Medidata Solutions 10-Q 6 Aug 19 2019 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2019	Jul. 31, 2019
Cover page.
Document type	10-Q
Document quarterly report	true
Document period end date	Jun. 30, 2019
Document transition report	false
Entity file number	001-34387
Entity registrant name	Medidata Solutions, Inc.
Entity incorporation, state or country code	DE
Entity tax identification number	13-4066508
Entity address, address line one	350 Hudson Street, 9th Floor
Entity address, city or town	New York
Entity address, state or province	NY
Entity address, postal zip code	10014
City area code	(212)
Local phone number	918-1800
Title of 12(b) security	Common stock, par value
Trading symbol	MDSO
Security exchange name	NASDAQ
Entity current reporting status	Yes
Entity interactive data current	Yes
Entity filer category	Large Accelerated Filer
Entity small business	false
Entity emerging growth company	false
Entity shell company	false
Entity central index key	0001453814
Amendment flag	false
Document fiscal period focus	Q2
Document fiscal year focus	2019
Current fiscal year end date	--12-31
Entity common stock, shares outstanding		62,456,410

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands		Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents		$ 139,104	$ 105,440
Marketable securities		66,914	135,105
Accounts receivable, net of allowance for doubtful accounts	[1]	198,166	170,744
Prepaid commission expense		24,426	22,247
Prepaid expenses and other current assets		37,615	28,949
Total current assets		466,225	462,485
Restricted cash		7,223	7,205
Operating lease assets	[2]	83,554	0
Furniture, fixtures and equipment, net		114,210	98,983
Goodwill		213,976	216,017
Intangible assets, net		26,406	29,546
Deferred income taxes- long-term		53,475	45,982
Other assets		58,697	52,994
Total assets		1,023,766	913,212
Current liabilities:
Accounts payable		10,672	7,482
Accrued payroll and other compensation		34,047	51,270
Accrued expenses and other		41,298	37,487
Operating lease liabilities	[2]	15,318	0
Deferred revenue		80,435	74,463
Total current liabilities		181,770	170,702
Noncurrent liabilities:
Term loans, net		84,844	88,366
Deferred revenue, less current portion		2,291	3,843
Deferred tax liabilities		101	99
Operating lease liabilities, noncurrent	[2]	92,611	0
Other long-term liabilities		1,690	18,754
Total noncurrent liabilities		181,537	111,062
Total liabilities		363,307	281,764
Commitments and contingencies
Stockholders' equity:
Preferred stock		0	0
Common stock		679	661
Additional paid-in capital		629,451	574,667
Treasury stock		(198,003)	(152,849)
Accumulated other comprehensive loss		(4,544)	(4,869)
Retained earnings		232,876	213,838
Total stockholders' equity		660,459	631,448
Total liabilities and stockholders' equity		$ 1,023,766	$ 913,212
[1]	Unbilled receivables of $51,421 and $38,601, respectively, are included in accounts receivable as of June 30, 2019 and December 31, 2018.
[2]	Figures as of June 30, 2019 reflect the Company's January 1, 2019 adoption of Accounting Standards Update ("ASU") No. 2016-02, Leases. For additional details, see Note 1, "Summary of Significant Accounting Policies — Recently Adopted Accounting Pronouncements."

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accounts receivable, allowance for doubtful accounts	$ 2,018	$ 1,999
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000	200,000
Common stock, shares issued	67,916	66,103
Common stock, shares outstanding	62,461	61,348
Treasury stock, shares	5,455	4,755

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Revenues		$ 180,460	$ 155,905	$ 353,964	$ 305,103
Cost of revenues:
Cost of revenues	[1],[2]	49,602	37,501	95,605	73,803
Gross profit		130,858	118,404	258,359	231,300
Operating costs and expenses:
Research and development	[2]	48,475	40,789	94,964	78,311
Sales and marketing	[1],[2]	44,388	37,106	87,784	73,967
General and administrative	[2]	36,090	27,672	68,724	52,859
Total operating costs and expenses		128,953	105,567	251,472	205,137
Operating income		1,905	12,837	6,887	26,163
Interest and other income (expense):
Interest expense		(1,110)	(5,700)	(2,220)	(11,275)
Interest income		599	2,328	1,544	4,416
Other income (expense), net		381	7,729	353	7,633
Total interest and other expense, net		(130)	4,357	(323)	774
Income before income taxes		1,775	17,194	6,564	26,937
Provision for income taxes		(6,118)	605	(12,474)	23
Net income		$ 7,893	$ 16,589	$ 19,038	$ 26,914
Earnings per share:
Basic		$ 0.13	$ 0.29	$ 0.32	$ 0.47
Diluted		$ 0.13	$ 0.27	$ 0.31	$ 0.44
Weighted average common shares outstanding, basic		60,081	57,448	59,888	57,252
Weighted average common shares outstanding, diluted		62,372	60,874	62,191	60,564
Share-based compensation and amortization of intangible assets:
Total stock-based compensation	[2]	$ 21,895	$ 15,119	$ 41,559	$ 28,274
Total amortization of intangible assets	[1]	1,870	1,436	3,740	2,650
Cost of revenues
Share-based compensation and amortization of intangible assets:
Total stock-based compensation	[2]	2,871	1,506	5,254	2,774
Total amortization of intangible assets	[1]	1,365	1,205	2,729	2,299
Research and development
Share-based compensation and amortization of intangible assets:
Total stock-based compensation	[2]	5,005	3,319	9,254	6,173
Sales and marketing
Share-based compensation and amortization of intangible assets:
Total stock-based compensation	[2]	6,046	2,917	11,472	5,561
Total amortization of intangible assets	[1]	505	231	1,011	351
General and administrative
Share-based compensation and amortization of intangible assets:
Total stock-based compensation	[2]	7,973	7,377	15,579	13,766
Subscription [Member]
Revenues:
Revenues		150,006	130,486	296,881	257,305
Cost of revenues:
Cost of revenues		29,306	21,602	56,034	41,943
Professional services [Member]
Revenues:
Revenues		30,454	25,419	57,083	47,798
Cost of revenues:
Cost of revenues		$ 20,296	$ 15,899	$ 39,571	$ 31,860
[1]	Amortization of intangible assets included in cost of revenues and operating costs and expenses
[2]	Stock-based compensation expense included in cost of revenues and operating costs and expenses

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net income	$ 7,893	$ 16,589	$ 19,038	$ 26,914
Other comprehensive income (loss):
Foreign currency translation adjustments	(605)	(1,954)	(233)	(684)
Unrealized gain (loss) on marketable securities	221	719	753	(307)
Other comprehensive income (loss)	(384)	(1,235)	520	(991)
Income tax effect of unrealized gain or loss on marketable securities	(57)	(180)	(195)	(122)
Other comprehensive income (loss), net of tax	(441)	(1,415)	325	(1,113)
Comprehensive income (loss), net of tax	$ 7,452	$ 15,174	$ 19,363	$ 25,801

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income		$ 19,038	$ 26,914
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of intangible assets and depreciation		22,175	16,218
Stock-based compensation	[1]	41,559	28,274
Amortization of operating lease assets	[2]	6,112	0
Amortization of capitalized contract costs		13,319	9,491	[3]
Amortization of discounts or premiums on marketable securities		55	50
Realized loss on available-for-sale securities		27	0
Deferred income taxes		(5,963)	106
Amortization of debt issuance costs		217	856
Amortization of debt discount		0	7,015
Provision for doubtful accounts		881	763
Loss on fixed asset disposal		166	127
Gain recognized on step acquisition		0	7,648
Changes in fair value of contingent consideration		240	7
Changes in operating assets and liabilities:
Accounts receivable		(28,303)	(27,247)
Prepaid commission expense		(19,339)	(16,696)	[3]
Prepaid expenses and other current assets		(8,666)	(3,008)
Other assets		(1,862)	1,591
Accounts payable		1,185	1,753
Accrued payroll and other compensation		(20,166)	(8,909)
Accrued expenses and other		6,795	3,236
Deferred revenue		4,420	(9,572)
Operating lease liabilities	[2]	(7,966)	0
Other long-term liabilities		6,484	455
Net cash provided by (used in) operating activities		30,408	23,776
Cash flows from investing activities:
Purchases of furniture, fixtures and equipment		(32,366)	(19,520)
Purchase of domain name		(600)	0
Purchases of available-for-sale securities		0	(69,214)
Proceeds from sale of available-for-sale securities		68,862	137,786
Acquisition of business, net of cash acquired		0	178,568
Net cash provided by (used in) investing activities		35,896	(129,516)
Cash flows from financing activities:
Proceeds from exercise of stock options		3,912	6,351
Proceeds from employee stock purchase plan		7,895	6,345
Acquisition of treasury stock		(40,594)	(18,257)
Term loan principal payments		(2,500)	(1,250)
Payment of acquisition-related earn-out		(1,233)	(4,087)
Payments of credit facility financing costs		0	(175)
Net cash provided by (used in) financing activities		(32,520)	(11,073)
Effect of exchange rate changes on cash, cash equivalents and restricted cash		(102)	(209)
Net increase (decrease) in cash, cash equivalents and restricted cash		33,682	(117,022)
Cash, cash equivalents and restricted cash - beginning of period		112,645	242,843
Cash, cash equivalents and restricted cash - end of period		146,327	125,821
Supplemental disclosures of cash flow information:
Interest paid		1,994	3,263
Proceeds from income tax refunds		(382)
Income taxes paid			2,253
Noncash activities:
Furniture, fixtures, and equipment acquired but not yet paid for at period-end		$ 5,628	$ 3,054
[1]	Stock-based compensation expense included in cost of revenues and operating costs and expenses
[2]	Figures as of June 30, 2019 reflect the Company's January 1, 2019 adoption of Accounting Standards Update ("ASU") No. 2016-02, Leases. For additional details, see Note 1, "Summary of Significant Accounting Policies — Recently Adopted Accounting Pronouncements."
[3]	Prior period recast to conform with current period presentation

