury stock method. The table below reflects the calculation of the weighted-average number of common shares outstanding, using the treasury stock method, used in computing basic and diluted earnings per common share: Three Months Ended March 31, 2018 2017 (in thousands) Basic weighted-average shares outstanding 34,049 33,737 Effect of dilutive stock options and warrants 1,430 90 Diluted weighted-average shares outstanding 35,479 33,827 Share-based compensation awards of 175,000 shares were excluded from the computation of diluted net income per share for the three months ended March 31, 2018 because the effect would be anti-dilutive. In addition, PSUs have been excluded from the computation of diluted net income per share for the three months ended March 31, 2018 as the performance conditions have not yet been met. The Company did not have any potential dilutive securities which were excluded from the computation of diluted net income per share for the three months ended March 31, 2017.
Use of Estimates	Use of Estimates The preparation of these condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements Accounting Pronouncements Adopted in 2018 Revenue from Contracts with Customers In May 2014, the Financial Accounting Standards Board (FASB) issued Topic 606, which provides new recognition and disclosure requirements for revenue from contracts with customers that supersedes the existing revenue recognition guidance. The new recognition requirements focus on when the customer obtains control of the goods or services, rather than the current risks and rewards model of recognition. The core principle of the new standard is that an entity will recognize revenue when it transfers goods or services to its customers in an amount that reflects the consideration an entity expects to be entitled to for those goods or services. The new disclosure requirements included in these financial statements contain information intended to communicate the nature, amount, timing and any uncertainty of revenue and cash flows from the applicable contracts, including any significant judgments and changes in judgments and assets recognized from the costs to obtain or fulfill a contract. The Company adopted Topic 606 as of January 1, 2018 with retrospective application to January 1, 2016 through December 31, 2017. See Note 2, Revenue from Contracts with Customers Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement,
Cash Flow Presentation	Cash Flow Presentation In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments Restricted Cash The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets which total the same such amounts in the condensed consolidated statements of cash flows: March 31, December 31, March 31, December 31, 2018 2017 2017 2016 (in thousands) Cash and cash equivalents $ 138,841 $ 148,113 $ 115,541 $ 119,066 Restricted cash 3,251 3,849 1,928 2,259 Restricted cash included within other noncurrent assets 475 475 2,538 8,538 Total cash, cash equivalents and restricted cash shown in the condensed consolidated statements of cash flows $ 142,567 $ 152,437 $ 120,007 $ 129,863 See Note 13, Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement,
Income Taxes	Income Taxes In December 2017, the SEC staff issued Staff Accounting Bulletin 118 (SAB 118), which provides relief for companies that have not completed their accounting for the effects of The Tax Cuts and Jobs Act (Tax Reform Act) but can determine a reasonable estimate of those effects to allow them to include a provisional amount based on their reasonable estimate in their financial statements. The guidance in SAB 118 also allows companies to adjust the provisional amounts during a one-year “measurement period” which is similar to the measurement period used when accounting for business combinations. In the accompanying consolidated financial statements, the Company has not completed its accounting for all the tax effects associated with the enactment of the Tax Reform Act. However, the Company has, in certain cases made a reasonable estimate of the effects on its existing deferred tax balances and the one-time transition tax. See Note 9, Income Taxes,
Leases	Leases In February 2016, the FASB issued ASU 2016-02, Leases

Summary of Operations and Sig22

Summary of Operations and Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Summary of Warranty Accrual	Warranty accrual at March 31 consisted of the following: 2018 (in thousands) Warranty accrual at beginning of year $ 30,419 Accrual during the period 3,621 Cost of warranty services provided during the period (306 ) Reversal of reserves upon warranty expiration (1,064 ) Warranty accrual at end of period $ 32,670
Calculation Of Weighted-Average Number Of Common Shares Outstanding	The table below reflects the calculation of the weighted-average number of common shares outstanding, using the treasury stock method, used in computing basic and diluted earnings per common share: Three Months Ended March 31, 2018 2017 (in thousands) Basic weighted-average shares outstanding 34,049 33,737 Effect of dilutive stock options and warrants 1,430 90 Diluted weighted-average shares outstanding 35,479 33,827
Reconciliation of Cash, Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets which total the same such amounts in the condensed consolidated statements of cash flows: March 31, December 31, March 31, December 31, 2018 2017 2017 2016 (in thousands) Cash and cash equivalents $ 138,841 $ 148,113 $ 115,541 $ 119,066 Restricted cash 3,251 3,849 1,928 2,259 Restricted cash included within other noncurrent assets 475 475 2,538 8,538 Total cash, cash equivalents and restricted cash shown in the condensed consolidated statements of cash flows $ 142,567 $ 152,437 $ 120,007 $ 129,863

Revenue From Contracts with C23

Revenue From Contracts with Customers (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue From Contract With Customer [Abstract]
Summary of Disaggregation of Revenue by Contract Type for Each of Reportable Segments	The following tables represents the disaggregation of revenue by contract type for each of our reportable segments: Three Months Ended March 31, 2018 U.S. Asia Mexico EMEA Total (in thousands) Wind blade sales $ 38,945 $ 68,171 $ 56,043 $ 71,021 $ 234,180 Precision molding and assembly systems sales 1,863 8,179 764 — 10,806 Transportation sales 4,053 — — — 4,053 Other sales 1,263 1,320 1,157 1,202 4,942 Total net sales: $ 46,124 $ 77,670 $ 57,964 $ 72,223 $ 253,981 Three Months Ended March 31, 2017 U.S. Asia Mexico EMEA Total (in thousands) Wind blade sales $ 41,970 $ 65,266 $ 45,199 $ 43,270 $ 195,705 Precision molding and assembly systems sales 3,336 3,664 655 — 7,655 Transportation sales 2,578 — — — 2,578 Other sales 83 567 1,094 933 2,677 Total net sales: $ 47,967 $ 69,497 $ 46,948 $ 44,203 $ 208,615
Summary of Contract Assets and Contract Liabilities	The following table reflects the changes in the Company’s contract assets and contract liabilities for the three months ended March 31, 2018: March 31, December 31, 2018 2017 $ Change (in thousands) Contract assets $ 130,015 $ 105,619 $ 24,396 March 31, December 31, 2018 2017 $ Change (in thousands) Contract liabilities $ 4,449 $ 2,763 $ 1,686

Accounts Receivable (Tables)

Accounts Receivable (Tables)	3 Months Ended
	Mar. 31, 2018
Receivables [Abstract]
Summary of Accounts Receivable	Accounts receivable consisted of the following: March 31, December 31, 2018 2017 (in thousands) Trade accounts receivable $ 114,411 $ 117,794 Other accounts receivable 3,539 3,782 Total accounts receivable $ 117,950 $ 121,576

Property, Plant, and Equipmen25

Property, Plant, and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2018
Property Plant And Equipment [Abstract]
Schedule of Property Plant and Equipment Net	Property, plant and equipment, net consisted of the following: March 31, December 31, 2018 2017 (in thousands) Machinery and equipment $ 100,974 $ 100,681 Buildings 14,385 14,711 Leasehold improvements 22,135 21,853 Office equipment and software 20,665 18,664 Furniture 19,831 19,017 Vehicles 277 294 Construction in progress 14,521 10,687 Total 192,788 185,907 Accumulated depreciation (65,928 ) (62,427 ) Property, plant and equipment, net $ 126,860 $ 123,480

