Altair Engineering (ALTR) 10-Q 8 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 22, 2019
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	ALTR
Entity Registrant Name	Altair Engineering Inc.
Entity Central Index Key	0001701732
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Current Reporting Status	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity File Number	001-38263
Entity Tax Identification Number	382591828
Entity Address, Address Line One	1820 East Big Beaver Road
Entity Address, City or Town	Troy
Entity Address, State or Province	Michigan
Entity Address, Postal Zip Code	48083
City Area Code	248
Local Phone Number	614-2400
Class A Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		39,734,927
Class B Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		31,900,732

Consolidated balance sheets

Consolidated balance sheets - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 251,828	$ 35,345
Accounts receivable, net	85,758	96,803
Income tax receivable	8,515	4,431
Prepaid expenses and other current assets	18,262	17,455
Total current assets	364,363	154,034
Property and equipment, net	34,050	30,153
Operating lease right of use assets	28,878
Goodwill	212,087	210,532
Other intangible assets, net	64,874	69,836
Deferred tax assets	5,901	5,354
Other long-term assets	19,567	17,288
TOTAL ASSETS	729,720	487,197
CURRENT LIABILITIES:
Current portion of long-term debt	472	331
Accounts payable	6,462	8,357
Accrued compensation and benefits	29,155	31,740
Current portion of operating lease liabilities	9,412
Other accrued expenses and current liabilities	27,979	27,039
Deferred revenue	67,587	59,765
Total current liabilities	141,067	127,232
Long-term debt, net of current portion	173,157	31,417
Operating lease liabilities, net of current portion	20,722
Deferred revenue, non-current	6,219	6,754
Other long-term liabilities	26,362	25,756
TOTAL LIABILITIES	367,527	191,159
Commitments and contingencies
MEZZANINE EQUITY	2,352	2,352
STOCKHOLDERS’ EQUITY:
Preferred stock ($0.0001 par value), authorized 45,000 shares, none issued and outstanding
Additional paid-in capital	433,902	379,832
Accumulated deficit	(64,964)	(74,863)
Accumulated other comprehensive loss	(9,104)	(11,290)
TOTAL STOCKHOLDERS’ EQUITY	359,841	293,686
TOTAL LIABILITIES, MEZZANINE EQUITY AND STOCKHOLDERS’ EQUITY	729,720	487,197
Class A Common Stock [Member]
STOCKHOLDERS’ EQUITY:
Common stock	4	4
Class B Common Stock [Member]
STOCKHOLDERS’ EQUITY:
Common stock	$ 3	$ 3

Consolidated balance sheets (Pa

Consolidated balance sheets (Parenthetical) - $ / shares	Jun. 30, 2019	Dec. 31, 2018
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	45,000,000	45,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Class A Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	513,797,000	513,797,000
Common stock, shares issued	39,672,000	38,349,000
Common stock, shares outstanding	39,672,000	38,349,000
Class B Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	41,203,000	41,203,000
Common stock, shares issued	31,901,000	32,171,000
Common stock, shares outstanding	31,901,000	32,171,000

Consolidated statements of oper

Consolidated statements of operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Total revenue	$ 106,773	$ 93,360	$ 234,632	$ 206,617
Total cost of revenue	31,023	29,456	63,908	58,498
Gross profit	75,750	63,904	170,724	148,119
Operating expenses:
Research and development	29,829	24,744	57,345	47,447
Sales and marketing	26,221	19,979	52,672	38,606
General and administrative	19,851	17,412	40,180	34,402
Amortization of intangible assets	3,600	1,986	7,128	3,926
Other operating income	(549)	(392)	(1,166)	(2,583)
Total operating expenses	78,952	63,729	156,159	121,798
Operating (loss) income	(3,202)	175	14,565	26,321
Interest expense	590	45	860	61
Other income, net	(505)	(176)	(115)	(1,076)
(Loss) income before income taxes	(3,287)	306	13,820	27,336
Income tax (benefit) expense	(167)	1,386	3,921	3,732
Net (loss) income	$ (3,120)	$ (1,080)	$ 9,899	$ 23,604
Income per share:
Net (loss) income per share attributable to common stockholders, basic	$ (0.04)	$ (0.02)	$ 0.14	$ 0.37
Net (loss) income per share attributable to common stockholders, diluted	$ (0.04)	$ (0.02)	$ 0.13	$ 0.32
Weighted average shares outstanding:
Weighted average number of shares used in computing net (loss) income per share, basic	71,373	65,580	71,081	64,614
Weighted average number of shares used in computing net (loss) income per share, diluted	71,373	65,580	77,017	72,881
License [Member]
Total revenue	$ 56,653	$ 46,700	$ 133,274	$ 113,635
Total cost of revenue	2,954	4,068	8,775	7,798
Maintenance and Other Services [Member]
Total revenue	27,755	23,907	54,425	46,641
Total cost of revenue	9,430	7,915	17,961	15,107
Total Software [Member]
Total revenue	84,408	70,607	187,699	160,276
Total cost of revenue	12,384	11,983	26,736	22,905
Software Related Services [Member]
Total revenue	7,907	8,707	17,679	18,180
Total cost of revenue	6,612	6,512	13,130	13,221
Total Software and Related Services [Member]
Total revenue	92,315	79,314	205,378	178,456
Total cost of revenue	18,996	18,495	39,866	36,126
Client Engineering Services [Member]
Total revenue	12,412	12,417	24,462	24,497
Total cost of revenue	10,033	9,960	19,833	20,160
Other [Member]
Total revenue	2,046	1,629	4,792	3,664
Total cost of revenue	$ 1,994	$ 1,001	$ 4,209	$ 2,212

Consolidated statements of comp

Consolidated statements of comprehensive income (loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (3,120)	$ (1,080)	$ 9,899	$ 23,604
Other comprehensive income (loss), net of tax:
Foreign currency translation (net of tax effect of $0, $0, $0 and $0, respectively)	1,605	(4,267)	1,942	(3,012)
Retirement related benefit plans (net of tax effect of $0 $(17), $0 and $(7), respectively)	16	118	244	106
Total other comprehensive income (loss)	1,621	(4,149)	2,186	(2,906)
Comprehensive (loss) income	$ (1,499)	$ (5,229)	$ 12,085	$ 20,698

Consolidated statements of co_2

Consolidated statements of comprehensive income (loss) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Foreign currency translation, tax effect	$ 0	$ 0	$ 0	$ 0
Retirement related benefit plans, tax effect	$ 0	$ (17)	$ 0	$ (7)

Consolidated statement of chang

Consolidated statement of changes in stockholders' equity - USD ($) shares in Thousands, $ 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]
Beginning balance at Dec. 31, 2017	$ 58,949	$ 2	$ 4	$ 232,156	$ (168,141)	$ (5,072)
Beginning balance (in shares) at Dec. 31, 2017		26,725	36,508
Net income (loss)	24,684				24,684
Adjustment for acquisitions	(96)			(96)
Exercise of stock options	301	$ 1		300
Exercise of stock options (in shares)		632
Stock-based compensation	216			216
Foreign currency translation, net of tax	1,255					1,255
Retirement related benefit plans, net of tax	(12)					(12)
Ending balance at Mar. 31, 2018	163,041	$ 3	$ 4	232,576	(65,713)	(3,829)
Ending balance (in shares) at Mar. 31, 2018		27,357	36,508
Beginning balance at Dec. 31, 2017	58,949	$ 2	$ 4	232,156	(168,141)	(5,072)
Beginning balance (in shares) at Dec. 31, 2017		26,725	36,508
Net income (loss)	23,604
Foreign currency translation, net of tax	(3,012)
Retirement related benefit plans, net of tax	106
Ending balance at Jun. 30, 2018	294,815	$ 4	$ 3	369,579	(66,793)	(7,978)
Ending balance (in shares) at Jun. 30, 2018		36,518	33,171
Beginning balance at Dec. 31, 2017	58,949	$ 2	$ 4	232,156	(168,141)	(5,072)
Beginning balance (in shares) at Dec. 31, 2017		26,725	36,508
Net income (loss)	15,535
Ending balance at Dec. 31, 2018	293,686	$ 4	$ 3	379,832	(74,863)	(11,290)
Ending balance (in shares) at Dec. 31, 2018		38,349	32,171
Cumulative effect of an accounting change	77,744				77,744
Beginning balance at Mar. 31, 2018	163,041	$ 3	$ 4	232,576	(65,713)	(3,829)
Beginning balance (in shares) at Mar. 31, 2018		27,357	36,508
Net income (loss)	(1,080)				(1,080)
Follow-on public offering, net of offering costs of $370	135,201	$ 1	$ (1)	135,201
Follow-on public offering, net of offering costs of $370 (shares)		5,731	(1,675)
Exercise of stock options	1,368			1,368
Exercise of stock options (in shares)		1,768
Conversion from Class B to Class A common stock		1,662	(1,662)
Stock-based compensation	434			434
Foreign currency translation, net of tax	(4,267)					(4,267)
Retirement related benefit plans, net of tax	118					118
Ending balance at Jun. 30, 2018	294,815	$ 4	$ 3	369,579	(66,793)	(7,978)
Ending balance (in shares) at Jun. 30, 2018		36,518	33,171
Beginning balance at Dec. 31, 2018	293,686	$ 4	$ 3	379,832	(74,863)	(11,290)
Beginning balance (in shares) at Dec. 31, 2018		38,349	32,171
Net income (loss)	13,019				13,019
Exercise of stock options	458			458
Exercise of stock options (in shares)		397
Vesting of restricted stock (in shares)		14
Stock-based compensation	869			869
Foreign currency translation, net of tax	337					337
Retirement related benefit plans, net of tax	228					228
Ending balance at Mar. 31, 2019	308,597	$ 4	$ 3	381,159	(61,844)	(10,725)
Ending balance (in shares) at Mar. 31, 2019		38,760	32,171
Beginning balance at Dec. 31, 2018	293,686	$ 4	$ 3	379,832	(74,863)	(11,290)
Beginning balance (in shares) at Dec. 31, 2018		38,349	32,171
Net income (loss)	9,899
Foreign currency translation, net of tax	1,942
Retirement related benefit plans, net of tax	244
Ending balance at Jun. 30, 2019	359,841	$ 4	$ 3	433,902	(64,964)	(9,104)
Ending balance (in shares) at Jun. 30, 2019		39,672	31,901
Beginning balance at Mar. 31, 2019	308,597	$ 4	$ 3	381,159	(61,844)	(10,725)
Beginning balance (in shares) at Mar. 31, 2019		38,760	32,171
Net income (loss)	(3,120)				(3,120)
Equity component of convertible senior notes, net of issuance costs	50,009			50,009
Exercise of stock options	812			812
Exercise of stock options (in shares)		608
Vesting of restricted stock (in shares)		34
Conversion from Class B to Class A common stock		270	(270)
Stock-based compensation	1,922			1,922
Foreign currency translation, net of tax	1,605					1,605
Retirement related benefit plans, net of tax	16					16
Ending balance at Jun. 30, 2019	$ 359,841	$ 4	$ 3	$ 433,902	$ (64,964)	$ (9,104)
Ending balance (in shares) at Jun. 30, 2019		39,672	31,901

Consolidated statement of cha_2

Consolidated statement of changes in stockholders' equity (Parenthetical) $ in Thousands	3 Months Ended
	Jun. 30, 2018USD ($)
Statement Of Stockholders Equity [Abstract]
Follow-on public offering, offering costs	$ 370

Consolidated statements of cash

Consolidated statements of cash flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
OPERATING ACTIVITIES:
Net income	$ 9,899	$ 23,604
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	10,468	7,525
Provision for bad debt	134	269
Amortization of debt discount and issuance costs	459	12
Stock-based compensation expense	3,292	650
Deferred income taxes	(703)	1,312
Other, net	(17)	(166)
Changes in assets and liabilities:
Accounts receivable	10,406	11,743
Prepaid expenses and other current assets	(4,952)	(3,454)
Other long-term assets	(2,300)	(276)
Accounts payable	(2,187)	335
Accrued compensation and benefits	(2,455)	73
Other accrued expenses and current liabilities	1,887	(4,511)
Operating lease right-of-use assets and liabilities, net	197
Deferred revenue	7,740	197
Net cash provided by operating activities	31,868	37,313
INVESTING ACTIVITIES:
Capital expenditures	(6,667)	(3,130)
Payments for acquisition of developed technology	(344)	(2,738)
Payments for acquisition of businesses, net of cash acquired	(709)	(7,028)
Other investing activities, net	16	38
Net cash used in investing activities	(7,704)	(12,858)
FINANCING ACTIVITIES:
Proceeds from issuance of convertible senior notes, net of underwriters' discount and commissions	223,101
Payments on revolving commitment	(127,941)
Borrowings under revolving commitment	96,991
Proceeds from the exercise of stock options	1,270	1,668
Payments for issuance costs of convertible senior notes	(1,018)
Payments for follow-on public offering and initial public offering costs		(468)
Proceeds from issuance of Class A common stock in follow-on public offering, net of underwriters' discounts and commissions		135,572
Other financing activities	(259)	(342)
Net cash provided by financing activities	192,144	136,430
Effect of exchange rate changes on cash, cash equivalents and restricted cash	187	(877)
Net increase in cash, cash equivalents and restricted cash	216,495	160,008
Cash, cash equivalents and restricted cash at beginning of year	35,685	39,578
Cash, cash equivalents and restricted cash at end of period	252,180	199,586
Supplemental disclosure of cash flow:
Interest paid	362	41
Income taxes paid	4,054	3,660
Supplemental disclosure of non-cash investing and financing activities:
Finance leases	566	1,010
Property and equipment in accounts payable	417	935
Convertible senior notes issuance costs in accounts payable	$ 216
Follow-on public offering costs in accounts payable		88
Promissory notes issued and deferred payment obligations for acquisitions		$ 278

Organization and Description of

Organization and Description of Business	6 Months Ended
	Jun. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and description of business Altair Engineering Inc. (“Altair” or the “Company”) is incorporated in the state of Delaware. The Company is a global technology company providing software and cloud solutions in the areas of product design and development, high performance computing and data intelligence. Altair enables organization across broad industry segments to complete more effectively in a connected world while creating a more sustainable future.