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Company — Medidata Solutions, Inc., together with its consolidated subsidiaries (collectively, the "Company"), is the leading global provider of cloud-based solutions for clinical research in life sciences, offering platform technology that transforms clinical development and increases the value of its customers' research investments. The Company was organized as a New York corporation in June 1999 and reincorporated as a Delaware corporation in May 2000. Except to the extent updated or described below, the Company’s significant accounting policies as of June 30, 2019 are the same as those at December 31, 2018 , which are included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018 , filed with the Securities and Exchange Commission (“SEC”) on March 1, 2019 . Merger Agreement — On June 11, 2019, the Company entered into an Agreement and Plan of Merger (the "Merger Agreement") with Dassault Systèmes SE ("Dassault Systèmes"), Dassault Systèmes Americas Corp. (the "Parent"), and 3DS Acquisition 6 Corp. (the "Merger Sub"), providing for, among other things, subject to the terms and conditions of the Merger Agreement, the acquisition of the Company by the Parent at a price of $92.25 per share in cash, without interest, through the Merger Sub and into the Company (the "Merger"), with the Company surviving the Merger as a wholly owned subsidiary of the Parent. On July 19, 2019, the Company filed its definitive proxy statement on Schedule 14A with the SEC for a special meeting of its stockholders to be held on August 16, 2019 in connection with the Merger. The transaction is expected to close during the second half of 2019, subject to certain conditions including regulatory and shareholder approvals. Until the close of the transaction, the Company will continue to operate independently. A description of the material terms of the Merger Agreement is available on the Company's Current Report on Form 8-K filed with the SEC on June 13, 2019; the full text of the Merger Agreement has been filed as Exhibit 2.1 thereto, and has been incorporated by reference as Exhibit 2.1 to this Quarterly Report on Form 10-Q. Basis of Presentation — The accompanying interim condensed consolidated balance sheets as of June 30, 2019 and December 31, 2018 , the condensed consolidated statements of operations for the three and six months ended June 30, 2019 and 2018 , the condensed consolidated statements of comprehensive income for the three and six months ended June 30, 2019 and 2018 , and the condensed consolidated statements of cash flows for the six months ended June 30, 2019 and 2018 are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the SEC for interim financial reporting. Accordingly, certain information and footnote disclosures have been condensed or omitted pursuant to SEC rules that would ordinarily be required by U.S. GAAP for complete financial statements. These unaudited interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes thereto for the fiscal year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the SEC on March 1, 2019 . The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all adjustments consisting of normal recurring accruals considered necessary to present fairly the Company’s financial position as of June 30, 2019 , results of its operations for the three and six months ended June 30, 2019 and 2018 , comprehensive income for the three and six months ended June 30, 2019 and 2018 , and cash flows for the six months ended June 30, 2019 and 2018 . The results of operations for the three and six months ended June 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 . Accounts Receivable — Accounts receivable are recorded at original invoice amount less an allowance that management believes will be adequate to absorb estimated losses on uncollectible accounts. This allowance is based on an evaluation of the collectability of accounts receivable and prior bad debt experience. Accounts receivable are written off when deemed uncollectible. Unbilled receivables consist of revenue recognized in excess of billings, substantially all of which is expected to be billed and collected within one year. As of June 30, 2019 and December 31, 2018 , unbilled accounts receivable of $51.4 million and $38.6 million , respectively, were included in accounts receivable on the Company's condensed consolidated balance sheets. Leases — At the inception of an arrangement, the Company evaluates the existence and type of lease; the Company has determined that all of its leases are operating leases, which are recognized as operating lease assets and operating lease liabilities on its condensed consolidated balance sheet as of June 30, 2019 (subsequent to the adoption of Accounting Standards Codification ("ASC") 842, Leases on January 1, 2019). Operating lease assets represent the right to use an underlying asset over the lease term, and operating lease liabilities represent the obligation to make lease payments. Some of the Company's leases contain options to extend or terminate; the Company is reasonably certain that it will not exercise these options and does not consider them in the determination of the lease term. Leases with an initial term of twelve months or less are not recorded on the balance sheet; the Company recognizes the related expense on a straight-line basis over the lease term. For leases beginning in 2019 and later, the Company accounts for lease components together with nonlease components. Operating lease assets and liabilities are recognized based on the present value of the remaining lease payments as of the commencement date. As the majority of its leases do not provide an implicit interest rate, the Company uses the estimated incremental borrowing rate that would be required to secure a loan from a third-party lender over the relevant term. For further information, see Note 9 , “Leases." Income Taxes — The Company’s interim period provision for income taxes is computed by using an estimate of the annual effective tax rate, adjusted for discrete items taken into account in the relevant period, if any. Each quarter, the annual effective income tax rate is recomputed and if there are material changes in the estimate, a cumulative adjustment is made. Recently Adopted Accounting Pronouncements — In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, Leases , which replaces previous lease guidance in its entirety with ASC 842 and requires lessees to recognize lease assets and lease liabilities for those arrangements classified as operating leases under previous guidance, with the exception of leases with a term of twelve months or less. The Company adopted ASU No. 2016-02 on January 1, 2019 using the additional transition method, which allows prior periods to be presented under previous lease accounting guidance. Refer to Note 9 , "Leases," for related disclosures. In February 2018, the FASB issued ASU No. 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, which permits companies to reclassify disproportionate tax effects in accumulated other comprehensive income caused by the U.S. Tax Cuts and Jobs Act enacted in December 2017 to retained earnings. ASU No. 2018-02 is effective for annual reporting periods beginning after December 15, 2018, and interim periods within those annual periods. The Company adopted ASU No. 2018-02 on January 1, 2019, and the adoption did not have a material impact on its condensed consolidated financial statements. Recently Issued Accounting Pronouncements — There have been no changes in the expected dates of adoption or estimated effects on the Company's consolidated financial statements of recently issued accounting pronouncements from those disclosed in the Company’s Annual Report on Form 10-K.

Revenues

Revenues	6 Months Ended
	Jun. 30, 2019
Revenues [Abstract]
REVENUES	REVENUES Disaggregation of Revenue The following tables provide information about the Company's revenues, disaggregated by geographical market and revenue type, for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended June 30, 2019 2018 Subscription Professional Services Total Subscription Professional Services Total Revenues: United States $ 111,245 $ 22,222 $ 133,467 $ 99,646 $ 18,526 $ 118,172 Rest of Americas 1,680 232 1,912 1,689 277 1,966 Total Americas 112,925 22,454 135,379 101,335 18,803 120,138 Japan 7,392 1,825 9,217 7,665 1,261 8,926 Rest of Asia Pacific 6,849 2,382 9,231 3,875 1,243 5,118 Total Asia Pacific 14,241 4,207 18,448 11,540 2,504 14,044 Europe, Middle East and Africa 22,840 3,793 26,633 17,611 4,112 21,723 Total $ 150,006 $ 30,454 $ 180,460 $ 130,486 $ 25,419 $ 155,905 Six Months Ended June 30, 2019 2018 Subscription Professional Services Total Subscription Professional Services Total Revenues: United States $ 220,081 $ 39,739 $ 259,820 $ 195,811 $ 34,510 $ 230,321 Rest of Americas 3,483 471 3,954 1,998 481 2,479 Total Americas 223,564 40,210 263,774 197,809 34,991 232,800 Japan 18,289 4,298 22,587 15,777 3,055 18,832 Rest of Asia Pacific 12,853 4,118 16,971 7,576 2,381 9,957 Total Asia Pacific 31,142 8,416 39,558 23,353 5,436 28,789 Europe, Middle East and Africa 42,175 8,457 50,632 36,143 7,371 43,514 Total $ 296,881 $ 57,083 $ 353,964 $ 257,305 $ 47,798 $ 305,103 The above tables present revenues according to the region in which they were generated, separately displaying those individual countries that, in any of the periods presented, constituted 5% or more or of total revenues. All of the Company's performance obligations are transferred to customers over time; as a result, no disaggregation of revenues by timing of revenue recognition is provided. Contract Balances The following table provides information about changes in the Company's deferred revenue balances during the six months ended June 30, 2019 and 2018 (in thousands): Deferred Revenue 2019 2018 Balance as of January 1 $ 78,306 $ 82,631 Revenue recognized that was included in deferred revenue at the beginning of the period (59,735 ) (71,137 ) Revenue recognized that was not included in deferred revenue at the beginning of the period (283,164 ) (233,400 ) Increases due to invoicing 341,248 297,161 Revenue recognized in excess of billings (billings in excess of revenue recognized) 12,820 (680 ) Other (6,749 ) 1,493 Balance as of June 30 $ 82,726 $ 76,068 Aside from the accounts receivable presented on its condensed consolidated balance sheets, the Company did not have any material contract assets for any of the periods presented. Transaction Price Allocated to the Remaining Performance Obligations As of June 30, 2019 , the Company has unsatisfied performance obligations associated with subscription services that extend through 2030 . The total multi-year transaction price allocated to unsatisfied subscription performance obligations is approximately $1,042 million as of June 30, 2019 . Of this amount, approximately $290 million , $440 million , and $312 million are expected to be recognized in 2019 , 2020 , and thereafter, respectively. As of June 30, 2019 , the total transaction price allocated to unsatisfied professional services performance obligations is immaterial. Costs to Obtain and Fulfill a Contract with a Customer Sales commissions earned are considered incremental and recoverable costs of obtaining a contract with a customer and therefore are capitalized as contract costs. Capitalized contract costs were $66.0 million and $60.0 million as of June 30, 2019 and December 31, 2018 , respectively. The current portion of capitalized contract costs is represented by capitalized contract costs on the Company's consolidated balance sheets; the long-term portion is included in other assets. Amortization of capitalized contract costs was $6.7 million and $4.6 million for the three months ended June 30, 2019 and 2018 , respectively and $13.3 million and $9.5 million for the six months ended June 30, 2019 and 2018 , respectively. There have been no impairment losses related to capitalized contract costs.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS' EQUITY Common Stock — Common stockholders are entitled to one vote for each share of common stock held. Common stockholders may receive dividends if and when the board of directors determines, at its sole discretion. Treasury Stock — From time to time, the Company grants nonvested restricted stock awards ("RSAs"), restricted stock units ("RSUs"), and performance-based restricted stock units ("PBRSUs") to its employees pursuant to the terms of its Second Amended and Restated 2017 Long-Term Incentive Plan, as Amended ("2017 Plan") and formerly pursuant to the terms of its Second Amended and Restated 2009 Long-Term Incentive Plan ("2009 Plan”). Under the provisions of the 2017 Plan and 2009 Plan, unless otherwise elected, participants fulfill their related income tax obligation by having shares withheld at the time of vesting. On the date of vesting, the Company divides the participant's income tax withholding obligation in dollars by the closing price of its common stock and withholds the resulting number of vested shares. The shares withheld are then transferred to the Company's treasury stock at cost. During the six months ended June 30, 2019 and 2018 , the Company withheld 452,021 shares at an average price of $74.99 and 271,585 shares at an average price of $67.23 , respectively, in connection with the vesting of equity awards. In addition, with regard to stock options granted under the 2009 Plan, option holders may pay option exercise price and applicable income tax obligations in shares with express approval by the Company's board of directors. Withheld shares are transferred to the Company's treasury stock at cost. During the six months ended June 30, 2019 , the Company withheld 123,363 shares at an average price of $91.22 in connection with the net exercise of stock options. Nonvested restricted stock awards forfeited by plan participants are transferred to the Company's treasury stock at par. During the six months ended June 30, 2019 and 2018 , 124,746 and 189,668 forfeited shares, respectively, were transferred to treasury stock at their par value of $0.01. Accumulated Other Comprehensive Loss — For the six months ended June 30, 2019 and 2018 , reclassifications of items from accumulated other comprehensive loss to net income were insignificant. The following reconciliations present significant changes in the components of stockholders' equity for the three and six months ended June 30, 2019 and 2018 (in thousands): Accumulated other comprehensive loss (amounts in thousands) Common stock Additional paid-in capital Treasury stock Foreign currency translation adjustments Unrealized gains (losses) on marketable securities Retained earnings Total Balance - January 1, 2019 $ 661 $ 574,667 $ (152,849 ) $ (4,255 ) $ (614 ) $ 213,838 $ 631,448 Comprehensive income, net — — — 372 394 11,145 11,911 Stock-based compensation — 19,730 — — — — 19,730 Issuance of shares under stock-based compensation plans 13 2,328 — — — — 2,341 Acquisition of treasury stock in connection with vesting of awards — — (28,704 ) — — — (28,704 ) Balance - March 31, 2019 $ 674 $ 596,725 $ (181,553 ) $ (3,883 ) $ (220 ) $ 224,983 $ 636,726 Comprehensive income, net — — — (605 ) 164 7,893 7,452 Stock-based compensation — 21,974 — — — — 21,974 Issuance of shares under stock-based compensation plans 5 10,751 — — — — 10,756 Acquisition of treasury stock in connection with vesting of awards and exercise of options — — (16,449 ) — — — (16,449 ) Forfeiture of nonvested restricted stock awards — 1 (1 ) — — — — Balance - June 30, 2019 $ 679 $ 629,451 $ (198,003 ) $ (4,488 ) $ (56 ) $ 232,876 $ 660,459 Accumulated other comprehensive loss (amounts in thousands) Common stock Additional paid-in capital Treasury stock Foreign currency translation adjustments Unrealized gains (losses) on marketable securities Retained earnings Total Balance - January 1, 2018 628 486,147 (132,705 ) (2,459 ) (918 ) 161,917 512,610 Comprehensive income, net — — — 1,270 (968 ) 10,325 10,627 Stock-based compensation — 13,214 — — — — 13,214 Issuance of shares under stock-based compensation plans 9 2,357 — — — — 2,366 Acquisition of treasury stock in connection with vesting of awards — — (16,614 ) — — — (16,614 ) Balance - March 31, 2018 $ 637 $ 501,718 $ (149,319 ) $ (1,189 ) $ (1,886 ) $ 172,242 $ 522,203 Comprehensive income, net — — — (1,954 ) 539 16,589 15,174 Stock-based compensation — 15,190 — — — — 15,190 Issuance of shares under stock-based compensation plans 6 10,427 — — — — 10,433 Acquisition of treasury stock in connection with vesting of awards — — (1,644 ) — — — (1,644 ) Forfeiture of nonvested restricted stock awards — 1 (1 ) — — — — Balance - June 30, 2018 $ 643 $ 527,336 $ (150,964 ) $ (3,143 ) $ (1,347 ) $ 188,831 $ 561,356