Long-Term Debt, Net of Debt I26

Long-Term Debt, Net of Debt Issuance Costs and Current Maturities (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Schedule of Long-Term Debt, Net of Debt Issuance Costs and Current Maturities	Long-term debt, net of debt issuance costs and current maturities, consisted of the following: March 31, December 31, 2018 2017 (in thousands) Senior term loan—U.S. $ 70,313 $ 71,250 Senior revolving loan—U.S. 2,820 2,820 Accounts receivable financing—EMEA 22,192 14,100 Equipment financing—EMEA 16,313 16,901 Equipment capital lease—U.S. 188 536 Equipment capital lease—EMEA 5,045 5,058 Equipment capital lease—Mexico 10,815 12,844 Equipment loan—Mexico 47 47 Total long-term debt 127,733 123,556 Less: Debt issuance costs (1,990 ) (2,171 ) Total long-term debt, net of debt issuance costs 125,743 121,385 Less: Current maturities of long-term debt (43,085 ) (35,506 ) Long-term debt, net of debt issuance costs and current maturities $ 82,658 $ 85,879

Share-Based Compensation Plans

Share-Based Compensation Plans (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Share-Based Compensation Expense recognized in the Condensed Consolidated Income Statements	The share-based compensation expense recognized in the condensed consolidated income statements was as follows: Three Months Ended March 31, 2018 2017 (in thousands) Cost of goods sold $ 412 $ 213 General and administrative expenses 1,976 1,494 Total share-based compensation expense $ 2,388 $ 1,707
Schedule of Share-based Compensation Arrangements by Share-based Payment Award	The share-based compensation expense recognized by award type was as follows: Three Months Ended March 31, 2018 2017 (in thousands) RSUs $ 1,318 $ 535 Stock options 990 1,172 PSUs 80 - Total share-based compensation expense $ 2,388 $ 1,707
Summary of Activity for Incentive Plans	The summary of activity for the Company’s incentive plans is as follows: Stock Options RSUs PSUs Shares Available for Grant Shares Weighted- Average Exercise Price Options Exercisable Units Weighted- Average Grant Date Fair Value Units Weighted- Average Grant Date Fair Value Balance as of December 31, 2017 4,731,117 3,203,290 $ 13.34 890,433 613,380 $ 15.02 — $ — Increase in shares authorized 1,360,826 — — — — — — Granted (423,136 ) 9,652 22.67 121,386 22.67 292,098 22.67 Exercised/vested — (53,250 ) 10.87 (38,196 ) 23.29 — — Forfeited/cancelled 576 — — (576 ) 23.29 — — Balance as of March 31, 2018 5,669,383 3,159,692 13.41 1,028,241 695,994 15.90 292,098 22.67
Summary of Outstanding and Exercisable Stock Option Awards	The following table summarizes the outstanding and exercisable stock option awards as of March 31, 2018: Options Outstanding Options Exercisable Range of Exercise Prices: Shares Weighted- Average Remaining Contractual Life ( in years Weighted- Average Exercise Price Shares Weighted- Average Exercise Price $8.49 22,728 1.8 $ 8.49 22,728 $ 8.49 $ 10.87 1,920,099 7.2 10.87 637,599 10.87 $11.00 to $16.53 656,523 7.8 16.12 239,872 16.23 $17.68 to $18.70 342,790 8.2 18.68 128,042 18.68 $18.77 to $22.34 217,552 9.5 19.92 — — $8.49 to $22.34 3,159,692 7.6 13.41 1,028,241 13.04

Concentration of Customers (Tab

Concentration of Customers (Tables)	3 Months Ended
	Mar. 31, 2018
Risks And Uncertainties [Abstract]
Schedule of Revenues from Customers	Revenues from certain customers in excess of 10 percent of total consolidated Company revenues (dollars in thousands) are as follows: Three Months Ended March 31, 2018 2017 Customer Revenues % of Total Revenues % of Total GE $ 87,828 34.6 % $ 91,528 43.9 % Vestas 85,269 33.6 48,263 23.1 Nordex Acciona 48,201 19.0 40,632 19.5 Siemens Gamesa 24,291 9.5 25,642 12.3 Other 8,392 3.3 2,550 1.2 Total $ 253,981 100.0 % $ 208,615 100.0 %
Schedule of Trade Accounts Receivable from Certain Customers	Trade accounts receivable from certain customers in excess of 10 percent of total consolidated Company trade accounts receivable are as follows: March 31, December 31, 2018 2017 Customer % of Total % of Total GE 18.8 % 18.9 % Vestas 40.3 % 52.4 % Nordex Acciona 30.4 % 19.5 %

Segment Reporting (Tables)

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Schedule of Segment Information	The following tables set forth certain information regarding each of the Company’s segments: Three Months Ended March 31, 2018 2017 (in thousands) Revenues by segment: U.S. $ 46,124 $ 47,967 Asia 77,670 69,497 Mexico 57,964 46,948 EMEA 72,223 44,203 Total revenues $ 253,981 $ 208,615 Revenues by geographic location (1): U.S. $ 46,124 $ 47,967 China 77,670 69,497 Mexico 57,964 46,948 Turkey 72,223 44,203 Total revenues $ 253,981 $ 208,615 Income (loss) from operations: U.S. (2) $ (9,050 ) $ (7,326 ) Asia 6,417 12,794 Mexico 4,258 2,844 EMEA 15,470 3,300 Total income from operations $ 17,095 $ 11,612 March 31, December 31, 2018 2017 (in thousands) Property, plant and equipment, net: U.S. $ 27,528 $ 24,575 Asia (China) 30,881 28,887 Mexico 38,466 39,756 EMEA (Turkey) 29,985 30,262 Total property, plant and equipment, net $ 126,860 $ 123,480 (1) Revenues are attributable to countries based on the location where the product is manufactured or the services are performed. (2) The losses from operations in the U.S. segment includes corporate general and administrative costs of $11.2 million and $8.3 million for the three months ended March 31, 2018 and 2017, respectively.