Accounting Policies

Accounting Policies	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Accounting Policies	2. Accounting policies Immaterial corrections of prior period financial statements In connection with the preparation of its financial statements for the quarter ended June 30, 2019, the Company identified and corrected certain errors that were immaterial to previously-reported consolidated financial statements. These errors related primarily to i) the cumulative effective adjustment for the income tax effect of intercompany transactions resulting from the adoption of Accounting Standards Codification (“ASC”) No. 606, Revenue from Contracts with Customers Materiality Considering the Effects of Prior Year Misstatements When Quantifying Misstatements in Current Year Financial Statements The following table presents the effect of the error corrections on the Company’s consolidated balance sheet for the period indicated (in thousands): December 31, 2018 As Reported Adjustments As Corrected Deferred tax assets $ 1,373 $ 3,981 $ 5,354 Total assets $ 483,216 $ 3,981 $ 487,197 Other accrued expenses and current liabilities $ 27,565 $ (526 ) $ 27,039 Total current liabilities $ 127,758 $ (526 ) $ 127,232 Other long-term liabilities $ 28,153 $ (2,397 ) $ 25,756 Total liabilities $ 194,082 $ (2,923 ) $ 191,159 Accumulated deficit $ (82,005 ) $ 7,142 $ (74,863 ) Accumulated other comprehensive loss $ (11,052 ) $ (238 ) $ (11,290 ) Total stockholders' equity $ 286,782 $ 6,904 $ 293,686 Total liabilities, mezzanine equity and stockholders' equity $ 483,216 $ 3,981 $ 487,197 The adjustments for amounts similar to the above were also made to the Company’s consolidated balance sheets as of March 31, 2018, June 30, 2018, September 30, 2018, and March 31, 2019, respectively. The following tables present the effect of the error corrections on the consolidated statements of operations for the periods indicated (in thousands, except per share data): Year Ended December 31, 2018 As Reported Adjustments As Corrected Income before income taxes $ 27,024 $ — $ 27,024 Income tax expense $ 13,309 $ (1,820 ) $ 11,489 Net income $ 13,715 $ 1,820 $ 15,535 Net income per share attributable to common stockholders, basic $ 0.20 $ 0.03 $ 0.23 Net income per share attributable to common stockholders, diluted $ 0.18 $ 0.03 $ 0.21 Year Ended December 31, 2017 As Reported Adjustments As Corrected Loss before income taxes $ (36,411 ) $ — $ (36,411 ) Income tax expense $ 62,996 $ 2,534 $ 65,530 Net loss $ (99,407 ) $ (2,534 ) $ (101,941 ) Net income per share attributable to common stockholders, basic $ (1.89 ) $ (0.05 ) $ (1.94 ) Net income per share attributable to common stockholders, diluted $ (1.89 ) $ (0.05 ) $ (1.94 ) Additionally, the Company revised income tax expense, net income, and net income per share attributable to common stockholders (basic and diluted) on the consolidated statement of operations for the year ended December 31, 2016, to correct these errors, resulting in an increase of $0.2 million, a decrease of $0.2 million and a decrease of $0.01, respectively, from the previously reported amounts. Basis of presentation The accompanying unaudited consolidated financial statements 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 unaudited 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, 2018, included in the most recent Annual Report on Form 10-K filed with the SEC. 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 six months ended June 30, 2019, are not necessarily indicative of the results that may be expected for any future period. The Company adopted Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842), Adoption of ASC 606, Revenue from Contracts with Customers In the fourth quarter of fiscal 2018, the Company adopted ASC 606 effective on January 1, 2018, using the modified retrospective approach for all contracts not completed as of the date of adoption. Results for the three and six months ended June 30, 2018, have been modified to reflect the adoption of ASC 606 on January 1, 2018. The Company recorded a decrease to accumulated deficit of $84.6 million, or $77.7 million net of tax, on January 1, 2018, due to the cumulative effect of the ASC 606 adoption, with the impact primarily derived from revenue related to software licenses recognized at a point in time under ASC 606 that were historically recognized over time. There was no impact on Client Engineering Services or Other revenue upon the adoption of ASC 606. 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. Reclassifications Certain prior period amounts included in the 2018 consolidated statement of operations and consolidated balance sheet have been reclassified to conform to the current year presentation. Use of estimates The preparation of the consolidated 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. On an ongoing basis, management evaluates its significant estimates including the stand alone selling price, or SSP, for each distinct performance obligation included in customer contracts with multiple performance obligations, the incremental borrowing rate used in the valuation of lease liabilities, the determination of the period of benefit for capitalized costs to obtain a contract, fair value of convertible senior notes, provision for doubtful accounts, tax valuation allowances, liabilities for uncertain tax provisions, impairment of goodwill and intangible assets, retirement obligations, useful lives of intangible assets, revenue for fixed price contracts, valuation of common stock, and stock-based compensation. Actual results could differ from those estimates. 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): June 30, 2019 December 31, 2018 Cash and cash equivalents $ 251,828 $ 35,345 Restricted cash included in other long-term assets 352 340 Total cash, cash equivalents, and restricted cash $ 252,180 $ 35,685 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. Inventory Inventory was $2.8 million and $2.0 million at June 30, 2019 and December 31, 2018, respectively, and is included in prepaid expenses and other current assets in the consolidated balance sheets. Inventory consist of finished goods and is stated at the lower of cost and net realizable value. Cost is determined using the first-in, first-out method. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonable predictable costs of completion, disposal and transportation. The valuation of inventory requires management to estimate excess inventory as well as inventory that is not of saleable quality. The determination of obsolete or excess inventory requires management to estimate market conditions and future demand for the Company’s products. Receivable for French 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 activities. The tax credit is deductible from French income tax and any excess is carried forward three years. After three years, any unused credit may be reimbursed to the Company by the French government. As of June 30, 2019, the Company had approximately $12.0 million receivable from the French government related to CIR, of which $1.3 million was recorded in income tax receivable and the remaining $10.7 million was recorded in other long-term assets. As of December 31, 2018, the Company had approximately $11.7 million receivable from the French government related to CIR, of which $2.6 million was recorded in income tax receivable and the remaining $9.1 million was recorded in other long-term assets. CIR is subject to customary audit by French tax authorities. Mezzanine equity In 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 at the issuance date and classified as mezzanine equity in the consolidated balance sheet. The put right option is terminated if the shareholders sell their shares. As of December 31, 2017, the Company concluded that it is no longer probable that the put option will be exercised as the put value is substantially below market value and subsequent adjustment is not required. Classification of the of instrument shall remain as mezzanine equity until one of the following three events take place: (1) shares are sold on the open market; (2) a redemption feature lapses; or (3) there is a modification of the terms of the instrument. As none of these events have taken place as of June 30, 2019, the classification remains as mezzanine equity. Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use (“ROU”) assets, current portion of operating lease liabilities, and operating lease liabilities, net of current portion on the Company’s consolidated balance sheets. Finance leases are included in property and equipment, current portion of long-term debt, and long-term debt, net of current portion on the consolidated balance sheets. (Loss) income per share Basic (loss) income per share attributable to common stockholders is computed using the weighted average number of shares of common stock outstanding for the period, excluding stock options and restricted stock units (“RSUs”). Diluted (loss) income 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 and RSUs under the treasury stock method. The following table sets forth the computation of the numerators and denominators used in the basic and diluted (loss) income per share amounts (in thousands, except per share data): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator: Net (loss) income $ (3,120 ) $ (1,080 ) $ 9,899 $ 23,604 Denominator: Denominator for basic (loss) income per share— weighted average shares 71,373 65,580 71,081 64,614 Effect of dilutive securities, stock options and RSUs — — 5,936 8,267 Denominator for dilutive (loss) income per share 71,373 65,580 77,017 72,881 Net (loss) income per share attributable to common stockholders, basic $ (0.04 ) $ (0.02 ) $ 0.14 $ 0.37 Net (loss) income per share attributable to common stockholders, diluted $ (0.04 ) $ (0.02 ) $ 0.13 $ 0.32 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 the three months ended June 30, 2019, there were 5.6 million anti-dilutive stock options excluded from the computation of (loss) income per share. For the three months ended June 30, 2018, there were 7.8 million anti-dilutive stock options excluded from the computation of (loss) income per share. For both the six months ended June 30, 2019 and 2018, there were no anti-dilutive shares excluded from the computation of (loss) income per share. The Company expects to settle the principal amount of the Convertible Notes (as defined in Note 8) in cash, and therefore, the Company uses the treasury stock method for calculating any potential dilutive effect of the Conversion Option (as defined in Note 8) on diluted net (loss) income per share, if applicable. The Conversion Option will have a dilutive impact on net income per share of common stock when the average market price of the Company’s Class A common stock for a given period exceeds the conversion price of the Convertible Notes of $46.50 per share. During the three months ended June 30, 2019, the Company's weighted average common stock price was below the conversion price of the Convertible Notes.

Recent Accounting Guidance

Recent Accounting Guidance	6 Months Ended
	Jun. 30, 2019
Accounting Changes And Error Corrections [Abstract]
Recent Accounting Guidance	3. Accounting standards adopted Leases —In February 2016, the Financial Accounting Standard Board, or “FASB”, issued Accounting Standards Update, or “ASU”, No. 2016-02, . This standard amends various aspects of existing accounting guidance for leases, including the recognition of a right-of-use (ROU) asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. The Company adopted ASU 2016-02 and its related amendments, on January 1, 2019 and elected the optional transition method and the package of practical expedients on adoption. Accordingly, t he prior period comparative information has not been restated and continues to be reported under the accounting guidance in effect for those periods, including the disclosure requirements. The most significant impact of the adoption of ASC 842 was the recognition of ROU assets and lease liabilities for operating leases on the Company’s consolidated balance sheet. On adoption, the Company recognized operating liabilities associated with leases of $30.1 million and corresponding ROU assets of $29.1 million, based on the present value of the remaining minimum rental payments under current leasing standards for existing operating leases. See Note 9 – Leases for further discussion. The Company’s accounting for finance leases (previously referred to as capital leases prior to the adoption of ASC 842) remained substantially unchanged. The standard had no impact on the Company’s consolidated net income or cash flows. Derivatives and Hedging – In August 2017, the FASB issued ASU 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities. This ASU amends the guidance with the objective of improving the financial reporting of hedging relationships to better portray the economic results of an entity’s risk management activities in its financial statements. In addition, this ASU amends the current guidance to simplify the application of the hedge accounting guidance. The Company adopted ASU 2017-12 on January 1, 2019. The adoption of this guidance did not have a material effect on the Company’s consolidated financial statements. Comprehensive Income – In February 2018, the FASB issued ASU 2018-02, , which gives entities the option to reclassify to retained earnings the tax effects resulting from the Tax Cuts and Jobs Act, or the “Tax Act”, related to items in AOCI that the FASB refers to as having been stranded in AOCI. The Company adopted this guidance on January 1, 2019 and elected not to reclassify amounts stranded in AOCI. The Company reclassifies taxes from AOCI to earnings as the items to which the tax effects relate are similarly reclassified. The adoption of ASU 2018-02 did not have a material effect on the Company’s consolidated financial statements. Stock Compensation – In June 2018, the FASB issued ASU 2018-07, This ASU simplifies the accounting for share-based payments to nonemployees by aligning it with the accounting for share-based payments to employees, with certain exceptions. The Company adopted this guidance on January 1, 2019, which did not have a material effect on the Company’s consolidated financial statements. Accounting standards not yet adopted Credit Losses – In June 2016, the FASB issued ASU 2016-13, Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The ASU significantly changes how entities will measure credit losses on most financial assets. This guidance is effective for annual periods beginning after 15 December 2019, and interim periods therein; early adoption is permitted. The Company is currently evaluating the impact of this new guidance on its consolidated financial statements and related disclosures. Goodwill Impairment —In January 2017, the FASB issued ASU No. 2017-04, , which simplifies accounting for goodwill impairments by eliminating step two from the goodwill impairment test. This guidance is effective for annual or interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted for interim and annual goodwill impairment tests performed on testing dates after January 1, 2017. The new standard must be applied on a prospective basis. The adoption of this guidance is not expected to have a material impact on the Company’s consolidated financial statements. Fair Value – In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement. This ASU modifies the disclosure requirements for fair value measurements, by removing, modifying, or adding certain disclosures. The amendments are effective for fiscal years, and interim reporting periods within those fiscal years, beginning after December 15, 2019. Early adoption is permitted for any removed or modified disclosures. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements and related disclosures. Retirement Benefits – In August 2018, the FASB issued ASU 2018-14, Compensation – Retirement Benefits- Defined Benefit Plans – General (Subtopic 715-20): Disclosure Framework – Changes to the Disclosure Requirements for Defined Benefit Plans. This ASU modifies the disclosure requirements for defined benefit pension or other postretirement plans. T he amendments are effective for fiscal years ending after December 15, 2020 ; e arly adoption is permitted. The adoption of this guidance is not expected to have a material impact on the Company’s consolidated financial statements. Intangibles – In August 2018, the FASB issued ASU 2018-15, Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract. This ASU clarifies and aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The amendments are effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years; early adoption is permitted. The Company is currently evaluating the impact of the new guidance on its consolidated financial statements and related disclosures.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	6 Months Ended
	Jun. 30, 2019
Revenue From Contract With Customer [Abstract]
Revenue from Contracts with Customers	4 . Revenue from contracts with customers Revenue recognition Software revenue Revenue is derived principally from the licensing of software products and from related maintenance contracts. The Company enters into contracts that include combinations of products, maintenance and services, which are accounted for as separate performance obligations with differing revenue recognition patterns. Revenue from term-based software licenses is classified as software revenue. Term-based licenses are sold only as a bundled arrangement that includes the rights to a term software license and post-contract customer support (PCS), which includes unspecified technical enhancements and customer support. Maximizing the use of observable inputs, the Company determined that a majority of the estimated standalone selling prices of the term-based license is attributable to the term license and a minority is attributable to the PCS. The license component is classified as license revenue and recognized as revenue upon the later of delivery of the licensed product or the beginning of the license period In addition to term-based software licenses, the Company sells perpetual licenses. Software revenue is recognized upon the later of delivery of the licensed product or the beginning of the license period Revenue from training, consulting and other services is recognized as the services are performed, and is classified as maintenance and other services in the consolidated statement of operations. For contracts in which the service consists of a single performance obligation, such as providing a training class to a customer, the Company recognizes revenue upon completion of the performance obligation. For service contracts that are longer in duration and often include multiple performance obligations (for example, point-in-time training and consulting), the Company measures the progress toward completion of the obligations and recognizes revenue accordingly. In measuring progress towards the completion of performance obligations, the Company typically utilizes output-based estimates for services with fixed fee arrangements, and estimates output based on the total tasks completed as compared to the total tasks required for each contract. Input-based estimates are utilized for services that involve general consultations with contractual billing arrangements based on time and materials, utilizing direct labor as the input measure. The Company also executes arrangements through indirect channel partners in which the channel partners are authorized to market and distribute the Company's software products to end users of the Company's products and services in specified territories. In sales facilitated by channel partners, the channel partner bears the risk of collection from the end-user customer. The Company recognizes revenue from transactions with channel partners when the channel partner submits a purchase commitment, collectability from the channel partner is probable, and the performance obligation is met, at a point in time or over time as appropriate, provided that all other revenue recognition criteria are satisfied. Revenue from channel partner transactions is the amount remitted to the Company by the channel partners. This amount includes a fee for PCS that is compensation for providing technical enhancements and the second level of technical support to the end user, which is recognized over the period that PCS is to be provided. The Company does not offer right of return, product rotation , or price protection to any of its channel partners. Non-income related taxes collected from customers and remitted to governmental authorities are recorded on the consolidated balance sheet as accounts receivable, net and other accrued expenses and current liabilities. These amounts are reported on a net basis in the consolidated statements of operations and do not impact reported revenues or expenses. Significant judgments Software revenue The Company’s contracts with customers typically include promises to transfer licenses and services to a customer. Judgment is required to determine if the promises are separate performance obligations within the context of the arrangement, and if so, the allocation of the transaction price to each performance obligation. The Company’s determination of standalone selling price for performance obligations is based on the midpoint of the range of historical observable prices for goods and services sold separately. In addition, the Company estimates the standalone selling price for certain performance obligations where observable prices are not directly available or a significant portion of historical prices are not within the range. The Company estimates standalone selling price at contract inception considering all information that is reasonably available and is based on the amount of consideration for which the Company expects to be entitled in exchange for transferring the promised good or service to the customer. The corresponding revenues are recognized as the related performance obligations are satisfied. The Company’s contracts do not include a significant financing component requiring adjustment to the transaction price. Payment terms vary by contract type; however, arrangements typically stipulate a requirement for the customer to pay within 30 days. The Company rarely enters into agreements to modify previously executed contracts, which constitute contract modifications. The Company assesses each of these contract modifications to determine (i) if the additional products and services are distinct from the products and services in the original arrangement; and (ii) if the amount of consideration expected for the added products and services reflects the stand-alone selling price of those products and services, as adjusted for contract-specific circumstances. A contract modification meeting both criteria is accounted for as a separate contract. A contract modification not meeting both criteria is considered a change to the original contract and is accounted for on either (i) a prospective basis as a termination of the existing contract and the creation of a new contract; or (ii) a cumulative catch-up basis. Generally, the Company’s contract modifications meet both criteria and are accounted for as a separate contract, as adjusted for contract-specific circumstances. Software related services revenue Consulting services from product design and development projects are considered distinct performance obligations and are provided to customers on a time-and-materials (“T&M”) or fixed-price basis. Altair recognizes software services revenue for T&M contracts based upon hours worked and contractually agreed-upon hourly rates using the input method. Revenue from fixed-price engagements is recognized using the output method based on the ratio of costs incurred, to the total estimated project costs. Client engineering services and Other revenue Client engineering services revenue are derived from professional services for staffing primarily representing engineers and data scientists located at a customer site. These professional services are considered distinct performance obligations and are provided to customers on a T&M basis. The Company recognizes this revenue for T&M contracts based upon hours worked and contractually agreed-upon hourly rates using the input method. No significant judgments were made for revenue recognition within Other revenue. Disaggregation of revenue The Company disaggregates its software revenue by type of performance obligation and timing of revenue recognition as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Software revenue: Term licenses $ 45,974 $ 38,707 $ 111,031 $ 95,872 Perpetual licenses 10,679 7,993 22,243 17,763 Maintenance 25,333 20,869 48,085 41,697 Professional services and other 2,422 3,038 6,340 4,944 Total software revenue $ 84,408 $ 70,607 $ 187,699 $ 160,276 T he Company derived approximately 10% of its total revenue through indirect sales channels for the six months ended June 30, 2019 and 2018. Software related services revenue, client engineering services revenue, and other revenue were categorized based on the nature and timing of revenue and cash flows effected by economic factors. Costs to obtain a contract The Company pays commissions for new software product and PCS sales as well as for renewals of existing software and PCS contracts. Commissions paid to obtain renewal contracts are not commensurate with the commissions paid for new product sales and therefore, a portion of the commissions paid for new contracts relate to future renewals. The Company accounts for new product sales commissions using a portfolio approach and allocates the cost of commissions in proportion to the allocation of transaction price of license and PCS performance obligations. Commissions allocated to the license and license renewal components are expensed at the time the license revenue is recognized. Commissions allocated to PCS are capitalized and amortized on a straight-line basis over a period of four years, reflecting the Company’s estimate of the expected period that it will benefit from those commissions. As of June 30, 2019 and December 31, 2018, capitalized costs to obtain a contract were $2.4 million and $2.0 million, respectively, recorded in prepaid and other current assets, and $0.4 million and $0.2 million, respectively, recorded in other long-term assets. Amortization expense was $1.2 million, $1.0 million, $2.2 million and $1.9 million for the three months ended June 30, 2019 and 2018 and six months ended June 30, 2019 and 2018, respectively, and was included in sales and marketing expense in the Company’s consolidated Contract assets At June 30, 2019 and December 31, 2018, contract assets were $5.6 million and $3.7 million, respectively, recorded in accounts receivable, and $3.5 million and $2.7 million, respectively, recorded in prepaid expenses and other current assets. Deferred revenue Deferred revenue consists of billings made or payments received in advance of revenue recognition from software license, PCS and professional services agreements. The timing of revenue recognition may differ from the timing of billings to customers. Payment terms vary by the type and location of customer and the products or services offered. The term between invoicing and when payment is due is not significant. The Company generally invoices its customers annually for the forthcoming year of software licenses, and more frequently for other products and services. Accordingly, the Company’s deferred revenue balance does not include revenue for future years of multiple year non-cancellable contracts that have not yet been billed. Approximately $45.0 million of revenue recognized during the six months ended June 30, 2019, was included in the deferred revenue balances at the beginning of the year.