Investments

Investments	6 Months Ended
	Jun. 30, 2019
Investments [Abstract]
INVESTMENTS	INVESTMENTS Marketable Securities Marketable securities, which the Company classifies as available-for-sale securities, primarily consist of high quality commercial paper, corporate bonds, and U.S. government debt obligations. Marketable securities with remaining effective maturities of twelve months or less from the balance sheet date are classified as short-term; otherwise, they are classified as long-term on the condensed consolidated balance sheets. The following tables provide the Company’s marketable securities by security type as of June 30, 2019 and December 31, 2018 (in thousands): As of June 30, 2019 Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper and corporate bonds $ 56,301 $ — $ (62 ) $ 56,239 U.S. government agency debt securities 10,690 — (15 ) 10,675 Total $ 66,991 $ — $ (77 ) $ 66,914 As of December 31, 2018 Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper and corporate bonds $ 125,245 $ — $ (747 ) $ 124,498 U.S. government agency debt securities 10,690 — (83 ) 10,607 Total $ 135,935 $ — $ (830 ) $ 135,105 Contractual maturities of the Company’s marketable securities as of June 30, 2019 and December 31, 2018 are summarized as follows (in thousands): As of June 30, 2019 As of December 31, 2018 Cost Estimated Fair Value Cost Estimated Fair Value Due in one year or less $ 66,991 $ 66,914 $ 135,935 $ 135,105 Due in one to five years — — — — Total $ 66,991 $ 66,914 $ 135,935 $ 135,105 At June 30, 2019 , the Company had $0.1 million of gross unrealized losses primarily due to a decrease in the fair value of certain corporate bonds. The Company regularly reviews its investment portfolio to identify and evaluate investments that have indications of possible impairment. Investments that are impaired are those that are considered to have losses that are other-than-temporary. Factors considered in determining whether a loss is temporary include: • the length of time and extent to which fair value has been lower than the cost basis; • the financial condition, credit quality and near-term prospects of the investee; and • whether it is more likely than not that the Company will be required to sell the security prior to recovery. As the Company has the ability and intent to hold these investments until a recovery of fair value, which may be maturity, the Company has determined that the gross unrealized losses on such investments at June 30, 2019 are temporary in nature. Accordingly, the Company did not consider its investments in marketable securities to be other-than-temporarily impaired as of June 30, 2019 . The following table provides the fair market value and gross unrealized losses of the Company's marketable securities with unrealized losses, aggregated by security type, as of June 30, 2019 and December 31, 2018 (in thousands In Loss Position for More than 12 Months As of June 30, 2019 As of December 31, 2018 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Commercial paper and corporate bonds $ 56,239 $ (62 ) $ 124,498 $ (747 ) U.S. government agency debt securities 10,675 (15 ) 10,607 (83 ) Total $ 66,914 $ (77 ) $ 135,105 $ (830 ) During the three and six months ended June 30, 2019 and 2018 , the Company recorded an insignificant amount of net realized gains and losses from the sale of marketable securities. Other Investments The Company holds shares of Series D Preferred Stock of Syapse Inc. purchased in a private placement. This investment does not have a readily determinable fair value and is carried at original cost in other assets on the Company's condensed consolidated balance sheets. This investment had a carrying value of $3.0 million as of June 30, 2019 and December 31, 2018 . The Company periodically evaluates this investment to determine if impairment charges are required; no impairment charges were recognized during the three or six months ended June 30, 2019 or 2018 .

Fair Value

Fair Value	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
FAIR VALUE	FAIR VALUE The following table summarizes, as of June 30, 2019 and December 31, 2018 , the Company's financial assets and liabilities that are measured at fair value on a recurring basis, according to the fair value hierarchy described in the significant accounting policies included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018 (in thousands): As of June 30, 2019 As of December 31, 2018 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash $ 118,449 $ — $ — $ 118,449 $ 103,859 $ — $ — $ 103,859 Money market funds 20,655 — — 20,655 1,581 — — 1,581 Total cash and cash equivalents 139,104 — — 139,104 105,440 — — 105,440 Commercial paper and corporate bonds — 56,239 — 56,239 — 124,498 — 124,498 U.S. government agency debt securities — 10,675 — 10,675 — 10,607 — 10,607 Total marketable securities — 66,914 — 66,914 — 135,105 — 135,105 Total financial assets measured at fair value on a recurring basis $ 139,104 $ 66,914 $ — $ 206,018 $ 105,440 $ 135,105 $ — $ 240,545 Contingent consideration – short-term $ — $ — $ 117 $ 117 $ — $ — $ 1,110 $ 1,110 Total financial liabilities measured at fair value on a recurring basis $ — $ — $ 117 $ 117 $ — $ — $ 1,110 $ 1,110 Investments in commercial paper, corporate bonds, and U.S. government agency debt securities have been classified as Level 2 as they are valued using quoted prices in less active markets or other directly or indirectly observable inputs. Fair values of corporate bonds and U.S. government agency debt securities were derived from a consensus or weighted-average price based on input of market prices from multiple sources at each reporting period. With regard to commercial paper, all of the securities had high credit ratings and one year or less to maturity; therefore, fair value was derived from accretion of purchase price to face value over the term of maturity or quoted market prices for similar instruments if available. During the three and six months ended June 30, 2019 and 2018 , there were no transfers of financial assets between Level 1 and Level 2. Contingent consideration liabilities associated with earn-out payments related to the Company's February 2017 acquisition of CHITA Inc. ("CHITA") are classified as Level 3 in the fair value hierarchy because they rely significantly on inputs that are unobservable in the market. The fair value of portions of contingent consideration related to the achievement of a technical milestone have been estimated using situation-based modeling, which considers the probability-weighted present value of the expected payout amount. The fair value of portions of contingent consideration related to achievement of revenue targets have been estimated using a Monte Carlo simulation to simulate future performance of the acquired business under a risk-neutral framework; significant inputs to the simulation include a risk-adjusted discount rate of 10.2% and revenue volatility of 8.0%. Contingent consideration is recorded in accrued expenses and other on the Company's condensed consolidated balance sheets. The following table provides a summary of changes in fair value of the Company's Level 3 contingent consideration liabilities during the six months ended June 30, 2019 (in thousands): Balance as of January 1, 2019 $ 1,110 Amounts earned by sellers (1,233 ) Fair value adjustment (included in general and administrative expenses) 240 Balance as of June 30, 2019 $ 117 The carrying amounts of all other current financial assets and current financial liabilities reflected in the condensed consolidated balance sheets approximate fair value due to their short-term nature.

Acquisition

Acquisition	6 Months Ended
	Jun. 30, 2019
Acquisition [Abstract]
ACQUISITION	ACQUISITION The Company did not make any acquisitions during the three and six months ended June 30, 2019 . During the three and six months ended June 30, 2018 , the Company acquired all outstanding equity interests in SHYFT Analytics, Inc. ("SHYFT"), a Waltham, Massachusetts provider of cloud data analytics for life sciences. The total purchase price of $196.3 million was composed of cash consideration of $183.6 million and the Company's previous investment in SHYFT, which had a fair value of $12.7 million as of the acquisition date.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	GOODWILL AND INTANGIBLE ASSETS The change in the carrying amount of goodwill during the six months ended June 30, 2019 was as follows (in thousands): Balance as of January 1, 2019 $ 216,017 Purchase price adjustments - SHYFT Analytics, Inc. (2,027 ) Foreign currency translation adjustments (14 ) Balance as of June 30, 2019 $ 213,976 Total intangible assets are summarized as follows (in thousands): As of June 30, 2019 As of December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Developed technology $ 31,353 $ (16,576 ) $ 14,777 $ 31,358 $ (13,852 ) $ 17,506 Customer relationships 9,166 (4,003 ) 5,163 9,167 (3,404 ) 5,763 Trade name 5,400 (370 ) 5,030 5,400 (190 ) 5,210 Non-competition agreements 1,460 (624 ) 836 1,460 (393 ) 1,067 Domain name (1) 600 — 600 — — — Total $ 47,979 $ (21,573 ) $ 26,406 $ 47,385 $ (17,839 ) $ 29,546 (1) The domain name medidata.com, purchased during the first quarter of 2019, is considered to have an indefinite life. Future amortization of intangible assets is expected to be as follows (in thousands): Remainder of 2019 $ 3,733 2020 6,730 2021 6,249 2022 3,465 2023 1,849 Thereafter 3,780 Total $ 25,806

Debt

Debt	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
DEBT	DEBT Credit Facility The Company's credit facility agreement (the "Credit Facility"), entered into in December 2017, consists of revolving commitments with a maximum borrowing amount of $400.0 million (the "Revolver"), currently undrawn, and term loans (the "Term Loans") in an aggregate principal amount of $100.0 million . The repayment terms of the Term Loans provide for monthly interest payments and quarterly principal payments, with a maturity date of December 2022. The Credit Facility consisted of the following components as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Term Loans $ 92,500 $ 95,000 Less: unamortized debt issuance costs (1,508 ) (1,725 ) Net carrying amount (1) $ 90,992 $ 93,275 (1) Of the total carrying amount of the Term Loans, short-term maturities of $6.1 million and $4.9 million were included in accrued expenses and other on the Company's condensed consolidated balance sheets as of June 30, 2019 and December 31, 2018, respectively. The following table sets forth total interest expense recognized related to the Credit Facility for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Contractual interest expense on Term Loans $ 850 $ 811 $ 1,704 $ 1,559 Amortization of debt issuance costs 108 109 217 217 Unused commitment fee on Revolver 151 209 298 409 Total $ 1,109 $ 1,129 $ 2,219 $ 2,185 Average contractual interest rate on Term Loans 3.527 % 3.465 % 3.576 % 3.347 % Average commitment fee rate on undrawn Revolver 0.150 % 0.200 % 0.150 % 0.200 % As of June 30, 2019 the remaining term of the Credit Facility is approximately 42 months . The Company was in compliance with all financial covenants related to the Credit Facility as of June 30, 2019 . 1.00% Convertible Senior Notes The Company's 1.00% convertible senior notes (the "Notes") were issued in August 2013 and settled on August 1, 2018 . Interest expense related to the Notes for the three months ended June 30, 2018 was $4.5 million , consisting of contractual interest expense of $0.7 million , amortization of debt issuance costs of $0.3 million , and amortization of debt discount of $3.5 million . The interest expense for the six months ended June 30, 2018 was $9.0 million , consisting of contractual interest expense of $1.4 million , amortization of debt issuance costs of $0.6 million , and amortization of debt discount of $7.0 million

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
LEASES	LEASES The Company leases office and data center space under operating lease agreements with remaining lease terms extending through 2031. During the three and six months ended June 30, 2019 the Company recognized operating lease costs of $4.6 million and $9.4 million , respectively; these amounts include $0.2 million and $0.4 million of short-term lease costs, respectively. During the three and six months ended June 30, 2018 , the Company recognized operating lease costs of $4.1 million and $8.0 million , respectively. Supplemental cash flow information related to leases for the six months ended June 30, 2019 was as follows (in thousands): Six Months Ended June 30, 2019 Cash paid for amounts included in the measurement of lease liabilities: Cash paid for operating leases $ (7,953 ) Noncash activities: Right-of-use assets obtained in exchange for new operating lease liabilities (1) $ — (1) No new operating leases were entered into during the six months ended June 30, 2019; all new operating lease liabilities recorded during the period are the result of the Company's January 1, 2019 adoption of ASC 842. As of June 30, 2019 , the weighted-average remaining lease term for operating lease liabilities was approximately 7.2 years and the weighted-average discount rate was approximately 3.60% . Maturities of operating lease liabilities are as follows (in thousands): Remainder of 2019 $ 9,287 2020 19,466 2021 19,177 2022 18,860 2023 18,120 Thereafter 38,497 Total lease payments 123,407 Less imputed interest (15,478 ) Total present value of operating lease liabilities $ 107,929 As of June 30, 2019 , the Company has additional operating leases, relating to the office spaces that have not yet commenced, of $28.7 million. These operating leases will commence in the second half of 2019 with lease terms of 3 to 10 years

