Altair Engineering (ALTR) 10-Q 1 Dec 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 27, 2017
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	ALTR
Entity Registrant Name	ALTAIR ENGINEERING INC.
Entity Central Index Key	1,701,732
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Class A Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		26,394,996
Class B Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		36,507,676

Consolidated balance sheets

Consolidated balance sheets - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
CURRENT ASSETS:
Cash and cash equivalents	$ 16,667	$ 16,874
Accounts receivable - net	63,530	70,498
Inventory - net	1,797	1,227
Income tax receivable	6,868	9,069
Prepaid expenses and other current assets	10,492	7,435
Total current assets	99,354	105,103
Property and equipment - net	29,892	29,708
Goodwill	68,891	36,625
Other intangible assets - net	15,379	11,168
Deferred tax assets	69,135	62,896
Other long-term assets	18,843	5,276
TOTAL ASSETS	301,494	250,776
CURRENT LIABILITIES:
Current portion of long-term debt	10,147	10,435
Accounts payable	3,987	5,009
Accrued compensation and benefits	23,946	22,955
Other accrued expenses and current liabilities	35,737	18,945
Deferred revenue	117,969	100,661
Total current liabilities	191,786	158,005
Long-term debt, net of current portion	81,939	74,806
Deferred revenue - non-current	12,495	13,268
Stock-based compensation awards	59,076	22,236
Other long-term liabilities	16,402	17,114
TOTAL LIABILITIES	361,698	285,429
Commitments and contingencies
MEZZANINE EQUITY	2,352
STOCKHOLDERS' DEFICIT:
Additional paid-incapital	49,347	39,688
Accumulated deficit	(106,152)	(67,092)
Accumulated other comprehensive loss	(5,756)	(7,264)
Total Altair Engineering Inc. stockholders' deficit	(62,556)	(34,663)
Noncontrolling interest		10
TOTAL STOCKHOLDERS' DEFICIT	(62,556)	(34,653)
TOTAL LIABILITIES, MEZZANINE EQUITY AND STOCKHOLDERS' DEFICIT	301,494	250,776
Class A Common Stock [Member]
STOCKHOLDERS' DEFICIT:
Common stock	1	1
Class B Common Stock [Member]
STOCKHOLDERS' DEFICIT:
Common stock	$ 4	$ 4

Consolidated balance sheets (Pa

Consolidated balance sheets (Parenthetical) - $ / shares	Sep. 30, 2017	Dec. 31, 2016
Class A Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	76,000	76,000
Common stock, shares issued	10,096	8,900
Common stock, shares outstanding	10,096	8,900
Class B Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	44,000	44,000
Common stock, shares issued	41,204	41,204
Common stock, shares outstanding	41,204	41,204

Consolidated statements of oper

Consolidated statements of operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenue
Software	$ 63,208	$ 55,804	$ 176,905	$ 162,733
Software related services	8,574	8,676	25,749	26,466
Total software	71,782	64,480	202,654	189,199
Client engineering services	11,477	12,146	36,071	36,435
Other	1,679	1,426	4,741	4,758
Total revenue	84,938	78,052	243,466	230,392
Cost of revenue
Software	9,166	8,479	26,799	23,500
Software related services	6,457	6,527	20,230	20,365
Total software	15,623	15,006	47,029	43,865
Client engineering services	9,231	9,579	29,200	28,786
Other	1,448	1,036	3,745	3,728
Total cost of revenue	26,302	25,621	79,974	76,379
Gross profit	58,636	52,431	163,492	154,013
Operating expenses:
Research and development	27,590	19,401	69,198	53,413
Sales and marketing	22,345	16,961	58,683	49,054
General and administrative	29,175	15,793	66,465	43,675
Amortization of intangible assets	1,189	875	3,287	2,352
Other operating income	(735)	(823)	(4,065)	(1,952)
Total operating expenses	79,564	52,207	193,568	146,542
Operating (loss) income	(20,928)	224	(30,076)	7,471
Interest expense	634	507	1,793	1,754
Other expense (income), net	52	148	838	(504)
(Loss) income before taxes	(21,614)	(431)	(32,707)	6,221
Income tax expense (benefit)	8,012	(745)	6,353	1,954
Net (loss) income	$ (29,626)	$ 314	$ (39,060)	$ 4,267
(Loss) income per share:
Net (loss) income per share attributable to common stockholders, basic	$ (0.59)	$ 0.01	$ (0.78)	$ 0.09
Net (loss) income per share attributable to common stockholders, diluted	$ (0.59)	$ 0.01	$ (0.78)	$ 0.07
Weighted average shares outstanding:
Weighted average number of shares used in computing net (loss) income per share, basic	50,606	49,761	50,374	48,521
Weighted average number of shares used in computing net (loss) income per share, diluted	50,606	59,326	50,374	58,086

Consolidated statements of comp

Consolidated statements of comprehensive income (loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (29,626)	$ 314	$ (39,060)	$ 4,267
Other comprehensive income (loss), net of tax:
Foreign currency translation (net of tax effect of $0, $31, $0 and $112, respectively)	(11)	805	1,500	(275)
Retirement related benefit plans (net of tax effect of $41, $0, $41 and $102, respectively)	52	(9)	8	5
Total other comprehensive income (loss)	41	796	1,508	(270)
Comprehensive (loss) income	$ (29,585)	$ 1,110	$ (37,552)	$ 3,997

Consolidated statements of com6

Consolidated statements of comprehensive income (loss) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Foreign currency translation, tax effect	$ 0	$ 31	$ 0	$ 112
Retirement related benefit plans, tax effect	$ 41	$ 0	$ 41	$ 102

Consolidated statement of chang

Consolidated statement of changes in stockholders' deficit - 9 months ended Sep. 30, 2017 - USD ($) $ in Thousands		Total	Common Stock [Member]Class A Common Stock [Member]		Common Stock [Member]Class B Common Stock [Member]		Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Total Altair Engineering' Inc. Stockholders' Deficit [Member]	Non-controlling Interest [Member]
Beginning balance at Dec. 31, 2016		$ (34,653)	$ 1	[1]	$ 4	[1]	$ 39,688	$ (67,092)	$ (7,264)	$ (34,663)	$ 10
Beginning balance (in shares) at Dec. 31, 2016	[1]		8,900		41,204
Net loss		(39,060)						(39,060)		(39,060)
Issuance of common stock		9,188					9,188			9,188
Issuance of common stock (in shares)	[1]		1,196
Purchase of noncontrolling interests		(29)					(19)			(19)	$ (10)
Amortization of mezzanine equity		(8)					(8)			(8)
Stock-based compensation		498					498			498
Foreign currency translation, net of tax		1,500							1,500	1,500
Retirement related benefit plans, net of tax		8							8	8
Ending balance at Sep. 30, 2017		$ (62,556)	$ 1	[1]	$ 4	[1]	$ 49,347	$ (106,152)	$ (5,756)	$ (62,556)
Ending balance (in shares) at Sep. 30, 2017	[1]		10,096		41,204
[1]	All references to Common stock refer to the Company's currently existing Class A and Class B shares following the Recapitalization as described in Note 12.

Consolidated statements of cash

Consolidated statements of cash flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
OPERATING ACTIVITIES:
Net (loss) income	$ (39,060)	$ 4,267
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	7,895	7,300
Provision for bad debt	517	354
Stock-based compensation expense	39,302	5,050
Deferred income taxes	(4,793)	(2,170)
Other, net	149
Changes in assets and liabilities:
Accounts receivable	12,016	11,483
Prepaid expenses and other current assets	431	(3,243)
Other long-term assets	(11,024)	(719)
Accounts payable	(1,583)	(871)
Accrued compensation and benefits	(211)	736
Other accrued expenses and current liabilities	6,122	(6,102)
Deferred revenue	7,694	5,277
Net cash provided by operating activities	17,455	21,362
INVESTING ACTIVITIES:
Payments for acquisition of businesses	(15,582)	(6,499)
Capital expenditures	(6,367)	(4,722)
Purchase of noncontrolling interests	(29)
Other investing activities, net	(100)	(61)
Net cash used in investing activities	(22,078)	(11,282)
FINANCING ACTIVITIES:
Borrowings under revolving commitment	86,270	126,203
Payments on revolving commitment	(71,676)	(117,919)
Principal payments on long-term debt	(8,392)	(13,628)
Payments of deferred offering costs	(2,595)
Payments for redemption of common stock	(918)	(1,828)
Proceeds from issuance of common stock	476	302
Principal payments on capital leases	(31)	(10)
Payment for return of capital		(724)
Proceeds from issuance of debt		2,030
Net cash provided by (used in) financing activities	3,134	(5,574)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	1,301	841
Net (decrease) increase in cash, cash equivalents and restricted cash	(188)	5,347
Cash, cash equivalents and restricted cash at beginning of year	17,139	14,013
Cash, cash equivalents and restricted cash at end of period	16,951	19,360
Supplemental disclosure of cash flow:
Interest paid	1,722	1,547
Income taxes paid	4,154	2,103
Supplemental disclosure of non-cash investing and financing activities:
Promissory notes issued and deferred payment obligations for acquisitions	12,440	4,171
Issuance of common stock in connection with acquisitions	8,712
Issuance of common stock with put rights	2,352
Deferred offering costs in other long-term assets	866
Property and equipment in accounts payable, other accrued expenses and current liabilities, and other liabilities	$ 144	1,918
Notes issued for stock redemptions		$ 577

Organization and Description of

Organization and Description of Business	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Organization and Description of Business	1. Organization and description of business Altair Engineering Inc. (“Altair” or the “Company”) incorporated in the state of Michigan in 1985 and became a Delaware corporation in October 2017. The Company is a provider of enterprise-class engineering software enabling innovation across the entire product lifecycle from concept design to in-service