Adjustments to Previously Rep30

Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement (Tables)	3 Months Ended
	Mar. 31, 2018
New Accounting Pronouncements And Changes In Accounting Principles [Abstract]
Summary of Effects of Adopting Topic 606 and ASU 2016-18 on Previously Reported Financial Statements	The following tables summarize the effects of adopting Topic 606 and ASU 2016-18 had on our previously reported financial statements. Condensed Consolidated Balance Sheet (In thousands, except par value data) December 31, 2017 As Reported Adoption of Topic 606 As Adjusted (Unaudited) Assets Current assets: Cash and cash equivalents $ 148,113 $ — $ 148,113 Restricted cash 3,849 — 3,849 Accounts receivable 121,576 — 121,576 Contract assets — 105,619 105,619 Inventories 67,064 (62,952 ) 4,112 Inventories held for customer orders 64,858 (64,858 ) — Prepaid expenses and other current assets 27,507 — 27,507 Total current assets 432,967 (22,191 ) 410,776 Property, plant, and equipment, net 123,480 — 123,480 Goodwill 2,807 — 2,807 Intangible assets, net 150 958 1,108 Other noncurrent assets 14,130 4,261 18,391 Total assets $ 573,534 $ (16,972 ) $ 556,562 Liabilities and Stockholders’ Equity Current liabilities: Accounts payable and accrued expenses $ 166,743 $ — $ 166,743 Accrued warranty 29,163 1,256 30,419 Deferred revenue 81,048 (81,048 ) — Customer deposits 10,134 (9,702 ) 432 Current maturities of long-term debt 35,506 — 35,506 Contract liabilities — 2,763 2,763 Total current liabilities 322,594 (86,731 ) 235,863 Long-term debt, net of debt issuance costs and current maturities 85,879 — 85,879 Other noncurrent liabilities 4,444 494 4,938 Total liabilities 412,917 (86,237 ) 326,680 Commitments and contingencies Stockholders’ equity: Common shares, $0.01 par value, 100,000 shares authorized and 34,049 shares issued and 34,021 shares outstanding at December 31, 2017 340 — 340 Paid-in capital 301,543 — 301,543 Accumulated other comprehensive loss (558 ) — (558 ) Accumulated deficit (140,197 ) 69,265 (70,932 ) Treasury stock, at cost, 28 shares at December 31, 2017 (511 ) — (511 ) Total stockholders’ equity 160,617 69,265 229,882 Total liabilities and stockholders’ equity $ 573,534 $ (16,972 ) $ 556,562 The primary effects of the adoption of Topic 606 on the Company’s balance sheet include 1) amounts being recognized as revenue for work performed as production takes place over time as contract assets, which differs from the prior practice of including the balances in inventory; 2) no longer reporting inventory held for customer orders or deferred revenue since revenue is now being recognized over the course of the production process, and before the product is delivered to the customer; 3) that contract liabilities are reported for amounts collected from customers in advance of the production of products, similar to our prior practice of recording customer deposits; and 4) the cumulative amount of the effect to prior periods’ net income related to the adoption of Topic 606 through December 31, 2017 is reflected in retained earnings. Condensed Consolidated Income Statement (In thousands, except per share data) Three Months Ended March 31, 2017 As Reported Adoption of Topic 606 As Adjusted (Unaudited) Net sales $ 191,602 $ 17,013 $ 208,615 Cost of sales 167,423 15,115 182,538 Startup and transition costs 6,159 — 6,159 Total cost of goods sold 173,582 15,115 188,697 Gross profit 18,020 1,898 19,918 General and administrative expenses 8,306 — 8,306 Income from operations 9,714 1,898 11,612 Other income (expense): Interest income 19 — 19 Interest expense (3,026 ) — (3,026 ) Realized loss on foreign currency remeasurement (1,381 ) — (1,381 ) Miscellaneous income 320 — 320 Total other expense (4,068 ) — (4,068 ) Income before income taxes 5,646 1,898 7,544 Income tax provision (2,101 ) (230 ) (2,331 ) Net income $ 3,545 $ 1,668 $ 5,213 Weighted-average common shares outstanding: Basic 33,737 33,737 33,737 Diluted 33,827 33,827 33,827 Net income per common share: Basic $ 0.11 $ 0.05 $ 0.15 Diluted $ 0.10 $ 0.05 $ 0.15 The primary effects of the adoption of Topic 606 on the Company’s condensed consolidated income statement relate to amounts being recognized as revenue for work performed as production takes place over time, which differs from the prior practice of recognizing revenue when the product was delivered to the customer. Condensed Consolidated Statement of Comprehensive Income (In thousands) Three Months Ended March 31, 2017 As Reported Adoption of Topic 606 As Adjusted (Unaudited) Net income $ 3,545 $ 1,668 $ 5,213 Other comprehensive income: Foreign currency translation adjustments 277 — 277 Comprehensive income $ 3,822 $ 1,668 $ 5,490 Condensed Consolidated Statements of Changes in Stockholders’ Equity (In thousands) Common Paid-in Accumulated other comprehensive Accumulated Treasury stock, Total stockholders' Shares Amount capital loss deficit at cost equity (Unaudited) Balance at December 31, 2017 - as reported 34,049 $ 340 $ 301,543 $ (558 ) $ (140,197 ) $ (511 ) $ 160,617 Cumulative effect of the adoption of Topic 606 — — — — 69,265 — 69,265 Balance at December 31, 2017 - as adjusted 34,049 $ 340 $ 301,543 $ (558 ) $ (70,932 ) $ (511 ) $ 229,882 The adoption of Topic 606 increased total stockholders’ equity in 2015 and 2016 by $61.2 million and $12.3 million, respectively and decreased total stockholders’ equity in 2017 by $4.2 million. Condensed Consolidated Statements of Cash Flows (In thousands) Three Months Ended March 31, 2017 As Reported Adoption of Topic 606 Adoption of ASU 2016-18 As Adjusted (Unaudited) Cash flows from operating activities: Net income $ 3,545 $ 1,668 $ — $ 5,213 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 3,829 123 — 3,952 Share-based compensation expense 1,707 — — 1,707 Amortization of debt issuance costs 143 — — 143 Changes in assets and liabilities: — — Accounts receivable (28,722 ) — — (28,722 ) Contract assets — 2,738 — 2,738 Inventories (15,220 ) 15,152 — (68 ) Prepaid expenses and other current assets 6,816 — — 6,816 Other noncurrent assets 5,871 (27 ) (6,000 ) (156 ) Accounts payable and accrued expenses 11,211 — — 11,211 Accrued warranty 1,983 97 — 2,080 Customer deposits 4,827 (4,110 ) — 717 Deferred revenue 19,751 (19,751 ) — — Contract liabilities — 4,110 — 4,110 Other noncurrent liabilities 197 — — 197 Net cash provided by (used in) operating activities 15,938 — (6,000 ) 9,938 Cash flows from investing activities: Purchase of property and equipment (16,922 ) — — (16,922 ) Net cash used in investing activities (16,922 ) — — (16,922 ) Cash flows from financing activities: Repayments of term loan (938 ) — — (938 ) Net repayments of accounts receivable financing (1,233 ) — — (1,233 ) Net proceeds from working capital loans 517 — — 517 Net repayments of other debt (1,155 ) — — (1,155 ) Restricted cash 331 — (331 ) — Net cash used in financing activities (2,478 ) — (331 ) (2,809 ) Impact of foreign exchange rates on cash and cash equivalents (63 ) — (63 ) Net change in cash and cash equivalents (3,525 ) — (6,331 ) (9,856 ) Cash, cash equivalents and restricted cash, beginning of year 119,066 10,797 129,863 Cash, cash equivalents and restricted cash, end of period $ 115,541 $ — $ 4,466 $ 120,007