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION For the three and six months ended June 30, 2019 and 2018 , the components of stock-based compensation expense were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Stock options $ 378 $ 522 $ 849 $ 1,094 Restricted stock awards and units 14,613 9,024 27,352 16,891 Performance-based restricted stock units 5,219 3,932 9,954 7,159 Employee stock purchase plan 1,764 1,712 3,549 3,260 Total stock-based compensation (1) $ 21,974 $ 15,190 $ 41,704 $ 28,404 (1) Total stock-based compensation is presented in this table on a gross basis, consistent with the additional paid-in capital impact recorded in stockholders' equity. On the Company's condensed consolidated statements of operations and condensed consolidated statements of cash flows, stock-based compensation is presented net of foreign exchange impact and capitalization of eligible software development-related costs. During the second quarter of 2019, the Company increased the number of shares reserved for issuance under the 2017 Plan from 2.5 million to 4.8 million . Stock Options Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Expected volatility — % 42 % — % 42 % Expected life N/A 4.78 years N/A 4.78 years Risk-free interest rate — % 2.82 % — % 2.82 % Dividend yield — — — — The following table summarizes the status of the Company's stock options as of June 30, 2019 , and changes during the six months then ended (in thousands, except per share data): Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (years) Aggregate Intrinsic Value Outstanding at January 1, 2019 1,088 $19.17 Granted — — Exercised (352 ) 15.42 Forfeited — — Expired (1 ) 13.99 Outstanding at June 30, 2019 735 $20.97 3.06 $51,066 Exercisable at June 30, 2019 648 $15.68 2.42 $48,506 Vested and expected to vest at June 30, 2019 730 $20.71 3.04 $50,981 No stock options were granted during the three and six months ended June 30, 2019 . The weighted-average grant-date fair value of stock options granted during the three and six months ended June 30, 2018 was $28.93 . The total intrinsic value of stock options exercised during the three months ended June 30, 2019 and 2018 was $23.9 million and $3.8 million , respectively. The total intrinsic value of stock options exercised during the six months ended June 30, 2019 and 2018 was $25.8 million and $11.4 million , respectively. As of June 30, 2019 , there was $2.1 million in unrecognized compensation cost related to all non-vested stock options granted. This cost is expected to be recognized over a weighted-average remaining period of 1.88 years . R estricted Stock Awards and Units The following table summarizes the status of the Company’s nonvested time-based RSAs and RSUs as of June 30, 2019 , and changes during the six months then ended (in thousands, except per share data): Number of Shares Weighted- Average Grant-Date Fair Value Nonvested at January 1, 2019 1,936 $61.45 Granted 958 72.08 Vested (689 ) 57.83 Forfeited (129 ) 71.07 Nonvested at June 30, 2019 2,076 $66.96 The total fair value of RSAs and RSUs vested during the three months ended June 30, 2019 and 2018 was $ 15.2 million and $5.7 million , respectively. The total fair value of RSAs and RSUs vested during the six months ended June 30, 2019 and 2018 was $ 53.4 million and $37.3 million , respectively. As of June 30, 2019 , there was $119.4 million in unrecognized compensation cost related to all nonvested RSAs and RSUs granted. This cost is expected to be recognized over a weighted-average remaining period of 2.67 years . Performance-Based Restricted Stock Units No PBRSUs were granted during the three months June 30, 2019 . During the three months June 30, 2018 , the Company granted (1) 6 thousand PBRSUs ("2018 TSR PBRSUs") with market conditions based on the Company's total stockholder return ("TSR") relative to that of the Russell 2000 Index over the three-year period ending December 31, 2020, vesting in full in three years with the number of shares ultimately earned ranging from zero to 200% of the target number of shares ; (2) 5 thousand PBRSUs ("2018 Net Income PBRSUs") with performance conditions based on the compound annual growth rate of net income over the three-year period ending December 31, 2020, vesting in full in three years with the number of shares ultimately earned ranging from zero to 200% of the target number of shares . The Company also granted an immaterial number of PBRSUs with performance conditions based on achievement of certain individual and team objectives. During the six months June 30, 2019 , the Company granted: (1) 155 thousand PBRSUs ("2019 TSR PBRSUs") with market conditions based on the Company's TSR relative to that of the Russell 2000 Index over the three-year period ending December 31, 2021, vesting in full in three years with the number of shares ultimately earned ranging from zero to 200% of the target number of shares ; (2) 155 thousand PBRSUs ("2019 Revenue PBRSUs") with performance conditions based on the compound annual growth rate of revenue over the three-year period ending December 31, 2021, vesting in full in three years with the number of shares ultimately earned ranging from zero to 250% of the target number of shares . During the six months June 30, 2018 , the Company granted: (1) 122 thousand 2018 TSR PBRSUs; (2) 122 thousand 2018 Net Income PBRSUs. The Company also granted an immaterial number of other PBRSUs with performance conditions based on achievement of certain individual and team objectives. The fair value of PBRSUs with market conditions granted during the three and six months ended June 30, 2019 and 2018 was estimated as of the date of grant using a Monte Carlo valuation model with the following weighted average assumptions: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Expected volatility - Medidata — % 36 % 35 % 37 % Expected volatility - comparison index — % 43 % 44 % 42 % Expected life N/A 2.69 years 2.88 years 2.85 years Risk-free interest rate — % 2.58 % 2.47 % 2.37 % Dividend yield — — — — The following table summarizes the status of the Company’s PBRSUs based upon expected performance as of June 30, 2019 , and changes during the six months then ended (in thousands, except per share data): Net Income TSR Revenue Other Total Number of Shares Weighted-Average Grant Date Fair Value Nonvested at January 1, 2019 210 793 — 23 1,026 $ 70.80 Granted (based on performance at 100% of targeted levels) — 155 155 — 310 88.56 Adjustment related to expected performance — 197 — — 197 104.95 Vested — (370 ) — — (370 ) 47.11 Forfeited — (14 ) (7 ) (1 ) (22 ) 93.43 Nonvested at June 30, 2019 210 761 148 22 1,141 $ 88.77 No PBRSUs vested during the three months ended June 30, 2019 and 2018 . The total fair value of PBRSUs vested during the six months ended June 30, 2019 and 2018 was $26.6 million and $8.1 million , respectively. As of June 30, 2019 , there was $38.0 million in unrecognized compensation cost related to all nonvested PBRSUs. This cost is expected to be recognized over a weighted-average remaining period of 1.67 years . Employee Stock Purchase Plan The fair value of shares granted under the Company's employee stock purchase plan ("ESPP") was estimated using a Black-Scholes pricing model with the following weighted-average assumptions: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Expected volatility 40 % 37 % 40 % 37 % Expected life 0.71 years 1.70 years 0.71 years 1.70 years Risk-free interest rate 2.39 % 1.09 % 2.39 % 1.09 % Dividend yield — — — — During the three and six and months ended June 30, 2019 , 135 thousand shares were purchased under the ESPP at a weighted-average price of $56.60 . During the three and six months ended June 30, 2018 , 150 thousand shares were purchased under the ESPP at a weighted-average price of $43.04 . As of June 30, 2019 , there was $7.7 million in unrecognized compensation cost related to ESPP shares. This cost is expected to be recognized over a weighted-average remaining period of 1.44 years. Modifications Aggregate incremental expense associated with modifications to stock options, RSAs and PBRSUs in connection with separation agreements during the three months ended June 30, 2019 and 2018 was $0.2 million and $0.2 million , respectively. Incremental expense during the six months ended June 30, 2019 and 2018 was $0.3 million and $0.4 million , respectively.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE Basic earnings per share is calculated by dividing net income available to common stockholders by the weighted-average number of shares outstanding during the period. The holders of unvested RSAs do not have nonforfeitable rights to dividends or dividend equivalents and therefore, such vested awards do not qualify as participating securities and are excluded from the basic earnings per share calculation. Diluted earnings per share includes the determinants of basic net income per share and, in addition, gives effect to the potential dilution that would occur if securities or other contracts to issue common stock are exercised, vested, or converted into common stock, unless they are anti-dilutive. In August 2018, the Company settled the principal amount of the Notes in cash and issued shares of common stock to settle the conversion premium. For the three and six months ended June 30, 2018 , the dilutive effect of the Notes is reflected in diluted earnings per share using the treasury stock method, which considers the number of shares that would have been required to settle the premium above principal at the average stock price for the period. A reconciliation of the numerator and denominator of basic earnings per share and diluted earnings per share for the three and six months ended June 30, 2019 and 2018 is shown in the following table (in thousands, except per share data): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator Net income $ 7,893 $ 16,589 $ 19,038 $ 26,914 Denominator Denominator for basic earnings per share: Weighted average common shares outstanding 60,081 57,448 59,888 57,252 Denominator for diluted earnings per share: Dilutive potential common shares: Stock options 740 866 762 897 Restricted stock awards and units 764 612 811 752 Performance-based restricted stock units 685 610 664 586 Employee stock purchase plan 102 220 66 181 Convertible senior notes — 1,118 — 896 Weighted average common shares outstanding with assumed conversion 62,372 60,874 62,191 60,564 Basic earnings per share $ 0.13 $ 0.29 $ 0.32 $ 0.47 Diluted earnings per share $ 0.13 $ 0.27 $ 0.31 $ 0.44 Anti-dilutive common stock equivalents excluded from the calculation of diluted earnings per share for the three and six months ended June 30, 2019 and 2018 are presented in the following table (in thousands, except per share data): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Stock options 49 79 62 78 Restricted stock awards and units 6 34 7 30 Performance-based restricted stock units — — — — Employee stock purchase plan — 84 474 84 Total 55 197 543 192

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES Unrecognized Tax Benefits The Company's unrecognized tax benefits were approximately $6.4 million as of June 30, 2019 , and were unchanged from December 31, 2018 .