Acquisitions

Acquisitions	6 Months Ended
	Jun. 30, 2019
Business Combinations [Abstract]
Acquisitions	5 . Acquisitions Datawatch Corporation On November 5, 2018, the Company entered into an Agreement and Plan of Merger (“Merger Agreement”) with Datawatch Corporation, a Delaware corporation (“Datawatch”), and Dallas Merger Sub, Inc., a Delaware corporation (“Purchaser”) and a wholly owned subsidiary of the Company. Pursuant to the Merger Agreement, the Purchaser commenced a tender offer to purchase all of the issued and outstanding shares of Datawatch common stock, (the “Shares”) at a purchase price of $13.10 per share, net to seller in cash, without interest and less any applicable withholding taxes (the “Offer”). On December 13, 2018, the Company accepted and paid for all Shares that were validly tendered and completed the acquisition of Datawatch through the merger of Purchaser with and into Datawatch, with Datawatch surviving as a wholly owned subsidiary of the Company. Altair completed the acquisition of Datawatch for consideration of approximately $183.4 million which consisted of consideration paid to former holders of common stock of Datawatch at $13.10 a share, or $168.2 million and approximately $6.7 million to former holders of outstanding Datawatch equity awards. In addition, Altair paid $8.0 million on the day of closing to settle all of Datawatch’s outstanding debt and incurred a liability of approximately $0.5 million payable to former holders of certain unvested Datawatch equity awards for which service had been rendered at the acquisition date. Altair financed the acquisition with cash on hand and a drawdown from its existing credit facility. The financial results of Datawatch have been included in the consolidated financial statements since the acquisition date. The acquisition of Datawatch has been accounted for as a business combination, under the acquisition method of accounting, which results in acquired assets and assumed liabilities being measured at their estimated fair values as of December 13, 2018, the acquisition date. As of the acquisition date, goodwill is measured as the excess of consideration transferred, which is also generally measured at fair value of the net acquisition date fair values of the assets acquired and liabilities assumed. The following table summarizes the preliminary purchase consideration transferred to acquire Datawatch and the amounts of identified assets acquired and liabilities assumed at the acquisition date (in thousands): Fair value of consideration transferred $ 183,427 Recognized amounts of identifiable assets acquired and liabilities assumed: Cash 8,278 Accounts receivable 10,384 Other assets 2,522 Property and equipment 980 Trade names 7,400 Developed technology (6-year life) 22,600 Customer relationships (10-year life) 16,700 Accounts payable and other liabilities (5,041 ) Deferred revenue (3,649 ) Other long-term liabilities (8,340 ) Total net identifiable assets acquired and liabilities assumed 51,834 Goodwill (1) $ 131,593 (1) Goodwill is primarily attributable to market synergies expected to arise after the acquisition and approximately $0.8 million is deductible for tax purposes. All goodwill is recorded in the Software segment. The excess of preliminary purchase consideration over the preliminary fair value of net tangible and identifiable intangible assets acquired was recorded as goodwill. The preliminary fair values assigned to tangible and identifiable intangible assets acquired and liabilities assumed are based on management’s estimates and assumptions. The deferred tax liability established was primarily a result of the difference in the book basis and tax basis related to the identifiable intangible assets. The preliminary estimated fair values of assets acquired and liabilities assumed, including current and noncurrent income taxes payable and deferred taxes, customer contract assets and liabilities and identifiable intangible assets may be subject to change as additional information is received and certain tax returns are finalized. Thus, the provisional measurements of fair value set forth above are subject to change. 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. SIMSOLID Corporation In October 2018, the Company acquired all of the outstanding capital stock

Property and Equipment, Net

Property and Equipment, Net	6 Months Ended
	Jun. 30, 2019
Property Plant And Equipment [Abstract]
Property and Equipment, Net	6 . Property and equipment, net Property and equipment consisted of the following (in thousands): June 30, December 31, 2019 2018 Land $ 7,994 $ 7,994 Building and improvements 13,379 13,120 Computer equipment and software 36,354 34,582 Office furniture and equipment 8,512 7,958 Leasehold improvements 8,500 6,926 Right-of-use assets under finance leases 2,607 — Total property and equipment 77,346 70,580 Less: accumulated depreciation and amortization 43,296 40,427 Property and equipment, net $ 34,050 $ 30,153 Depreciation expense, including amortization of ROU assets under finance leases, was $1.6 million and $3.3 million for the three and six months ended June 30, 2019, respectively, and 2.0 million and $3.6 million for the three and six months ended June 30, 2018, respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	6 Months Ended
	Jun. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	7 . Goodwill and other intangible assets Goodwill The changes in the carrying amount of goodwill, which is attributable to the Software reporting segment, were as follows (in thousands): Balance at December 31, 2018 $ 210,532 Effects of foreign currency translation and other 1,555 Balance at June 30, 2019 $ 212,087 Other intangible assets A summary of other intangible assets is shown below (in thousands): June 30, 2019 Weighted average amortization period Gross carrying amount Accumulated amortization Net carrying amount Definite-lived intangible assets: Developed technology 4-6 years $ 56,385 $ 20,654 $ 35,731 Customer relationships 7-10 years 28,750 9,405 19,345 Other intangibles 10 years 219 60 159 Total definite-lived intangible assets 85,354 30,119 55,235 Indefinite-lived intangible assets: Trade names 9,639 9,639 Total other intangible assets $ 94,993 $ 30,119 $ 64,874 December 31, 2018 Weighted average amortization period Gross carrying amount Accumulated amortization Net carrying amount Definite-lived intangible assets: Developed technology 4-6 years $ 54,530 $ 15,517 $ 39,013 Customer relationships 7-10 years 28,422 7,309 21,113 Other intangibles 10 years 109 56 53 Total definite-lived intangible assets 83,061 22,882 60,179 Indefinite-lived intangible assets: Trade names 9,657 9,657 Total other intangible assets $ 92,718 $ 22,882 $ 69,836 Amortization expense related to intangible assets was $3.6 million and $7.1 million for the three and six months ended June 30, 2019, respectively, and $2.0 million and $3.9 million for the three and six months ended June 30, 2018, respectively.

Debt

Debt	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Debt	8 . Debt The carrying value of debt is as follows (in thousands): June 30, December 31, 2019 2018 Convertible senior notes $ 230,000 $ — Revolving credit facility — 30,950 Obligations for finance leases 1,298 813 Other borrowings 25 75 Total debt 231,323 31,838 Less: unamortized debt discount 51,443 — Less: unamortized debt issuance costs 6,251 90 Less: current portion of long-term debt 472 331 Long-term debt, net of current portion $ 173,157 $ 31,417 Convertible senior notes In June 2019, the Company issued $230.0 million aggregate principal amount of 0.25% convertible senior notes due in 2024 (the "Convertible Notes"), which includes the underwriters’ exercise in full of their option to purchase an additional $30.0 million principal amount of the Convertible Notes, in a public offering. The net proceeds from the issuance of the Convertible Notes were $221.9 million after deducting the underwriting discounts and commissions and estimated issuance costs. The Company entered into a First Supplemental Indenture relating to the issuance by the Company of the Convertible Notes (the “Supplemental Indenture”) supplementing the Indenture, dated June 10, 2019 (the “Base Indenture,” and together with the Supplemental Indenture, the “Indenture”), by and between the Company and U.S. Bank National Association, as trustee (the “Trustee”). The Indenture includes customary covenants and sets forth certain events of default after which the Convertible Notes may be declared immediately due and payable and sets forth certain types of bankruptcy or insolvency events of default involving the Company after which the Convertible Notes become automatically due and payable. The Convertible Notes are senior unsecured obligations of the Company. The Convertible Notes bear interest at a rate of 0.25% per year, payable semi-annually in arrears on June 1 and December 1 of each year, commencing December 1, 2019. The Convertible Notes will mature on June 1, 2024, unless, earlier repurchased or redeemed by the Company or converted pursuant to their terms. The Convertible Notes have an initial conversion rate of 21.5049 shares of the Company's Class A common stock per $1,000 principal amount of Convertible Notes, which is equivalent to an initial conversion price of approximately $46.50 per share of its Class A common stock. The conversion rate will be subject to adjustment upon the occurrence of certain events specified in the Indenture but will not be adjusted for any accrued and unpaid interest. In addition, upon the occurrence of a make whole fundamental change or a redemption period (each as defined in the Indenture), the Company will, in certain circumstances, increase the conversion rate by a specified number of additional shares for a holder who elects to convert its Convertible Notes in connection with such make whole fundamental change or during the relevant redemption period. Holders of the Convertible Notes may convert all or any portion of their Convertible Notes at any time prior to the close of business on December 1, 2023, in integral multiples of $1,000 principal amount, only under the following circumstances: • During any calendar quarter commencing after the calendar quarter ending on September 30, 2019 (and only during such calendar quarter), if the last reported sale price of the Class A Common Stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; • During the five business day period after any five consecutive trading day period (the “measurement period”) in which the trading price (as defined in the Indenture) per $1,000 principal amount of Convertible Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Class A Common Stock and the conversion rate on each such trading day; • If the Company calls any or all of the Convertible Notes for redemption (which the Company may not do prior to June 6, 2022), at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date; or • Upon the occurrence of specified corporate events. On or after December 1, 2023 until the close of business on the business day immediately preceding the maturity date, holders may convert their Convertible Notes at any time, regardless of the foregoing circumstances. Upon conversion, the Company may satisfy its conversion obligation by paying and/or delivering, as the case may be, cash, shares of Class A Common Stock or a combination of cash and shares of the Class A Common Stock, at the Company’s election, in the manner and subject to the terms and conditions provided in the Indenture. During the period ended June 30, 2019, the conditions allowing holders of the Convertible Notes to convert were not met. Therefore, the Convertible Notes were classified as long-term debt on the consolidated balance sheet as of June 30, 2019. The Company accounts for the Convertible Notes as separate liability and equity components. The carrying amount of the liability component of the Convertible Notes was calculated by measuring the fair value of similar debt instruments that do not have an associated convertible feature. The Company determined the carrying amount of the liability component as the present value of its cash flows using a discount rate of approximately 5.5%. The estimated interest rate was applied to the Convertible Notes, which resulted in a fair value of the liability component of $178.2 million upon issuance, calculated as the present value of future contractual payments based on the $230.0 million aggregate principal amount. The excess of the principal amount of the liability component over its carrying amount, or the debt discount, is amortized to interest expense over the term of the Convertible Notes using the effective interest method. The $51.8 million difference between the gross proceeds received from issuance of the Convertible Notes of $230.0 million and the estimated fair value of the liability component represents the equity component, or the “Conversion Option”, of the Convertible Notes and was recorded in additional paid-in capital. The equity component is not remeasured as long as it continues to meet the conditions for equity classification. The Company allocates issuance costs related to the issuance of the Convertible Notes to the liability and equity components using the same proportions as the initial carrying value of the Convertible Notes. Issuance costs attributable to the liability component were $6.3 million and are being amortized to interest expense using the effective interest method over the term of the Convertible Notes. Issuance costs attributable to the equity components were $1.8 million and are netted with the equity component of the Convertible Notes in stockholders’ equity on the condensed consolidated balance sheets. The net carrying value of the liability component of the Convertible Notes was as follows (in thousands): June 30, 2019 Principal $ 230,000 Less: unamortized debt discount 51,443 Less: unamortized debt issuance costs 6,251 Net carrying amount $ 172,306 The net carrying value of the equity component of the Convertible Notes was as follows (in thousands): June 30, 2019 Proceeds allocated to the conversion option (debt discount) $ 51,842 Less: issuance costs 1,833 Net carrying amount $ 50,009 The interest expense recognized related to the Convertible Notes was as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2019 Contractual interest expense $ 25 $ 25 Amortization of debt issuance cost and discount 447 447 Total $ 472 $ 472 Credit agreement Revolving credit facility The Company has a $150.0 million credit facility that was amended on June 5, 2019, to permit the issuance of the Convertible Notes and extend the maturity date of the credit facility to December 15, 2023 (“2019 Amended Credit Agreement”). The 2019 Amended Credit Agreement provides for an accordion feature that allows the Company to expand the size of the revolving line of credit by an additional $50.0 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 2019 Amended Credit Agreement). As of June 30, 2019, the Company had no outstanding borrowings under the 2019 Amended Credit Agreement and there was $150.0 million available for future borrowing. The 2019 Amended Credit Agreement is available for general corporate purposes, including working capital, capital expenditures, and permitted acquisitions. Borrowings under the 2019 Amended Credit Agreement 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 2019 Amended Credit Agreement) in effect on such day, (2) the Federal Funds Effective Rate (as defined in the 2019 Amended Credit Agreement) in effect on such day plus 1/2 of 1.00% or (3) the Adjusted LIBO Rate (as defined in the 2019 Amended Credit Agreement) 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 2019 Amended Credit Agreement is 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 and swingline loans, 0.25% to 1.00%. The Company pays a commitment fee (based on the Company’s most recently tested consolidated total senior secured net leverage ratio) ranging from 0.15% to 0.30% on the unused portion of the 2019 Amended Credit Agreement. Collateral and guarantees The 2019 Amended Credit Agreement is secured by collateral including (i) substantially all of the Company’s properties and assets, and the properties and assets of the Company’s direct and indirect 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 direct and indirect domestic subsidiaries (subject in each case to certain exceptions as provided for under the 2019 Amended Credit Agreement). The Company’s direct and indirect domestic subsidiaries are guarantors of all the obligations under the 2019 Amended Credit Agreement. Debt covenants The 2019 Amended Credit Agreement requires the Company to maintain the following financial covenants: • Maximum Net Leverage Ratio : On the last day of each fiscal quarter, the Company on a consolidated basis will not permit the ratio of total indebtedness (net of unrestricted domestic cash in excess of $20.0 million) to EBITDA, as such terms are defined in the 2019 Amended Credit Agreement, for the rolling four quarter period ending on such date to be greater than 5.00 to 1.00 as of the last day of any such fiscal quarter. • Senior Secured Leverage Ratio : On the last day of each fiscal quarter, the Company on a consolidated basis will not permit the ratio of total indebtedness secured by a lien (net of unrestricted domestic cash in excess of $20.0 million) to EBITDA, as such terms are defined in the 2019 Amended Credit Agreement, for the rolling four quarter period ending on such date to be greater than 3.00 to 1.00 as of the last day of any such fiscal quarter. • Consolidated Interest Coverage Ratio : On the last day of each fiscal quarter, the Company on a consolidated basis will not permit the ratio of (x) EBITDA to (y) cash Consolidated Interest Expense, as such terms are defined in the 2019 Amended Credit Agreement, in each case for the rolling four quarter period ending on such date, to be less than 3.00 to 1.00 as of the last day of any such fiscal quarter. At June 30, 2019, the Company was in compliance with all the financial covenants.