Accounting Policies

Accounting Policies	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Accounting Policies	2. Accounting policies Basis of presentation The accompanying unaudited consolidated financial statements of Altair Engineering Inc. have been prepared in accordance with United States generally accepted accounting principles (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial information. Accordingly, the accompanying statements do not include all the information and notes required by GAAP for complete financial statements. The accompanying consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements (and notes thereto) for the year ended December 31, 2016, included in the final prospectus dated October 31, 2017 (the “Prospectus”) filed with the SEC pursuant to Rule 424(b) under the Securities Act of 1933, as amended. In the opinion of management, all adjustments considered necessary for a fair presentation of the financial statements have been included, and all adjustments are of a normal and recurring nature. The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosures of contingent assets and liabilities at the date of the financial statements, and reported amounts of revenue and expenses during the reporting periods. Considerable judgment is often involved in making these determinations; use of different assumptions could result in significantly different results. Management believes its assumptions and estimates are reasonable and appropriate. However, actual results may differ from those estimates. In addition, the results of operations for the three and nine months ended September 30, 2017 are not necessarily indicative of the results that may be expected for any future period. There have been no material changes to Altair’s significant accounting policies as compared to the significant accounting policies described in the Prospectus. The Company has concluded that all material transactions that have occurred that require disclosure or adjustments to the consolidated financial statements have been reported herein. See Note 20 – Subsequent events for additional information. Delaware conversion and stock split On October 5, 2017, the Company became a Delaware corporation and effected a four-for-one four-for-one four-for-one four-for-one In connection with the Company becoming a Delaware corporation, 2,495,752 shares of Class B common stock, held by holders of less than 3% of Class B common stock immediately prior to the conversion, converted into Class A common stock. Pursuant to the Company’s Delaware certificate of incorporation, the Company’s authorized capital consists of 513,796,572 shares of Class A common stock, 41,203,428 shares of Class B common stock and 45,000,000 shares of preferred stock. Deferred offering costs Deferred offering costs, which consist of direct incremental legal and accounting fees, and other direct costs relating to the Company’s initial public offering (“IPO”) were capitalized and will be offset against IPO proceeds upon the completion of the IPO in the fourth quarter. As of September 30, 2017, the Company deferred $3.5 million, which were recorded as other long-term assets in the accompanying consolidated balance sheet. No amounts were deferred as of December 31, 2016. Cash, cash equivalents and restricted cash The Company considers all highly liquid investments with original or remaining maturities of 90 days or less at the date of purchase to be cash equivalents. Cash and cash equivalents are recorded at cost, which approximates fair value. Restricted cash is included in other long-term assets on the consolidated balance sheets. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported in the consolidated balance sheet that sum to the total of the amounts reported in the consolidated statement of cash flows (in thousands): September 30, Cash and cash equivalents $ 16,667 Restricted cash included in other long-term assets 284 Total cash, cash equivalents, and restricted cash shown in the statement of cash flows $ 16,951 Restricted cash represents amounts required for a contractual agreement with an insurer for the payment of potential health insurance claims, and term deposits for bank guarantees. Receivable for R&D credit The French government provides a research and development (“R&D) tax credit known as Credit Impôt Recherche, or CIR, in order to encourage Companies to invest in R&D. The tax credit is deductible from the French income tax and any excess is carried forward 3 years. After three years, any unused credit may be reimbursed to the Company by the French government. As of September 30, 2017, the Company had approximately $9.8 million receivable from the French government related to CIR, of which $3.2 million is recorded in income tax receivable and the remaining $6.6 million is recorded in other long-term assets. Mezzanine equity During the quarter ended June 30, 2017, the Company issued 200,000 shares of Class A common stock to a third party as partial consideration for the purchase of developed technology. These shares have a put right that can be exercised by the holder five years from date of purchase at $12.50 per share that requires the shares to be recorded at fair value and classified as mezzanine equity in the consolidated balance sheet. The put right option is terminated if the shareholders sell their shares. Income (loss) per share Basic income (loss) per share attributable to Class A and Class B common stockholders is computed using the weighted average number of shares of common stock outstanding for the period, excluding stock options. Diluted income (loss) per share attributable to common stockholders is based upon the weighted average number of shares of common stock outstanding for the period and potentially dilutive common shares, including the effect of stock options under the treasury stock method. The following table sets forth the computation of the numerators and denominators used in the basic and diluted income (loss) per share amounts (in thousands, except per share data): Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Numerator: Net (loss) income $ (29,626 ) $ 314 $ (39,060 ) $ 4,267 Denominator: Denominator for basic (loss) income per share—weighted average shares 50,606 49,761 50,374 48,521 Effect of dilutive securities, stock options — 9,565 — 9,565 Denominator for dilutive (loss) income per share 50,606 59,326 50,374 58,086 Net (loss) income per share attributable to common stockholders, basic $ (0.59 ) $ 0.01 $ (0.78 ) $ 0.09 Net (loss) income per share attributable to common stockholders, diluted $ (0.59 ) $ 0.01 $ (0.78 ) $ 0.07 The computation of diluted (loss) income per share does not include shares that are anti-dilutive under the treasury stock method because their exercise prices are higher than the average fair value of the Company’s stock during the period or due to a net loss in the period. For both the three and nine months ended September 30, 2017, there were 10.1 million and 9.8 million anti-dilutive shares, respectively, excluded from the computation of income (loss) per share. For the three and nine months ended September 30, 2016, there were no anti-dilutive shares excluded from the computation of income (loss) per share.

Recent Accounting Guidance

Recent Accounting Guidance	9 Months Ended
	Sep. 30, 2017
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Guidance	3. Recent accounting guidance Accounting standards adopted The Company adopted Accounting Standards Update (“ASU”) No. 2015-11 , Inventory: Simplifying the Measurement of Inventory 2015-11, 2015-11 2015-11 Accounting standards not yet adopted Revenue Recognition No. 2014-09, Revenue from Contracts with Customers 2014-09”). 2014-09 2015-14, Revenue from Contracts with Customers: Deferral of the Effective Date 2014-09 The Company is evaluating the use of either the retrospective or modified retrospective transition method and the timing of adopting this standard. Under existing GAAP, the Company does not have vendor-specific objective evidence (“VSOE”) of fair value for post-contract customer support (“PCS”) sold along with software products licenses; therefore, revenues for the software products licenses (including perpetual licenses), PCS and professional services, if applicable, are considered to be one accounting unit and, once all services have commenced, are recognized ratably over the remaining period of the arrangement (the longer of the contractual service term or PCS term). Under ASU 2014-09, 2014-09 Financial Instruments No. 2016-01, Financial Instruments—Overall: Recognition and Measurement of Financial Assets and Financial Liabilities 2016-01”). 2016-01 2016-01 Leases No. 2016-02, Leases 2016-02”). This right-of-use 2016-02 2016-02 Employee Share-Based Payment Accounting No. 2016-09, Improvements to Employee Share-Based Payment Accounting 2016-09”). 2016-09 2016-09 Cash Classification 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments 2016-15”), to 2016-15 2016-15 No. 2016-15 Business Combinations No. 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business (“ASU-2017-01”). 2017-01

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair value measurements The accounting guidance for fair value, among other things, defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or nonrecurring basis. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The framework for measuring fair value consists of a three-level valuation hierarchy that prioritizes the inputs to valuation techniques used to measure fair value based upon whether such inputs are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect market assumptions made by the reporting entity. The three-level hierarchy for the inputs to valuation techniques is briefly summarized as follows: Level 1 Quoted prices in active markets for identical assets and liabilities at the measurement date; Level 2 – Observable inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and Level 3 – Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. An asset’s or liability’s fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. Valuation techniques used need to maximize the use of observable inputs and minimize the use of unobservable inputs. Items measured at fair value on a recurring basis The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial liabilities (in thousands): Liability for Liability for Balance at December 31, 2016 $ 10,632 $ 11,604 Shares issued upon exercise of stock options — — Exercise of stock options 385 (364 ) Forfeitures of stock options — (139 ) Change in fair value and other 15,974 20,984 Balance at September 30, 2017 $ 26,991 $ 32,085 The carrying value of cash and cash equivalents, accounts receivable and accounts payable approximate fair value due to their short maturities. Interest on the Company’s long-term debt is at a variable rate, and as such the debt obligation outstanding approximates fair value. The carrying value of the Company’s derivative financial instruments are measured at fair value on a recurring basis. The fair value of derivatives is determined based on inputs derived from or corroborated by observable market data pertaining to relevant interest rates and is considered a level 2 fair value measurement. See Note 11—Financial instruments for additional information regarding the use and fair value of derivatives.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Acquisitions	5. Acquisitions Runtime Design Automation On September 28, 2017, the Company acquired 100% of the shares of Runtime Design Automation (“Runtime”) for a total of $18.7 million in cash, of which $8.7 million is payable one year from the acquisition date, and 708,000 shares of the Company’s Class A common stock. Runtime complements Altair’s PBS Works™ suite of products for comprehensive, secure workload management for HPS and cloud environments and has solutions to manage highly complex workflows. PBS Works targets product design, weather prediction, oil exploration and bio-informatics, The following table summarizes the consideration transferred to acquire Runtime and the preliminary amounts of identified assets acquired and liabilities assumed at the acquisition date (in thousands): Fair value of consideration transferred $ 25,691 Recognized amounts of identifiable assets acquired and liabilities assumed: Cash 564 Accounts receivable 2,257 Deferred tax assets 1,965 Other assets 256 Accounts payable and other liabilities (889 ) Deferred revenue (2,199 ) Deferred tax liabilities (770 ) Total net identifiable assets acquired and liabilities assumed 1,184 Goodwill – preliminary $ 24,507 The allocation of fair value of purchase consideration is incomplete pending the final determination of the fair value of assets acquired and liabilities assumed, and is subject to change within the measurement period (up to one year from the acquisition date). The primary areas that remain preliminary relate to the fair value of intangible assets acquired, certain tangible assets and liabilities acquired, income taxes and residual goodwill. Goodwill is primarily attributable to synergies expected to arise after the acquisition. The Company does not expect the goodwill resulting from the acquisition to be deductible for tax purposes. Carriots S.L In May 2017, the Company acquired 100% of the shares of Carriots S.L. (“Carriots”) for $3.6 million cash, $2.7 million notes payable, and 80,000 shares of the Company’s Class A common stock. Carriots is an Internet of Things (“IoT”) Cloud platform that allows easy development of new IoT enabled products. Carriots complements Altair’s other product suites to provide a comprehensive solution for customers to design and implement IoT enabled products. The following table summarizes the consideration transferred to acquire Carriots and the amounts of identified assets acquired and liabilities assumed at the acquisition date (in thousands): Fair value of consideration transferred $ 6,657 Recognized amounts of identifiable assets acquired and liabilities assumed: Deferred tax assets 394 Other assets 472 Trade names 252 Developed technology (4-year 1,317 Customer relationships (7-year 296 Accounts payable and other liabilities (1,015 ) Total net identifiable assets acquired and liabilities assumed 1,716 Goodwill $ 4,941 The allocation of the consideration transferred to the assets and the liabilities assumed is substantially complete however, finalization of the valuation is still in process. Goodwill is primarily attributable to synergies expected to arise after the acquisition. The Company does not expect the goodwill resulting from the acquisition to be deductible for tax purposes. The Company engaged a third-party valuation firm to assist in valuing certain assets and liabilities acquired.

Inventory

Inventory	9 Months Ended
	Sep. 30, 2017
Inventory Disclosure [Abstract]
Inventory	6. Inventory Inventory is stated at the lower of cost and net realizable value. Cost is determined using the first-in, first-out Inventory consisted of the following (in thousands): September 30, December 31, 2017 2016 Raw materials $ 13 $ 52 Finished goods 1,784 1,175 Total inventory – net $ 1,797 $ 1,227

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	7. Property and equipment, net Property and equipment consists of the following (in thousands): September 30, December 31, 2017 2016 Land $ 7,994 $ 7,994 Building and improvements 15,000 14,956 Computer equipment and software 31,077 27,461 Office furniture and equipment 6,038 5,306 Leasehold improvements 5,961 5,397 Total property and equipment 66,070 61,114 Less: accumulated depreciation and amortization 36,178 31,406 Property and equipment, net $ 29,892 $ 29,708 Depreciation expense was $1.6 million and $1.5 million for the three months ended September 30, 2017 and 2016, and $4.6 million and $4.9 million for the nine months ended September 30, 2017 and 2016, respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	8. Goodwill and other intangible assets Goodwill The changes in the carrying amount of goodwill, which is attributable to the Software reporting segment, are as follows (in thousands): Balance at December 31, 2016 $ 36,625 Acquisitions 29,448 Effects of foreign currency translation 2,818 Balance at September 30, 2017 $ 68,891 Other intangible assets A summary of other intangible assets is shown below (in thousands): September 30, 2017 Weighted average amortization period Gross carrying amount Accumulated amortization Net carrying Definite-lived intangible assets: Developed technology 4 years $ 17,347 $ 7,642 $ 9,705 Customer relationships 7 years 9,235 5,816 3,419 Noncompete agreements 5 years 824 824 — Other intangibles 10 years 119 45 74 Total definite-lived intangible assets 27,525 14,327 13,198 Indefinite-lived intangible assets: Trade names 2,181 2,181 Total other intangible assets $ 29,706 $ 14,327 $ 15,379 December 31, 2016 Weighted Gross Accumulated Net carrying Definite-lived intangible assets: Developed technology 4 years $ 10,631 $ 5,034 $ 5,597 Customer relationships 7 years 8,646 4,977 3,669 Noncompete agreements 5 years 824 824 — Other intangibles 10 years 117 40 77 Total definite-lived intangible assets 20,218 10,875 9,343 Indefinite-lived intangible assets: Trade names 1,825 1,825 Total other intangible assets $ 22,043 $ 10,875 $ 11,168 In May 2017, the Company entered into a software assignment agreement with Easii IC SAS, a Société par Actions Simplifiée, or Easii, and acquired all rights, title and interests in certain of Easii’s software, known as Modeliis, for $2.0 million and 200,000 shares of the Company’s Class A common stock. These shares have a put right that can be exercised by the holder five years from date of purchase at $12.50 per share. This software was recorded as developed technology in the consolidated balance sheet. Amortization expense related to amortizing intangible assets was $1.2 million and $0.9 million for the three months ended September 30, 2017 and 2016, and $3.3 million and $2.4 million for the nine months ended September 30, 2017 and 2016, respectively.