Summary of Operations and Sig31

Summary of Operations and Significant Accounting Policies - Public Offerings and Stock Split - Additional Information (Detail)	1 Months Ended
	May 31, 2017USD ($)$ / sharesshares	Jul. 31, 2016USD ($)$ / sharesshares
Initial Public Offering [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Public offering shares		7,187,500
Share price | $ / shares		$ 11
Net proceeds from Initial public offering | $		$ 67,200,000
Initial Public Offering [Member] | Subordinated Convertible Promissory Notes [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Share price | $ / shares		$ 11
Debt instrument convertible number of equity shares		1,079,749
Initial Public Offering [Member] | Common Stock Warrants [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Number of common stock issue on conversion of preferred share		120,923
Initial Public Offering [Member] | Redeemable Preferred Shares [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Number of common stock issue on conversion of preferred share		21,110,204
Initial Public Offering [Member] | Investors, Non-employee Director and Executive Officers [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Public offering shares		1,250,000
Underwriters Over-allotment Option [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Public offering shares		937,500
Underwriters Over-allotment Option [Member] | Existing Shareholders and Executive Officers [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Public offering shares	575,000
Initial Public Offering and Stock Split [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Conversion of convertible promissory notes | $		$ 11,900,000
Prior to IPO [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Common stock forward stock split ratio		360
Secondary Public Offering [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Public offering shares	0
Net proceeds from secondary public offering to selling shareholders | $	$ 78,800,000
Proceeds from secondary public offering | $	0
Secondary Public Offering [Member] | General and Administrative Costs [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Offering costs paid | $	$ 800,000
Secondary Public Offering [Member] | Existing Shareholders and Executive Officers [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Public offering shares	5,075,000
Share price | $ / shares	$ 16.35

Summary of Operations and Sig32

Summary of Operations and Significant Accounting Policies - Basis of Presentation - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018SegmentFacility
Operations And Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | Segment	4
Mexico [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Number of manufacturing facilities	3
EMEA [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Number of manufacturing facilities	2
Asia Segment [Member] | Dafeng [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Number of manufacturing facilities	2

Summary of Operations and Sig33

Summary of Operations and Significant Accounting Policies - Warranty Expense - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018
Minimum [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Limited warranty period	2 years
Maximum [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Limited warranty period	5 years

Summary of Operations and Sig34

Summary of Operations and Significant Accounting Policies - Summary of Warranty Accrual (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Product Warranties Disclosures [Abstract]
Warranty accrual at beginning of year	$ 30,419
Accrual during the period	3,621
Cost of warranty services provided during the period	(306)
Reversal of reserves upon warranty expiration	(1,064)
Warranty accrual at end of period	$ 32,670

Summary of Operations and Sig35

Summary of Operations and Significant Accounting Policies - Calculation Of Weighted-Average Number Of Common Shares Outstanding (Detail) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Basic weighted-average shares outstanding	34,049	33,737
Effect of dilutive stock options and warrants	1,430	90
Diluted weighted-average shares outstanding	35,479	33,827

Summary of Operations and Sig36

Summary of Operations and Significant Accounting Policies - Net Income Per Common Share Calculation - Additional Information (Detail) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operations And Summary Of Significant Accounting Policies [Line Items]
Anti-dilutive shares excluded from computation of diluted net income per share		0
Share-Based Compensation Awards [Member]
Operations And Summary Of Significant Accounting Policies [Line Items]
Anti-dilutive shares excluded from computation of diluted net income per share	175,000

Summary of Operations and Sig37

Summary of Operations and Significant Accounting Policies - Reconciliation of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Cash and cash equivalents	$ 138,841	$ 148,113
Restricted cash	3,251	3,849
Total cash, cash equivalents and restricted cash shown in the condensed consolidated statements of cash flows	142,567	152,437	$ 120,007	$ 129,863
ASU 2016-15 [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Cash and cash equivalents	138,841	148,113	115,541	119,066
Restricted cash	3,251	3,849	1,928	2,259
Restricted cash included within other noncurrent assets	475	475	2,538	8,538
Total cash, cash equivalents and restricted cash shown in the condensed consolidated statements of cash flows	$ 142,567	$ 152,437	$ 120,007	$ 129,863

Revenue From Contracts with C38

Revenue From Contracts with Customers - Summary of Disaggregation of Revenue by Contract Type for Each of Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation Of Revenue [Line Items]
Revenue	$ 253,981	$ 208,615
Wind Blades [Member]
Disaggregation Of Revenue [Line Items]
Revenue	234,180	195,705
Precision Molding and Assembly Systems [Member]
Disaggregation Of Revenue [Line Items]
Revenue	10,806	7,655
Transportation [Member]
Disaggregation Of Revenue [Line Items]
Revenue	4,053	2,578
Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue	4,942	2,677
U.S. Segment [Member]
Disaggregation Of Revenue [Line Items]
Revenue	46,124	47,967
U.S. Segment [Member] | Wind Blades [Member]
Disaggregation Of Revenue [Line Items]
Revenue	38,945	41,970
U.S. Segment [Member] | Precision Molding and Assembly Systems [Member]
Disaggregation Of Revenue [Line Items]
Revenue	1,863	3,336
U.S. Segment [Member] | Transportation [Member]
Disaggregation Of Revenue [Line Items]
Revenue	4,053	2,578
U.S. Segment [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue	1,263	83
Asia Segment [Member]
Disaggregation Of Revenue [Line Items]
Revenue	77,670	69,497
Asia Segment [Member] | Wind Blades [Member]
Disaggregation Of Revenue [Line Items]
Revenue	68,171	65,266
Asia Segment [Member] | Precision Molding and Assembly Systems [Member]
Disaggregation Of Revenue [Line Items]
Revenue	8,179	3,664
Asia Segment [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue	1,320	567
Mexico Segment [Member]
Disaggregation Of Revenue [Line Items]
Revenue	57,964	46,948
Mexico Segment [Member] | Wind Blades [Member]
Disaggregation Of Revenue [Line Items]
Revenue	56,043	45,199
Mexico Segment [Member] | Precision Molding and Assembly Systems [Member]
Disaggregation Of Revenue [Line Items]
Revenue	764	655
Mexico Segment [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue	1,157	1,094
EMEA Segment [Member]
Disaggregation Of Revenue [Line Items]
Revenue	72,223	44,203
EMEA Segment [Member] | Wind Blades [Member]
Disaggregation Of Revenue [Line Items]
Revenue	71,021	43,270
EMEA Segment [Member] | Other [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 1,202	$ 933

Revenue From Contracts with C39

Revenue From Contracts with Customers - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Revenue From Contract With Customer [Line Items]
Increase in contracts assets	$ 24,396	$ (2,738)
Incremental in unbilled production	28,200
Increase in contracts liabilities	1,686	$ 4,110
Contract liability revenue recognized	2,700
Net revenue recognized from performance obligations satisfied in previous periods, decreased amount	4,900
Transaction price allocated to remaining performance obligations	$ 4,300,000
Expects to recognize remaining performance obligations as revenue, percent in remainder of 2018	16.00%
Expects to recognize remaining performance obligations as revenue, percent in 2019	24.00%
Expects to recognize remaining performance obligations as revenue, percent in 2020	26.00%
Expects to recognize remaining performance obligations as revenue, percent in 2021	17.00%
Expects to recognize remaining performance obligations as revenue, percent in 2022	12.00%
Expects to recognize remaining performance obligations as revenue, percent in 2023	5.00%
Capitalized contract cost	$ 2,800		$ 2,400
Capitalized contract cost, accumulated amortization	$ 1,600		$ 1,400
Revenue, practical expedient, incremental cost of obtaining contract	true
Minimum [Member]
Revenue From Contract With Customer [Line Items]
Production hours of single blade	24 hours
Production time of mold	3 months
Maximum [Member]
Revenue From Contract With Customer [Line Items]
Production hours of single blade	36 hours
Production time of mold	6 months
Long-term Contract with Customer [Member] | Net Sales, Directly to Consumer [Member]
Revenue From Contract With Customer [Line Items]
Contracts with customer, lenght	5 years