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Legal Matters — The Company is subject to legal proceedings and claims that arise in the ordinary course of business and records an estimated liability for these matters when an adverse outcome is considered to be probable and can be reasonably estimated. Although the outcome of this routine litigation cannot be predicted with certainty and some lawsuits, claims, or proceedings may be disposed of unfavorably to the Company, which could materially and adversely affect its financial condition or results of operations, the Company does not believe that it is currently a party to any material legal proceedings in the ordinary course of business. In addition, four complaints were filed against the Company and its board of directors relating to the Merger with Dassault Systèmes announced on June 12, 2019. As of August 5, 2019, the Company had received the following complaints. On July 22, 2019, a putative class action lawsuit, Kent v. Medidata Solutions, Inc., et al., 1:19-cv-01361-RGA, was filed by purported shareholder Michael Kent against the Company and its board of directors in the United States District Court for the District of Delaware. On July 25, 2019, a complaint, Stein v. Medidata Solutions, Inc., et al., 1:19-cv-06933, was filed as an individual action by purported shareholder Shiva Stein against the Company and its board of directors in the United States District Court for the Southern District of New York. On July 30, 2019, a complaint, Sivigny v. Medidata Solutions, Inc., et al., 2:19-cv-16113, was filed as an individual action by purported shareholder Robert Sivigny against the Company and its board of directors in the United States District Court for the District of New Jersey. On July 31, 2019, a complaint, Borodin v. Medidata Solutions, Inc., et al., 1:19-cv-07176, was filed as an individual action by purported shareholder Suvi Borodin against the Company and its board of directors in the United States District Court for the Southern District of New York. The Company refers to the Kent, Stein, and Sivigny, and Borodin cases as the “merger actions.” The merger actions generally allege that the Company’s proxy statement filed on July 19, 2019 misrepresents and/or omits certain purportedly material information and assert violations of Sections 14(a) of the Securities Exchange Act of 1934 (the “Exchange Act”) and Rule 14a-9 promulgated thereunder against all defendants and violations of Section 20(a) of the Exchange Act against the directors. The merger actions seek, among other things, an injunction enjoining consummation of the merger, costs of the action, including plaintiff’s attorneys’ fees and experts’ fees, declaratory relief, and any other relief the court may deem just and proper. Contractual Warranties — The Company typically provides contractual warranties to its customers covering its solutions and services. To date, any refunds provided to customers have been immaterial. Change in Control Agreements — The Company has change in control agreements with its chief executive officer and certain other executive officers. These agreements provide for payments to be made to such officers upon involuntary termination of their employment by the Company without cause or by such officers for good reason as defined in the agreements, within a period of 1 year following a change in control. For purposes of any equity or equity-based awards granted by the Company prior to the closing of the Merger that are converted into Dassault Systèmes restricted stock units in accordance with the terms of the Merger Agreement, such converted equity awards will vest upon a termination of employment by the Company without cause or by the officer for good reason, in either case within a period of 2 years following a change in control. The agreements provide that, upon a qualifying termination event, such officers will be entitled to (a) a severance payment equal to the sum of the officer’s base salary and target bonus amount (except that such payment for the Company's chief executive officer and president would be two times such sum); (b) continuation of health benefits for one year (except that such continuation for the Company's chief executive officer and president would be for two years); and (c) immediate vesting of remaining unvested equity awards, unless otherwise specified in the equity award agreements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Basis of presentation	Basis of Presentation — The accompanying interim condensed consolidated balance sheets as of June 30, 2019 and December 31, 2018 , the condensed consolidated statements of operations for the three and six months ended June 30, 2019 and 2018 , the condensed consolidated statements of comprehensive income for the three and six months ended June 30, 2019 and 2018 , and the condensed consolidated statements of cash flows for the six months ended June 30, 2019 and 2018 are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and applicable rules and regulations of the SEC for interim financial reporting. Accordingly, certain information and footnote disclosures have been condensed or omitted pursuant to SEC rules that would ordinarily be required by U.S. GAAP for complete financial statements. These unaudited interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes thereto for the fiscal year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the SEC on March 1, 2019 . The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all adjustments consisting of normal recurring accruals considered necessary to present fairly the Company’s financial position as of June 30, 2019 , results of its operations for the three and six months ended June 30, 2019 and 2018 , comprehensive income for the three and six months ended June 30, 2019 and 2018 , and cash flows for the six months ended June 30, 2019 and 2018 . The results of operations for the three and six months ended June 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 .
Accounts receivable	Accounts Receivable — Accounts receivable are recorded at original invoice amount less an allowance that management believes will be adequate to absorb estimated losses on uncollectible accounts. This allowance is based on an evaluation of the collectability of accounts receivable and prior bad debt experience. Accounts receivable are written off when deemed uncollectible. Unbilled receivables consist of revenue recognized in excess of billings, substantially all of which is expected to be billed and collected within one year. As of June 30, 2019 and December 31, 2018 , unbilled accounts receivable of $51.4 million and $38.6 million , respectively, were included in accounts receivable on the Company's condensed consolidated balance sheets.
Leases	Leases — At the inception of an arrangement, the Company evaluates the existence and type of lease; the Company has determined that all of its leases are operating leases, which are recognized as operating lease assets and operating lease liabilities on its condensed consolidated balance sheet as of June 30, 2019 (subsequent to the adoption of Accounting Standards Codification ("ASC") 842, Leases on January 1, 2019). Operating lease assets represent the right to use an underlying asset over the lease term, and operating lease liabilities represent the obligation to make lease payments. Some of the Company's leases contain options to extend or terminate; the Company is reasonably certain that it will not exercise these options and does not consider them in the determination of the lease term.
Income taxes	Income Taxes — The Company’s interim period provision for income taxes is computed by using an estimate of the annual effective tax rate, adjusted for discrete items taken into account in the relevant period, if any. Each quarter, the annual effective income tax rate is recomputed and if there are material changes in the estimate, a cumulative adjustment is made.
Recently issued accounting pronouncements	Recently Adopted Accounting Pronouncements — In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2016-02, Leases , which replaces previous lease guidance in its entirety with ASC 842 and requires lessees to recognize lease assets and lease liabilities for those arrangements classified as operating leases under previous guidance, with the exception of leases with a term of twelve months or less. The Company adopted ASU No. 2016-02 on January 1, 2019 using the additional transition method, which allows prior periods to be presented under previous lease accounting guidance. Refer to Note 9 , "Leases," for related disclosures. In February 2018, the FASB issued ASU No. 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, which permits companies to reclassify disproportionate tax effects in accumulated other comprehensive income caused by the U.S. Tax Cuts and Jobs Act enacted in December 2017 to retained earnings. ASU No. 2018-02 is effective for annual reporting periods beginning after December 15, 2018, and interim periods within those annual periods. The Company adopted ASU No. 2018-02 on January 1, 2019, and the adoption did not have a material impact on its condensed consolidated financial statements. Recently Issued Accounting Pronouncements — There have been no changes in the expected dates of adoption or estimated effects on the Company's consolidated financial statements of recently issued accounting pronouncements from those disclosed in the Company’s Annual Report on Form 10-K.
Earnings per share	Basic earnings per share is calculated by dividing net income available to common stockholders by the weighted-average number of shares outstanding during the period. The holders of unvested RSAs do not have nonforfeitable rights to dividends or dividend equivalents and therefore, such vested awards do not qualify as participating securities and are excluded from the basic earnings per share calculation. Diluted earnings per share includes the determinants of basic net income per share and, in addition, gives effect to the potential dilution that would occur if securities or other contracts to issue common stock are exercised, vested, or converted into common stock, unless they are anti-dilutive. In August 2018, the Company settled the principal amount of the Notes in cash and issued shares of common stock to settle the conversion premium. For the three and six months ended June 30, 2018 , the dilutive effect of the Notes is reflected in diluted earnings per share using the treasury stock method, which considers the number of shares that would have been required to settle the premium above principal at the average stock price for the period.

Revenues (Tables)

Revenues (Tables)	6 Months Ended
	Jun. 30, 2019
Revenues [Abstract]
Disaggregation of revenue	The following tables provide information about the Company's revenues, disaggregated by geographical market and revenue type, for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended June 30, 2019 2018 Subscription Professional Services Total Subscription Professional Services Total Revenues: United States $ 111,245 $ 22,222 $ 133,467 $ 99,646 $ 18,526 $ 118,172 Rest of Americas 1,680 232 1,912 1,689 277 1,966 Total Americas 112,925 22,454 135,379 101,335 18,803 120,138 Japan 7,392 1,825 9,217 7,665 1,261 8,926 Rest of Asia Pacific 6,849 2,382 9,231 3,875 1,243 5,118 Total Asia Pacific 14,241 4,207 18,448 11,540 2,504 14,044 Europe, Middle East and Africa 22,840 3,793 26,633 17,611 4,112 21,723 Total $ 150,006 $ 30,454 $ 180,460 $ 130,486 $ 25,419 $ 155,905 Six Months Ended June 30, 2019 2018 Subscription Professional Services Total Subscription Professional Services Total Revenues: United States $ 220,081 $ 39,739 $ 259,820 $ 195,811 $ 34,510 $ 230,321 Rest of Americas 3,483 471 3,954 1,998 481 2,479 Total Americas 223,564 40,210 263,774 197,809 34,991 232,800 Japan 18,289 4,298 22,587 15,777 3,055 18,832 Rest of Asia Pacific 12,853 4,118 16,971 7,576 2,381 9,957 Total Asia Pacific 31,142 8,416 39,558 23,353 5,436 28,789 Europe, Middle East and Africa 42,175 8,457 50,632 36,143 7,371 43,514 Total $ 296,881 $ 57,083 $ 353,964 $ 257,305 $ 47,798 $ 305,103
Contract balances	The following table provides information about changes in the Company's deferred revenue balances during the six months ended June 30, 2019 and 2018 (in thousands): Deferred Revenue 2019 2018 Balance as of January 1 $ 78,306 $ 82,631 Revenue recognized that was included in deferred revenue at the beginning of the period (59,735 ) (71,137 ) Revenue recognized that was not included in deferred revenue at the beginning of the period (283,164 ) (233,400 ) Increases due to invoicing 341,248 297,161 Revenue recognized in excess of billings (billings in excess of revenue recognized) 12,820 (680 ) Other (6,749 ) 1,493 Balance as of June 30 $ 82,726 $ 76,068

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Schedule of stockholders' equity	The following reconciliations present significant changes in the components of stockholders' equity for the three and six months ended June 30, 2019 and 2018 (in thousands): Accumulated other comprehensive loss (amounts in thousands) Common stock Additional paid-in capital Treasury stock Foreign currency translation adjustments Unrealized gains (losses) on marketable securities Retained earnings Total Balance - January 1, 2019 $ 661 $ 574,667 $ (152,849 ) $ (4,255 ) $ (614 ) $ 213,838 $ 631,448 Comprehensive income, net — — — 372 394 11,145 11,911 Stock-based compensation — 19,730 — — — — 19,730 Issuance of shares under stock-based compensation plans 13 2,328 — — — — 2,341 Acquisition of treasury stock in connection with vesting of awards — — (28,704 ) — — — (28,704 ) Balance - March 31, 2019 $ 674 $ 596,725 $ (181,553 ) $ (3,883 ) $ (220 ) $ 224,983 $ 636,726 Comprehensive income, net — — — (605 ) 164 7,893 7,452 Stock-based compensation — 21,974 — — — — 21,974 Issuance of shares under stock-based compensation plans 5 10,751 — — — — 10,756 Acquisition of treasury stock in connection with vesting of awards and exercise of options — — (16,449 ) — — — (16,449 ) Forfeiture of nonvested restricted stock awards — 1 (1 ) — — — — Balance - June 30, 2019 $ 679 $ 629,451 $ (198,003 ) $ (4,488 ) $ (56 ) $ 232,876 $ 660,459 Accumulated other comprehensive loss (amounts in thousands) Common stock Additional paid-in capital Treasury stock Foreign currency translation adjustments Unrealized gains (losses) on marketable securities Retained earnings Total Balance - January 1, 2018 628 486,147 (132,705 ) (2,459 ) (918 ) 161,917 512,610 Comprehensive income, net — — — 1,270 (968 ) 10,325 10,627 Stock-based compensation — 13,214 — — — — 13,214 Issuance of shares under stock-based compensation plans 9 2,357 — — — — 2,366 Acquisition of treasury stock in connection with vesting of awards — — (16,614 ) — — — (16,614 ) Balance - March 31, 2018 $ 637 $ 501,718 $ (149,319 ) $ (1,189 ) $ (1,886 ) $ 172,242 $ 522,203 Comprehensive income, net — — — (1,954 ) 539 16,589 15,174 Stock-based compensation — 15,190 — — — — 15,190 Issuance of shares under stock-based compensation plans 6 10,427 — — — — 10,433 Acquisition of treasury stock in connection with vesting of awards — — (1,644 ) — — — (1,644 ) Forfeiture of nonvested restricted stock awards — 1 (1 ) — — — — Balance - June 30, 2018 $ 643 $ 527,336 $ (150,964 ) $ (3,143 ) $ (1,347 ) $ 188,831 $ 561,356

Investments (Tables)

Investments (Tables)	6 Months Ended
	Jun. 30, 2019
Investments [Abstract]
Marketable securities by security type	The following tables provide the Company’s marketable securities by security type as of June 30, 2019 and December 31, 2018 (in thousands): As of June 30, 2019 Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper and corporate bonds $ 56,301 $ — $ (62 ) $ 56,239 U.S. government agency debt securities 10,690 — (15 ) 10,675 Total $ 66,991 $ — $ (77 ) $ 66,914 As of December 31, 2018 Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper and corporate bonds $ 125,245 $ — $ (747 ) $ 124,498 U.S. government agency debt securities 10,690 — (83 ) 10,607 Total $ 135,935 $ — $ (830 ) $ 135,105
Contractual maturities of marketable securities	Contractual maturities of the Company’s marketable securities as of June 30, 2019 and December 31, 2018 are summarized as follows (in thousands): As of June 30, 2019 As of December 31, 2018 Cost Estimated Fair Value Cost Estimated Fair Value Due in one year or less $ 66,991 $ 66,914 $ 135,935 $ 135,105 Due in one to five years — — — — Total $ 66,991 $ 66,914 $ 135,935 $ 135,105
Fair market value and gross unrealized losses of marketable securities	The following table provides the fair market value and gross unrealized losses of the Company's marketable securities with unrealized losses, aggregated by security type, as of June 30, 2019 and December 31, 2018 (in thousands In Loss Position for More than 12 Months As of June 30, 2019 As of December 31, 2018 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Commercial paper and corporate bonds $ 56,239 $ (62 ) $ 124,498 $ (747 ) U.S. government agency debt securities 10,675 (15 ) 10,607 (83 ) Total $ 66,914 $ (77 ) $ 135,105 $ (830 )