Debt

Debt	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Debt	9. Debt The carrying value of debt is as follows (in thousands): September 30, December 31, 2017 2016 Secured Credit Agreement: Revolving Credit Facility $ 41,950 $ 27,355 Term Loan A 50,000 57,500 Obligations held under capital leases 166 196 Other borrowings 66 330 Total debt 92,182 85,381 Less: unamortized debt issuance costs 96 140 Less: current portion of long-term debt 10,147 10,435 Long-term debt, net of current portion $ 81,939 $ 74,806 In October 2017, the Company entered into an amended and restated credit agreement. See Note 20 – Subsequent events for additional information regarding the changes to the Company’s credit facility. Secured credit agreement On June 14, 2017, the Company entered into an amended and restated credit agreement with JPMorgan Chase Bank, N.A., as administrative agent, which restated the Company’s prior credit agreement, as amended, in its entirety (“2017 Credit Agreement” or the “Credit Agreement”). This amendment was administrative in nature and did not change amounts, terms, or rates. On September 28, 2017, the Credit Agreement was amended to permit the Runtime acquisition as the purchase price exceeded the level of permitted acquisitions in the Credit Agreement covenants. See Note 5 – Acquisitions for additional information regarding the acquisition of Runtime. As of September 30, 2017, the Company’s Credit Agreement consisted of a $50.0 million term loan (“Term Loan A”), a $60.0 million revolving commitment (“Revolving Credit Facility”) and a $4.0 million ancillary facility. Included in the Revolving Credit Facility are a $5.0 million swingline subfacility, and a letter of credit subfacility. Interest rates on borrowings outstanding under the Credit Agreement range from (i) an adjusted LIBO rate (the London interbank offered rate multiplied by the Statutory Reserve Rate) plus 1.5% to 2.0% (dependent upon the Company’s leverage ratio) for Eurodollar-based borrowings or (ii) the CB floating rate (the greater of the Prime Rate or the adjusted LIBO rate plus 2.5%) for CBFR borrowings (any loan bearing interest at the CB floating rate). The Company can elect the type of borrowing for each loan. Term loan facilities The Company is required to make quarterly principal payments on Term Loan A of $2.5 million in 2017, 2018 and March 2019. Any outstanding principal balance is to be paid in full on the maturity date of April 18, 2019. Revolving credit facilities As of September 30, 2017, the Company had $42.0 million outstanding under the Revolving Credit Facility and $18.0 million available for future borrowing. The Revolving Credit Facility is available for general corporate purposes, including working capital, capital expenditures, and permitted acquisitions. All borrowings under the Revolving Credit Facility are due on the termination date in April 2019. The Company pays quarterly commitment fees of 0.25% per annum on the unused portion of the Revolving Credit Facility. Fees with respect to letters of credit accrue daily based on the stated amount of each outstanding letter of credit at the adjusted LIBO rate plus 1.5% to 2.0% (dependent upon the Company’s leverage ratio). Debt covenants The Credit Agreement contains a number of covenants that, among other things, restrict, subject to certain exceptions, the Company’s ability to incur additional indebtedness; create liens on assets; make investments, loans, advances or acquisitions; pay dividends or other distributions; redeem or repurchase certain equity interests; guarantee the obligations of others; and change the business conducted by the Company. In addition, the Credit Agreement contains financial covenants relating to minimum liquidity of $20.0 million, maintaining a minimum debt service coverage ratio of 1.3 to 1.0 and maximum leverage ratio of 3.0 to 1.0, as defined in the Credit Agreement. At September 30, 2017, the Company was in compliance with all such covenants. Collateral and guarantees The Credit Agreement is unconditionally guaranteed by the Company and all existing and subsequently acquired controlled domestic subsidiaries. Any obligations of foreign subsidiaries are unconditionally guaranteed by the Company and certain foreign subsidiaries. Furthermore, the Credit Agreement is collateralized by a first priority, perfected security interest in, and mortgages on, substantially all tangible assets of the Company. In addition, foreign borrowings under the credit agreement will be secured by assets of the foreign borrowers.

Other Liabilities

Other Liabilities	9 Months Ended
	Sep. 30, 2017
Other Liabilities Disclosure [Abstract]
Other Liabilities	10. Other liabilities The following table provides the details of other accrued expenses and current liabilities (in thousands): September 30, December 31, 2017 2016 Obligations for acquisition of businesses $ 13,453 $ 2,649 Income taxes payable 6,759 2,156 Accrued professional fees 3,168 1,389 Accrued VAT 2,135 3,928 Accrued royalties 1,930 1,583 Defined contribution plan liabilities 1,164 1,139 Self-insurance and other insurance reserves 818 764 Non-income 638 739 Billings in excess of cost 380 1,021 Related party liabilities 242 1,045 Other current liabilities 5,050 2,532 $ 35,737 $ 18,945 The following table provides details of other long-term liabilities (in thousands): September 30, December 31, 2017 2016 Pension and other post retirement liabilities $ 7,174 $ 5,959 Deferred tax liabilities 1,106 1,379 Other liabilities 8,122 9,776 $ 16,402 $ 17,114

Financial Instruments

Financial Instruments	9 Months Ended
	Sep. 30, 2017
Investments, All Other Investments [Abstract]
Financial Instruments	11. Financial instruments The Company is exposed to certain financial market risks related to its ongoing business operations. The primary risks managed through derivative financial instruments and hedging activities are foreign currency exchange rate risk and interest rate risk. Derivative financial instruments and hedging activities are utilized to protect the Company’s cash flow from adverse movements in foreign currency exchange rates and to manage interest costs when appropriate. Although the Company is exposed to credit loss in the event of nonperformance by the counterparty to the derivative financial instruments, the Company attempts to limit this exposure by entering into agreements directly with major financial institutions that meet the Company’s credit standards and that are expected to fully satisfy their obligations under the contracts. Interest rate swaps Interest rate exposures are reviewed periodically and the Company may enter into interest rate swap agreements to manage its exposure. The Company’s exposure to interest rate risk arises primarily from changes in the LIBO rate. The Company will hold these derivatives for economic purposes but does not designate these derivatives to obtain hedge accounting treatment. As such, gains or losses on these contracts (including contracts that do not qualify for hedge accounting under ASC 815), are reported in earnings immediately as Other expense (income), net. These contracts limit exposure to changes in interest payments associated with variable rate debt. However, as the change in the fair value of the interest rate swaps is impacted by both realized and unrealized gains and losses on the contracts, the amount recognized in earnings may not offset the changes in the variability of interest expense during a given period. As of September 30, 2017, and December 31, 2016, the Company had an interest rate swap outstanding with a notional value of $4.5 million. This interest rate swap matures at various dates through December 23, 2019.

Stockholders' Deficit

Stockholders' Deficit	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Stockholders' Deficit	12. Stockholders’ deficit Recapitalization On April 3, 2017, the Company completed a recapitalization (the “Recapitalization”) of its capital stock by filing a certificate of amendment to its articles of incorporation with the State of Michigan pursuant to which, (i) each share of the Company’s Class A voting common stock, or old Class A shares, automatically converted into one share of new Class B voting common stock entitled to ten votes per share, and (ii) each share of the Company’s Class B non-voting Subsequent to the Recapitalization, the Company’s authorized common stock consists of 76,000,000 shares no par, Class A Common Stock and 44,000,000 shares of no par, Class B Common Stock. See discussion of the Company’s conversion to a Delaware company on October 5, 2017, in Note 2 – Accounting policies.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	13. Stock-based compensation 2001 stock-based compensation plans Nonqualified stock option plan In 2001, the Company established the Nonqualified Stock Option Plan (“NSO Plan”) under which 6,347,840 stock options with an exercise price of $0.000025 remain outstanding at September 30, 2017. The NSO Plan was terminated in 2003. Stock options under the NSO plan were immediately vested and have a contractual term of 35 years from the date of grant. The outstanding awards will continue to be governed by their existing terms under the NSO Plan. The NSO Plan is accounted for as an equity plan. The following table summarizes the stock option activity under the NSO Plan: Number of options Weighted average exercise price per share Weighted average remaining contractual term (years) Outstanding at January 1, 2017 6,347,840 $ 0.000025 20 Exercised — $ 0.000025 Forfeited — $ 0.000025 Outstanding at September 30, 2017 6,347,840 $ 0.000025 19 Exercisable at September 30, 2017 6,347,840 $ 0.000025 19 Incentive and nonqualified stock-based plan Also in 2001, the Company established the Incentive and Nonqualified Stock-based Plan (“ISO Plan”) which was terminated in 2011 and was authorized to issue nonqualified stock options (“NQSO”) and incentive stock options (“ISO”) totaling 11,153,872 shares of old Class B, nonvoting stock. The NQSO grants could be issued at less than the fair market value at date of grant under the terms of the ISO Plan, while ISO grants were issued at a price equal to or greater than the fair market value at date of grant. Options generally vested over a two to three-year period. All options have a contractual term of ten years from the date of grant. At September 30, 2017 and December 31, 2016, there were 2,926,980 and 2,972,744 options for Class A common stock outstanding, respectively, under the ISO Plan. Options granted under the ISO Plan are accounted for as liability awards as the terms of the awards could require or allow repurchase of the shares at amounts different than fair value. The Company made the accounting policy election to use the intrinsic value method of accounting to determine stock-based compensation liabilities for these awards. During the quarter ended June 30, 2017, the Company changed its accounting policy to measure the fair value of its liability awards using the Black-Scholes option pricing model as a result of the Company no longer meeting the definition of a non-public The ISO Plan also includes stock-based compensation liability for 2,329,796 shares of Class A common stock outstanding at September 30, 2017, and 2,340,596 of old Class B shares outstanding at December 31, 2016, resulting from the Company’s call feature with an exercise price that may be set at less than the fair market value at date of grant under the terms of the ISO Plan. The Company utilized fair value of the outstanding Class A shares and old Class B shares to determine the stock-based compensation liabilities for these shares, based on the respective dates. The following table summarizes the stock option activity under the 2001 Stock-based compensation plans for the periods indicated as follows: Number of Options Weighted average exercise price per share Weighted average remaining contractual term (years) Outstanding at January 1, 2017 2,972,744 $ 0.64 3.4 Granted — — Exercised (33,200 ) $ 0.64 Forfeited (12,564 ) $ 0.53 Outstanding at September 30, 2017 2,926,980 $ 0.64 2.6 Exercisable at September 30, 2017 2,926,980 $ 0.64 2.6 In connection with the Company’s IPO, the Company’s CEO exercised and sold 1,734,996 stock options from the 2001 ISO and NQSO Plan. As of September 30, 2017, these 1,734,996 options are reflected as outstanding in the table above. The 2001 ISO and NQSO Plan option awards are accounted for as liability awards as of September 30, 2017. Upon IPO effectiveness in the fourth quarter, the call feature is terminated resulting in a modification of the option awards. Upon assessment of the modification, the Company concluded the option awards will be accounted for as equity awards post IPO. 2012 stock-based compensation plans During 2012, the Company established the 2012 Incentive and Nonqualified Stock Option Plan (“2012 Plan”) which permits the issuance of 5,200,000 shares of old Class B Nonvoting Common Stock for the grant NQSO’s and ISO’s for management, other employees, and board members of the Company. The options are issued at a price equal to or greater than fair market value at date of grant. All options have a contractual term of 10 years from date of grant. The 2012 Plan is accounted for as an equity plan. For those options expected to vest, compensation expense is recognized on a straight-line basis over a four-year period, the total requisite service period of the awards. The following table summarizes the stock option activity under the 2012 Plan for the periods indicated as follows: Number of options Weighted average exercise price per share Weighted average remaining contractual term (years) Outstanding at January 1, 2017 1,797,252 $ 3.13 7.5 Granted 608,948 $ 5.18 Exercised (174,692 ) $ 2.61 Forfeited (27,524 ) $ 3.91 Outstanding at September 30, 2017 2,203,984 $ 3.73 7.6 Exercisable at September 30, 2017 1,085,748 $ 2.86 6.2 The Company measures the fair value of its equity awards on the date of grant using the Black-Scholes option pricing model. This valuation model requires the Company to make certain estimates and assumptions, including assumptions related to the expected price volatility of the Company’s stock, the period under which the options will be outstanding, the rate of return on risk-free investments, and the expected dividend yield for the Company’s stock. The weighted average assumptions used in the Black-Scholes option pricing model used to calculate the fair value of options granted during the nine months ended September 30, 2017 were as follows: 2017 grants Weighted average grant date fair value per share $ 1.86 Expected volatility 34 % Expected term (in years) 5.75-6.25 Risk-free interest rate 2.02 % Expected dividend yield 0 % The Company’s equity value was estimated utilizing a combination of the Discounted Cash Flow Method under the Income Approach, the Guideline Public Company Method, and the Transaction Method under the Market Approach. The equity value is used to derive the fair value per share which is used as an input in the Black Scholes option pricing model. The estimated volatility was derived using the historical volatility of the returns of comparable publicly traded companies. The risk-free rate was based on U.S. Treasury zero-coupon In connection with the acquisition of Runtime Design Automation (“RTDA”), all outstanding stock options of RTDA became fully vested and exercisable prior to the date of consummation which represents an acceleration to full vesting of all unvested stock options as of the date of the business combination. The appropriate accounting treatment for the outstanding stock options in the context of the business combination was to allocate the fair market value of RTDA’s options at the date of consummation attributable to pre-combination pre-combination The estimated post combination expense to the Company as a result of the business combination was approximately $2.0 million which was immediately expensed in the post combination financial statements for the three months ended September 30, 2017, as there are no further service conditions. The Company determined that the Black-Scholes model was an appropriate valuation model for the employee share options as all of RTDA’s stock options had only service conditions. The stock-based compensation expense was recorded as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Cost of revenue – software $ 326 $ 1 $ 342 $ 15 Research and development 6,711 1,320 10,495 1,361 Sales and marketing 4,045 728 6,160 763 General and administrative 14,183 2,826 22,305 2,911 Total stock-based compensation expense $ 25,265 $ 4,875 $ 39,302 $ 5,050 On September 27, 2017, the Company’s board of directors adopted the 2017 Equity Incentive Plan (“2017 Plan”), and the 2017 Plan was approved by our stockholders. The 2017 Plan became effective on October 30, 2017, which was one business day prior to the effective date of the Company’s IPO. The 2017 Plan provides for the grant of incentive stock options to the Company’s employees and any parent and subsidiary corporations’ employees, and for the grant of nonstatutory stock options, stock appreciation rights, restricted stock, restricted stock units, performance units, performance shares, other cash-based awards and other stock-based awards to the Company’s employees, directors and consultants and the Company’s parent, subsidiary, and affiliate corporations’ employees and consultants. The 2017 Plan has 6,207,976 authorized shares of the Company’s Class A common stock reserved for issuance.