Revenue From Contracts with C40

Revenue From Contracts with Customers - Summary of Contract Assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Revenue From Contract With Customer [Abstract]
Contract assets	$ 130,015		$ 105,619
Contract assets, Change	$ 24,396	$ (2,738)

Revenue From Contracts with C41

Revenue From Contracts with Customers - Summary of Contract Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Revenue From Contract With Customer [Abstract]
Contract liabilities	$ 4,449		$ 2,763
Contract liabilities, Change	$ 1,686	$ 4,110

Significant Risks and Uncerta42

Significant Risks and Uncertainties - Additional Information (Detail) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Concentration Risk [Line Items]
Cash in short-term deposits in interest bearing accounts	$ 3,251,000	$ 3,849,000
U.S. [Member]
Concentration Risk [Line Items]
Cash in deposit accounts	103,400,000	98,900,000
China [Member]
Concentration Risk [Line Items]
Cash in deposit accounts	29,200,000
Cash in short-term deposits in interest bearing accounts	3,300,000
Turkey [Member]
Concentration Risk [Line Items]
Cash in deposit accounts	1,100,000
Mexico [Member]
Concentration Risk [Line Items]
Cash in deposit accounts	5,100,000
Iowa [Member]
Concentration Risk [Line Items]
Cash in long term deposits in interest bearing accounts	500,000
Maximum [Member]
Concentration Risk [Line Items]
Cash deposit insured amount	$ 250,000	$ 250,000

Related-Party Transactions - Ad

Related-Party Transactions - Additional Information (Detail) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended		6 Months Ended
	May 31, 2017$ / sharesshares	Jul. 31, 2016$ / sharesshares	Mar. 31, 2018USD ($)Agreement	Mar. 31, 2017USD ($)	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Initial Public Offering [Member]
Related Party Transaction [Line Items]
Public offering shares		7,187,500
Share price | $ / shares		$ 11
Secondary Public Offering [Member]
Related Party Transaction [Line Items]
Public offering shares	0
Investor, Executive Officers and Director [Member] | Initial Public Offering [Member]
Related Party Transaction [Line Items]
Public offering shares		1,250,000
Subordinated Convertible Promissory Notes [Member] | Initial Public Offering [Member]
Related Party Transaction [Line Items]
Debt instrument convertible number of equity shares		1,079,749
Share price | $ / shares		$ 11
GE [Member]
Related Party Transaction [Line Items]
Number of supply agreements | Agreement			5
Proceeds from sales | $			$ 87.8	$ 91.5	$ 187.3
Accounts receivables, related party | $			$ 21.6			$ 22.2
GE [Member] | Agreements in Taicang Port and Izmir [Member]
Related Party Transaction [Line Items]
Agreement expiration date			Dec. 31, 2017
GE [Member] | Maximum [Member]
Related Party Transaction [Line Items]
Percentage of common stock outstanding					5.00%
Certain Entities Associated with Element Partners, Angeleno Group Landmark Partners and NGP Energy Technology Partners, L.P and Certain Executive Officers [Member] | Secondary Public Offering [Member]
Related Party Transaction [Line Items]
Public offering shares	5,075,000
Share price | $ / shares	$ 16.35

Accounts Receivable - Summary o

Accounts Receivable - Summary of Accounts Receivable (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	$ 117,950	$ 121,576
Trade Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	114,411	117,794
Other Accounts Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total accounts receivable	$ 3,539	$ 3,782

Property, Plant, and Equipmen45

Property, Plant, and Equipment, Net - Schedule of Property Plant and Equipment Net (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 192,788	$ 185,907
Accumulated depreciation	(65,928)	(62,427)
Property, plant and equipment, net	126,860	123,480
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	100,974	100,681
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	14,385	14,711
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	22,135	21,853
Office Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	20,665	18,664
Furniture [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	19,831	19,017
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	277	294
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 14,521	$ 10,687

Property, Plant, and Equipmen46

Property, Plant, and Equipment, Net - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Property Plant And Equipment [Abstract]
Total depreciation expense	$ 6.8	$ 3.8

Long-Term Debt, Net of Debt I47

Long-Term Debt, Net of Debt Issuance Costs and Current Maturities - Schedule of Long-Term Debt, Net of Debt Issuance Costs and Current Maturities (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Total long-term debt
Total long-term debt	$ 127,733	$ 123,556
Less: Debt issuance costs	(1,990)	(2,171)
Total long-term debt, net of debt issuance costs	125,743	121,385
Less: Current maturities of long-term debt	(43,085)	(35,506)
Long-term debt, net of debt issuance costs and current maturities	82,658	85,879
Senior Term Loan [Member] | U.S. [Member]
Total long-term debt
Total long-term debt	70,313	71,250
Senior Revolving Loan [Member] | U.S. [Member]
Total long-term debt
Total long-term debt	2,820	2,820
Accounts Receivable Financing [Member] | EMEA [Member]
Total long-term debt
Total long-term debt	22,192	14,100
Equipment Financing [Member] | EMEA [Member]
Total long-term debt
Total long-term debt	16,313	16,901
Equipment Capital Lease [Member] | U.S. [Member]
Total long-term debt
Total long-term debt	188	536
Equipment Capital Lease [Member] | EMEA [Member]
Total long-term debt
Total long-term debt	5,045	5,058
Equipment Capital Lease [Member] | Mexico [Member]
Total long-term debt
Total long-term debt	10,815	12,844
Equipment Loan [Member] | Mexico [Member]
Total long-term debt
Total long-term debt	$ 47	$ 47

Share-Based Compensation Plan48

Share-Based Compensation Plans - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)shares
Timed-Based Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation plans, shares issued	121,386
Performance-Based Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation plans, shares issued	121,386
Performance-Based Restricted Stock Units [Member] | Certain Stock Price Hurdles [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation plans, shares issued	170,712
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation plans, shares issued	121,386
Unamortized amount of share-based compensation expense | $	$ 6.4
Unrecognized cost expects to recognize, weighted-avergae period	2 years 1 month 6 days
Fair value of awards vested during period | $	$ 0.8
Shares repurchased for awards	13,441
Shares repurchased for tax witholding requirements, value | $	$ 0.3
Performance-based Restricted Stock Units (PSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation plans, shares issued	292,098
Unamortized amount of share-based compensation expense | $	$ 4.8
Unrecognized cost expects to recognize, weighted-avergae period	3 years
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized cost expects to recognize, weighted-avergae period	1 year 8 months 12 days
Total unrecognized cost related to non-vested stock option awards | $	$ 4

Share-Based Compensation Plan49

Share-Based Compensation Plans - Schedule of Share Based Compensation Expense Recognized in Condensed Consolidated Income Statements (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 2,388	$ 1,707
Cost of Goods Sold [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	412	213
General and Administrative Costs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 1,976	$ 1,494

Share-Based Compensation Plan50

Share-Based Compensation Plans - Schedule of Share-based Compensation Arrangements by Share-based Payment Award (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 2,388	$ 1,707
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	1,318	535
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	990	$ 1,172
Performance-based Restricted Stock Units (PSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 80