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases	9 . Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease assets and operating lease obligations on the Company’s consolidated balance sheets. Finance leases are included in property and equipment, current portion of long-term debt, and long-term debt on the consolidated balance sheets. ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments under the lease. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at commencement date. At commencement date, the ROU asset also includes adjustments for lease prepayments, lease incentives received and the lessee's initial direct costs, if applicable. As most of the Company’s leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The incremental borrowing rates are determined using rates specific to the term of the lease, economic environments where lease activity is concentrated, value of lease portfolio, and assuming full collateralization of the loans. Subsequent to the commencement date, the operating ROU asset is equal to the remeasured lease liability adjusted for cumulative prepaid or accrued rent if the lease payments are uneven throughout the lease term, unamortized lease incentives, unamortized initial direct costs and any impairment of the ROU assets. The lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease cost for minimum lease payments is recognized on a straight-line basis over the lease term. The Company has elected not to recognize a lease liability or ROU asset for short-term leases (leases with a term of twelve months or less). For contracts with lease and non-lease components, the Company has elected not to allocate the contract consideration, and account for the lease and non-lease components as a single lease component. The Company’s operating leases consist of office facilities, office equipment and cars and the Company’s finance leases consist of office equipment and cars. The Company’s leases have remaining terms of less than one year to 8.8 years, some of which include one or more options to renew, with renewal terms up to six years and some of which include options to terminate the leases within the next four years. The components of lease cost were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2019 Operating lease cost $ 3,359 $ 6,783 Finance lease cost: Amortization of ROU assets $ 126 $ 247 Interest on lease liabilities 5 10 Total finance lease cost $ 131 $ 257 Operating lease cost includes short-term leases and variable lease costs, which are immaterial. Rent cost related to operating leases for office facilities was $2.9 million and $6.0 million for the three and six months ended June 30, 2019, respectively, and $2.3 million and $4.6 million for the three and six months ended June 30, 2018, respectively. Supplemental balance sheet information related to lease liabilities at June 30, 2019, was as follows: (in thousands, except lease term and discount rate) Operating leases: Operating lease ROU assets $ 28,878 Current portion of operating lease liabilities $ 9,412 Operating lease liabilities, net of current portion 20,722 Total operating lease liabilities $ 30,134 Weighted average remaining lease term 4.2 years Weighted average discount rate 5.3 % Finance leases: Property and equipment $ 2,607 Accumulated depreciation (1,111 ) Property and equipment, net $ 1,496 Current portion of long-term debt $ 447 Long-term debt, net of current portion 851 Total finance lease liabilities $ 1,298 Weighted average remaining lease term 3.2 years Weighted average discount rate 3.4 % Supplemental cash flow information related to leases for the six months ended June 30, 2019, was as follows (in thousands): Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ (5,665 ) Operating cash flows from finance leases $ (25 ) Financing cash flows from finance leases $ (209 ) ROU assets obtained in exchange for lease obligations: Operating leases $ 6,545 Finance leases $ 566 Maturities of operating lease liabilities at June 30, 2019, were as follows (in thousands): Year ending December 31, 2019 (excluding the six months ended June 30, 2019) $ 5,715 2020 9,508 2021 7,089 2022 4,811 2023 2,971 Thereafter 3,335 Total lease payments 33,429 Less: imputed interest 3,295 Total operating lease liabilities $ 30,134 Total obligations for finance leases, previously referred to as capital leases prior to the adoption of Topic 842

Other Liabilities

Other Liabilities	6 Months Ended
	Jun. 30, 2019
Other Liabilities Disclosure [Abstract]
Other Liabilities	10 . Other liabilities The following table provides the details of other accrued expenses and current liabilities (in thousands): June 30, December 31, 2019 2018 Income taxes payable $ 7,732 $ 3,932 Accrued VAT 3,985 4,536 Accrued royalties 3,527 2,613 Accrued professional fees 3,403 3,165 Defined contribution plan liabilities 1,225 1,376 Government grants 859 915 Non-income tax liabilities 685 853 Billings in excess of cost 520 1,504 Other current liabilities 6,043 8,145 Total $ 27,979 $ 27,039 The following table provides details of other long-term liabilities (in thousands): June 30, December 31, 2019 2018 Pension and other post retirement liabilities $ 9,782 $ 9,111 Deferred tax liabilities 5,725 5,339 Other liabilities 10,855 11,306 Total $ 26,362 $ 25,756

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	11. 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 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. 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. As of June 30, 2019, the fair value of the Convertible Notes was $249.6 million. The estimated fair values of the Convertible Notes, which the Company has classified as Level 2 financial instruments, were determined based on quoted bid prices of the Convertible Notes on the last trading day of each reporting period. The Company carries the convertible senior notes at face value less unamortized debt discount and issuance costs on its consolidated balance sheet, and it presents the fair value for required disclosure purposes only. For further information on the Convertible Notes see Note 8. – Debt.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	12 . 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 3,815,348 stock options with an exercise price of $0.000025 remain outstanding at June 30, 2019. 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 for the period: Number of options Weighted average exercise price per share Weighted average remaining contractual term (years) Aggregate intrinsic value (in millions) Outstanding at January 1, 2019 4,337,856 $ 0.000025 18.0 $ 119.6 Exercised (522,508 ) $ 0.000025 Forfeited — — Outstanding and exercisable at June 30, 2019 3,815,348 $ 0.000025 17.5 $ 154.1 The total intrinsic value of the NSO Plan stock options exercised during the six months ended June 30, 2019, was $19.8 million. 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”) covering 11,153,872 shares of Class A common 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. The following table summarizes the stock option activity under the 2001 stock-based compensation plans for the period: Number of options Weighted average exercise price per share Weighted average remaining contractual term (years) Aggregate intrinsic value (in millions) Outstanding at January 1, 2019 532,220 $ 0.65 1.4 $ 14.3 Exercised (218,693 ) $ 0.67 Forfeited — — Outstanding and exercisable at June 30, 2019 313,527 $ 0.64 0.8 $ 12.5 The total intrinsic value of the ISO Plan stock options exercised during the six months ended June 30, 2019, was $7.4 million. 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 Class A common stock for the grant of nonqualified stock options and incentive stock options 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. Total compensation cost related to nonvested awards not yet recognized as of June 30, 2019, totaled $0.6 million, and is expected to be recognized over a weighted average period of 1.6 years. The following table summarizes the stock option activity under the 2012 Plan for the period: Number of options Weighted average exercise price per share Weighted average remaining contractual term (years) Aggregate intrinsic value (in millions) Outstanding at January 1, 2019 1,541,165 $ 4.12 6.9 $ 36.2 Granted — — Exercised (264,551 ) $ 3.76 Forfeited (3,303 ) $ 4.44 Outstanding at June 30, 2019 1,273,311 $ 4.20 6.5 Exercisable at June 30, 2019 892,645 $ 3.94 6.1 $ 32.5 The total intrinsic value of the 2012 Plan stock options exercised during the six months ended June 30, 2019, was $8.5 million. Other In connection with the acquisition of Datawatch, all outstanding unvested Datawatch RSUs were converted into a right to receive cash (the “Replacement Awards”). The payment to the holders of unvested Datawatch RSUs will be payable on or after the date that such RSUs would have otherwise vested in accordance with its original terms. The accounting treatment for the outstanding unvested Datawatch RSUs in the context of the business combination was to allocate the fair value of the RSUs at the date of consummation attributable to pre-combination service to the aggregate merger consideration. The difference between the fair value of the Replacement Awards and the amount allocable to pre-combination service was considered a post-combination expense to the Company after the consummation date. The estimated post combination expense to the Company as a result of the business combination was approximately $3.4 million which will be recognized on a straight-line basis over the remaining service period that was stipulated in each holder’s original RSU agreement. The weighted average remaining service period is 1.50 years. Once the vesting conditions of the service period are met, Altair will cash-settle the Replacement Awards. The liability related to the Datawatch RSUs as of June 30, 2019 and December 31, 2018, was $0.1 million and $0.6 million, respectively, and is recorded in other accrued expenses and current liabilities. 2017 stock-based compensation plan In 2017, the Company’s board of directors adopted the 2017 Equity Incentive Plan (“2017 Plan”), which was approved by the Company’s stockholders. 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 8,104,971 authorized shares of the Company’s Class A common stock reserved for issuance. The following table summarizes the restricted stock units , or RSU s, awarded under the 2017 Plan for the period: Number of RSUs Outstanding at January 1, 2019 206,061 Granted 634,985 Vested (47,425 ) Forfeited (31,596 ) Outstanding at June 30, 2019 762,025 The weighted average grant date fair value of the RSUs was $36.18 and the RSUs generally vest in four equal annual installments. Total compensation cost related to nonvested awards not yet recognized as of June 30, 2019, totaled $25.6 million, and is expected to be recognized over a weighted average period of approximately four years. The following table summarizes the stock option activity under the 2017 Plan for the period: Number of options Weighted average exercise price per share Weighted average remaining contractual term (years) Aggregate intrinsic value (in millions) Outstanding at January 1, 2019 — $ — Granted 20,000 $ 38.11 Exercised — $ — Forfeited — $ — Outstanding at June 30, 2019 20,000 $ 38.11 9.7 Exercisable at June 30, 2019 — $ — — $ — 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 fair values of the Company’s stock options granted during the six months ended June 30, 2019, were estimated using the following assumptions: 2019 grants Weighted average grant date fair value per share $ 38.11 Expected volatility 42 % Expected term (in years) 6.25 Risk-free interest rate 1.80 % Expected dividend yield 0 % These assumptions and estimates are as follows: • Fair Value of Common Stock . The Company used the publicly quoted price as reported on the Nasdaq Global Select Market as the fair value of its common stock. • Expected Term . The Company used the simplified method to determine the expected term. • Risk-Free Interest Rate . The Company based the risk-free interest rate on U.S. Treasury zero-coupon yield curves with a remaining term equal to the expected term of the option. • Expected Volatility . As the Company does not have an extensive trading history for its common stock, the expected volatility was derived using the historical volatility of the returns of comparable publicly traded companies combined with the brief trading history of the Company’s common stock. Stock-based compensation expense The stock-based compensation expense was recorded as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Cost of revenue – software $ 279 $ 8 $ 343 $ 16 Research and development 579 108 937 155 Sales and marketing 475 134 937 175 General and administrative 747 184 1,075 304 Total stock-based compensation expense $ 2,080 $ 434 $ 3,292 $ 650

Other Income, Net

Other Income, Net	6 Months Ended
	Jun. 30, 2019
Other Income And Expenses [Abstract]
Other Income, Net	1 3 . Other income, net Other income, net consists of the following (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Foreign exchange loss (gain) $ (237 ) $ 217 $ 180 $ (580 ) Other (268 ) (393 ) (295 ) (496 ) Other income, net $ (505 ) $ (176 ) $ (115 ) $ (1,076 )

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	1 4 . 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 income (loss) before income taxes. The income tax provision or benefit related to unusual or infrequent items, if applicable, that will be separately reported or reported net of their related tax effects are individually computed and recognized in the interim period in which those items occur. In addition, the effect of changes in enacted tax laws or rates, tax status, judgment on the realizability of a beginning-of-the-year deferred tax asset in future years or income tax contingencies is recognized in the interim period in which the change occurs. 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 tax jurisdictions, including applicable foreign taxes withheld at the source, 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 loss for which no tax benefit can be recognized due to a valuation allowance are excluded from the estimated annual effective tax rate. The impact of such an exclusion could result in a higher or lower effective tax rate during a particular quarter, based upon the composition and timing of actual earnings compared to annual projections. The estimates used to compute the provision or benefit for income taxes may change as new events occur, additional information is obtained or the Company’s tax environment changes. To the extent that the expected annual effective income tax rate changes, the effect of the change on prior interim periods is included in the income tax provision in the period in which the change in estimate occurs. The Company’s income tax (benefit) expense and effective tax rate for the three and six months ended June 30, 2019 and 2018, were as follows (in thousands, except percentages): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Income tax (benefit) expense $ (167 ) $ 1,386 $ 3,921 $ 3,732 Effective tax rate 5 % 453 % 28 % 14 % 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 2019 as compared to 2018, primarily related to United States pre-tax loss of $8.3 million for the three months ended June 30, 2019, and income of $ 5.3 million for the six months ended June 30, 2019, for which tax expense was not recognized due to the valuation allowance , compared to United States pre-tax loss of $ million for the three months ended June 30 , 2018, and income of $ 12.0 million for the six months ended June 30, 2018, for which tax expense was not recognized due to the valuation allowance . Offsetting the impact to the tax expense and the effective tax rate for June 30, 2019, was a reversal of reserve adjustments recorded for uncertain tax positions of $ 1.1 million. The Tax Act subjects a U.S. shareholder to current tax on global intangible low-taxed income (“GILTI”) earned by certain foreign subsidiaries. The impact of GILTI resulted in no incremental tax expense for the three or six months ended June 30, 2019, due to a full valuation allowance on U.S. net deferred tax assets.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Accumulated Other Comprehensive Loss	1 5 . 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 January 1, 2019 $ (8,823 ) $ (2,467 ) $ (11,290 ) Other comprehensive income before reclassification 1,942 (3 ) 1,939 Amounts reclassified from accumulated other comprehensive loss — 247 247 Tax effects — — — Other comprehensive income 1,942 244 2,186 Balance at June 30, 2019 $ (6,881 ) $ (2,223 ) $ (9,104 )