Other Expense (Income), Net

Other Expense (Income), Net	9 Months Ended
	Sep. 30, 2017
Other Income and Expenses [Abstract]
Other Expense (Income), Net	14. Other expense (income), net Other expense (income), net consists of the following (in thousands): Three months ended Nine months ended September 30, 2017 2016 2017 2016 Foreign exchange loss (gain) $ 105 $ 241 $ 1,022 $ (423 ) Other (53 ) (93 ) (184 ) (81 ) Other expense (income), net $ 52 $ 148 $ 838 $ (504 )

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	15. Income taxes At the end of each interim period, the Company makes its best estimate of the annual expected effective income tax rate and applies that rate to its ordinary year-to-date beginning-of-the-year The computation of the annual expected effective income tax rate at each interim period requires certain estimates and assumptions including, but not limited to, the expected income (loss) before income taxes for the year, projections of the proportion of income (and/or loss) earned and taxed in respective jurisdictions, permanent and temporary differences, and the likelihood of the realizability of deferred tax assets generated in the current year. Jurisdictions with a projected loss for the year or a year-to-date The Company’s income tax expense (benefit) and effective tax rate for the three and nine months ended September 30, 2016 and 2017 were as follows (in thousands, except percentages): Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Income tax expense (benefit) $ 8,012 $ (745 ) $ 6,353 $ 1,954 Effective tax rate (37 %) 173 % (19 %) 31 % The tax rate is affected by the Company being a U.S. resident taxpayer, the tax rates in the U.S. and other jurisdictions in which the Company operates, the relative amount of income earned by jurisdiction and the relative amount of losses or income for which no benefit or expense is recognized. The effective tax rate was impacted by the geographic income mix in 2017 as compared to 2016, primarily related to United States pre-tax pre-tax non-deductible

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Accumulated Other Comprehensive Loss	16. Accumulated other comprehensive loss The components of accumulated other comprehensive loss were as follows (in thousands): Foreign currency translation Retirement related benefit plans Total Balance at December 31, 2016 $ (5,725 ) $ (1,539 ) $ (7,264 ) Other comprehensive income (loss) before reclassification 1,500 (173 ) 1,327 Amounts reclassified from accumulated other comprehensive loss — 140 140 Tax effects — 41 41 Other comprehensive income (loss) 1,500 8 1,508 Balance at September 30, 2017 $ (4,225 ) $ (1,531 ) $ (5,756 )

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2017
Related Party Transactions [Abstract]
Related Party Transactions	17. Related party transactions In June 2016, the Company redeemed 137,268 shares of old Class B Non-Voting In January 2016, the Company redeemed 350,400 shares of old Class B Non-Voting At September 30, 2017, the Company had obligations to related parties for $0.2 million recorded in other accrued expenses and current liabilities. At December 31, 2016, the Company had obligations to related parties for $1.0 million recorded in other accrued expenses and current liabilities and $0.1 million recorded in other long-term liabilities. At September 30, 2017 and December 31, 2016, the Company had receivables from an equity investment for $0.5 million and $0.4 million, respectively, recorded in other long-term assets.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	18. Commitments and contingencies MSC Litigation In July 2007, MSC Software Corporation filed a lawsuit against the Company alleging misappropriation of trade secrets, breach of confidentiality and other claims. On April 10, 2014, a jury returned a verdict against the Company. The Company challenged the verdict and on November 13, 2014, a judge vacated all but $0.4 million of the judgment and ordered a new trial on damages. No trial date is scheduled. On August 21, 2017, the court granted Altair’s motion to strike the testimony of MSC’s damage expert. On October 11, 2017, the court mooted the remaining pre-trial Legal proceedings From time to time, the Company may be subject to legal proceedings and claims in the ordinary course of business. The Company has received, and may in the future continue to receive, claims from third parties asserting, among other things, infringement of their intellectual property rights. Future litigation may be necessary to defend the Company, its partners and its customers by determining the scope, enforceability and validity of third party proprietary rights, or to establish and enforce the Company’s proprietary rights. The results of any current or future litigation cannot be predicted with certainty and regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources and other factors.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segment Information	19. Segment information The Company defines its operating segments as components of its business where separate financial information is available and used by the chief operating decision maker (“CODM”) in deciding how to allocate resources to its segments and in assessing performance. The Company’s CODM is its Chief Executive Officer. The Company has identified two reportable segments for financial reporting purposes: Software and Client Engineering Services. The primary measure of segment operating performance is Adjusted EBITDA, which is defined as net income (loss) adjusted for income tax expense (benefit), interest expense, interest income and other, depreciation and amortization, stock-based compensation expense, restructuring charges, asset impairment charges and other special items as determined by management. Adjusted EBITDA includes an allocation of corporate headquarters costs. The Software reportable segment derives revenue from the sale and subscription of licenses for software products focused on the development and application of simulation technology to synthesize and optimize designs, processes and decisions for improved business performance. The Software segment also derives revenue from software support, upgrades, training and consulting services focused on product design and development expertise and analysis support from the component level up to complete product engineering at any stage of the lifecycle. The Client Engineering Services reportable segment provides support to its customers with long-term ongoing product design and development expertise in its market segments of Solvers & Optimization, Modeling & Visualization, Industrial and Concept Design, and high-performance computing. The Company hires simulation specialists, industrial designers, design engineers, materials experts, development and test specialists, manufacturing engineers and information technology specialists for placement at customer sites for specific customer-directed assignments. The “All other” represents innovative services and products, including toggled ® ® Inter-segment sales are not significant for any period presented. The CODM does not review asset information by segment when assessing performance, therefore no asset information is provided for reportable segments. The following tables are in thousands: Three months ended September 30, 2017 Software Client All other Total Revenue $ 71,782 $ 11,477 $ 1,679 $ 84,938 Adjusted EBITDA $ 7,278 $ 1,432 $ (1,667 ) $ 7,043 Three months ended September 30, 2016 Software Client All other Total Revenue $ 64,480 $ 12,146 $ 1,426 $ 78,052 Adjusted EBITDA $ 6,880 $ 1,549 $ (1,118 ) $ 7,311 Nine months ended September 30, 2017 Software Client engineering Services All other Total Revenue $ 202,654 $ 36,071 $ 4,741 $ 243,466 Adjusted EBITDA $ 14,001 $ 4,174 $ (4,076 ) $ 14,099 Nine months ended September 30, 2016 Software Client engineering services All other Total Revenue $ 189,199 $ 36,435 $ 4,758 $ 230,392 Adjusted EBITDA $ 18,678 $ 4,463 $ (2,897 ) $ 20,244 Three months ended September 30, Nine months ended 2017 2016 2017 2016 Reconciliation of Adjusted EBITDA to U.S. GAAP Income (loss) before income taxes: Adjusted EBITDA $ 7,043 $ 7,311 $ 14,099 $ 20,244 Stock-based compensation expense (25,265 ) (4,875 ) (39,302 ) (5,050 ) Interest expense (634 ) (507 ) (1,793 ) (1,754 ) Interest income and other (1) 53 93 2,184 81 Depreciation and amortization (2,811 ) (2,453 ) (7,895 ) (7,300 ) (Loss) income before income taxes $ (21,614 ) $ (431 ) $ (32,707 ) $ 6,221 (1) Includes a non-recurring

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	20. Subsequent events Initial public offering In November 2017, the Company closed its IPO, in which the Company issued and sold 9,865,004 shares of Class A common stock inclusive of the underwriters’ option to purchase additional shares that was exercised in full. The price per share to the public was $13.00. The Company received aggregate proceeds of $119.3 million from the IPO, net of underwriters’ discounts and commissions, before deducting offering costs of approximately $4.1 million. The IPO also included the sale of 3,934,996 shares of Class A common stock by certain stockholders, giving effect to the conversion of 2,200,000 shares of the Company’s Class B common stock into an equivalent number of shares of Class A common stock, and 1,734,996 stock options for Class A common stock exercised by the Company’s chief executive officer. The Company did not receive any proceeds from the sale of shares of Class A common stock by the selling stockholders. New revolving credit facility On November 3, 2017, in connection with the completion of the Company’s IPO, the Company repaid in full all outstanding debt under the Company’s 2017 Credit Agreement. The Company paid a total of approximately $93.1 million, which included outstanding principal, interest, and other nominal costs. Upon the repayment of the credit facility, all unamortized discounts were recorded as interest expense. On October 19, 2017, the Company entered into an amended and restated credit agreement with Altair Engineering Inc., as borrower, JPMorgan Chase Bank, N.A., as the lead arranger, sole book runner, the administrative agent, swingline lender and letter of credit issuer, and a syndicate of lenders (“New Credit Facility”.) The New Credit Facility became effective on satisfaction of certain conditions including the closing of the Company’s IPO and provides for an initial aggregate commitment amount of $100.0 million, with a sublimit for the issuance of letters of credit of up to $5.0 million and a sublimit for swingline loans of up to $5.0 million. The New Credit Facility will mature five years following the signing date of the New Credit Facility. The New Credit Facility will be available (i) to finance working capital needs, (ii) for general corporate purposes of the Company including permitted acquisitions, (iii) to refinance certain existing indebtedness, and (iv) to pay fees and expenses related to the New Credit Facility. The New Credit Facility allows the Company to request that the aggregate commitments under the New Credit Facility be increased by up to $50.0 million for a total of $150.0 million, subject to certain conditions, by obtaining additional commitments from the existing lenders or by causing a person acceptable to the administrative agent to become a lender (in each case subject to the terms and conditions set forth in the New Credit Facility). Borrowings under the New Credit Facility will bear interest at a rate per annum equal to an agreed upon applicable margin plus, at the Company’s option, either the Alternate Base Rate (defined as the greatest of (1) the Prime Rate (as defined in the New Credit Facility) in effect on such day, (2) the Federal Funds Effective Rate (as defined in the New Credit Facility) in effect on such day plus 1/2 of 1.00% or (3) the Adjusted LIBO Rate (as defined in the New Credit Facility) for a one month interest period on such day (or if such day is not a business day, the immediately preceding business day) plus 1.00%) or the Adjusted LIBO Rate. The applicable margin for borrowings under the New Credit Facility will be based on the Company’s most recently tested consolidated total net leverage ratio and will vary from (a) in the case of Eurodollar loans, 1.25% to 2.00%, and (b) in the case of ABR loans or swingline loans, 0.25% to 1.00%. The unused portion of the New Credit Facility will be subject to a commitment fee ranging from 0.15% to 0.30%. The New Credit Facility will be secured by collateral including (i) substantially all of the Company’s properties and assets, and the properties and assets of the Company’s domestic subsidiaries but excluding any patents, copyrights, patent applications or copyright applications or any trade secrets or software products and (ii) pledges of the equity interests in all present and future domestic subsidiaries (subject to certain exceptions as provided for under the New Credit Facility). The Company’s direct and indirect domestic subsidiaries are guarantors of all of the obligations under the New Credit Facility. The New Credit Facility requires the Company to maintain the following financial covenants: • Maximum Net Leverage Ratio • Consolidated Interest Coverage Ratio Valuation allowance In connection with the Company’s IPO, a significant number of non-qualified