Share-Based Compensation Plan51

Share-Based Compensation Plans - Summary of Activity for Incentive Plans (Detail)	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock Options, Shares Available for Grant, Beginning balance	4,731,117
Stock Options, Shares Available for Grant, Increase in shares authorized	1,360,826
Stock Options, Shares Available for Grant, Granted	(423,136)
Stock Options, Shares Available for Grant, Exercised/vested	0
Stock Options, Shares Available for Grant, Forfeited/cancelled	576
Stock Options, Shares Available for Grant, Ending balance	5,669,383
Stock Options, Shares, Beginning balance	3,203,290
Stock Options, Shares, Increase in shares authorized	0
Stock Options, Shares, Granted	9,652
Stock Options, Shares, Exercised/vested	(53,250)
Stock Options, Shares, Forfeited/cancelled	0
Stock Options, Shares, Ending balance	3,159,692
Stock Options, Weighted-Average Exercise Price, Beginning balance | $ / shares	$ 13.34
Stock Options, Weighted-Average Exercise Price, Increase in shares authorized | $ / shares	0
Stock Options, Weighted-Average Exercise Price, Granted | $ / shares	22.67
Stock Options, Weighted-Average Exercise Price, Exercised/vested | $ / shares	10.87
Stock Options, Weighted-Average Exercise Price, Forfeited/cancelled | $ / shares	0
Stock Options, Weighted-Average Exercise Price, Ending balance | $ / shares	$ 13.41
Stock Options, Options Exercisable, Beginning balance	890,433
Stock Options, Options Exercisable, Ending balance	1,028,241
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units, Beginning balance	613,380
Units, Increase in shares authorized	0
Units, Granted	121,386
Units, Exercised/vested	(38,196)
Units, Forfeited/cancelled	(576)
Units, Ending balance	695,994
Weighted-Average Grant Date Fair Value, Beginning balance | $ / shares	$ 15.02
Weighted-Average Grant Date Fair Value, Increase in shares authorized | $ / shares	0
Weighted-Average Grant Date Fair Value, Granted | $ / shares	22.67
Weighted-Average Grant Date Fair Value, Exercised/vested | $ / shares	23.29
Weighted-Average Grant Date Fair Value, Forfeited/cancelled | $ / shares	23.29
Weighted-Average Grant Date Fair Value, Ending balance | $ / shares	$ 15.90
Performance-based Restricted Stock Units (PSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units, Beginning balance	0
Units, Increase in shares authorized	0
Units, Granted	292,098
Units, Exercised/vested	0
Units, Forfeited/cancelled	0
Units, Ending balance	292,098
Weighted-Average Grant Date Fair Value, Beginning balance | $ / shares	$ 0
Weighted-Average Grant Date Fair Value, Increase in shares authorized | $ / shares	0
Weighted-Average Grant Date Fair Value, Granted | $ / shares	22.67
Weighted-Average Grant Date Fair Value, Exercised/vested | $ / shares	0
Weighted-Average Grant Date Fair Value, Forfeited/cancelled | $ / shares	0
Weighted-Average Grant Date Fair Value, Ending balance | $ / shares	$ 22.67

Share-Based Compensation Plan52

Share-Based Compensation Plans - Summary of Outstanding and Exercisable Stock Option Awards (Detail)	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Range One [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	$ 8.49
Options Outstanding, Shares | shares	22,728
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	1 year 9 months 18 days
Options Outstanding, Weighted-Average Exercise Price	$ 8.49
Options Exercisable, Shares | shares	22,728
Options Exercisable, Weighted-Average Exercise Price	$ 8.49
Range Two [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	$ 10.87
Options Outstanding, Shares | shares	1,920,099
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	7 years 2 months 12 days
Options Outstanding, Weighted-Average Exercise Price	$ 10.87
Options Exercisable, Shares | shares	637,599
Options Exercisable, Weighted-Average Exercise Price	$ 10.87
Range Three [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	11
Range of Exercise Prices, Maximum	$ 16.53
Options Outstanding, Shares | shares	656,523
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	7 years 9 months 18 days
Options Outstanding, Weighted-Average Exercise Price	$ 16.12
Options Exercisable, Shares | shares	239,872
Options Exercisable, Weighted-Average Exercise Price	$ 16.23
Range Four [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	17.68
Range of Exercise Prices, Maximum	$ 18.70
Options Outstanding, Shares | shares	342,790
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	8 years 2 months 12 days
Options Outstanding, Weighted-Average Exercise Price	$ 18.68
Options Exercisable, Shares | shares	128,042
Options Exercisable, Weighted-Average Exercise Price	$ 18.68
Range Five [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	18.77
Range of Exercise Prices, Maximum	$ 22.34
Options Outstanding, Shares | shares	217,552
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	9 years 6 months
Options Outstanding, Weighted-Average Exercise Price	$ 19.92
Range Six [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of Exercise Prices, Minimum	8.49
Range of Exercise Prices, Maximum	$ 22.34
Options Outstanding, Shares | shares	3,159,692
Options Outstanding, Weighted-Average Remaining Contractual Life (in years)	7 years 7 months 6 days
Options Outstanding, Weighted-Average Exercise Price	$ 13.41
Options Exercisable, Shares | shares	1,028,241
Options Exercisable, Weighted-Average Exercise Price	$ 13.04

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal corporate income tax rate	21.00%	35.00%
Incremental tax expense	$ 0

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - SVP–Asia [Member] - Transition Agreement [Member] $ in Millions	1 Months Ended
	Apr. 30, 2016USD ($)shares
Commitments and Contingencies [Line Items]
Compensation and fees demanded by plaintiff | $	$ 2.6
Termination of options to purchase common stock	164,880
Termination of options to purchase restricted stock	77,760

Concentration of Customers - Ad

Concentration of Customers - Additional Information (Detail) - Customer Concentration Risk [Member]	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Sales Revenues [Member]
Concentration Risk [Line Items]
Customer risk percentage	100.00%	100.00%
Sales Revenues [Member] | Minimum [Member]
Concentration Risk [Line Items]
Customer risk percentage	10.00%	10.00%
Accounts Receivable [Member] | Minimum [Member]
Concentration Risk [Line Items]
Customer risk percentage	10.00%		10.00%

Concentration of Customers - Sc

Concentration of Customers - Schedule of Revenues from Customers (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Concentration Risk [Line Items]
Revenues	$ 253,981	$ 208,615
Sales Revenues [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Revenues	$ 253,981	$ 208,615
Percentage of Total	100.00%	100.00%
Sales Revenues [Member] | GE [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Revenues	$ 87,828	$ 91,528
Percentage of Total	34.60%	43.90%
Sales Revenues [Member] | Vestas [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Revenues	$ 85,269	$ 48,263
Percentage of Total	33.60%	23.10%
Sales Revenues [Member] | Nordex Acciona [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Revenues	$ 48,201	$ 40,632
Percentage of Total	19.00%	19.50%
Sales Revenues [Member] | Siemens Gamesa [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Revenues	$ 24,291	$ 25,642
Percentage of Total	9.50%	12.30%
Sales Revenues [Member] | Other [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Revenues	$ 8,392	$ 2,550
Percentage of Total	3.30%	1.20%