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	1 6 . Commitments and contingencies Swedish Tax Litigation The Swedish Tax Authorities, or STA, have assessed tax (net of utilization of tax attributes), penalties and interest in the amount of $6.6 million related to the acquisition of Panopticon AB by Datawatch, in 2013 for the years 2013, 2014 and 2015. The STA, upon auditing the acquisition transaction, reached a conclusion that post acquisition, certain assets were removed from Sweden, triggering the tax obligation. The STA is also of the opinion that some services related to product development provided to the new parent company in the U.S. were performed by Panopticon AB at a price below market price triggering tax obligations. Datawatch contested the findings by the STA throughout the audit process including contesting the STA position in the first level of administrative courts. On July 4, 2019, subsequent to the quarter ended June 30, 2018, the STA filed an appeal of the Administrative Court ruling with the Administrative Court of Appeal in Stockholm, effectively continuing to assert that the assessments are in fact appropriate. The Company expects to continue to contest the assessment through the appeals process and has until late September to submit any filings to the Administrative Court of Appeal in Stockholm. The Company does not believe that this subsequent event will have a material effect to its financial statements for the quarter ended September 30, 2019. Potential Export Violation As previously disclosed on Form 8-K on May 10, 2019, the Company discovered potential violations of U.S. economic sanctions and export control laws and immediately filed preliminary self-disclosure notices with the U.S. Treasury Department’s Office of Foreign Assets Control (“OFAC”) and the U.S. Commerce Department’s Bureau of Industry & Security (“BIS”). The Company subsequently conducted an internal investigation into these issues under the direction of outside legal counsel and filed voluntary self-disclosures with both agencies on July 25, 2019. These disclosures describe the unintentional transfer of commercial software and trial software licenses to various individuals located in Iran and other restricted countries. These transfers involved freeware, trial software licenses, and volunteer software testing communities. The Company did not discover any evidence indicating any commercial transactions with restricted parties or countries. In addition to filing voluntary self-disclosures with OFAC and BIS, the Company has implemented a series of additional compliance measures to prevent unintentional transfers of the sort described above. These measures will further enhance the Company’s international trade compliance program, which is designed to assure that the Company does not conduct business directly or indirectly with any countries or parties subject to U.S. economic sanctions and export control laws. Although it is too early to predict what action, if any, that OFAC or BIS might take, the Company does not currently have any reason to believe that its voluntary self-disclosures (or any related U.S. Government investigations) will have a meaningful impact on its operations, results of operations for any future period, or financial condition. Other 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	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Segment Information	1 7 . 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, or “CES”. 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, high performance computing, and data intelligence 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, high performance computing, data intelligence, and analysis support throughout product lifecycles. To a much lesser extent, the Software segment also includes revenue from the sale of hardware products, primarily as a result of recent business acquisitions. 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, data scientists 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 June 30, 2019 Software CES All other Total Revenue $ 92,315 $ 12,412 $ 2,046 $ 106,773 Adjusted EBITDA $ 5,207 $ 1,467 $ (1,509 ) $ 5,165 Three Months Ended June 30, 2018 Software CES All other Total Revenue $ 79,314 $ 12,417 $ 1,629 $ 93,360 Adjusted EBITDA $ 4,718 $ 1,508 $ (923 ) $ 5,303 Six Months Ended June 30, 2019 Software CES All other Total Revenue $ 205,378 $ 24,462 $ 4,792 $ 234,632 Adjusted EBITDA $ 29,249 $ 2,573 $ (2,673 ) $ 29,149 Six Months Ended June 30, 2018 Software CES All other Total Revenue $ 178,456 $ 24,497 $ 3,664 $ 206,617 Adjusted EBITDA $ 33,746 $ 2,564 $ (1,457 ) $ 34,853 Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Reconciliation of Adjusted EBITDA to U.S. GAAP (Loss) income before income taxes: Adjusted EBITDA $ 5,165 $ 5,303 $ 29,149 $ 34,853 Stock-based compensation expense (2,080 ) (434 ) (3,292 ) (650 ) Interest expense (590 ) (45 ) (860 ) (61 ) Interest income and other (1) (508 ) (536 ) (709 ) 719 Depreciation and amortization (5,274 ) (3,982 ) (10,468 ) (7,525 ) (Loss) income before income taxes $ (3,287 ) $ 306 $ 13,820 $ 27,336 (1) Includes an impairment charge for royalty contracts resulting in $0.8 million and $1.0 million of expense for the three and six months ended June 30, 2019, respectively, and $0.9 million and $1.8 million of expense for the three and six months ended June 30, 2018, respectively. Includes a non-recurring adjustment for a change in estimated legal expenses resulting in $2.0 million of income for the six months ended June 30, 2018

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	18. Subsequent events In July 2019, the Company decided to sunset operations of its WEYV business, a consumer music and content service. The WEYV business is reported in All Other within the Company’s segment disclosures.

Accounting Policies (Policies)

Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Immaterial Corrections of Prior Period Financial Statements	Immaterial corrections of prior period financial statements In connection with the preparation of its financial statements for the quarter ended June 30, 2019, the Company identified and corrected certain errors that were immaterial to previously-reported consolidated financial statements. These errors related primarily to i) the cumulative effective adjustment for the income tax effect of intercompany transactions resulting from the adoption of Accounting Standards Codification (“ASC”) No. 606, Revenue from Contracts with Customers Materiality Considering the Effects of Prior Year Misstatements When Quantifying Misstatements in Current Year Financial Statements The following table presents the effect of the error corrections on the Company’s consolidated balance sheet for the period indicated (in thousands): December 31, 2018 As Reported Adjustments As Corrected Deferred tax assets $ 1,373 $ 3,981 $ 5,354 Total assets $ 483,216 $ 3,981 $ 487,197 Other accrued expenses and current liabilities $ 27,565 $ (526 ) $ 27,039 Total current liabilities $ 127,758 $ (526 ) $ 127,232 Other long-term liabilities $ 28,153 $ (2,397 ) $ 25,756 Total liabilities $ 194,082 $ (2,923 ) $ 191,159 Accumulated deficit $ (82,005 ) $ 7,142 $ (74,863 ) Accumulated other comprehensive loss $ (11,052 ) $ (238 ) $ (11,290 ) Total stockholders' equity $ 286,782 $ 6,904 $ 293,686 Total liabilities, mezzanine equity and stockholders' equity $ 483,216 $ 3,981 $ 487,197 The adjustments for amounts similar to the above were also made to the Company’s consolidated balance sheets as of March 31, 2018, June 30, 2018, September 30, 2018, and March 31, 2019, respectively. The following tables present the effect of the error corrections on the consolidated statements of operations for the periods indicated (in thousands, except per share data): Year Ended December 31, 2018 As Reported Adjustments As Corrected Income before income taxes $ 27,024 $ — $ 27,024 Income tax expense $ 13,309 $ (1,820 ) $ 11,489 Net income $ 13,715 $ 1,820 $ 15,535 Net income per share attributable to common stockholders, basic $ 0.20 $ 0.03 $ 0.23 Net income per share attributable to common stockholders, diluted $ 0.18 $ 0.03 $ 0.21 Year Ended December 31, 2017 As Reported Adjustments As Corrected Loss before income taxes $ (36,411 ) $ — $ (36,411 ) Income tax expense $ 62,996 $ 2,534 $ 65,530 Net loss $ (99,407 ) $ (2,534 ) $ (101,941 ) Net income per share attributable to common stockholders, basic $ (1.89 ) $ (0.05 ) $ (1.94 ) Net income per share attributable to common stockholders, diluted $ (1.89 ) $ (0.05 ) $ (1.94 ) Additionally, the Company revised income tax expense, net income, and net income per share attributable to common stockholders (basic and diluted) on the consolidated statement of operations for the year ended December 31, 2016, to correct these errors, resulting in an increase of $0.2 million, a decrease of $0.2 million and a decrease of $0.01, respectively, from the previously reported amounts.
Basis of Presentation	Basis of presentation The accompanying unaudited consolidated financial statements 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 unaudited 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, 2018, included in the most recent Annual Report on Form 10-K filed with the SEC. 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 six months ended June 30, 2019, are not necessarily indicative of the results that may be expected for any future period. The Company adopted Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842),
Adoption of ASC 606, Revenue from Contracts with Customers	Adoption of ASC 606, Revenue from Contracts with Customers In the fourth quarter of fiscal 2018, the Company adopted ASC 606 effective on January 1, 2018, using the modified retrospective approach for all contracts not completed as of the date of adoption. Results for the three and six months ended June 30, 2018, have been modified to reflect the adoption of ASC 606 on January 1, 2018. The Company recorded a decrease to accumulated deficit of $84.6 million, or $77.7 million net of tax, on January 1, 2018, due to the cumulative effect of the ASC 606 adoption, with the impact primarily derived from revenue related to software licenses recognized at a point in time under ASC 606 that were historically recognized over time. There was no impact on Client Engineering Services or Other revenue upon the adoption of ASC 606. 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.
Reclassifications	Reclassifications Certain prior period amounts included in the 2018 consolidated statement of operations and consolidated balance sheet have been reclassified to conform to the current year presentation.
Use of Estimates	Use of estimates The preparation of the consolidated 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. On an ongoing basis, management evaluates its significant estimates including the stand alone selling price, or SSP, for each distinct performance obligation included in customer contracts with multiple performance obligations, the incremental borrowing rate used in the valuation of lease liabilities, the determination of the period of benefit for capitalized costs to obtain a contract, fair value of convertible senior notes, provision for doubtful accounts, tax valuation allowances, liabilities for uncertain tax provisions, impairment of goodwill and intangible assets, retirement obligations, useful lives of intangible assets, revenue for fixed price contracts, valuation of common stock, and stock-based compensation. Actual results could differ from those estimates.
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): June 30, 2019 December 31, 2018 Cash and cash equivalents $ 251,828 $ 35,345 Restricted cash included in other long-term assets 352 340 Total cash, cash equivalents, and restricted cash $ 252,180 $ 35,685 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.
Inventory	Inventory Inventory was $2.8 million and $2.0 million at June 30, 2019 and December 31, 2018, respectively, and is included in prepaid expenses and other current assets in the consolidated balance sheets. Inventory consist of finished goods and is stated at the lower of cost and net realizable value. Cost is determined using the first-in, first-out method. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonable predictable costs of completion, disposal and transportation. The valuation of inventory requires management to estimate excess inventory as well as inventory that is not of saleable quality. The determination of obsolete or excess inventory requires management to estimate market conditions and future demand for the Company’s products.
Receivable for French R&D Credit	Receivable for French 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 activities. The tax credit is deductible from French income tax and any excess is carried forward three years. After three years, any unused credit may be reimbursed to the Company by the French government. As of June 30, 2019, the Company had approximately $12.0 million receivable from the French government related to CIR, of which $1.3 million was recorded in income tax receivable and the remaining $10.7 million was recorded in other long-term assets. As of December 31, 2018, the Company had approximately $11.7 million receivable from the French government related to CIR, of which $2.6 million was recorded in income tax receivable and the remaining $9.1 million was recorded in other long-term assets. CIR is subject to customary audit by French tax authorities.
Mezzanine Equity	Mezzanine equity In 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 at the issuance date and classified as mezzanine equity in the consolidated balance sheet. The put right option is terminated if the shareholders sell their shares. As of December 31, 2017, the Company concluded that it is no longer probable that the put option will be exercised as the put value is substantially below market value and subsequent adjustment is not required. Classification of the of instrument shall remain as mezzanine equity until one of the following three events take place: (1) shares are sold on the open market; (2) a redemption feature lapses; or (3) there is a modification of the terms of the instrument. As none of these events have taken place as of June 30, 2019, the classification remains as mezzanine equity.
Leases	Leases The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease right-of-use (“ROU”) assets, current portion of operating lease liabilities, and operating lease liabilities, net of current portion on the Company’s consolidated balance sheets. Finance leases are included in property and equipment, current portion of long-term debt, and long-term debt, net of current portion on the consolidated balance sheets.
(Loss) Income Per Share	(Loss) income per share Basic (loss) income per share attributable to common stockholders is computed using the weighted average number of shares of common stock outstanding for the period, excluding stock options and restricted stock units (“RSUs”). Diluted (loss) income 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 and RSUs under the treasury stock method. The following table sets forth the computation of the numerators and denominators used in the basic and diluted (loss) income per share amounts (in thousands, except per share data): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator: Net (loss) income $ (3,120 ) $ (1,080 ) $ 9,899 $ 23,604 Denominator: Denominator for basic (loss) income per share— weighted average shares 71,373 65,580 71,081 64,614 Effect of dilutive securities, stock options and RSUs — — 5,936 8,267 Denominator for dilutive (loss) income per share 71,373 65,580 77,017 72,881 Net (loss) income per share attributable to common stockholders, basic $ (0.04 ) $ (0.02 ) $ 0.14 $ 0.37 Net (loss) income per share attributable to common stockholders, diluted $ (0.04 ) $ (0.02 ) $ 0.13 $ 0.32 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 the three months ended June 30, 2019, there were 5.6 million anti-dilutive stock options excluded from the computation of (loss) income per share. For the three months ended June 30, 2018, there were 7.8 million anti-dilutive stock options excluded from the computation of (loss) income per share. For both the six months ended June 30, 2019 and 2018, there were no anti-dilutive shares excluded from the computation of (loss) income per share. The Company expects to settle the principal amount of the Convertible Notes (as defined in Note 8) in cash, and therefore, the Company uses the treasury stock method for calculating any potential dilutive effect of the Conversion Option (as defined in Note 8) on diluted net (loss) income per share, if applicable. The Conversion Option will have a dilutive impact on net income per share of common stock when the average market price of the Company’s Class A common stock for a given period exceeds the conversion price of the Convertible Notes of $46.50 per share. During the three months ended June 30, 2019, the Company's weighted average common stock price was below the conversion price of the Convertible Notes.

Accounting Policies (Tables)

Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2019
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): June 30, 2019 December 31, 2018 Cash and cash equivalents $ 251,828 $ 35,345 Restricted cash included in other long-term assets 352 340 Total cash, cash equivalents, and restricted cash $ 252,180 $ 35,685
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 (loss) income per share amounts (in thousands, except per share data): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator: Net (loss) income $ (3,120 ) $ (1,080 ) $ 9,899 $ 23,604 Denominator: Denominator for basic (loss) income per share— weighted average shares 71,373 65,580 71,081 64,614 Effect of dilutive securities, stock options and RSUs — — 5,936 8,267 Denominator for dilutive (loss) income per share 71,373 65,580 77,017 72,881 Net (loss) income per share attributable to common stockholders, basic $ (0.04 ) $ (0.02 ) $ 0.14 $ 0.37 Net (loss) income per share attributable to common stockholders, diluted $ (0.04 ) $ (0.02 ) $ 0.13 $ 0.32
ASC 606 [Member]
Effect of Error Correction on Company's Financial Statements	The following table presents the effect of the error corrections on the Company’s consolidated balance sheet for the period indicated (in thousands): December 31, 2018 As Reported Adjustments As Corrected Deferred tax assets $ 1,373 $ 3,981 $ 5,354 Total assets $ 483,216 $ 3,981 $ 487,197 Other accrued expenses and current liabilities $ 27,565 $ (526 ) $ 27,039 Total current liabilities $ 127,758 $ (526 ) $ 127,232 Other long-term liabilities $ 28,153 $ (2,397 ) $ 25,756 Total liabilities $ 194,082 $ (2,923 ) $ 191,159 Accumulated deficit $ (82,005 ) $ 7,142 $ (74,863 ) Accumulated other comprehensive loss $ (11,052 ) $ (238 ) $ (11,290 ) Total stockholders' equity $ 286,782 $ 6,904 $ 293,686 Total liabilities, mezzanine equity and stockholders' equity $ 483,216 $ 3,981 $ 487,197 The adjustments for amounts similar to the above were also made to the Company’s consolidated balance sheets as of March 31, 2018, June 30, 2018, September 30, 2018, and March 31, 2019, respectively. The following tables present the effect of the error corrections on the consolidated statements of operations for the periods indicated (in thousands, except per share data): Year Ended December 31, 2018 As Reported Adjustments As Corrected Income before income taxes $ 27,024 $ — $ 27,024 Income tax expense $ 13,309 $ (1,820 ) $ 11,489 Net income $ 13,715 $ 1,820 $ 15,535 Net income per share attributable to common stockholders, basic $ 0.20 $ 0.03 $ 0.23 Net income per share attributable to common stockholders, diluted $ 0.18 $ 0.03 $ 0.21 Year Ended December 31, 2017 As Reported Adjustments As Corrected Loss before income taxes $ (36,411 ) $ — $ (36,411 ) Income tax expense $ 62,996 $ 2,534 $ 65,530 Net loss $ (99,407 ) $ (2,534 ) $ (101,941 ) Net income per share attributable to common stockholders, basic $ (1.89 ) $ (0.05 ) $ (1.94 ) Net income per share attributable to common stockholders, diluted $ (1.89 ) $ (0.05 ) $ (1.94 )

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue From Contract With Customer [Abstract]
Schedule of Disaggregation of Revenue	The Company disaggregates its software revenue by type of performance obligation and timing of revenue recognition as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Software revenue: Term licenses $ 45,974 $ 38,707 $ 111,031 $ 95,872 Perpetual licenses 10,679 7,993 22,243 17,763 Maintenance 25,333 20,869 48,085 41,697 Professional services and other 2,422 3,038 6,340 4,944 Total software revenue $ 84,408 $ 70,607 $ 187,699 $ 160,276

Acquisitions (Tables)

Acquisitions (Tables)	6 Months Ended
	Jun. 30, 2019
Business Combinations [Abstract]
Summary of Amounts of Identified Assets Acquired and Liabilities Assumed at the Acquisition Date	The following table summarizes the preliminary purchase consideration transferred to acquire Datawatch and the amounts of identified assets acquired and liabilities assumed at the acquisition date (in thousands): Fair value of consideration transferred $ 183,427 Recognized amounts of identifiable assets acquired and liabilities assumed: Cash 8,278 Accounts receivable 10,384 Other assets 2,522 Property and equipment 980 Trade names 7,400 Developed technology (6-year life) 22,600 Customer relationships (10-year life) 16,700 Accounts payable and other liabilities (5,041 ) Deferred revenue (3,649 ) Other long-term liabilities (8,340 ) Total net identifiable assets acquired and liabilities assumed 51,834 Goodwill (1) $ 131,593 (1) Goodwill is primarily attributable to market synergies expected to arise after the acquisition and approximately $0.8 million is deductible for tax purposes. All goodwill is recorded in the Software segment.