Accounting Policies (Policies)

Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of presentation The accompanying unaudited consolidated financial statements of Altair Engineering Inc. have been prepared in accordance with United States generally accepted accounting principles (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial information. Accordingly, the accompanying statements do not include all the information and notes required by GAAP for complete financial statements. The accompanying consolidated financial statements should be read in conjunction with the Company’s audited consolidated financial statements (and notes thereto) for the year ended December 31, 2016, included in the final prospectus dated October 31, 2017 (the “Prospectus”) filed with the SEC pursuant to Rule 424(b) under the Securities Act of 1933, as amended. In the opinion of management, all adjustments considered necessary for a fair presentation of the financial statements have been included, and all adjustments are of a normal and recurring nature. The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosures of contingent assets and liabilities at the date of the financial statements, and reported amounts of revenue and expenses during the reporting periods. Considerable judgment is often involved in making these determinations; use of different assumptions could result in significantly different results. Management believes its assumptions and estimates are reasonable and appropriate. However, actual results may differ from those estimates. In addition, the results of operations for the three and nine months ended September 30, 2017 are not necessarily indicative of the results that may be expected for any future period. There have been no material changes to Altair’s significant accounting policies as compared to the significant accounting policies described in the Prospectus. The Company has concluded that all material transactions that have occurred that require disclosure or adjustments to the consolidated financial statements have been reported herein. See Note 20 – Subsequent events for additional information.
Delaware Conversion and Stock Split	Delaware conversion and stock split On October 5, 2017, the Company became a Delaware corporation and effected a four-for-one four-for-one four-for-one four-for-one In connection with the Company becoming a Delaware corporation, 2,495,752 shares of Class B common stock, held by holders of less than 3% of Class B common stock immediately prior to the conversion, converted into Class A common stock. Pursuant to the Company’s Delaware certificate of incorporation, the Company’s authorized capital consists of 513,796,572 shares of Class A common stock, 41,203,428 shares of Class B common stock and 45,000,000 shares of preferred stock.
Deferred Offering Costs	Deferred offering costs Deferred offering costs, which consist of direct incremental legal and accounting fees, and other direct costs relating to the Company’s initial public offering (“IPO”) were capitalized and will be offset against IPO proceeds upon the completion of the IPO in the fourth quarter. As of September 30, 2017, the Company deferred $3.5 million, which were recorded as other long-term assets in the accompanying consolidated balance sheet. No amounts were deferred as of December 31, 2016.
Cash, Cash Equivalents and Restricted Cash	Cash, cash equivalents and restricted cash The Company considers all highly liquid investments with original or remaining maturities of 90 days or less at the date of purchase to be cash equivalents. Cash and cash equivalents are recorded at cost, which approximates fair value. Restricted cash is included in other long-term assets on the consolidated balance sheets. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported in the consolidated balance sheet that sum to the total of the amounts reported in the consolidated statement of cash flows (in thousands): September 30, Cash and cash equivalents $ 16,667 Restricted cash included in other long-term assets 284 Total cash, cash equivalents, and restricted cash shown in the statement of cash flows $ 16,951 Restricted cash represents amounts required for a contractual agreement with an insurer for the payment of potential health insurance claims, and term deposits for bank guarantees.
Receivable for R&D Credit	Receivable for R&D credit The French government provides a research and development (“R&D) tax credit known as Credit Impôt Recherche, or CIR, in order to encourage Companies to invest in R&D. The tax credit is deductible from the French income tax and any excess is carried forward 3 years. After three years, any unused credit may be reimbursed to the Company by the French government. As of September 30, 2017, the Company had approximately $9.8 million receivable from the French government related to CIR, of which $3.2 million is recorded in income tax receivable and the remaining $6.6 million is recorded in other long-term assets.
Mezzanine Equity	Mezzanine equity During the quarter ended June 30, 2017, the Company issued 200,000 shares of Class A common stock to a third party as partial consideration for the purchase of developed technology. These shares have a put right that can be exercised by the holder five years from date of purchase at $12.50 per share that requires the shares to be recorded at fair value and classified as mezzanine equity in the consolidated balance sheet. The put right option is terminated if the shareholders sell their shares.
Income (Loss) Per Share	Income (loss) per share Basic income (loss) per share attributable to Class A and Class B common stockholders is computed using the weighted average number of shares of common stock outstanding for the period, excluding stock options. Diluted income (loss) per share attributable to common stockholders is based upon the weighted average number of shares of common stock outstanding for the period and potentially dilutive common shares, including the effect of stock options under the treasury stock method. The following table sets forth the computation of the numerators and denominators used in the basic and diluted income (loss) per share amounts (in thousands, except per share data): Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Numerator: Net (loss) income $ (29,626 ) $ 314 $ (39,060 ) $ 4,267 Denominator: Denominator for basic (loss) income per share—weighted average shares 50,606 49,761 50,374 48,521 Effect of dilutive securities, stock options — 9,565 — 9,565 Denominator for dilutive (loss) income per share 50,606 59,326 50,374 58,086 Net (loss) income per share attributable to common stockholders, basic $ (0.59 ) $ 0.01 $ (0.78 ) $ 0.09 Net (loss) income per share attributable to common stockholders, diluted $ (0.59 ) $ 0.01 $ (0.78 ) $ 0.07 The computation of diluted (loss) income per share does not include shares that are anti-dilutive under the treasury stock method because their exercise prices are higher than the average fair value of the Company’s stock during the period or due to a net loss in the period. For both the three and nine months ended September 30, 2017, there were 10.1 million and 9.8 million anti-dilutive shares, respectively, excluded from the computation of income (loss) per share. For the three and nine months ended September 30, 2016, there were no anti-dilutive shares excluded from the computation of income (loss) per share.

Accounting Policies (Tables)

Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Reconciliation of Cash, Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported in the consolidated balance sheet that sum to the total of the amounts reported in the consolidated statement of cash flows (in thousands): September 30, Cash and cash equivalents $ 16,667 Restricted cash included in other long-term assets 284 Total cash, cash equivalents, and restricted cash shown in the statement of cash flows $ 16,951
Computation of Numerators and Denominators Used in Basic and Diluted Income (Loss) per Share Amounts	The following table sets forth the computation of the numerators and denominators used in the basic and diluted income (loss) per share amounts (in thousands, except per share data): Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Numerator: Net (loss) income $ (29,626 ) $ 314 $ (39,060 ) $ 4,267 Denominator: Denominator for basic (loss) income per share—weighted average shares 50,606 49,761 50,374 48,521 Effect of dilutive securities, stock options — 9,565 — 9,565 Denominator for dilutive (loss) income per share 50,606 59,326 50,374 58,086 Net (loss) income per share attributable to common stockholders, basic $ (0.59 ) $ 0.01 $ (0.78 ) $ 0.09 Net (loss) income per share attributable to common stockholders, diluted $ (0.59 ) $ 0.01 $ (0.78 ) $ 0.07

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Summary of Changes in the Fair Value of Company's Level 3 Financial Liabilities	The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial liabilities (in thousands): Liability for Liability for Balance at December 31, 2016 $ 10,632 $ 11,604 Shares issued upon exercise of stock options — — Exercise of stock options 385 (364 ) Forfeitures of stock options — (139 ) Change in fair value and other 15,974 20,984 Balance at September 30, 2017 $ 26,991 $ 32,085

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2017
Runtime Design Automation [Member]
Summary of Amounts of Identified Assets Acquired and Liabilities Assumed at the Acquisition Date	The following table summarizes the consideration transferred to acquire Runtime and the preliminary amounts of identified assets acquired and liabilities assumed at the acquisition date (in thousands): Fair value of consideration transferred $ 25,691 Recognized amounts of identifiable assets acquired and liabilities assumed: Cash 564 Accounts receivable 2,257 Deferred tax assets 1,965 Other assets 256 Accounts payable and other liabilities (889 ) Deferred revenue (2,199 ) Deferred tax liabilities (770 ) Total net identifiable assets acquired and liabilities assumed 1,184 Goodwill – preliminary $ 24,507
Carriots [Member]
Summary of Amounts of Identified Assets Acquired and Liabilities Assumed at the Acquisition Date	The following table summarizes the consideration transferred to acquire Carriots and the amounts of identified assets acquired and liabilities assumed at the acquisition date (in thousands): Fair value of consideration transferred $ 6,657 Recognized amounts of identifiable assets acquired and liabilities assumed: Deferred tax assets 394 Other assets 472 Trade names 252 Developed technology (4-year 1,317 Customer relationships (7-year 296 Accounts payable and other liabilities (1,015 ) Total net identifiable assets acquired and liabilities assumed 1,716 Goodwill $ 4,941

Inventory (Tables)

Inventory (Tables)	9 Months Ended
	Sep. 30, 2017
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consisted of the following (in thousands): September 30, December 31, 2017 2016 Raw materials $ 13 $ 52 Finished goods 1,784 1,175 Total inventory – net $ 1,797 $ 1,227

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment	Property and equipment consists of the following (in thousands): September 30, December 31, 2017 2016 Land $ 7,994 $ 7,994 Building and improvements 15,000 14,956 Computer equipment and software 31,077 27,461 Office furniture and equipment 6,038 5,306 Leasehold improvements 5,961 5,397 Total property and equipment 66,070 61,114 Less: accumulated depreciation and amortization 36,178 31,406 Property and equipment, net $ 29,892 $ 29,708

Goodwill and Other Intangible35

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in Carrying Amount of Goodwill Attributable to Software Reporting Segment	The changes in the carrying amount of goodwill, which is attributable to the Software reporting segment, are as follows (in thousands): Balance at December 31, 2016 $ 36,625 Acquisitions 29,448 Effects of foreign currency translation 2,818 Balance at September 30, 2017 $ 68,891
Summary of Other Intangible Assets	A summary of other intangible assets is shown below (in thousands): September 30, 2017 Weighted average amortization period Gross carrying amount Accumulated amortization Net carrying Definite-lived intangible assets: Developed technology 4 years $ 17,347 $ 7,642 $ 9,705 Customer relationships 7 years 9,235 5,816 3,419 Noncompete agreements 5 years 824 824 — Other intangibles 10 years 119 45 74 Total definite-lived intangible assets 27,525 14,327 13,198 Indefinite-lived intangible assets: Trade names 2,181 2,181 Total other intangible assets $ 29,706 $ 14,327 $ 15,379 December 31, 2016 Weighted Gross Accumulated Net carrying Definite-lived intangible assets: Developed technology 4 years $ 10,631 $ 5,034 $ 5,597 Customer relationships 7 years 8,646 4,977 3,669 Noncompete agreements 5 years 824 824 — Other intangibles 10 years 117 40 77 Total definite-lived intangible assets 20,218 10,875 9,343 Indefinite-lived intangible assets: Trade names 1,825 1,825 Total other intangible assets $ 22,043 $ 10,875 $ 11,168