Concentration of Customers - 57

Concentration of Customers - Schedule of Trade Accounts Receivable from Certain Customers (Detail) - Accounts Receivable [Member] - Customer Concentration Risk [Member]	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
GE [Member]
Concentration Risk [Line Items]
Percentage of Total	18.80%	18.90%
Vestas [Member]
Concentration Risk [Line Items]
Percentage of Total	40.30%	52.40%
Nordex Acciona [Member]
Concentration Risk [Line Items]
Percentage of Total	30.40%	19.50%

Segment Reporting - Additional

Segment Reporting - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2018Segment
Segment Reporting [Abstract]
Number of reportable segments	4

Segment Reporting - Schedule of

Segment Reporting - Schedule of Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total revenues	$ 253,981	$ 208,615
Total income from operations	17,095	11,612
Total property, plant and equipment, net	126,860		$ 123,480
U.S. Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	46,124	47,967
Total income from operations	(9,050)	(7,326)
Total property, plant and equipment, net	27,528		24,575
Asia Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	77,670	69,497
Total income from operations	6,417	12,794
Total property, plant and equipment, net	30,881		28,887
Mexico Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	57,964	46,948
Total income from operations	4,258	2,844
Total property, plant and equipment, net	38,466		39,756
EMEA Segment [Member]
Segment Reporting Information [Line Items]
Total revenues	72,223	44,203
Total income from operations	15,470	3,300
Total property, plant and equipment, net	29,985		$ 30,262
U.S. [Member]
Segment Reporting Information [Line Items]
Total revenues	46,124	47,967
China [Member]
Segment Reporting Information [Line Items]
Total revenues	77,670	69,497
Mexico [Member]
Segment Reporting Information [Line Items]
Total revenues	57,964	46,948
Turkey [Member]
Segment Reporting Information [Line Items]
Total revenues	$ 72,223	$ 44,203

Segment Reporting - Schedule 60

Segment Reporting - Schedule of Segment Information (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
General and administrative costs	$ 11,163	$ 8,306
U.S. Segment [Member]
Segment Reporting Information [Line Items]
General and administrative costs	$ 11,200	$ 8,300

Adjustments to Previously Rep61

Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement - Condensed Consolidated Balance Sheet (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 138,841	$ 148,113
Restricted cash	3,251	3,849
Accounts receivable	117,950	121,576
Contract assets	130,015	105,619
Inventories	4,205	4,112
Prepaid expenses and other current assets	35,718	27,507
Total current assets	429,980	410,776
Property, plant, and equipment, net	126,860	123,480
Goodwill		2,807
Intangible assets, net		1,108
Other noncurrent assets		18,391
Total assets	579,864	556,562
Current liabilities:
Accounts payable and accrued expenses		166,743
Accrued warranty	32,670	30,419
Customer deposits		432
Current maturities of long-term debt	43,085	35,506
Contract liabilities	4,449	2,763
Total current liabilities	249,383	235,863
Long-term debt, net of debt issuance costs and current maturities	82,658	85,879
Other noncurrent liabilities	4,791	4,938
Total liabilities	336,832	326,680
Commitments and contingencies
Stockholders’ equity:
Common shares, $0.01 par value, 100,000 shares authorized and 34,049 shares issued and 34,021 shares outstanding at December 31, 2017	341	340
Paid-in capital	304,230	301,543
Accumulated other comprehensive loss	1,332	(558)
Accumulated deficit	(62,284)	(70,932)
Treasury stock, at cost, 28 shares at December 31, 2017	(587)	(511)
Total stockholders’ equity	243,032	229,882
Total liabilities and stockholders’ equity	$ 579,864	556,562
As Reported [Member] | ASU 2014-09 [Member]
Current assets:
Cash and cash equivalents		148,113
Restricted cash		3,849
Accounts receivable		121,576
Inventories		67,064
Inventories held for customer orders		64,858
Prepaid expenses and other current assets		27,507
Total current assets		432,967
Property, plant, and equipment, net		123,480
Goodwill		2,807
Intangible assets, net		150
Other noncurrent assets		14,130
Total assets		573,534
Current liabilities:
Accounts payable and accrued expenses		166,743
Accrued warranty		29,163
Deferred revenue		81,048
Customer deposits		10,134
Current maturities of long-term debt		35,506
Total current liabilities		322,594
Long-term debt, net of debt issuance costs and current maturities		85,879
Other noncurrent liabilities		4,444
Total liabilities		412,917
Commitments and contingencies
Stockholders’ equity:
Common shares, $0.01 par value, 100,000 shares authorized and 34,049 shares issued and 34,021 shares outstanding at December 31, 2017		340
Paid-in capital		301,543
Accumulated other comprehensive loss		(558)
Accumulated deficit		(140,197)
Treasury stock, at cost, 28 shares at December 31, 2017		(511)
Total stockholders’ equity		160,617
Total liabilities and stockholders’ equity		573,534
Adoption of Topic 606 [Member] | ASU 2014-09 [Member]
Current assets:
Contract assets		105,619
Inventories		(62,952)
Inventories held for customer orders		(64,858)
Total current assets		(22,191)
Intangible assets, net		958
Other noncurrent assets		4,261
Total assets		(16,972)
Current liabilities:
Accrued warranty		1,256
Deferred revenue		(81,048)
Customer deposits		(9,702)
Contract liabilities		2,763
Total current liabilities		(86,731)
Other noncurrent liabilities		494
Total liabilities		(86,237)
Commitments and contingencies
Stockholders’ equity:
Accumulated deficit		69,265
Total stockholders’ equity		69,265
Total liabilities and stockholders’ equity		$ (16,972)

Adjustments to Previously Rep62

Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement - Condensed Consolidated Balance Sheet (Parenthetical) (Detail) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Revenue Initial Application Period Cumulative Effect Transition [Abstract]
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	34,128,000	34,049,000
Common stock, shares outstanding	34,097,000	34,021,000
Treasury stock, shares	31,000	28,000

Adjustments to Previously Rep63

Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement - Condensed Consolidated Income Statement (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	$ 253,981	$ 208,615
Cost of sales	210,988	182,538
Startup and transition costs	14,735	6,159
Total cost of goods sold	225,723	188,697
Gross profit	28,258	19,918
General and administrative expenses	11,163	8,306
Income from operations	17,095	11,612
Other income (expense):
Interest income	41	19
Interest expense	(3,338)	(3,026)
Realized loss on foreign currency remeasurement	(4,011)	(1,381)
Miscellaneous income	818	320
Total other expense	(6,490)	(4,068)
Income before income taxes	10,605	7,544
Income tax provision	(1,957)	(2,331)
Net income	$ 8,648	$ 5,213
Weighted-average common shares outstanding:
Basic	34,049	33,737
Diluted	35,479	33,827
Net income per common share:
Basic	$ 0.25	$ 0.15
Diluted	$ 0.24	$ 0.15
As Reported [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Net sales		$ 191,602
Cost of sales		167,423
Startup and transition costs		6,159
Total cost of goods sold		173,582
Gross profit		18,020
General and administrative expenses		8,306
Income from operations		9,714
Other income (expense):
Interest income		19
Interest expense		(3,026)
Realized loss on foreign currency remeasurement		(1,381)
Miscellaneous income		320
Total other expense		(4,068)
Income before income taxes		5,646
Income tax provision		(2,101)
Net income		$ 3,545
Weighted-average common shares outstanding:
Basic		33,737
Diluted		33,827
Net income per common share:
Basic		$ 0.11
Diluted		$ 0.10
Adoption of Topic 606 [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Net sales		$ 17,013
Cost of sales		15,115
Total cost of goods sold		15,115
Gross profit		1,898
Income from operations		1,898
Other income (expense):
Income before income taxes		1,898
Income tax provision		(230)
Net income		$ 1,668
Weighted-average common shares outstanding:
Basic		33,737
Diluted		33,827
Net income per common share:
Basic		$ 0.05
Diluted		$ 0.05