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Financial assets and liabilities measured at fair value on a recurring basis	The following table summarizes, as of June 30, 2019 and December 31, 2018 , the Company's financial assets and liabilities that are measured at fair value on a recurring basis, according to the fair value hierarchy described in the significant accounting policies included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018 (in thousands): As of June 30, 2019 As of December 31, 2018 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash $ 118,449 $ — $ — $ 118,449 $ 103,859 $ — $ — $ 103,859 Money market funds 20,655 — — 20,655 1,581 — — 1,581 Total cash and cash equivalents 139,104 — — 139,104 105,440 — — 105,440 Commercial paper and corporate bonds — 56,239 — 56,239 — 124,498 — 124,498 U.S. government agency debt securities — 10,675 — 10,675 — 10,607 — 10,607 Total marketable securities — 66,914 — 66,914 — 135,105 — 135,105 Total financial assets measured at fair value on a recurring basis $ 139,104 $ 66,914 $ — $ 206,018 $ 105,440 $ 135,105 $ — $ 240,545 Contingent consideration – short-term $ — $ — $ 117 $ 117 $ — $ — $ 1,110 $ 1,110 Total financial liabilities measured at fair value on a recurring basis $ — $ — $ 117 $ 117 $ — $ — $ 1,110 $ 1,110
Changes in fair value of level 3 liabilities	The following table provides a summary of changes in fair value of the Company's Level 3 contingent consideration liabilities during the six months ended June 30, 2019 (in thousands): Balance as of January 1, 2019 $ 1,110 Amounts earned by sellers (1,233 ) Fair value adjustment (included in general and administrative expenses) 240 Balance as of June 30, 2019 $ 117

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Changes in the carrying amount of goodwill	The change in the carrying amount of goodwill during the six months ended June 30, 2019 was as follows (in thousands): Balance as of January 1, 2019 $ 216,017 Purchase price adjustments - SHYFT Analytics, Inc. (2,027 ) Foreign currency translation adjustments (14 ) Balance as of June 30, 2019 $ 213,976
Intangible assets	Total intangible assets are summarized as follows (in thousands): As of June 30, 2019 As of December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Developed technology $ 31,353 $ (16,576 ) $ 14,777 $ 31,358 $ (13,852 ) $ 17,506 Customer relationships 9,166 (4,003 ) 5,163 9,167 (3,404 ) 5,763 Trade name 5,400 (370 ) 5,030 5,400 (190 ) 5,210 Non-competition agreements 1,460 (624 ) 836 1,460 (393 ) 1,067 Domain name (1) 600 — 600 — — — Total $ 47,979 $ (21,573 ) $ 26,406 $ 47,385 $ (17,839 ) $ 29,546 (1) The domain name medidata.com, purchased during the first quarter of 2019, is considered to have an indefinite life.
Annual amortization for the next five years	Future amortization of intangible assets is expected to be as follows (in thousands): Remainder of 2019 $ 3,733 2020 6,730 2021 6,249 2022 3,465 2023 1,849 Thereafter 3,780 Total $ 25,806

Debt (Tables)

Debt (Tables) - Credit facility [Member]	6 Months Ended
	Jun. 30, 2019
Debt Instrument [Line Items]
Schedule of debt	The Credit Facility consisted of the following components as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Term Loans $ 92,500 $ 95,000 Less: unamortized debt issuance costs (1,508 ) (1,725 ) Net carrying amount (1) $ 90,992 $ 93,275 (1) Of the total carrying amount of the Term Loans, short-term maturities of $6.1 million and $4.9 million were included in accrued expenses and other on the Company's condensed consolidated balance sheets as of June 30, 2019 and December 31, 2018, respectively.
Interest expense	The following table sets forth total interest expense recognized related to the Credit Facility for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Contractual interest expense on Term Loans $ 850 $ 811 $ 1,704 $ 1,559 Amortization of debt issuance costs 108 109 217 217 Unused commitment fee on Revolver 151 209 298 409 Total $ 1,109 $ 1,129 $ 2,219 $ 2,185 Average contractual interest rate on Term Loans 3.527 % 3.465 % 3.576 % 3.347 % Average commitment fee rate on undrawn Revolver 0.150 % 0.200 % 0.150 % 0.200 %

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Supplemental cash flow information related to operating leases	Supplemental cash flow information related to leases for the six months ended June 30, 2019 was as follows (in thousands): Six Months Ended June 30, 2019 Cash paid for amounts included in the measurement of lease liabilities: Cash paid for operating leases $ (7,953 ) Noncash activities: Right-of-use assets obtained in exchange for new operating lease liabilities (1) $ — (1) No new operating leases were entered into during the six months ended June 30, 2019; all new operating lease liabilities recorded during the period are the result of the Company's January 1, 2019 adoption of ASC 842.
Maturities of operating lease liabilities	Maturities of operating lease liabilities are as follows (in thousands): Remainder of 2019 $ 9,287 2020 19,466 2021 19,177 2022 18,860 2023 18,120 Thereafter 38,497 Total lease payments 123,407 Less imputed interest (15,478 ) Total present value of operating lease liabilities $ 107,929

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Components of stock-based compensation expense	For the three and six months ended June 30, 2019 and 2018 , the components of stock-based compensation expense were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Stock options $ 378 $ 522 $ 849 $ 1,094 Restricted stock awards and units 14,613 9,024 27,352 16,891 Performance-based restricted stock units 5,219 3,932 9,954 7,159 Employee stock purchase plan 1,764 1,712 3,549 3,260 Total stock-based compensation (1) $ 21,974 $ 15,190 $ 41,704 $ 28,404 (1) Total stock-based compensation is presented in this table on a gross basis, consistent with the additional paid-in capital impact recorded in stockholders' equity. On the Company's condensed consolidated statements of operations and condensed consolidated statements of cash flows, stock-based compensation is presented net of foreign exchange impact and capitalization of eligible software development-related costs.
Fair value of stock option grants	Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Expected volatility — % 42 % — % 42 % Expected life N/A 4.78 years N/A 4.78 years Risk-free interest rate — % 2.82 % — % 2.82 % Dividend yield — — — —
Summary of activities and changes in stock option plans	The following table summarizes the status of the Company's stock options as of June 30, 2019 , and changes during the six months then ended (in thousands, except per share data): Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (years) Aggregate Intrinsic Value Outstanding at January 1, 2019 1,088 $19.17 Granted — — Exercised (352 ) 15.42 Forfeited — — Expired (1 ) 13.99 Outstanding at June 30, 2019 735 $20.97 3.06 $51,066 Exercisable at June 30, 2019 648 $15.68 2.42 $48,506 Vested and expected to vest at June 30, 2019 730 $20.71 3.04 $50,981
Summary of nonvested restricted stock awards	The following table summarizes the status of the Company’s nonvested time-based RSAs and RSUs as of June 30, 2019 , and changes during the six months then ended (in thousands, except per share data): Number of Shares Weighted- Average Grant-Date Fair Value Nonvested at January 1, 2019 1,936 $61.45 Granted 958 72.08 Vested (689 ) 57.83 Forfeited (129 ) 71.07 Nonvested at June 30, 2019 2,076 $66.96
Fair value of TSR PBRSUs	The fair value of PBRSUs with market conditions granted during the three and six months ended June 30, 2019 and 2018 was estimated as of the date of grant using a Monte Carlo valuation model with the following weighted average assumptions: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Expected volatility - Medidata — % 36 % 35 % 37 % Expected volatility - comparison index — % 43 % 44 % 42 % Expected life N/A 2.69 years 2.88 years 2.85 years Risk-free interest rate — % 2.58 % 2.47 % 2.37 % Dividend yield — — — —
Summary of performance-based restricted stock units based on expected performance	The following table summarizes the status of the Company’s PBRSUs based upon expected performance as of June 30, 2019 , and changes during the six months then ended (in thousands, except per share data): Net Income TSR Revenue Other Total Number of Shares Weighted-Average Grant Date Fair Value Nonvested at January 1, 2019 210 793 — 23 1,026 $ 70.80 Granted (based on performance at 100% of targeted levels) — 155 155 — 310 88.56 Adjustment related to expected performance — 197 — — 197 104.95 Vested — (370 ) — — (370 ) 47.11 Forfeited — (14 ) (7 ) (1 ) (22 ) 93.43 Nonvested at June 30, 2019 210 761 148 22 1,141 $ 88.77
Fair value of employee stock purchase plan shares	The fair value of shares granted under the Company's employee stock purchase plan ("ESPP") was estimated using a Black-Scholes pricing model with the following weighted-average assumptions: Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Expected volatility 40 % 37 % 40 % 37 % Expected life 0.71 years 1.70 years 0.71 years 1.70 years Risk-free interest rate 2.39 % 1.09 % 2.39 % 1.09 % Dividend yield — — — —

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Reconciliation of the numerators and denominators of basic and diluted earnings per share	A reconciliation of the numerator and denominator of basic earnings per share and diluted earnings per share for the three and six months ended June 30, 2019 and 2018 is shown in the following table (in thousands, except per share data): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator Net income $ 7,893 $ 16,589 $ 19,038 $ 26,914 Denominator Denominator for basic earnings per share: Weighted average common shares outstanding 60,081 57,448 59,888 57,252 Denominator for diluted earnings per share: Dilutive potential common shares: Stock options 740 866 762 897 Restricted stock awards and units 764 612 811 752 Performance-based restricted stock units 685 610 664 586 Employee stock purchase plan 102 220 66 181 Convertible senior notes — 1,118 — 896 Weighted average common shares outstanding with assumed conversion 62,372 60,874 62,191 60,564 Basic earnings per share $ 0.13 $ 0.29 $ 0.32 $ 0.47 Diluted earnings per share $ 0.13 $ 0.27 $ 0.31 $ 0.44
Schedule of antidilutive securities excluded from computation of earnings per share	Anti-dilutive common stock equivalents excluded from the calculation of diluted earnings per share for the three and six months ended June 30, 2019 and 2018 are presented in the following table (in thousands, except per share data): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Stock options 49 79 62 78 Restricted stock awards and units 6 34 7 30 Performance-based restricted stock units — — — — Employee stock purchase plan — 84 474 84 Total 55 197 543 192

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Unbilled receivables	$ 51.4	$ 38.6

Revenues (Details)