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Schedule of Carrying Value of Debt	The carrying value of debt is as follows (in thousands): September 30, December 31, 2017 2016 Secured Credit Agreement: Revolving Credit Facility $ 41,950 $ 27,355 Term Loan A 50,000 57,500 Obligations held under capital leases 166 196 Other borrowings 66 330 Total debt 92,182 85,381 Less: unamortized debt issuance costs 96 140 Less: current portion of long-term debt 10,147 10,435 Long-term debt, net of current portion $ 81,939 $ 74,806

Other Liabilities (Tables)

Other Liabilities (Tables)	9 Months Ended
	Sep. 30, 2017
Other Liabilities Disclosure [Abstract]
Summary of Other Accrued Expenses and Current Liabilities	The following table provides the details of other accrued expenses and current liabilities (in thousands): September 30, December 31, 2017 2016 Obligations for acquisition of businesses $ 13,453 $ 2,649 Income taxes payable 6,759 2,156 Accrued professional fees 3,168 1,389 Accrued VAT 2,135 3,928 Accrued royalties 1,930 1,583 Defined contribution plan liabilities 1,164 1,139 Self-insurance and other insurance reserves 818 764 Non-income 638 739 Billings in excess of cost 380 1,021 Related party liabilities 242 1,045 Other current liabilities 5,050 2,532 $ 35,737 $ 18,945
Summary of Other Long-term Liabilities	The following table provides details of other long-term liabilities (in thousands): September 30, December 31, 2017 2016 Pension and other post retirement liabilities $ 7,174 $ 5,959 Deferred tax liabilities 1,106 1,379 Other liabilities 8,122 9,776 $ 16,402 $ 17,114

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2017
Weighted Average Assumptions to Calculate Fair Value of Options Granted	The weighted average assumptions used in the Black-Scholes option pricing model used to calculate the fair value of options granted during the nine months ended September 30, 2017 were as follows: 2017 grants Weighted average grant date fair value per share $ 1.86 Expected volatility 34 % Expected term (in years) 5.75-6.25 Risk-free interest rate 2.02 % Expected dividend yield 0 %
Summary of Stock-Based Compensation Expense	The stock-based compensation expense was recorded as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Cost of revenue – software $ 326 $ 1 $ 342 $ 15 Research and development 6,711 1,320 10,495 1,361 Sales and marketing 4,045 728 6,160 763 General and administrative 14,183 2,826 22,305 2,911 Total stock-based compensation expense $ 25,265 $ 4,875 $ 39,302 $ 5,050
NSO Plan [Member]
Summary of Stock Option Activity	The following table summarizes the stock option activity under the NSO Plan: Number of options Weighted average exercise price per share Weighted average remaining contractual term (years) Outstanding at January 1, 2017 6,347,840 $ 0.000025 20 Exercised — $ 0.000025 Forfeited — $ 0.000025 Outstanding at September 30, 2017 6,347,840 $ 0.000025 19 Exercisable at September 30, 2017 6,347,840 $ 0.000025 19
ISO Plan [Member]
Summary of Stock Option Activity	The following table summarizes the stock option activity under the 2001 Stock-based compensation plans for the periods indicated as follows: Number of Options Weighted average exercise price per share Weighted average remaining contractual term (years) Outstanding at January 1, 2017 2,972,744 $ 0.64 3.4 Granted — — Exercised (33,200 ) $ 0.64 Forfeited (12,564 ) $ 0.53 Outstanding at September 30, 2017 2,926,980 $ 0.64 2.6 Exercisable at September 30, 2017 2,926,980 $ 0.64 2.6
2012 Plan [Member]
Summary of Stock Option Activity	The following table summarizes the stock option activity under the 2012 Plan for the periods indicated as follows: Number of options Weighted average exercise price per share Weighted average remaining contractual term (years) Outstanding at January 1, 2017 1,797,252 $ 3.13 7.5 Granted 608,948 $ 5.18 Exercised (174,692 ) $ 2.61 Forfeited (27,524 ) $ 3.91 Outstanding at September 30, 2017 2,203,984 $ 3.73 7.6 Exercisable at September 30, 2017 1,085,748 $ 2.86 6.2

Other Expense (Income), Net (Ta

Other Expense (Income), Net (Tables)	9 Months Ended
	Sep. 30, 2017
Other Income and Expenses [Abstract]
Schedule of Other Expense (Income), Net	Other expense (income), net consists of the following (in thousands): Three months ended Nine months ended September 30, 2017 2016 2017 2016 Foreign exchange loss (gain) $ 105 $ 241 $ 1,022 $ (423 ) Other (53 ) (93 ) (184 ) (81 ) Other expense (income), net $ 52 $ 148 $ 838 $ (504 )

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Schedule of Income Tax Expense (Benefit) and Effective Tax Rate	The Company’s income tax expense (benefit) and effective tax rate for the three and nine months ended September 30, 2016 and 2017 were as follows (in thousands, except percentages): Three months ended September 30, Nine months ended September 30, 2017 2016 2017 2016 Income tax expense (benefit) $ 8,012 $ (745 ) $ 6,353 $ 1,954 Effective tax rate (37 %) 173 % (19 %) 31 %

Accumulated Other Comprehensi41

Accumulated Other Comprehensive Loss (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Components of Accumulated Other Comprehensive Loss	The components of accumulated other comprehensive loss were as follows (in thousands): Foreign currency translation Retirement related benefit plans Total Balance at December 31, 2016 $ (5,725 ) $ (1,539 ) $ (7,264 ) Other comprehensive income (loss) before reclassification 1,500 (173 ) 1,327 Amounts reclassified from accumulated other comprehensive loss — 140 140 Tax effects — 41 41 Other comprehensive income (loss) 1,500 8 1,508 Balance at September 30, 2017 $ (4,225 ) $ (1,531 ) $ (5,756 )

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Schedule of Segment Reporting Information	The following tables are in thousands: Three months ended September 30, 2017 Software Client All other Total Revenue $ 71,782 $ 11,477 $ 1,679 $ 84,938 Adjusted EBITDA $ 7,278 $ 1,432 $ (1,667 ) $ 7,043 Three months ended September 30, 2016 Software Client All other Total Revenue $ 64,480 $ 12,146 $ 1,426 $ 78,052 Adjusted EBITDA $ 6,880 $ 1,549 $ (1,118 ) $ 7,311 Nine months ended September 30, 2017 Software Client engineering Services All other Total Revenue $ 202,654 $ 36,071 $ 4,741 $ 243,466 Adjusted EBITDA $ 14,001 $ 4,174 $ (4,076 ) $ 14,099 Nine months ended September 30, 2016 Software Client engineering services All other Total Revenue $ 189,199 $ 36,435 $ 4,758 $ 230,392 Adjusted EBITDA $ 18,678 $ 4,463 $ (2,897 ) $ 20,244
Reconciliation of U.S. GAAP Income (loss) before income taxes to Adjusted EBITDA	Three months ended September 30, Nine months ended 2017 2016 2017 2016 Reconciliation of Adjusted EBITDA to U.S. GAAP Income (loss) before income taxes: Adjusted EBITDA $ 7,043 $ 7,311 $ 14,099 $ 20,244 Stock-based compensation expense (25,265 ) (4,875 ) (39,302 ) (5,050 ) Interest expense (634 ) (507 ) (1,793 ) (1,754 ) Interest income and other (1) 53 93 2,184 81 Depreciation and amortization (2,811 ) (2,453 ) (7,895 ) (7,300 ) (Loss) income before income taxes $ (21,614 ) $ (431 ) $ (32,707 ) $ 6,221 (1) Includes a non-recurring

Organization and Description 43

Organization and Description of Business - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2017
IPO [Member]
Organization Consolidation And Presentation Of Financial Statements [Line Items]
Entity incorporation state	Michigan

Accounting Policies - Additiona

Accounting Policies - Additional Information (Detail) - USD ($)	Oct. 05, 2017	Apr. 03, 2017	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Accounting Policies [Line Items]
Common stock conversion description						On October 5, 2017, the Company became a Delaware corporation and effected a four-for-one stock split of its common stock. On the effective date of the Company becoming a Delaware corporation, (i) each share of outstanding common stock was increased to four shares of common stock, par value $0.0001 per share, (ii) the number of shares of common stock issuable under each outstanding option to purchase common stock was increased on a four-for-one basis, (iii) the exercise price of each outstanding option to purchase common stock was reduced on a four-for-one basis, and (iv) the redemption price of each outstanding put option was reduced on a four-for-one basis. All share and per share information referenced throughout the consolidated financial statements and notes thereto have been retroactively adjusted to reflect this stock split.
Deferred offering costs			$ 3,500,000			$ 3,500,000		$ 0
Anti-dilutive shares excluded from computation of income (loss) per share			10,100,000		0	9,800,000	0
Ministry of the Economy, Finance and Industry, France [Member] | Research and Development Tax Credit Carryforward [Member]
Accounting Policies [Line Items]
Tax credit carryforward, period						3 years
Tax credit carryforward			$ 9,800,000			$ 9,800,000
Income tax receivable [Member] | Ministry of the Economy, Finance and Industry, France [Member] | Research and Development Tax Credit Carryforward [Member]
Accounting Policies [Line Items]
Tax credit carryforward			3,200,000			3,200,000
Other long-term assets [Member] | Ministry of the Economy, Finance and Industry, France [Member] | Research and Development Tax Credit Carryforward [Member]
Accounting Policies [Line Items]
Tax credit carryforward			$ 6,600,000			$ 6,600,000
Subsequent Event [Member]
Accounting Policies [Line Items]
Stock split ratio	4
Common stock, par value	$ 0.0001
Subsequent Event [Member] | Preferred Stock [Member]
Accounting Policies [Line Items]
Capital units authorized	45,000,000
Class A Common Stock [Member]
Accounting Policies [Line Items]
Common stock, par value			$ 0.0001			$ 0.0001		$ 0.0001
Common stock conversion		1
Put right exercise period from date of purchase				5 years
Class A Common Stock [Member] | Put Option [Member]
Accounting Policies [Line Items]
Shares issued				200,000
Put right, exercise price				$ 12.50
Class A Common Stock [Member] | Subsequent Event [Member]
Accounting Policies [Line Items]
Capital units authorized	513,796,572
Class B Common Stock [Member]
Accounting Policies [Line Items]
Common stock, par value			$ 0.0001			$ 0.0001		$ 0.0001
Common stock conversion		1
Class B Common Stock [Member] | Subsequent Event [Member]
Accounting Policies [Line Items]
Common stock conversion	2,495,752
Capital units authorized	41,203,428
Class B Common Stock [Member] | Subsequent Event [Member] | Maximum [Member]
Accounting Policies [Line Items]
Percentage of stock held by holders	3.00%

Accounting Policies - Reconcili

Accounting Policies - Reconciliation of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Cash and cash equivalents	$ 16,667	$ 16,874
Restricted cash included in other long-term assets	284
Total cash, cash equivalents, and restricted cash shown in the statement of cash flows	$ 16,951	$ 17,139	$ 19,360	$ 14,013

Accounting Policies - Computati

Accounting Policies - Computation of Numerators and Denominators Used in Basic and Diluted Income (Loss) per Share Amounts (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Numerator:
Net (loss) income	$ (29,626)	$ 314	$ (39,060)	$ 4,267
Denominator:
Denominator for basic (loss) income per share-weighted average shares	50,606	49,761	50,374	48,521
Effect of dilutive securities, stock options		9,565		9,565
Denominator for dilutive (loss) income per share	50,606	59,326	50,374	58,086
Net (loss) income per share attributable to common stockholders, basic	$ (0.59)	$ 0.01	$ (0.78)	$ 0.09
Net (loss) income per share attributable to common stockholders, diluted	$ (0.59)	$ 0.01	$ (0.78)	$ 0.07

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Changes in the Fair Value of Company's Level 3 Financial Liabilities (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Liability for Class A Redeemable Common Shares [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at December 31, 2016	$ 10,632
Shares issued upon exercise of stock options	0
Exercise of stock options	385
Change in fair value and other	15,974
Balance at September 30, 2017	26,991
Liability for Stock-Based Compensation Awards [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at December 31, 2016	11,604
Shares issued upon exercise of stock options	0
Exercise of stock options	(364)
Forfeitures of stock options	(139)
Change in fair value and other	20,984
Balance at September 30, 2017	$ 32,085