Adjustments to Previously Rep64

Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement - Condensed Consolidated Statement of Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Net income	$ 8,648	$ 5,213
Other comprehensive income:
Foreign currency translation adjustments	1,890	277
Comprehensive income	$ 10,538	5,490
As Reported [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Net income		3,545
Other comprehensive income:
Foreign currency translation adjustments		277
Comprehensive income		3,822
Adoption of Topic 606 [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Net income		1,668
Other comprehensive income:
Comprehensive income		$ 1,668

Adjustments to Previously Rep65

Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement - Condensed Consolidated Statements of Changes in Stockholders' Equity (Detail) - USD ($) shares in Thousands, $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017	$ 243,032	$ 229,882
As Reported [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017		160,617
Adoption of Topic 606 [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017		69,265
Cumulative effect of the adoption of Topic 606		69,265
Common Stock [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017		$ 340
Beginning balance, shares		34,049
Common Stock [Member] | As Reported [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017		$ 340
Beginning balance, shares		34,049
Paid-in Capital [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017		$ 301,543
Paid-in Capital [Member] | As Reported [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017		301,543
Accumulated Other Comprehensive Loss [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017		(558)
Accumulated Other Comprehensive Loss [Member] | As Reported [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017		(558)
Accumulated Deficit [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017		(70,932)
Accumulated Deficit [Member] | As Reported [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017		(140,197)
Accumulated Deficit [Member] | Adoption of Topic 606 [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Cumulative effect of the adoption of Topic 606		69,265
Treasury Stock, at Cost [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017		(511)
Treasury Stock, at Cost [Member] | As Reported [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Balance at December 31, 2017		$ (511)

Adjustments to Previously Rep66

Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Adoption of Topic 606 [Member] | ASU 2014-09 [Member]
Revenue Initial Application Period Cumulative Effect Transition [Line Items]
Increase (decrease) in stockholder's equity	$ (4.2)	$ 12.3	$ 61.2

Adjustments to Previously Rep67

Adjustments to Previously Reported Financial Statements from the Adoption of an Accounting Pronouncement - Condensed Consolidated Statements of Cash Flows (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 8,648	$ 5,213
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	7,072	3,952
Share-based compensation expense	2,388	1,707
Amortization of debt issuance costs	181	143
Changes in assets and liabilities:
Accounts receivable	3,626	(28,722)
Contract assets	(24,396)	2,738
Inventories	(93)	(68)
Prepaid expenses and other current assets	(8,211)	6,816
Other noncurrent assets	734	(156)
Accounts payable and accrued expenses		11,211
Accrued warranty	2,250	2,080
Customer deposits		717
Contract liabilities	1,686	4,110
Other noncurrent liabilities	(158)	197
Net cash provided by (used in) operating activities	(3,032)	9,938
Cash flows from investing activities:
Purchase of property and equipment	(11,714)	(16,922)
Net cash used in investing activities	(11,714)	(16,922)
Cash flows from financing activities:
Repayments of term loan	(938)	(938)
Net repayments of accounts receivable financing	8,093	(1,233)
Net proceeds from working capital loans		517
Net repayments of other debt	(2,978)	(1,155)
Net cash provided by (used in) financing activities	4,490	(2,809)
Impact of foreign exchange rates on cash and cash equivalents		(63)
Net change in cash and cash equivalents		(9,856)
Cash, cash equivalents and restricted cash, beginning of year	152,437	129,863
Cash, cash equivalents and restricted cash, end of period	$ 142,567	120,007
As Reported [Member]
Cash flows from operating activities:
Net income		3,545
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		3,829
Share-based compensation expense		1,707
Amortization of debt issuance costs		143
Changes in assets and liabilities:
Accounts receivable		(28,722)
Inventories		(15,220)
Prepaid expenses and other current assets		6,816
Other noncurrent assets		5,871
Accounts payable and accrued expenses		11,211
Accrued warranty		1,983
Customer deposits		4,827
Deferred revenue		19,751
Other noncurrent liabilities		197
Net cash provided by (used in) operating activities		15,938
Cash flows from investing activities:
Purchase of property and equipment		(16,922)
Net cash used in investing activities		(16,922)
Cash flows from financing activities:
Repayments of term loan		(938)
Net repayments of accounts receivable financing		(1,233)
Net proceeds from working capital loans		517
Net repayments of other debt		(1,155)
Restricted cash		331
Net cash provided by (used in) financing activities		(2,478)
Impact of foreign exchange rates on cash and cash equivalents		(63)
Net change in cash and cash equivalents		(3,525)
Cash, cash equivalents and restricted cash, beginning of year		119,066
Cash, cash equivalents and restricted cash, end of period		115,541
Adoption of ASU 2016-18 [Member]
Changes in assets and liabilities:
Other noncurrent assets		(6,000)
Net cash provided by (used in) operating activities		(6,000)
Cash flows from financing activities:
Restricted cash		(331)
Net cash provided by (used in) financing activities		(331)
Net change in cash and cash equivalents		(6,331)
Cash, cash equivalents and restricted cash, beginning of year		10,797
Cash, cash equivalents and restricted cash, end of period		4,466
Adoption of Topic 606 [Member] | ASU 2014-09 [Member]
Cash flows from operating activities:
Net income		1,668
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		123
Changes in assets and liabilities:
Contract assets		2,738
Inventories		15,152
Other noncurrent assets		(27)
Accrued warranty		97
Customer deposits		(4,110)
Deferred revenue		(19,751)
Contract liabilities		$ 4,110

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Subsequent Event [Member]	1 Months Ended
	Apr. 30, 2018USD ($)Lender
Subsequent Event [Line Items]
Number of lenders | Lender	4
Debt instrument, maturity date	Apr. 6, 2023
Debt instrument frequency of periodic payment	monthly
Debt instrument, payment terms	Interest is payable monthly and the Company is not obligated to make any principal repayments prior to the maturity date so long as the Company is not in default under the Credit Agreement. The Company may prepay borrowings without penalty under the Credit Agreement.
Interest Rate Swap Arrangement [Member]
Subsequent Event [Line Items]
Derivative notional amount	$ 75,000,000
Derivative effective rate	4.19%
Derivative term	5 years
LIBOR [Member]
Subsequent Event [Line Items]
Debt instrument, variable interest rate	1.50%
Revolving Credit Facility [Member]
Subsequent Event [Line Items]
Credit facility, amount	$ 150,000,000
Proceeds from Lines of Credit	75,400,000
Letter of Credit [Member]
Subsequent Event [Line Items]
Credit facility, amount	$ 25,000,000