Revenues (Details) - 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]
Revenues	$ 180,460	$ 155,905	$ 353,964	$ 305,103
United States
Disaggregation of Revenue [Line Items]
Revenues	133,467	118,172	259,820	230,321
Rest of Americas [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,912	1,966	3,954	2,479
Total Americas [Member]
Disaggregation of Revenue [Line Items]
Revenues	135,379	120,138	263,774	232,800
Japan
Disaggregation of Revenue [Line Items]
Revenues	9,217	8,926	22,587	18,832
Rest of Asia Pacific
Disaggregation of Revenue [Line Items]
Revenues	9,231	5,118	16,971	9,957
Total Asia Pacific
Disaggregation of Revenue [Line Items]
Revenues	18,448	14,044	39,558	28,789
Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenues	26,633	21,723	50,632	43,514
Subscription [Member]
Disaggregation of Revenue [Line Items]
Revenues	150,006	130,486	296,881	257,305
Subscription [Member] | United States
Disaggregation of Revenue [Line Items]
Revenues	111,245	99,646	220,081	195,811
Subscription [Member] | Rest of Americas [Member]
Disaggregation of Revenue [Line Items]
Revenues	1,680	1,689	3,483	1,998
Subscription [Member] | Total Americas [Member]
Disaggregation of Revenue [Line Items]
Revenues	112,925	101,335	223,564	197,809
Subscription [Member] | Japan
Disaggregation of Revenue [Line Items]
Revenues	7,392	7,665	18,289	15,777
Subscription [Member] | Rest of Asia Pacific
Disaggregation of Revenue [Line Items]
Revenues	6,849	3,875	12,853	7,576
Subscription [Member] | Total Asia Pacific
Disaggregation of Revenue [Line Items]
Revenues	14,241	11,540	31,142	23,353
Subscription [Member] | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenues	22,840	17,611	42,175	36,143
Professional services [Member]
Disaggregation of Revenue [Line Items]
Revenues	30,454	25,419	57,083	47,798
Professional services [Member] | United States
Disaggregation of Revenue [Line Items]
Revenues	22,222	18,526	39,739	34,510
Professional services [Member] | Rest of Americas [Member]
Disaggregation of Revenue [Line Items]
Revenues	232	277	471	481
Professional services [Member] | Total Americas [Member]
Disaggregation of Revenue [Line Items]
Revenues	22,454	18,803	40,210	34,991
Professional services [Member] | Japan
Disaggregation of Revenue [Line Items]
Revenues	1,825	1,261	4,298	3,055
Professional services [Member] | Rest of Asia Pacific
Disaggregation of Revenue [Line Items]
Revenues	2,382	1,243	4,118	2,381
Professional services [Member] | Total Asia Pacific
Disaggregation of Revenue [Line Items]
Revenues	4,207	2,504	8,416	5,436
Professional services [Member] | Europe, Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenues	$ 3,793	$ 4,112	$ 8,457	$ 7,371

Revenues (Details 1)

Revenues (Details 1) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Change in contract liabilities
Contract liabilities, balance at beginning of period	$ 78,306	$ 82,631
Revenue recognized that was included in deferred revenue at the beginning of the period	(59,735)	(71,137)
Revenue recognized that was not included in deferred revenue at the beginning of the period	(283,164)	(233,400)
Increase due to invoicing	341,248	297,161
Revenue recognized in excess of billings	12,820	(680)
Other	(6,749)	1,493
Contract liabilities, balance at end of period	$ 82,726	$ 76,068

Revenues (Details Textual)

Revenues (Details Textual) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Revenues [Abstract]
Basis for disaggregation			The above tables present revenues according to the region in which they were generated, separately displaying those individual countries that, in any of the periods presented, constituted 5% or more or of total revenues.
Performance obligations, description of timing			All of the Company's performance obligations are transferred to customers over time; as a result, no disaggregation of revenues by timing of revenue recognition is provided.
Year through which remaining performance obligations extend	2030		2030
Unsatisfied subscription performance obligations	$ 1,042		$ 1,042
Unsatisfied subscription performance obligations, portion expected to be satisfied in current fiscal year	290		290
Unsatisfied subscription performance obligations, portion expected to be satisfied in following fiscal year	440		440
Unsatisfied subscription performance obligations, portion expected to be satisfied thereafter	312		$ 312
Capitalized cost, judgment			Sales commissions earned are considered incremental and recoverable costs of obtaining a contract with a customer and therefore are capitalized as contract costs.
Capitalized contract costs	66		$ 66		$ 60
Capitalized contract costs, amortization	6.7	$ 4.6	13.3	$ 9.5
Capitalized contract costs, accumulated impairment	$ 0		$ 0

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Stockholders' equity - beginning of period	$ 636,726	$ 631,448	$ 522,203	$ 512,610	$ 631,448	$ 512,610
Comprehensive income (loss), net of tax	7,452	11,911	15,174	10,627	19,363	25,801
Stock-based compensation	21,974	19,730	15,190	13,214
Issuance of shares under stock-based compensation plans	10,756	2,341	10,433	2,366
Acquisition of treasury stock in connection with award vesting	(16,449)	(28,704)	(1,644)	(16,614)
Restricted stock awards forfeited	0		0
Stockholders' equity - end of period	660,459	636,726	561,356	522,203	660,459	561,356
Common stock [Member]
Stockholders' equity - beginning of period	674	661	637	628	661	628
Comprehensive income (loss), net of tax	0	0	0	0
Stock-based compensation	0	0	0	0
Issuance of shares under stock-based compensation plans	5	13	6	9
Acquisition of treasury stock in connection with award vesting	0	0	0	0
Restricted stock awards forfeited	0		0
Stockholders' equity - end of period	679	674	643	637	679	643
Additional paid-in capital [Member]
Stockholders' equity - beginning of period	596,725	574,667	501,718	486,147	574,667	486,147
Comprehensive income (loss), net of tax	0	0	0	0
Stock-based compensation	21,974	19,730	15,190	13,214
Issuance of shares under stock-based compensation plans	10,751	2,328	10,427	2,357
Acquisition of treasury stock in connection with award vesting	0	0	0	0
Restricted stock awards forfeited	(1)		(1)
Stockholders' equity - end of period	629,451	596,725	527,336	501,718	629,451	527,336
Treasury stock [Member]
Stockholders' equity - beginning of period	(181,553)	(152,849)	(149,319)	(132,705)	(152,849)	(132,705)
Comprehensive income (loss), net of tax	0	0	0	0
Stock-based compensation	0	0	0	0
Issuance of shares under stock-based compensation plans	0	0	0	0
Acquisition of treasury stock in connection with award vesting	(16,449)	(28,704)	(1,644)	(16,614)
Restricted stock awards forfeited	(1)		(1)
Stockholders' equity - end of period	(198,003)	(181,553)	(150,964)	(149,319)	(198,003)	(150,964)
Foreign currency translation adjustments
Stockholders' equity - beginning of period	(3,883)	(4,255)	(1,189)	(2,459)	(4,255)	(2,459)
Comprehensive income (loss), net of tax	(605)	372	(1,954)	1,270
Stock-based compensation	0	0	0	0
Issuance of shares under stock-based compensation plans	0	0	0	0
Acquisition of treasury stock in connection with award vesting	0	0	0	0
Restricted stock awards forfeited	0		0
Stockholders' equity - end of period	(4,488)	(3,883)	(3,143)	(1,189)	(4,488)	(3,143)
Unrealized gains (losses) on marketable securities
Stockholders' equity - beginning of period	(220)	(614)	(1,886)	(918)	(614)	(918)
Comprehensive income (loss), net of tax	164	394	539	(968)
Stock-based compensation	0	0	0	0
Issuance of shares under stock-based compensation plans	0	0	0	0
Acquisition of treasury stock in connection with award vesting	0	0	0	0
Restricted stock awards forfeited	0		0
Stockholders' equity - end of period	(56)	(220)	(1,347)	(1,886)	(56)	(1,347)
Retained earnings [Member]
Stockholders' equity - beginning of period	224,983	213,838	172,242	161,917	213,838	161,917
Comprehensive income (loss), net of tax	7,893	11,145	16,589	10,325
Stock-based compensation	0	0	0	0
Issuance of shares under stock-based compensation plans	0	0	0	0
Acquisition of treasury stock in connection with award vesting	0	0	0	0
Restricted stock awards forfeited	0		0
Stockholders' equity - end of period	$ 232,876	$ 224,983	$ 188,831	$ 172,242	$ 232,876	$ 188,831

Stockholders' Equity (Details T

Stockholders' Equity (Details Textual) - $ / shares	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Equity [Abstract]
Shares paid for tax withholding for share based compensation	452,021	271,585
Shares paid for tax withholding for share based compensation, average price	$ 74.99	$ 67.23
Shares paid for tax withholding and exercise price on net option exercises	123,363
Shares paid for tax withholding and exercise price on net option exercises, average price	$ 91.22
Forfeited restricted stock awards transferred to treasury stock	124,746	189,668

Investments (Details)

Investments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Marketable securities by security type
Cost	$ 66,991	$ 135,935
Gross unrealized gains	0	0
Gross unrealized losses	(77)	(830)
Estimated fair value	66,914	135,105
Commercial paper and corporate bonds [Member]
Marketable securities by security type
Cost	56,301	125,245
Gross unrealized gains	0	0
Gross unrealized losses	(62)	(747)
Estimated fair value	56,239	124,498
U.S. government agency debt securities [Member]
Marketable securities by security type
Cost	10,690	10,690
Gross unrealized gains	0	0
Gross unrealized losses	(15)	(83)
Estimated fair value	$ 10,675	$ 10,607

Investments (Details 1)

Investments (Details 1) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Marketable securities by contractual maturity
Cost	$ 66,991	$ 135,935
Estimated fair value	66,914	135,105
Due in one year or less [Member]
Marketable securities by contractual maturity
Cost	66,991	135,935
Estimated fair value	66,914	135,105
Due in one to five years [Member]
Marketable securities by contractual maturity
Cost	0	0
Estimated fair value	$ 0	$ 0

Investments (Details 2)

Investments (Details 2) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Fair market value and gross unrealized losses of marketable securities
12 months or more in unrealized loss position - fair value	$ 66,914	$ 135,105
12 months or more in unrealized loss position - gross unrealized losses	(77)	(830)
Commercial paper and corporate bonds [Member]
Fair market value and gross unrealized losses of marketable securities
12 months or more in unrealized loss position - fair value	56,239	124,498
12 months or more in unrealized loss position - gross unrealized losses	(62)	(747)
U.S. government agency debt securities [Member]
Fair market value and gross unrealized losses of marketable securities
12 months or more in unrealized loss position - fair value	10,675	10,607
12 months or more in unrealized loss position - gross unrealized losses	$ (15)	$ (83)

Investments (Details Textual)

Investments (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Investment [Line Items]
Net realized gains (losses) from the sale of marketable securities	$ 0	$ 0	$ (27)	$ 0
Syapse [Member]
Investment [Line Items]
Investments without readily determinable fair value, description			The Company holds shares of Series D Preferred Stock of Syapse Inc. purchased in a private placement. This investment does not have a readily determinable fair value and is carried at original cost in other assets on the Company's condensed consolidated balance sheets.
Investments without readily determinable fair value, original cost	3,000		$ 3,000		$ 3,000
Investments without readily determinable fair value, impairments recognized	$ 0		$ 0

Fair Value (Details)

Fair Value (Details) - Fair value, recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Assets
Cash and cash equivalents	$ 139,104	$ 105,440
Marketable securities	66,914	135,105
Total financial assets	206,018	240,545
Contingent consideration [Member]
Liabilities
Contingent consideration - short-term	117	1,110
Total financial liabilities	117	1,110
Cash [Member]
Assets
Cash and cash equivalents	118,449	103,859
Money market funds [Member]
Assets
Cash and cash equivalents	20,655	1,581
Commercial paper and corporate bonds [Member]
Assets
Marketable securities	56,239	124,498
U.S. government agency debt securities [Member]
Assets
Marketable securities	10,675	10,607
Level 1 [Member]
Assets
Cash and cash equivalents	139,104	105,440
Marketable securities	0	0
Total financial assets	139,104	105,440
Level 1 [Member] | Contingent consideration [Member]
Liabilities
Contingent consideration - short-term	0	0
Total financial liabilities	0	0
Level 1 [Member] | Cash [Member]
Assets
Cash and cash equivalents	118,449	103,859
Level 1 [Member] | Money market funds [Member]
Assets
Cash and cash equivalents	20,655	1,581
Level 1 [Member] | Commercial paper and corporate bonds [Member]
Assets
Marketable securities	0	0
Level 1 [Member] | U.S. government agency debt securities [Member]
Assets
Marketable securities	0	0
Level 2 [Member]
Assets
Cash and cash equivalents	0	0
Marketable securities	66,914	135,105
Total financial assets	66,914	135,105
Level 2 [Member] | Contingent consideration [Member]
Liabilities
Contingent consideration - short-term	0	0
Total financial liabilities	0	0
Level 2 [Member] | Cash [Member]
Assets
Cash and cash equivalents	0	0
Level 2 [Member] | Money market funds [Member]
Assets
Cash and cash equivalents	0	0
Level 2 [Member] | Commercial paper and corporate bonds [Member]
Assets
Marketable securities	56,239	124,498
Level 2 [Member] | U.S. government agency debt securities [Member]
Assets
Marketable securities	10,675	10,607
Level 3 [Member]
Assets
Cash and cash equivalents	0	0
Marketable securities	0	0
Total financial assets	0	0
Level 3 [Member] | Contingent consideration [Member]
Liabilities
Contingent consideration - short-term	117	1,110
Total financial liabilities	117	1,110
Level 3 [Member] | Cash [Member]
Assets
Cash and cash equivalents	0	0
Level 3 [Member] | Money market funds [Member]
Assets
Cash and cash equivalents	0	0
Level 3 [Member] | Commercial paper and corporate bonds [Member]
Assets
Marketable securities	0	0
Level 3 [Member] | U.S. government agency debt securities [Member]
Assets
Marketable securities	$ 0	$ 0