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 28, 2017	May 31, 2017	Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Business acquisition, cash paid			$ 15,582	$ 6,499
Runtime Design Automation [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of interest acquired	100.00%
Business acquisition, cash paid	$ 18,700
Consideration payable within one year from acquistion date	$ 8,700
Runtime Design Automation [Member] | Class A Common Stock [Member]
Business Acquisition [Line Items]
Business acquisition, shares issued	708,000
Carriots [Member]
Business Acquisition [Line Items]
Business acquisition, percentage of interest acquired		100.00%
Business acquisition, cash paid		$ 3,600
Business acquisition, notes payable		$ 2,700
Carriots [Member] | Class A Common Stock [Member]
Business Acquisition [Line Items]
Business acquisition, shares issued		80,000

Acquisitions - Summary of Amoun

Acquisitions - Summary of Amounts of Identified Assets Acquired and Liabilities Assumed at the Acquisition Date (Detail) - USD ($) $ in Thousands	Sep. 28, 2017	May 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill			$ 68,891	$ 36,625
Runtime Design Automation [Member]
Business Acquisition [Line Items]
Fair value of consideration transferred	$ 25,691
Recognized amounts of identifiable assets acquired and liabilities assumed:
Cash	564
Accounts receivable	2,257
Deferred tax assets	1,965
Other assets	256
Accounts payable and other liabilities	(889)
Deferred revenue	(2,199)
Deferred tax liabilities	(770)
Total net identifiable assets acquired and liabilities assumed	1,184
Goodwill	$ 24,507
Carriots [Member]
Business Acquisition [Line Items]
Fair value of consideration transferred		$ 6,657
Recognized amounts of identifiable assets acquired and liabilities assumed:
Deferred tax assets		394
Other assets		472
Accounts payable and other liabilities		(1,015)
Total net identifiable assets acquired and liabilities assumed		1,716
Goodwill		4,941
Carriots [Member] | Trade Names [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed:
Indefinite-lived intangibles		252
Carriots [Member] | Developed Technology [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangibles		1,317
Carriots [Member] | Customer Relationships [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangibles		$ 296

Acquisitions - Summary of Amo50

Acquisitions - Summary of Amounts of Identified Assets Acquired and Liabilities Assumed at the Acquisition Date (Parenthetical) (Detail)	1 Months Ended	9 Months Ended	12 Months Ended
	May 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Developed Technology [Member]
Business Acquisition [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets		4 years	4 years
Developed Technology [Member] | Carriots [Member]
Business Acquisition [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets	4 years
Customer Relationships [Member]
Business Acquisition [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets		7 years	7 years
Customer Relationships [Member] | Carriots [Member]
Business Acquisition [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets	7 years

Inventory - Schedule of Invento

Inventory - Schedule of Inventory (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 13	$ 52
Finished goods	1,784	1,175
Total inventory - net	$ 1,797	$ 1,227

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 66,070	$ 61,114
Less: accumulated depreciation and amortization	36,178	31,406
Property and equipment, net	29,892	29,708
Land [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	7,994	7,994
Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	15,000	14,956
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	31,077	27,461
Office Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	6,038	5,306
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 5,961	$ 5,397

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 1.6	$ 1.5	$ 4.6	$ 4.9

Goodwill and Other Intangible54

Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill Attributable to Software Reporting Segment (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Balance at December 31, 2016	$ 36,625
Acquisitions	29,448
Effects of foreign currency translation	2,818
Balance at September 30, 2017	$ 68,891

Goodwill and Other Intangible55

Goodwill and Other Intangible Assets - Summary of Other Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Summary Of Other Intangible Assets [Line Items]
Gross carrying amount	$ 29,706	$ 22,043
Accumulated amortization	14,327	10,875
Net carrying amount	15,379	11,168
Gross carrying amount	27,525	20,218
Accumulated amortization	14,327	10,875
Net carrying amount	$ 13,198	$ 9,343
Developed Technology [Member]
Summary Of Other Intangible Assets [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets	4 years	4 years
Gross carrying amount	$ 17,347	$ 10,631
Accumulated amortization	7,642	5,034
Net carrying amount	$ 9,705	$ 5,597
Customer Relationships [Member]
Summary Of Other Intangible Assets [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets	7 years	7 years
Gross carrying amount	$ 9,235	$ 8,646
Accumulated amortization	5,816	4,977
Net carrying amount	$ 3,419	$ 3,669
Noncompete Agreements [Member]
Summary Of Other Intangible Assets [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets	5 years	5 years
Gross carrying amount	$ 824	$ 824
Accumulated amortization	$ 824	$ 824
Other Intangibles [Member]
Summary Of Other Intangible Assets [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets	10 years	10 years
Gross carrying amount	$ 119	$ 117
Accumulated amortization	45	40
Net carrying amount	74	77
Trade Names [Member]
Summary Of Other Intangible Assets [Line Items]
Net carrying amount	$ 2,181	$ 1,825

Goodwill and Other Intangible56

Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended			9 Months Ended
	May 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Intangible Assets [Line Items]
Amortization of intangible assets		$ 1,189		$ 875	$ 3,287	$ 2,352
Class A Common Stock [Member]
Intangible Assets [Line Items]
Put right exercise period from date of purchase			5 years
Class A Common Stock [Member] | Put Option [Member]
Intangible Assets [Line Items]
Put right, exercise price			$ 12.50
Modeliis Software [Member]
Intangible Assets [Line Items]
Payment to acquire intangible asset	$ 2,000
Modeliis Software [Member] | Class A Common Stock [Member]
Intangible Assets [Line Items]
Number to share issued to acquire software	200,000
Put right exercise period from date of purchase	5 years
Modeliis Software [Member] | Class A Common Stock [Member] | Put Option [Member]
Intangible Assets [Line Items]
Put right, exercise price	$ 12.50

Debt - Schedule of Carrying Val

Debt - Schedule of Carrying Value of Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Total debt	$ 92,182	$ 85,381
Less: unamortized debt issuance costs	96	140
Less: current portion of long-term debt	10,147	10,435
Long-term debt, net of current portion	81,939	74,806
Term Loan A [Member]
Debt Instrument [Line Items]
Total debt	50,000	57,500
Capital Lease Obligations [Member]
Debt Instrument [Line Items]
Total debt	166	196
Other Borrowings [Member]
Debt Instrument [Line Items]
Total debt	66	330
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total debt	$ 41,950	$ 27,355

Debt - Additional Information (

Debt - Additional Information (Detail) - Secured Credit Agreement [Member] - JPMorgan Chase Bank, N.A. [Member]	9 Months Ended
	Sep. 30, 2017USD ($)
Debt Instrument [Line Items]
Covenant terms, description	The Credit Agreement contains a number of covenants that, among other things, restrict, subject to certain exceptions, the Company’s ability to incur additional indebtedness; create liens on assets; make investments, loans, advances or acquisitions; pay dividends or other distributions; redeem or repurchase certain equity interests; guarantee the obligations of others; and change the business conducted by the Company.
Minimum liquidity, amount	$ 20,000,000
Minimum debt service coverage ratio	130.00%
Maximum leverage ratio	300.00%
Covenant compliance, description	At September 30, 2017, the Company was in compliance with all such covenants.
Term Loan A [Member]
Debt Instrument [Line Items]
Amount available under secured credit agreement	$ 50,000,000
Quarterly principal payments on Term Loan A in 2017, 2018 and March 2019	$ 2,500,000
Maturity date	Apr. 18, 2019
Frequency of periodic payment	Quarterly
Ancillary Facility [Member]
Debt Instrument [Line Items]
Amount available under secured credit agreement	$ 4,000,000
Prime Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.50%
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.50%
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.00%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Amount available under secured credit agreement	$ 60,000,000
Carrying value of debt under secured credit agreement	42,000,000
Amount available for future borrowing	$ 18,000,000
Termination date	2019-04
Commitment fees on unused portion of the Revolving Credit Facility	0.25%
Revolving Credit Facility [Member] | Swingline Subfacility and Letter of Credit Subfacility [Member]
Debt Instrument [Line Items]
Amount available under secured credit agreement	$ 5,000,000
Letter of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.50%
Letter of Credit [Member] | London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.00%

Other Liabilities - Summary of

Other Liabilities - Summary of Other Accrued Expenses and Current Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Obligations for acquisition of businesses	$ 13,453	$ 2,649
Income taxes payable	6,759	2,156
Accrued professional fees	3,168	1,389
Accrued VAT	2,135	3,928
Accrued royalties	1,930	1,583
Defined contribution plan liabilities	1,164	1,139
Self-insurance and other insurance reserves	818	764
Non-income tax liabilities	638	739
Billings in excess of cost	380	1,021
Related party liabilities	242	1,045
Other current liabilities	5,050	2,532
Other accrued expenses and current liabilities	$ 35,737	$ 18,945

Other Liabilities - Summary o60

Other Liabilities - Summary of Other Long-term Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Other Liabilities Disclosure [Abstract]
Pension and other post retirement liabilities	$ 7,174	$ 5,959
Deferred tax liabilities	1,106	1,379
Other liabilities	8,122	9,776
Other long-term liabilities	$ 16,402	$ 17,114

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail) - Interest Rate Swap [Member] - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivatives outstanding notional value	$ 4,500,000	$ 4,500,000
Derivatives maturity date	Dec. 23, 2019
Derivatives maturity date description	This interest rate swap matures at various dates through December 23, 2019.

Stockholders' Deficit - Additio

Stockholders' Deficit - Additional Information (Detail)	Apr. 03, 2017Voteshares	Sep. 30, 2017shares	Apr. 04, 2017$ / sharesshares	Dec. 31, 2016shares
Class B Common Stock [Member]
Class of Stock [Line Items]
Common stock voting rights description		Each share of the Company's Class A voting common stock, or old Class A shares, automatically converted into one share of new Class B voting common stock entitled to ten votes per share
Conversion of stock, shares converted	1
Number of votes entitled to common stockholders per share | Vote	10
Common stock, shares authorized		44,000	44,000,000	44,000
Common stock, no par value | $ / shares
Class A Common Stock [Member]
Class of Stock [Line Items]
Common stock voting rights description		Each share of the Company's Class B non-voting common stock, or old Class B shares, automatically converted into one share of new Class A voting common stock entitled to one vote per share, in each case, without any further action on the part of the holders thereof.
Conversion of stock, shares converted	1
Number of votes entitled to common stockholders per share | Vote	1
Common stock, shares authorized		76,000	76,000,000	76,000
Common stock, no par value | $ / shares

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Sep. 27, 2017	Dec. 31, 2016	Dec. 31, 2012	Dec. 31, 2001
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Business combination, estimated post combination expense	$ 2
IPO [Member] | Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, outstanding	1,734,996	1,734,996
Class B Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding	41,204	41,204		41,204
Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding	10,096	10,096		8,900
2012 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, outstanding	2,203,984	2,203,984		1,797,252
Exercise price stock options outstanding	$ 3.73	$ 3.73		$ 3.13
Contractual term		10 years
Total requisite service period of awards		4 years
2012 Plan [Member] | Old Class B Nonvoting Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized					5,200,000
NSO Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, outstanding	6,347,840	6,347,840		6,347,840
Exercise price stock options outstanding	$ 0.000025	$ 0.000025		$ 0.000025
Contractual term		35 years
ISO Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, outstanding	2,926,980	2,926,980		2,972,744
Exercise price stock options outstanding	$ 0.64	$ 0.64		$ 0.64
Contractual term		10 years
ISO Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options vesting period		2 years
ISO Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options vesting period		3 years
ISO Plan [Member] | Old Class B Nonvoting Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized						11,153,872
Shares outstanding				2,340,596
ISO Plan [Member] | Class B Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding	2,329,796	2,329,796
2017 Plan [Member] | Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance			6,207,976

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Stock Option Activity under NSO Plan (Detail) - NSO Plan [Member] - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Outstanding, Beginning Balance	6,347,840
Number of options, Exercised	0
Number of options, Forfeited	0
Number of options, Outstanding, Ending Balance	6,347,840	6,347,840
Number of options, Exercisable	6,347,840
Weighted average exercise price per share, Outstanding, Beginning Balance	$ 0.000025
Weighted average exercise price per share, Exercised	0.000025
Weighted average exercise price per share, Forfeited	0.000025
Weighted average exercise price per share, Outstanding, Ending Balance	0.000025	$ 0.000025
Weighted average exercise price per share, Exercisable	$ 0.000025
Weighted average remaining contractual term (years), Outstanding	19 years	20 years
Weighted average remaining contractual term (years), Exercisable	19 years