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	6 Months Ended
	Jun. 30, 2019
Property Plant And Equipment [Abstract]
Summary of Property and Equipment	Property and equipment consisted of the following (in thousands): June 30, December 31, 2019 2018 Land $ 7,994 $ 7,994 Building and improvements 13,379 13,120 Computer equipment and software 36,354 34,582 Office furniture and equipment 8,512 7,958 Leasehold improvements 8,500 6,926 Right-of-use assets under finance leases 2,607 — Total property and equipment 77,346 70,580 Less: accumulated depreciation and amortization 43,296 40,427 Property and equipment, net $ 34,050 $ 30,153

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2019
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, were as follows (in thousands): Balance at December 31, 2018 $ 210,532 Effects of foreign currency translation and other 1,555 Balance at June 30, 2019 $ 212,087
Schedule of Other Intangible Assets	A summary of other intangible assets is shown below (in thousands): June 30, 2019 Weighted average amortization period Gross carrying amount Accumulated amortization Net carrying amount Definite-lived intangible assets: Developed technology 4-6 years $ 56,385 $ 20,654 $ 35,731 Customer relationships 7-10 years 28,750 9,405 19,345 Other intangibles 10 years 219 60 159 Total definite-lived intangible assets 85,354 30,119 55,235 Indefinite-lived intangible assets: Trade names 9,639 9,639 Total other intangible assets $ 94,993 $ 30,119 $ 64,874 December 31, 2018 Weighted average amortization period Gross carrying amount Accumulated amortization Net carrying amount Definite-lived intangible assets: Developed technology 4-6 years $ 54,530 $ 15,517 $ 39,013 Customer relationships 7-10 years 28,422 7,309 21,113 Other intangibles 10 years 109 56 53 Total definite-lived intangible assets 83,061 22,882 60,179 Indefinite-lived intangible assets: Trade names 9,657 9,657 Total other intangible assets $ 92,718 $ 22,882 $ 69,836

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Schedule of Carrying Value of Debt	The carrying value of debt is as follows (in thousands): June 30, December 31, 2019 2018 Convertible senior notes $ 230,000 $ — Revolving credit facility — 30,950 Obligations for finance leases 1,298 813 Other borrowings 25 75 Total debt 231,323 31,838 Less: unamortized debt discount 51,443 — Less: unamortized debt issuance costs 6,251 90 Less: current portion of long-term debt 472 331 Long-term debt, net of current portion $ 173,157 $ 31,417
Schedule of Net Carrying Value of Liability Component of Convertible Notes	The net carrying value of the liability component of the Convertible Notes was as follows (in thousands): June 30, 2019 Principal $ 230,000 Less: unamortized debt discount 51,443 Less: unamortized debt issuance costs 6,251 Net carrying amount $ 172,306
Schedule of Net Carrying Value of Equity Component of Convertible Notes	The net carrying value of the equity component of the Convertible Notes was as follows (in thousands): June 30, 2019 Proceeds allocated to the conversion option (debt discount) $ 51,842 Less: issuance costs 1,833 Net carrying amount $ 50,009
Schedule of Interest Expense Recognized Related to Convertible Notes	The interest expense recognized related to the Convertible Notes was as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2019 Contractual interest expense $ 25 $ 25 Amortization of debt issuance cost and discount 447 447 Total $ 472 $ 472

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Schedule of Components of Lease Cost	The components of lease cost were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2019 Operating lease cost $ 3,359 $ 6,783 Finance lease cost: Amortization of ROU assets $ 126 $ 247 Interest on lease liabilities 5 10 Total finance lease cost $ 131 $ 257
Schedule of Supplemental Balance Sheet Information Related to Lease Liabilities	Supplemental balance sheet information related to lease liabilities at June 30, 2019, was as follows: (in thousands, except lease term and discount rate) Operating leases: Operating lease ROU assets $ 28,878 Current portion of operating lease liabilities $ 9,412 Operating lease liabilities, net of current portion 20,722 Total operating lease liabilities $ 30,134 Weighted average remaining lease term 4.2 years Weighted average discount rate 5.3 % Finance leases: Property and equipment $ 2,607 Accumulated depreciation (1,111 ) Property and equipment, net $ 1,496 Current portion of long-term debt $ 447 Long-term debt, net of current portion 851 Total finance lease liabilities $ 1,298 Weighted average remaining lease term 3.2 years Weighted average discount rate 3.4 %
Schedule of Supplemental Cash Flow Information Related to Leases	Supplemental cash flow information related to leases for the six months ended June 30, 2019, was as follows (in thousands): Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ (5,665 ) Operating cash flows from finance leases $ (25 ) Financing cash flows from finance leases $ (209 ) ROU assets obtained in exchange for lease obligations: Operating leases $ 6,545 Finance leases $ 566
Schedule of Maturities of Operating Lease Liabilities	Maturities of operating lease liabilities at June 30, 2019, were as follows (in thousands): Year ending December 31, 2019 (excluding the six months ended June 30, 2019) $ 5,715 2020 9,508 2021 7,089 2022 4,811 2023 2,971 Thereafter 3,335 Total lease payments 33,429 Less: imputed interest 3,295 Total operating lease liabilities $ 30,134

Other Liabilities (Tables)

Other Liabilities (Tables)	6 Months Ended
	Jun. 30, 2019
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): June 30, December 31, 2019 2018 Income taxes payable $ 7,732 $ 3,932 Accrued VAT 3,985 4,536 Accrued royalties 3,527 2,613 Accrued professional fees 3,403 3,165 Defined contribution plan liabilities 1,225 1,376 Government grants 859 915 Non-income tax liabilities 685 853 Billings in excess of cost 520 1,504 Other current liabilities 6,043 8,145 Total $ 27,979 $ 27,039
Summary of Other Long-term Liabilities	The following table provides details of other long-term liabilities (in thousands): June 30, December 31, 2019 2018 Pension and other post retirement liabilities $ 9,782 $ 9,111 Deferred tax liabilities 5,725 5,339 Other liabilities 10,855 11,306 Total $ 26,362 $ 25,756

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2019
Summary of Restricted Stock Units Awarded	The following table summarizes the restricted stock units , or RSU s, awarded under the 2017 Plan for the period: Number of RSUs Outstanding at January 1, 2019 206,061 Granted 634,985 Vested (47,425 ) Forfeited (31,596 ) Outstanding at June 30, 2019 762,025
Summary of Fair value of Company's Stock Options Granted	The fair values of the Company’s stock options granted during the six months ended June 30, 2019, were estimated using the following assumptions: 2019 grants Weighted average grant date fair value per share $ 38.11 Expected volatility 42 % Expected term (in years) 6.25 Risk-free interest rate 1.80 % Expected dividend yield 0 %
Summary of Stock-Based Compensation	The stock-based compensation expense was recorded as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Cost of revenue – software $ 279 $ 8 $ 343 $ 16 Research and development 579 108 937 155 Sales and marketing 475 134 937 175 General and administrative 747 184 1,075 304 Total stock-based compensation expense $ 2,080 $ 434 $ 3,292 $ 650
NSO Plan [Member]
Summary of Stock Option Activity	The following table summarizes the stock option activity under the NSO Plan for the period: Number of options Weighted average exercise price per share Weighted average remaining contractual term (years) Aggregate intrinsic value (in millions) Outstanding at January 1, 2019 4,337,856 $ 0.000025 18.0 $ 119.6 Exercised (522,508 ) $ 0.000025 Forfeited — — Outstanding and exercisable at June 30, 2019 3,815,348 $ 0.000025 17.5 $ 154.1
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 period: Number of options Weighted average exercise price per share Weighted average remaining contractual term (years) Aggregate intrinsic value (in millions) Outstanding at January 1, 2019 532,220 $ 0.65 1.4 $ 14.3 Exercised (218,693 ) $ 0.67 Forfeited — — Outstanding and exercisable at June 30, 2019 313,527 $ 0.64 0.8 $ 12.5
2012 Plan [Member]
Summary of Stock Option Activity	The following table summarizes the stock option activity under the 2012 Plan for the period: Number of options Weighted average exercise price per share Weighted average remaining contractual term (years) Aggregate intrinsic value (in millions) Outstanding at January 1, 2019 1,541,165 $ 4.12 6.9 $ 36.2 Granted — — Exercised (264,551 ) $ 3.76 Forfeited (3,303 ) $ 4.44 Outstanding at June 30, 2019 1,273,311 $ 4.20 6.5 Exercisable at June 30, 2019 892,645 $ 3.94 6.1 $ 32.5
2017 Plan [Member]
Summary of Stock Option Activity	The following table summarizes the stock option activity under the 2017 Plan for the period: Number of options Weighted average exercise price per share Weighted average remaining contractual term (years) Aggregate intrinsic value (in millions) Outstanding at January 1, 2019 — $ — Granted 20,000 $ 38.11 Exercised — $ — Forfeited — $ — Outstanding at June 30, 2019 20,000 $ 38.11 9.7 Exercisable at June 30, 2019 — $ — — $ —

Other Income, Net (Tables)

Other Income, Net (Tables)	6 Months Ended
	Jun. 30, 2019
Other Income And Expenses [Abstract]
Schedule of Other Income, Net	Other income, net consists of the following (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Foreign exchange loss (gain) $ (237 ) $ 217 $ 180 $ (580 ) Other (268 ) (393 ) (295 ) (496 ) Other income, net $ (505 ) $ (176 ) $ (115 ) $ (1,076 )

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Schedule of Income Tax Expense (Benefit) and Effective Tax Rate	The Company’s income tax (benefit) expense and effective tax rate for the three and six months ended June 30, 2019 and 2018, were as follows (in thousands, except percentages): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Income tax (benefit) expense $ (167 ) $ 1,386 $ 3,921 $ 3,732 Effective tax rate 5 % 453 % 28 % 14 %

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Jun. 30, 2019
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 January 1, 2019 $ (8,823 ) $ (2,467 ) $ (11,290 ) Other comprehensive income before reclassification 1,942 (3 ) 1,939 Amounts reclassified from accumulated other comprehensive loss — 247 247 Tax effects — — — Other comprehensive income 1,942 244 2,186 Balance at June 30, 2019 $ (6,881 ) $ (2,223 ) $ (9,104 )

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Schedule of Segment Reporting Information	The following tables are in thousands: Three Months Ended June 30, 2019 Software CES All other Total Revenue $ 92,315 $ 12,412 $ 2,046 $ 106,773 Adjusted EBITDA $ 5,207 $ 1,467 $ (1,509 ) $ 5,165 Three Months Ended June 30, 2018 Software CES All other Total Revenue $ 79,314 $ 12,417 $ 1,629 $ 93,360 Adjusted EBITDA $ 4,718 $ 1,508 $ (923 ) $ 5,303 Six Months Ended June 30, 2019 Software CES All other Total Revenue $ 205,378 $ 24,462 $ 4,792 $ 234,632 Adjusted EBITDA $ 29,249 $ 2,573 $ (2,673 ) $ 29,149 Six Months Ended June 30, 2018 Software CES All other Total Revenue $ 178,456 $ 24,497 $ 3,664 $ 206,617 Adjusted EBITDA $ 33,746 $ 2,564 $ (1,457 ) $ 34,853
Reconciliation of U.S. GAAP Income Before Income Taxes to Adjusted EBITDA	Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Reconciliation of Adjusted EBITDA to U.S. GAAP (Loss) income before income taxes: Adjusted EBITDA $ 5,165 $ 5,303 $ 29,149 $ 34,853 Stock-based compensation expense (2,080 ) (434 ) (3,292 ) (650 ) Interest expense (590 ) (45 ) (860 ) (61 ) Interest income and other (1) (508 ) (536 ) (709 ) 719 Depreciation and amortization (5,274 ) (3,982 ) (10,468 ) (7,525 ) (Loss) income before income taxes $ (3,287 ) $ 306 $ 13,820 $ 27,336 (1) Includes an impairment charge for royalty contracts resulting in $0.8 million and $1.0 million of expense for the three and six months ended June 30, 2019, respectively, and $0.9 million and $1.8 million of expense for the three and six months ended June 30, 2018, respectively. Includes a non-recurring adjustment for a change in estimated legal expenses resulting in $2.0 million of income for the six months ended June 30, 2018

Accounting policies - Effect of

Accounting policies - Effect of Error Correction on Company's Financial Statements (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effect of error correction on Balance Sheet [Abstract]
Deferred tax assets	$ 5,901				$ 5,901		$ 5,354
Total assets	729,720				729,720		487,197
Other accrued expenses and current liabilities	27,979				27,979		27,039
Total current liabilities	141,067				141,067		127,232
Other long-term liabilities	26,362				26,362		25,756
Total liabilities	367,527				367,527		191,159
Accumulated deficit	(64,964)				(64,964)		(74,863)
Accumulated other comprehensive loss	(9,104)				(9,104)		(11,290)
Total stockholders' equity	359,841	$ 308,597	$ 294,815	$ 163,041	359,841	$ 294,815	293,686	$ 58,949
Total liabilities, mezzanine equity and stockholders' equity	729,720				729,720		487,197
Effect of error corrections on statements of operations [Abstract]
Income (loss) before income taxes	(3,287)		306		13,820	27,336	27,024	(36,411)
Income tax expense	(167)		1,386		3,921	3,732	11,489	65,530
Net income (loss)	$ (3,120)	$ 13,019	$ (1,080)	$ 24,684	$ 9,899	$ 23,604	$ 15,535	$ (101,941)
Net income per share attributable to common stockholders, basic	$ (0.04)		$ (0.02)		$ 0.14	$ 0.37	$ 0.23	$ (1.94)
Net income per share attributable to common stockholders, diluted	$ (0.04)		$ (0.02)		$ 0.13	$ 0.32	$ 0.21	$ (1.94)
As Reported | ASC 606 [Member]
Effect of error correction on Balance Sheet [Abstract]
Deferred tax assets							$ 1,373
Total assets							483,216
Other accrued expenses and current liabilities							27,565
Total current liabilities							127,758
Other long-term liabilities							28,153
Total liabilities							194,082
Accumulated deficit							(82,005)
Accumulated other comprehensive loss							(11,052)
Total stockholders' equity							286,782
Total liabilities, mezzanine equity and stockholders' equity							483,216
Effect of error corrections on statements of operations [Abstract]
Income (loss) before income taxes							27,024	$ (36,411)
Income tax expense							13,309	62,996
Net income (loss)							$ 13,715	$ (99,407)
Net income per share attributable to common stockholders, basic							$ 0.20	$ (1.89)
Net income per share attributable to common stockholders, diluted							$ 0.18	$ (1.89)
Adjustments [Member] | ASC 606 [Member]
Effect of error correction on Balance Sheet [Abstract]
Deferred tax assets							$ 3,981
Total assets							3,981
Other accrued expenses and current liabilities							(526)
Total current liabilities							(526)
Other long-term liabilities							(2,397)
Total liabilities							(2,923)
Accumulated deficit							7,142
Accumulated other comprehensive loss							(238)
Total stockholders' equity							6,904	$ 1,600
Total liabilities, mezzanine equity and stockholders' equity							3,981
Effect of error corrections on statements of operations [Abstract]
Income tax expense							(1,820)	2,534	$ 200
Net income (loss)							$ 1,820	$ (2,534)	$ (200)
Net income per share attributable to common stockholders, basic							$ 0.03	$ 0.05
Net income per share attributable to common stockholders, diluted							$ 0.03	$ 0.05