Stock-based Compensation - Su65

Stock-based Compensation - Summary of Stock Option Activity under ISO Plan (Detail) - ISO Plan [Member] - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Outstanding, Beginning Balance	2,972,744
Number of options, Granted	0
Number of options, Exercised	(33,200)
Number of options, Forfeited	(12,564)
Number of options, Outstanding, Ending Balance	2,926,980	2,972,744
Number of options, Exercisable	2,926,980
Weighted average exercise price per share, Outstanding, Beginning Balance	$ 0.64
Weighted average exercise price per share, Granted	0
Weighted average exercise price per share, Exercised	0.64
Weighted average exercise price per share, Forfeited	0.53
Weighted average exercise price per share, Outstanding, Ending Balance	0.64	$ 0.64
Weighted average exercise price per share, Exercisable	$ 0.64
Weighted average remaining contractual term (years), Outstanding	2 years 7 months 6 days	3 years 4 months 24 days
Weighted average remaining contractual term (years), Exercisable	2 years 7 months 6 days

Stock-based Compensation - Su66

Stock-based Compensation - Summary of Stock Option Activity under 2012 Plan (Detail) - 2012 Plan [Member] - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, Outstanding, Beginning Balance	1,797,252
Number of options, Granted	608,948
Number of options, Exercised	(174,692)
Number of options, Forfeited	(27,524)
Number of options, Outstanding, Ending Balance	2,203,984	1,797,252
Number of options, Exercisable	1,085,748
Weighted average exercise price per share, Outstanding, Beginning Balance	$ 3.13
Weighted average exercise price per share, Granted	5.18
Weighted average exercise price per share, Exercised	2.61
Weighted average exercise price per share, Forfeited	3.91
Weighted average exercise price per share, Outstanding, Ending Balance	3.73	$ 3.13
Weighted average exercise price per share, Exercisable	$ 2.86
Weighted average remaining contractual term (years), Outstanding	7 years 7 months 6 days	7 years 6 months
Weighted average remaining contractual term (years), Exercisable	6 years 2 months 12 days

Stock-based Compensation - Weig

Stock-based Compensation - Weighted Average Assumptions To Calculate Fair Value of Options Granted (Detail)	9 Months Ended
	Sep. 30, 2017$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value per share	$ 1.86
Expected volatility	34.00%
Risk-free interest rate	2.02%
Expected dividend yield	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	5 years 9 months
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years 2 months 30 days

Stock-based Compensation - Su68

Stock-based Compensation - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 25,265	$ 4,875	$ 39,302	$ 5,050
Cost of Revenue - Software [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	326	1	342	15
Research and development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	6,711	1,320	10,495	1,361
Sales and marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	4,045	728	6,160	763
General and administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation expense	$ 14,183	$ 2,826	$ 22,305	$ 2,911

Other Expense (Income), Net - S

Other Expense (Income), Net - Schedule of Other Expense (Income), Net (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other Income and Expenses [Abstract]
Foreign exchange loss (gain)	$ 105	$ 241	$ 1,022	$ (423)
Other	(53)	(93)	(184)	(81)
Other expense (income), net	$ 52	$ 148	$ 838	$ (504)

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax Expense (Benefit) and Effective Tax Rate (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ 8,012	$ (745)	$ 6,353	$ 1,954
Effective tax rate	(37.00%)	173.00%	(19.00%)	31.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Income Tax Disclosure [Abstract]
United States pre-tax loss	$ 41.5	$ 4.6
Non-deductible stock-based compensation expense	$ 24.9	$ 2.9

Accumulated Other Comprehensi72

Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			$ (34,653)
Total other comprehensive income (loss)	$ 41	$ 796	1,508	$ (270)
Ending balance	(62,556)		(62,556)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(5,725)
Other comprehensive income (loss) before reclassification			1,500
Total other comprehensive income (loss)			1,500
Ending balance	(4,225)		(4,225)
Retirement Related Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(1,539)
Other comprehensive income (loss) before reclassification			(173)
Amounts reclassified from accumulated other comprehensive loss			140
Tax effects			41
Total other comprehensive income (loss)			8
Ending balance	(1,531)		(1,531)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(7,264)
Other comprehensive income (loss) before reclassification			1,327
Amounts reclassified from accumulated other comprehensive loss			140
Tax effects			41
Total other comprehensive income (loss)			1,508
Ending balance	$ (5,756)		$ (5,756)

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) $ in Thousands	1 Months Ended
	Jun. 30, 2016USD ($)Installmentshares	Jan. 31, 2016USD ($)Installmentshares	Sep. 30, 2017USD ($)	Dec. 31, 2016USD ($)
Related Party Transaction [Line Items]
Obligations to related parties, current			$ 242	$ 1,045
Other accrued expenses and current liabilities [Member]
Related Party Transaction [Line Items]
Obligations to related parties, current			200	1,000
Other long-term liabilities [Member]
Related Party Transaction [Line Items]
obligations to related parties, non-current				100
Other long-term assets [Member]
Related Party Transaction [Line Items]
Receivables from equity investment			$ 500	$ 400
Founder Stockholders [Member] | Old Class B Nonvoting Stock [Member]
Related Party Transaction [Line Items]
Stock redeemed in shares | shares		350,400
Stock redeemed aggregate purchase price		$ 1,300
Number of installments | Installment		12
Related Party [Member] | Old Class B Nonvoting Stock [Member]
Related Party Transaction [Line Items]
Stock redeemed in shares | shares	137,268
Stock redeemed aggregate purchase price	$ 500
Number of installments | Installment	2

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	Nov. 13, 2014USD ($)
Commitments and Contingencies Disclosure [Abstract]
Damages amount on MSC litigation	$ 0.4

Segment Information - Additiona

Segment Information - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2017Segment
Segment Reporting [Abstract]
Number of reportable segments	2

Segment Information - Schedule

Segment Information - Schedule of Segment Reporting Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Revenue	$ 84,938	$ 78,052	$ 243,466	$ 230,392
Adjusted EBITDA	7,043	7,311	14,099	20,244
Software [Member]
Segment Reporting Information [Line Items]
Revenue	71,782	64,480	202,654	189,199
Adjusted EBITDA	7,278	6,880	14,001	18,678
Client Engineering Services [Member]
Segment Reporting Information [Line Items]
Revenue	11,477	12,146	36,071	36,435
Adjusted EBITDA	1,432	1,549	4,174	4,463
All Other [Member]
Segment Reporting Information [Line Items]
Revenue	1,679	1,426	4,741	4,758
Adjusted EBITDA	$ (1,667)	$ (1,118)	$ (4,076)	$ (2,897)

Segment Information - Reconcili

Segment Information - Reconciliation of U.S. GAAP Income (Loss) Before Income Taxes to Adjusted EBITDA (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting [Abstract]
Adjusted EBITDA	$ 7,043	$ 7,311	$ 14,099	$ 20,244
Stock-based compensation expense	(25,265)	(4,875)	(39,302)	(5,050)
Interest expense	(634)	(507)	(1,793)	(1,754)
Interest income and other	53	93	2,184	81
Depreciation and amortization	(2,811)	(2,453)	(7,895)	(7,300)
(Loss) income before taxes	$ (21,614)	$ (431)	$ (32,707)	$ 6,221

Segment Information - Reconci78

Segment Information - Reconciliation of U.S. GAAP Income (Loss) Before Income Taxes to Adjusted EBITDA (Parenthetical) (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)
Segment Reporting [Abstract]
Income recognized in non-recurring adjustment for change in estimated legal expenses	$ 2

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - USD ($)	Nov. 03, 2017	Oct. 19, 2017	Nov. 30, 2017	Sep. 30, 2017	Sep. 30, 2016
Subsequent Event [Line Items]
Repayment of outstanding debt				$ 8,392,000	$ 13,628,000
Revolving Credit Facility [Member] | JPMorgan Chase Bank, N.A. [Member]
Subsequent Event [Line Items]
Purpose of new credit facility				The New Credit Facility will be available (i) to finance working capital needs, (ii) for general corporate purposes of the Company including permitted acquisitions, (iii) to refinance certain existing indebtedness, and (iv) to pay fees and expenses related to the New Credit Facility.
Subsequent Event [Member] | IPO [Member]
Subsequent Event [Line Items]
Number of shares issued and sold			9,865,004
Price per share			$ 13
Aggregate proceeds from IPO			$ 119,300,000
Stock issuance, offering costs			$ 4,100,000
Number of shares of common stock sold			3,934,996
Subsequent Event [Member] | IPO [Member] | Class A Common Stock [Member]
Subsequent Event [Line Items]
Shares issued upon conversion			2,200,000
Subsequent Event [Member] | IPO [Member] | Class A Common Stock [Member] | Chief Executive Officer [Member]
Subsequent Event [Line Items]
Number of stock options exercised			1,734,996
Subsequent Event [Member] | Maximum [Member]
Subsequent Event [Line Items]
Deferred tax assets, valuation allowance		$ 63,000,000
Subsequent Event [Member] | Minimum [Member]
Subsequent Event [Line Items]
Deferred tax assets, valuation allowance		60,000,000
Subsequent Event [Member] | Credit Facility [Member]
Subsequent Event [Line Items]
Repayment of outstanding debt	$ 93,100,000
Subsequent Event [Member] | Revolving Credit Facility [Member] | JPMorgan Chase Bank, N.A. [Member]
Subsequent Event [Line Items]
Aggregate commitment amount under credit facility		$ 100,000,000
Maturity term		5 years
Amount available under secured credit agreement		$ 150,000,000
Increase in line of credit borrowing capacity		$ 50,000,000
Maximum leverage ratio		300.00%
Minimum liquidity, amount		$ 20,000,000
Subsequent Event [Member] | Revolving Credit Facility [Member] | JPMorgan Chase Bank, N.A. [Member] | Federal Funds Effective Swap Rate [Member]
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate		0.50%
Subsequent Event [Member] | Revolving Credit Facility [Member] | JPMorgan Chase Bank, N.A. [Member] | London Interbank Offered Rate (LIBOR) [Member]
Subsequent Event [Line Items]
Debt instrument, basis spread on variable rate		1.00%
Subsequent Event [Member] | Revolving Credit Facility [Member] | Maximum [Member] | JPMorgan Chase Bank, N.A. [Member]
Subsequent Event [Line Items]
Commitment fees on unused portion of the Revolving Credit Facility		0.30%
Subsequent Event [Member] | Revolving Credit Facility [Member] | Maximum [Member] | JPMorgan Chase Bank, N.A. [Member] | Swingline Loans [Member]
Subsequent Event [Line Items]
Aggregate commitment amount under credit facility		$ 5,000,000
Applicable margin for borrowings under new credit facility		1.00%
Subsequent Event [Member] | Revolving Credit Facility [Member] | Maximum [Member] | JPMorgan Chase Bank, N.A. [Member] | Eurodollar Loans [Member]
Subsequent Event [Line Items]
Applicable margin for borrowings under new credit facility		2.00%
Subsequent Event [Member] | Revolving Credit Facility [Member] | Maximum [Member] | JPMorgan Chase Bank, N.A. [Member] | Letter of Credit [Member]
Subsequent Event [Line Items]
Aggregate commitment amount under credit facility		$ 5,000,000
Subsequent Event [Member] | Revolving Credit Facility [Member] | Minimum [Member] | JPMorgan Chase Bank, N.A. [Member]
Subsequent Event [Line Items]
Commitment fees on unused portion of the Revolving Credit Facility		0.15%
EBITDA to cash Consolidated Interest Expense ratio		300.00%
Subsequent Event [Member] | Revolving Credit Facility [Member] | Minimum [Member] | JPMorgan Chase Bank, N.A. [Member] | Swingline Loans [Member]
Subsequent Event [Line Items]
Applicable margin for borrowings under new credit facility		0.25%
Subsequent Event [Member] | Revolving Credit Facility [Member] | Minimum [Member] | JPMorgan Chase Bank, N.A. [Member] | Eurodollar Loans [Member]
Subsequent Event [Line Items]
Applicable margin for borrowings under new credit facility		1.25%