Accounting Policies - Additiona

Accounting Policies - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Line Items]
Stockholders' equity	$ 359,841	$ 308,597	$ 294,815	$ 163,041	$ 359,841	$ 294,815	$ 293,686	$ 58,949
Income tax expense	(167)		1,386		3,921	3,732	11,489	65,530
Net income (loss)	(3,120)	$ 13,019	$ (1,080)	24,684	9,899	$ 23,604	15,535	$ (101,941)
Cumulative effect on accumulated deficit, before tax				84,600
Cumulative effect on accumulated deficit, net of tax				$ 77,700
Inventory	$ 2,800				$ 2,800		2,000
Anti-dilutive stock options excluded from computation of income (loss) per share	5,600,000		7,800,000		0	0
Class A Common Stock [Member] | Convertible Senior Notes Due in 2024 [Member]
Accounting Policies [Line Items]
Debt instrument convertible initial conversion price per share of common stock	$ 46.50				$ 46.50
Class A Common Stock [Member] | Put Option [Member]
Accounting Policies [Line Items]
Shares issued								200,000
Put right, exercise price								$ 12.50
Put right exercise period from date of purchase								5 years
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	$ 12,000				$ 12,000		11,700
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	1,300				1,300		2,600
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	$ 10,700				$ 10,700		9,100
Adjustments [Member] | ASC 606 [Member]
Accounting Policies [Line Items]
Stockholders' equity							6,904	$ 1,600
Income tax expense							(1,820)	2,534	$ 200
Net income (loss)							$ 1,820	$ (2,534)	$ (200)
Net income per share attributable to common stockholders (basic and diluted)									$ (0.01)

Accounting Policies - Reconcili

Accounting Policies - Reconciliation of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Cash and cash equivalents	$ 251,828	$ 35,345
Restricted cash included in other long-term assets	352	340
Total cash, cash equivalents, and restricted cash	$ 252,180	$ 35,685	$ 199,586	$ 39,578

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				6 Months Ended		12 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net (loss) income	$ (3,120)	$ 13,019	$ (1,080)	$ 24,684	$ 9,899	$ 23,604	$ 15,535	$ (101,941)
Denominator:
Denominator for basic (loss) income per share— weighted average shares	71,373		65,580		71,081	64,614
Effect of dilutive securities, stock options and RSUs					5,936	8,267
Denominator for dilutive (loss) income per share	71,373		65,580		77,017	72,881
Net (loss) income per share attributable to common stockholders, basic	$ (0.04)		$ (0.02)		$ 0.14	$ 0.37	$ 0.23	$ (1.94)
Net (loss) income per share attributable to common stockholders, diluted	$ (0.04)		$ (0.02)		$ 0.13	$ 0.32	$ 0.21	$ (1.94)

Recent Accounting Guidance - Ad

Recent Accounting Guidance - Additional Information (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Operating lease liabilities	$ 30,134
Operating lease ROU assets	$ 28,878
ASU 2016-02 [Member]
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Operating lease liabilities		$ 30,100
Operating lease ROU assets		$ 29,100

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Schedule of Disaggregation of Revenue (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation Of Revenue [Line Items]
Total revenue	$ 106,773	$ 93,360	$ 234,632	$ 206,617
Term Licenses [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	45,974	38,707	111,031	95,872
Perpetual Licenses [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	10,679	7,993	22,243	17,763
Maintenance [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	25,333	20,869	48,085	41,697
Professional Services and Other [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	2,422	3,038	6,340	4,944
Software [Member]
Disaggregation Of Revenue [Line Items]
Total revenue	$ 84,408	$ 70,607	$ 187,699	$ 160,276

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Revenue From Contracts With Customers [Line Items]
Percentage of net revenues through indirect channels			10.00%	10.00%
Capitalized contract cost, amortization period	4 years		4 years
Capitalized contract cost, amortization method			straight-line basis
Deferred revenue, revenue recognized			$ 45
Sales and Marketing Expense [Member]
Revenue From Contracts With Customers [Line Items]
Capitalized contract cost, amortization expense	$ 1.2	$ 1	2.2	$ 1.9
Prepaid and Other Current Assets [Member]
Revenue From Contracts With Customers [Line Items]
Capitalized contract cost net, current	2.4		2.4		$ 2
Contract assets	3.5		3.5		2.7
Other long-term assets [Member]
Revenue From Contracts With Customers [Line Items]
Capitalized contract cost net, noncurrent	0.4		0.4		0.2
Accounts Receivable [Member]
Revenue From Contracts With Customers [Line Items]
Contract assets	$ 5.6		$ 5.6		$ 3.7

Acquisitions - Additional Infor

Acquisitions - Additional Information (Detail) - USD ($)	Nov. 05, 2018	Oct. 31, 2018	Jun. 30, 2019
Datawatch Corporation [Member]
Business Acquisition [Line Items]
Business acquisition purchase price	$ 13.10		$ 13.10
Business acquisition, consideration			$ 183,400,000
Business combination, consideration transferred value			168,200,000
Business combination, consideration transferred, liabilities incurred			500,000
Business combination, consideration transferred for outstanding equity awards			6,700,000
Payments of outstanding debt			8,000,000
Fair value of consideration transferred	$ 183,427,000
Fair value of assets acquired and liabilities assumed	$ 51,834,000
SIMSOLID Corporation [Member]
Business Acquisition [Line Items]
Fair value of consideration transferred		$ 22,100,000
Fair value of assets acquired and liabilities assumed			$ 0

Acquisitions - Summary of Amoun

Acquisitions - Summary of Amounts of Identified Assets Acquired and Liabilities Assumed at the Acquisition Date (Detail) - USD ($) $ in Thousands	Nov. 05, 2018	Jun. 30, 2019	Dec. 31, 2018
Recognized amounts of identifiable assets acquired and liabilities assumed:
Goodwill		$ 212,087	$ 210,532
Datawatch Corporation [Member]
Business Acquisition [Line Items]
Fair value of consideration transferred	$ 183,427
Recognized amounts of identifiable assets acquired and liabilities assumed:
Cash	8,278
Accounts receivable	10,384
Other assets	2,522
Property and equipment	980
Accounts payable and other liabilities	(5,041)
Deferred revenue	(3,649)
Other long-term liabilities	(8,340)
Total net identifiable assets acquired and liabilities assumed	51,834
Goodwill	131,593
Datawatch Corporation [Member] | Trade Names [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed:
Indefinite-lived intangibles	7,400
Datawatch Corporation [Member] | Developed Technology [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangibles	22,600
Datawatch Corporation [Member] | Customer Relationships [Member]
Recognized amounts of identifiable assets acquired and liabilities assumed:
Finite-lived intangibles	$ 16,700

Acquisitions - Summary of Amo_2

Acquisitions - Summary of Amounts of Identified Assets Acquired and Liabilities Assumed at the Acquisition Date (Parenthetical) (Detail) - Datawatch Corporation [Member] $ in Millions	6 Months Ended
	Jun. 30, 2019USD ($)
Software [Member]
Business Acquisition [Line Items]
Goodwill deductible for tax purposes	$ 0.8
Developed Technology [Member]
Business Acquisition [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets	6 years
Customer Relationships [Member]
Business Acquisition [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets	10 years

Property and Equipment, Net - S

Property and Equipment, Net - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 77,346	$ 70,580
Less: accumulated depreciation and amortization	43,296	40,427
Property and equipment, net	34,050	30,153
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	13,379	13,120
Computer Equipment and Software [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	36,354	34,582
Office Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	8,512	7,958
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	8,500	$ 6,926
Right-of-Use Assets Under Finance Leases [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 2,607

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Property Plant And Equipment [Abstract]
Depreciation expense, including amortization of right-of-use assets under finance leases	$ 1.6	$ 2	$ 3.3	$ 3.6

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Changes in Carrying Amount of Goodwill Attributable to Software Reporting Segment (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning Balance	$ 210,532
Effects of foreign currency translation and other	1,555
Ending Balance	$ 212,087

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Schedule of Other Intangible Assets (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Summary Of Other Intangible Assets [Line Items]
Gross carrying amount	$ 85,354	$ 83,061
Accumulated amortization	30,119	22,882
Net carrying amount	55,235	60,179
Gross carrying amount	94,993	92,718
Accumulated amortization	30,119	22,882
Net carrying amount	64,874	69,836
Developed Technology [Member]
Summary Of Other Intangible Assets [Line Items]
Gross carrying amount	56,385	54,530
Accumulated amortization	20,654	15,517
Net carrying amount	$ 35,731	$ 39,013
Developed Technology [Member] | Minimum [Member]
Summary Of Other Intangible Assets [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets	4 years	4 years
Developed Technology [Member] | Maximum [Member]
Summary Of Other Intangible Assets [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets	6 years	6 years
Customer Relationships
Summary Of Other Intangible Assets [Line Items]
Gross carrying amount	$ 28,750	$ 28,422
Accumulated amortization	9,405	7,309
Net carrying amount	$ 19,345	$ 21,113
Customer Relationships | Minimum [Member]
Summary Of Other Intangible Assets [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets	7 years	7 years
Customer Relationships | Maximum [Member]
Summary Of Other Intangible Assets [Line Items]
Weighted-average useful life of acquired finite-lived intangible assets	10 years	10 years
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	$ 219	$ 109
Accumulated amortization	60	56
Net carrying amount	159	53
Trade Names
Summary Of Other Intangible Assets [Line Items]
Net carrying amount	$ 9,639	$ 9,657

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 3,600	$ 1,986	$ 7,128	$ 3,926

Debt - Schedule of Carrying Val

Debt - Schedule of Carrying Value of Debt (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total debt	$ 231,323	$ 31,838
Less: unamortized debt discount	51,443
Less: unamortized debt issuance costs	6,251	90
Current portion of long-term debt	472	331
Long-term debt, net of current portion	173,157	31,417
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Total debt		30,950
Convertible Senior Notes [Member]
Debt Instrument [Line Items]
Total debt	230,000
Obligations for Finance Leases [Member]
Debt Instrument [Line Items]
Total debt	1,298	813
Other Borrowings [Member]
Debt Instrument [Line Items]
Total debt	$ 25	$ 75

Debt - Additional Information (

Debt - Additional Information (Detail)	Jun. 05, 2019USD ($)	Jun. 30, 2019USD ($)d$ / sharesshares	Jun. 30, 2019USD ($)$ / shares	Jun. 30, 2019USD ($)$ / shares
Debt Instrument [Line Items]
Debt instrument, equity component recorded in additional paid-in capital			$ 50,009,000
Convertible Senior Notes Due in 2024 [Member]
Debt Instrument [Line Items]
Debt instrument, aggregate principal amount		$ 230,000,000	$ 230,000,000	$ 230,000,000
Debt instrument interest rate		0.25%	0.25%	0.25%
Additional principal amount of notes to underwriters		$ 30,000,000	$ 30,000,000	$ 30,000,000
Net proceeds from issuance of costs		$ 221,900,000
Debt instrument frequency of periodic payment				semi-annually
Interest payment commencement date		Dec. 1, 2019
Debt instrument maturity date		Jun. 1, 2024
Debt instrument, description				The Convertible Notes bear interest at a rate of 0.25% per year, payable semi-annually in arrears on June 1 and December 1 of each year, commencing December 1, 2019.
Debt interument conversion rate principal amount of notes		$ 1,000	$ 1,000	$ 1,000
Debt instrument, convertible, terms of conversion feature				The Convertible Notes have an initial conversion rate of 21.5049 shares of the Company's Class A common stock per $1,000 principal amount of Convertible Notes, which is equivalent to an initial conversion price of approximately $46.50 per share of its Class A common stock.
Debt instrument, convertible, discount rate		5.50%	5.50%	5.50%
Debt instrument, fair value of the liability component		$ 178,200,000	$ 178,200,000	$ 178,200,000
Debt instrument, equity component recorded in additional paid-in capital		51,800,000
Issuance costs attributable to liability component		6,300,000	6,300,000	6,300,000
Issuance costs attributable to equity component		$ 1,800,000	1,800,000	1,800,000
Convertible Senior Notes Due in 2024 [Member] | Class A Common Stock [Member]
Debt Instrument [Line Items]
Debt conversion, converted instrument, shares issued | shares		21.5049
Debt interument conversion rate principal amount of notes		$ 1,000	$ 1,000	$ 1,000
Debt instrument convertible initial conversion price per share of common stock | $ / shares		$ 46.50	$ 46.50	$ 46.50
Convertible Senior Notes Due in 2024 [Member] | Class A Common Stock [Member] | Convertible Notes, Holders Conversion Rights, Circumstances 1 [Member]
Debt Instrument [Line Items]
Debt instrument, convertible, consecutive trading days | d		30
Convertible Senior Notes Due in 2024 [Member] | Class A Common Stock [Member] | Convertible Notes, Holders Conversion Rights, Circumstances 1 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, convertible, trading days | d		20
Debt instrument, convertible, threshold percentage of conversion price		130.00%
Convertible Senior Notes Due in 2024 [Member] | Class A Common Stock [Member] | Convertible Notes, Holders Conversion Rights, Circumstances 2 [Member]
Debt Instrument [Line Items]
Debt interument conversion rate principal amount of notes		$ 1,000	$ 1,000	$ 1,000
Debt instrument, convertible, consecutive trading days | d		5
Debt instrument, convertible, business days | d		5
Debt instrument, convertible, maximum threshold percentage of sale price of common stock during measurement period		98.00%
Twenty Nineteen Credit Agreement
Debt Instrument [Line Items]
Maturity date	Dec. 15, 2023
Credit facility	$ 150,000,000
Increase in line of credit borrowing capacity	50,000,000
Increase in unrestricted domestic cash	$ 20,000,000
Maximum leverage ratio	5.00%
Twenty Nineteen Credit Agreement | Federal Funds Effective Swap Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	0.50%
Twenty Nineteen Credit Agreement | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.00%
Twenty Nineteen Credit Agreement | Minimum [Member]
Debt Instrument [Line Items]
Commitment fees on unused portion of the Revolving Credit Facility				0.15%
Senior secured leverage ratio	3.00%
Twenty Nineteen Credit Agreement | Minimum [Member] | Eurodollar Loans [Member]
Debt Instrument [Line Items]
Applicable margin for borrowings under new credit facility	1.25%
Twenty Nineteen Credit Agreement | Minimum [Member] | Swingline Loans [Member]
Debt Instrument [Line Items]
Applicable margin for borrowings under new credit facility	0.25%
Twenty Nineteen Credit Agreement | Minimum [Member] | APR Loans [Member]
Debt Instrument [Line Items]
Applicable margin for borrowings under new credit facility	0.25%
Twenty Nineteen Credit Agreement | Maximum [Member]
Debt Instrument [Line Items]
Commitment fees on unused portion of the Revolving Credit Facility				0.30%
EBITDA to cash Consolidated Interest Expense ratio	3.00%
Twenty Nineteen Credit Agreement | Maximum [Member] | Eurodollar Loans [Member]
Debt Instrument [Line Items]
Applicable margin for borrowings under new credit facility	2.00%
Twenty Nineteen Credit Agreement | Maximum [Member] | Swingline Loans [Member]
Debt Instrument [Line Items]
Applicable margin for borrowings under new credit facility	1.00%
Twenty Nineteen Credit Agreement | Maximum [Member] | APR Loans [Member]
Debt Instrument [Line Items]
Applicable margin for borrowings under new credit facility	1.00%
Secured Credit Agreement [Member]
Debt Instrument [Line Items]
Loan outstanding		$ 0	0	$ 0
Amount available for future borrowing		$ 150,000,000	$ 150,000,000	$ 150,000,000

Debt - Schedule of Net Carrying

Debt - Schedule of Net Carrying Value of Liability Component of Convertible Notes (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Principal	$ 231,323	$ 31,838
Less: unamortized debt discount	51,443
Less: unamortized debt issuance costs	6,251	$ 90
Convertible Senior Notes Due in 2024 [Member]
Debt Instrument [Line Items]
Principal	230,000
Less: unamortized debt discount	51,443
Less: unamortized debt issuance costs	6,251
Net carrying amount	$ 172,306

Debt - Schedule of Net Carryi_2

Debt - Schedule of Net Carrying Value of Equity Component of Convertible Notes (Detail) - Convertible Senior Notes Due in 2024 [Member] $ in Thousands	Jun. 30, 2019USD ($)
Debt Instrument [Line Items]
Proceeds allocated to the conversion option (debt discount)	$ 51,842
Less: issuance costs	1,833
Net carrying amount	$ 50,009

Debt - Schedule of Interest Exp

Debt - Schedule of Interest Expense Recognized Related to Convertible Notes (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018
Debt Instrument [Line Items]
Amortization of debt issuance cost and discount		$ 459	$ 12
Convertible Senior Notes Due in 2024 [Member]
Debt Instrument [Line Items]
Contractual interest expense	$ 25	25
Amortization of debt issuance cost and discount	447	447
Total	$ 472	$ 472

Leases - Additional Information

Leases - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Lessee Lease Description [Line Items]
Rent cost for operating leases	$ 2,900	$ 2,300	$ 6,000	$ 4,600
Finance lease obligations, total	$ 1,298		$ 1,298
Adoption of Topic 842 [Member]
Lessee Lease Description [Line Items]
Finance lease obligations, total					$ 800
Minimum [Member]
Lessee Lease Description [Line Items]
Leases, remaining lease term			0 years
Maximum [Member]
Lessee Lease Description [Line Items]
Leases, remaining lease term			8 years 9 months 18 days
Operating leases, options to extend lease term	6 years		6 years
Leases, options to terminate leases			4 years

Leases - Schedule of Components

Leases - Schedule of Components of Lease Cost (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Leases [Abstract]
Operating lease cost	$ 3,359	$ 6,783
Finance lease cost:
Amortization of ROU assets	126	247
Interest on lease liabilities	5	10
Total finance lease cost	$ 131	$ 257

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Balance Sheet Information Related to Lease Liabilities (Detail) $ in Thousands	Jun. 30, 2019USD ($)
Operating leases:
Operating lease ROU assets	$ 28,878
Current portion of operating lease liabilities	9,412
Operating lease liabilities, net of current portion	20,722
Total operating lease liabilities	$ 30,134
Weighted average remaining lease term	4 years 2 months 12 days
Weighted average discount rate	5.30%
Finance leases:
Property and equipment	$ 2,607
Accumulated depreciation	(1,111)
Property and equipment, net	$ 1,496
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet
Current portion of long-term debt	$ 447
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:LongTermDebtAndCapitalLeaseObligationsCurrent
Long-term debt, net of current portion	$ 851
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:LongTermDebtAndCapitalLeaseObligations
Total finance lease liabilities	$ 1,298
Weighted average remaining lease term	3 years 2 months 12 days
Weighted average discount rate	3.40%

Leases - Schedule of Suppleme_2

Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Detail) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ (5,665)
Operating cash flows from finance leases	(25)
Financing cash flows from finance leases	(209)
ROU assets obtained in exchange for lease obligations:
Operating leases	6,545
Finance leases	$ 566

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Operating Lease Liabilities (Detail) $ in Thousands	Jun. 30, 2019USD ($)
Leases [Abstract]
2019 (excluding the six months ended June 30, 2019)	$ 5,715
2020	9,508
2021	7,089
2022	4,811
2023	2,971
Thereafter	3,335
Total lease payments	33,429
Less: imputed interest	3,295
Total operating lease liabilities	$ 30,134

Other Liabilities - Summary of

Other Liabilities - Summary of Other Accrued Expenses and Current Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Income taxes payable	$ 7,732	$ 3,932
Accrued VAT	3,985	4,536
Accrued royalties	3,527	2,613
Accrued professional fees	3,403	3,165
Defined contribution plan liabilities	1,225	1,376
Government grants	859	915
Non-income tax liabilities	685	853
Billings in excess of cost	520	1,504
Other current liabilities	6,043	8,145
Total	$ 27,979	$ 27,039

Other Liabilities - Summary o_2

Other Liabilities - Summary of Other Long-term Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Pension and other post retirement liabilities	$ 9,782	$ 9,111
Deferred tax liabilities	5,725	5,339
Other liabilities	10,855	11,306
Total	$ 26,362	$ 25,756

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) $ in Millions	Jun. 30, 2019USD ($)
Fair Value Disclosures [Abstract]
Fair value of convertible notes	$ 249.6

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Detail) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)Installment$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares	Sep. 27, 2017shares	Dec. 31, 2012shares	Dec. 31, 2001shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other accrued expenses and current liabilities	$ 27,979	$ 27,039
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Business combination, estimated post combination expense	$ 3,400
Weighted average remaining service period	1 year 6 months
Other accrued expenses and current liabilities	$ 100	$ 600
NSO Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, outstanding | shares	3,815,348	4,337,856
Exercise price stock options outstanding | $ / shares	$ 0.000025	$ 0.000025
Contractual term	35 years
Intrinsic value of options exercised	$ 19,800
ISO Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, outstanding | shares		532,220
Exercise price stock options outstanding | $ / shares		$ 0.65
Contractual term	10 years
Intrinsic value of options exercised	$ 7,400
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] | Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized | shares					11,153,872
2012 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, outstanding | shares	1,273,311	1,541,165
Exercise price stock options outstanding | $ / shares	$ 4.20	$ 4.12
Contractual term	10 years
Intrinsic value of options exercised	$ 8,500
Total requisite service period of awards	4 years
Compensation cost related to nonvested awards not yet recognized	$ 600
Weighted average period of recognition	1 year 7 months 6 days
2012 Plan [Member] | Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized | shares				5,200,000
2017 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options, outstanding | shares	20,000	0
Exercise price stock options outstanding | $ / shares	$ 38.11	$ 0
2017 Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost related to nonvested awards not yet recognized	$ 25,600
Weighted average period of recognition	4 years
Weighted average grant date fair value of RSUs | $ / shares	$ 36.18
Number of vesting equal annual installments | Installment	4
2017 Plan [Member] | Class A Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance | shares			8,104,971

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Stock Option Activity under NSO Plan (Detail) - NSO Plan [Member] $ / shares in Units, $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of options, Outstanding, Beginning Balance | shares	4,337,856
Number of options, Exercised | shares	(522,508)
Number of options, Forfeited | shares	0
Number of options, Outstanding and exercisable, Ending Balance | shares	3,815,348
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price per share, Outstanding, Beginning Balance | $ / shares	$ 0.000025
Weighted average exercise price per share, Exercised | $ / shares	0.000025
Weighted average exercise price per share, Forfeited | $ / shares	0
Weighted average exercise price per share, Outstanding and exercisable, Ending Balance | $ / shares	$ 0.000025
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term (years), Outstanding		18 years
Weighted average remaining contractual term (years), Outstanding and exercisable	17 years 6 months
Aggregate intrinsic value, Outstanding | $		$ 119.6
Aggregate intrinsic value, Outstanding and exercisable | $	$ 154.1

Stock-based Compensation - Su_2

Stock-based Compensation - Summary of Stock Option Activity under ISO Plan (Detail) - ISO Plan [Member] $ / shares in Units, $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of options, Outstanding, Beginning Balance | shares	532,220
Number of options, Exercised | shares	(218,693)
Number of options, Forfeited | shares	0
Number of options, Outstanding and exercisable, Ending Balance | shares	313,527
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price per share, Outstanding, Beginning Balance | $ / shares	$ 0.65
Weighted average exercise price per share, Exercised | $ / shares	0.67
Weighted average exercise price per share, Forfeited | $ / shares	0
Weighted average exercise price per share, Outstanding and exercisable, Ending Balance | $ / shares	$ 0.64
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term (years), Outstanding		1 year 4 months 24 days
Weighted average remaining contractual term (years), Outstanding and exercisable	9 months 18 days
Aggregate intrinsic value, Outstanding | $		$ 14.3
Aggregate intrinsic value, Outstanding and exercisable | $	$ 12.5

Stock-based Compensation - Su_3

Stock-based Compensation - Summary of Stock Option Activity under 2012 Plan (Detail) - 2012 Plan [Member] $ / shares in Units, $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of options, Outstanding, Beginning Balance | shares	1,541,165
Number of options, Granted | shares	0
Number of options, Exercised | shares	(264,551)
Number of options, Forfeited | shares	(3,303)
Number of options, Outstanding, Ending Balance | shares	1,273,311	1,541,165
Number of options, Exercisable | shares	892,645
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price per share, Outstanding, Beginning Balance | $ / shares	$ 4.12
Weighted average exercise price per share, Granted | $ / shares	0
Weighted average exercise price per share, Exercised | $ / shares	3.76
Weighted average exercise price per share, Forfeited | $ / shares	4.44
Weighted average exercise price per share, Outstanding, Ending Balance | $ / shares	4.20	$ 4.12
Weighted average exercise price per share, Exercisable | $ / shares	$ 3.94
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term (years), Outstanding	6 years 6 months	6 years 10 months 24 days
Weighted average remaining contractual term (years), Exercisable	6 years 1 month 6 days
Aggregate intrinsic value, Outstanding | $		$ 36.2
Aggregate intrinsic value, Exercisable | $	$ 32.5

Stock-based Compensation - Su_4

Stock-based Compensation - Summary of Restricted Stock Units Awarded (Detail) - 2017 Plan [Member] - Restricted Stock Units (RSUs) [Member]	6 Months Ended
	Jun. 30, 2019shares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Number of RSUs, Outstanding Beginning Balance	206,061
Number of RSUs, Granted	634,985
Number of RSUs, Vested	(47,425)
Number of RSUs, Forfeited	(31,596)
Number of RSUs, Outstanding Ending Balance	762,025

Stock-based Compensation - Su_5

Stock-based Compensation - Summary of Stock Option Activity under 2017 Plan (Detail) - 2017 Plan [Member] - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of options, Outstanding, Beginning Balance	0
Number of options, Granted	20,000
Exercise of stock options (in shares)	0
Number of options, Forfeited	0
Number of options, Outstanding, Ending Balance	20,000
Number of options, Exercisable	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price per share, Outstanding, Beginning Balance	$ 0
Weighted average exercise price per share, Granted	38.11
Weighted average exercise price per share, Exercised	0
Weighted average exercise price per share, Forfeited	0
Weighted average exercise price per share, Outstanding, Ending Balance	38.11
Weighted average exercise price per share, Exercisable	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average remaining contractual term (years), Outstanding	9 years 8 months 12 days
Weighted average remaining contractual term (years), Exercisable	0 years
Aggregate intrinsic value, Exercisable	$ 0

Stock-based compensation - Su_6

Stock-based compensation - Summary of Fair value of Company's Stock Options Granted (Detail)	6 Months Ended
	Jun. 30, 2019$ / shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Weighted average grant date fair value per share	$ 38.11
Expected volatility	42.00%
Expected term (in years)	6 years 3 months
Risk-free interest rate	1.80%
Expected dividend yield	0.00%

Stock-based Compensation - Su_7

Stock-based Compensation - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 2,080	$ 434	$ 3,292	$ 650
Cost of Revenue - Software [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	279	8	343	16
Research and development [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	579	108	937	155
Sales and marketing [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	475	134	937	175
General and administrative [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 747	$ 184	$ 1,075	$ 304

Other Income, Net - Schedule of

Other Income, Net - Schedule of Other Income, Net (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Other Income And Expenses [Abstract]
Foreign exchange loss (gain)	$ (237)	$ 217	$ 180	$ (580)
Other	(268)	(393)	(295)	(496)
Other income, net	$ (505)	$ (176)	$ (115)	$ (1,076)

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax Expense (Benefit) and Effective Tax Rate (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax (benefit) expense	$ (167)	$ 1,386	$ 3,921	$ 3,732	$ 11,489	$ 65,530
Effective tax rate	5.00%	453.00%	28.00%	14.00%

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
United States pre-tax income (loss)	$ (8.3)	$ (6)	$ 5.3	$ 12
Reversal of reserve adjustments recorded for uncertain tax positions			$ 1.1

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss - Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income before reclassification			$ 1,939
Amounts reclassified from accumulated other comprehensive loss			247
Total other comprehensive income (loss)	$ 1,621	$ (4,149)	2,186	$ (2,906)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(8,823)
Other comprehensive income before reclassification			1,942
Total other comprehensive income (loss)			1,942
Ending balance	(6,881)		(6,881)
Retirement Related Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(2,467)
Other comprehensive income before reclassification			(3)
Amounts reclassified from accumulated other comprehensive loss			247
Total other comprehensive income (loss)			244
Ending balance	(2,223)		(2,223)
Accumulated Other Comprehensive Loss [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(11,290)
Ending balance	$ (9,104)		$ (9,104)

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2013USD ($)
Datawatch Corporation [Member] | Panopticon AB [Member] | Swedish Tax Authorities [Member]
Loss Contingencies [Line Items]
Tax assessment, penalties and interest amount related to acquisition	$ 6.6

Segment Information - Additiona

Segment Information - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2019Segment
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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Revenue	$ 106,773	$ 93,360	$ 234,632	$ 206,617
Adjusted EBITDA	5,165	5,303	29,149	34,853
Software [Member]
Segment Reporting Information [Line Items]
Revenue	92,315	79,314	205,378	178,456
Adjusted EBITDA	5,207	4,718	29,249	33,746
CES [Member]
Segment Reporting Information [Line Items]
Revenue	12,412	12,417	24,462	24,497
Adjusted EBITDA	1,467	1,508	2,573	2,564
All Other [Member]
Segment Reporting Information [Line Items]
Revenue	2,046	1,629	4,792	3,664
Adjusted EBITDA	$ (1,509)	$ (923)	$ (2,673)	$ (1,457)

Segment Information - Reconcili

Segment Information - Reconciliation of U.S. GAAP Income Before Income Taxes to Adjusted EBITDA (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting [Abstract]
Adjusted EBITDA		$ 5,165	$ 5,303	$ 29,149	$ 34,853
Stock-based compensation expense		(2,080)	(434)	(3,292)	(650)
Interest expense		(590)	(45)	(860)	(61)
Interest income and other	[1]	(508)	(536)	(709)	719
Depreciation and amortization		(5,274)	(3,982)	(10,468)	(7,525)
(Loss) income before income taxes		$ (3,287)	$ 306	$ 13,820	$ 27,336	$ 27,024	$ (36,411)
[1]	Includes an impairment charge for royalty contracts resulting in $0.8 million and $1.0 million of expense for the three and six months ended June 30, 2019, respectively, and $0.9 million and $1.8 million of expense for the three and six months ended June 30, 2018, respectively. Includes a non-recurring adjustment for a change in estimated legal expenses resulting in $2.0 million of income for the six months ended June 30, 2018

Segment Information - Reconci_2

Segment Information - Reconciliation of U.S. Gaap Income Before Income Taxes to Adjusted EBITDA (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting [Abstract]
Impairment charge recognized in non-recurring adjustment for royalty contracts	$ 0.8	$ 0.9	$ 1	$ 1.8
Income recognized in non-recurring adjustment for change in estimated legal expenses				$ 2