Fair Value (Details 1)

Fair Value (Details 1) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Contingent consideration, fair value - beginning of period	$ 1,110
Contingent consideration, earned by sellers	(1,233)
Contingent consideration, fair value adjustment	240
Contingent consideration, fair value - end of period	$ 117

Fair Value (Details Textual)

Fair Value (Details Textual) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers of financial assets between Level 1 and Level 2	$ 0	$ 0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs and techniques	Investments in commercial paper, corporate bonds, and U.S. government agency debt securities have been classified as Level 2 as they are valued using quoted prices in less active markets or other directly or indirectly observable inputs. Fair values of corporate bonds and U.S. government agency debt securities were derived from a consensus or weighted-average price based on input of market prices from multiple sources at each reporting period. With regard to commercial paper, all of the securities had high credit ratings and one year or less to maturity; therefore, fair value was derived from accretion of purchase price to face value over the term of maturity or quoted market prices for similar instruments if available.
Level 3 [Member] | Contingent consideration [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value inputs and techniques	Contingent consideration liabilities associated with earn-out payments related to the Company's February 2017 acquisition of CHITA Inc. ("CHITA") are classified as Level 3 in the fair value hierarchy because they rely significantly on inputs that are unobservable in the market. The fair value of portions of contingent consideration related to the achievement of a technical milestone have been estimated using situation-based modeling, which considers the probability-weighted present value of the expected payout amount. The fair value of portions of contingent consideration related to achievement of revenue targets have been estimated using a Monte Carlo simulation to simulate future performance of the acquired business under a risk-neutral framework; significant inputs to the simulation include a risk-adjusted discount rate of 10.2% and revenue volatility of 8.0%.

Acquisition (Details)

Acquisition (Details) $ in Millions	6 Months Ended
	Jun. 30, 2018USD ($)
Acquisition [Abstract]
Control obtained description	the Company acquired all outstanding equity interests in SHYFT Analytics, Inc.
Description of acquiree	a Waltham, Massachusetts provider of cloud data analytics for life sciences.
Consideration transferred	$ 196.3
Cash consideration, gross	183.6
Fair value of previous investment in acquired entity	$ 12.7

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Changes in the carrying amount of goodwill
Balance as of beginning of period	$ 216,017
Purchase price adjustment	(2,027)
Foreign currency translation adjustments	(14)
Balance as of end of period	$ 213,976

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets (Details 1) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Intangible assets
Gross carrying amount	$ 47,979	$ 47,385
Accumulated amortization	(21,573)	(17,839)
Net carrying amount	26,406	29,546
Developed technology [Member]
Intangible assets
Gross carrying amount	31,353	31,358
Accumulated amortization	(16,576)	(13,852)
Net carrying amount	14,777	17,506
Customer relationships [Member]
Intangible assets
Gross carrying amount	9,166	9,167
Accumulated amortization	(4,003)	(3,404)
Net carrying amount	5,163	5,763
Trade name [Member]
Intangible assets
Gross carrying amount	5,400	5,400
Accumulated amortization	(370)	(190)
Net carrying amount	5,030	5,210
Non-competition agreements [Member]
Intangible assets
Gross carrying amount	1,460	1,460
Accumulated amortization	(624)	(393)
Net carrying amount	836	1,067
Domain name [Member]
Intangible assets
Gross carrying amount	600	0
Accumulated amortization	0	0
Net carrying amount	$ 600	$ 0

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets (Details 2) $ in Thousands	Jun. 30, 2019USD ($)
Annual amortization for the next five years
Remainder of year current year	$ 3,733
Next twelve months	6,730
Year two	6,249
Year three	3,465
Year four	1,849
Thereafter	$ 3,780

Debt (Details)

Debt (Details) - Term loans (under credit facility) [Member] - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Dec. 21, 2017
Debt Instrument [Line Items]
Principal amount	$ 92,500	$ 95,000	$ 100,000
Unamortized debt issuance costs	(1,508)	(1,725)
Net carrying amount	$ 90,992	$ 93,275

Debt (Details 1)

Debt (Details 1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Debt Instrument [Line Items]
Amortization of debt issuance costs			$ 217	$ 856
Credit facility [Member]
Debt Instrument [Line Items]
Contractual interest expense	$ 850	$ 811	1,704	1,559
Amortization of debt issuance costs	108	109	217	217
Unused commitment fee	151	209	298	409
Total interest expense	$ 1,109	$ 1,129	$ 2,219	$ 2,185
Interest rate during period	3.527%	3.465%	3.576%	3.347%
Unused commitment fee rate	0.15%	0.20%	0.15%	0.20%

Debt (Details Textual)

Debt (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Dec. 21, 2017
Debt Instrument [Line Items]
Amortization of debt issuance costs			$ 217	$ 856
Amortization of debt discount			$ 0	7,015
Credit facility [Member]
Debt Instrument [Line Items]
Approximate remaining life			42 months
Covenant compliance			The Company was in compliance with all financial covenants related to the Credit Facility
Total interest expense	$ 1,109	$ 1,129	$ 2,219	2,185
Contractual interest expense	850	811	1,704	1,559
Amortization of debt issuance costs	108	$ 109	$ 217	$ 217
Term loans (under credit facility) [Member]
Debt Instrument [Line Items]
Maturity date description			The repayment terms of the Term Loans provide for monthly interest payments and quarterly principal payments, with a maturity date of December 2022.
Principal amount	92,500		$ 92,500		$ 95,000	$ 100,000
Current maturities of long-term debt	6,100		6,100		$ 4,900
Revolver (under credit facility) [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 400,000
Remaining borrowing capacity	$ 400,000		$ 400,000
1.00% convertible senior notes [Member]
Debt Instrument [Line Items]
Contractual interest rate		1.00%		1.00%
Maturity date description				settled on August 1, 2018
Total interest expense		$ 4,500		$ 9,000
Contractual interest expense		700		1,400
Amortization of debt issuance costs		300		600
Amortization of debt discount		$ 3,500		$ 7,000

Leases (Details)

Leases (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Leases [Abstract]
Cash paid for operating leases	$ (7,953)
Right-of-use assets obtained in exchange for new operating leases	$ 0	[1]
[1]	No new operating leases were entered into during the three and six months ended June 30, 2019; all changes in operating lease liabilities during that period are the result of the Company's January 1, 2019 adoption of ASC 842.

Leases (Details 1)

Leases (Details 1) $ in Thousands	Jun. 30, 2019USD ($)
Leases [Abstract]
Operating lease liability maturities, remainder of fiscal year	$ 9,287
Year two	19,466
Year three	19,177
Year four	18,860
Year five	18,120
Thereafter	38,497
Total lease payments	123,407
Less imputed interest	(15,478)
Total present value of operating lease liabilities	$ 107,929

Leases (Details Textual)

Leases (Details Textual) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Description of operating leases not yet commenced			the Company has additional operating leases, relating to the office spaces that have not yet commenced, of $28.7 million.
Description of operating leases			The Company leases office and data center space under operating lease agreements with remaining lease terms extending through 2031.
Operating lease expense	$ 4.6	$ 4.1	$ 9.4	$ 8
Short-term lease costs	$ 0.2		$ 0.4
Weighted average remaining operating lease term	7 years 2 months 12 days		7 years 2 months 12 days
Weighted average discount rate	3.60%		3.60%
Minimum [Member]
Term(s) of operating leases not yet commenced	3 years		3 years
Maximum [Member]
Term(s) of operating leases not yet commenced	10 years		10 years

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
[Line Items]
Total stock-based compensation	[1]	$ 21,974	$ 15,190	$ 41,704	$ 28,404
Stock options [Member]
[Line Items]
Total stock-based compensation		378	522	849	1,094
Restricted stock awards and units [Member]
[Line Items]
Total stock-based compensation		14,613	9,024	27,352	16,891
Performance-based restricted stock units [Member]
[Line Items]
Total stock-based compensation		5,219	3,932	9,954	7,159
Employee stock purchase plan [Member]
[Line Items]
Total stock-based compensation		$ 1,764	$ 1,712	$ 3,549	$ 3,260
[1]	Total stock-based compensation is presented in this table on a gross basis, consistent with the additional paid-in capital impact recorded in stockholders' equity. On the Company's consolidated statements of operations and consolidated statements of cash flows, stock-based compensation is presented net of foreign exchange impact and capitalization of eligible software development-related costs.

Stock-Based Compensation (Det_2

Stock-Based Compensation (Details 1) - Stock options [Member]	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Weighted-average Black-Scholes assumptions used to estimate fair value of stock options granted
Expected volatility	0.00%	42.00%	0.00%	42.00%
Expected term		4 years 9 months 10 days		4 years 9 months 10 days
Risk-free interest rate	0.00%	2.82%	0.00%	2.82%
Dividend yield	0.00%	0.00%	0.00%	0.00%

Stock-Based Compensation (Det_3

Stock-Based Compensation (Details 2) - Stock options [Member] $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)$ / sharesshares
Summary of activities and changes in stock option plans
Number of shares outstanding at beginning of period | shares	1,088
Weighted-average exercise price outstanding at beginning of period | $ / shares	$ 19.17
Number of shares granted | shares	0
Weighted-average exercise price granted | $ / shares	$ 0
Number of shares exercised | shares	(352)
Weighted-average exercise price exercised | $ / shares	$ 15.42
Number of shares forfeited | shares	0
Weighted-average exercise price forfeited | $ / shares	$ 0
Number of shares expired | shares	(1)
Weighted-average exercise price expired | $ / shares	$ 13.99
Number of shares outstanding at end of period | shares	735
Weighted-average exercise price outstanding at end of period | $ / shares	$ 20.97
Weighted average remaining contractual term outstanding at end of period	3 years 21 days
Aggregate intrinsic value outstanding at end of period | $	$ 51,066
Number of shares exercisable at end of period | shares	648
Weighted-average exercise price exercisable at end of period | $ / shares	$ 15.68
Weighted average remaining contractual term exercisable at end of period	2 years 5 months 1 day
Aggregate intrinsic value exercisable at end of period | $	$ 48,506
Number of shares vested and expected to vest at end of period | shares	730
Weighted-average exercise price vested and expected to vest at end of period | $ / shares	$ 20.71
Weighted average remaining contractual term vested and expected to vest at end of period	3 years 14 days
Aggregate intrinsic value vested and expected to vest at end of period | $	$ 50,981

Stock-Based Compensation (Det_4

Stock-Based Compensation (Details 3) - Restricted stock awards and units [Member] shares in Thousands	6 Months Ended
	Jun. 30, 2019$ / sharesshares
Summary of time-based nonvested restricted stock awards and units
Nonvested number of shares/units at beggining of period | shares	1,936
Nonvested weighted-average grant-date fair value at beginning of period | $ / shares	$ 61.45
Granted number of shares | shares	958
Granted weighted-average grant-date fair value | $ / shares	$ 72.08
Vested number of shares/units | shares	(689)
Vested weighted-average grant-date fair value | $ / shares	$ 57.83
Forfeited number of shares/units | shares	(129)
Forfeited weighted-average grant-date fair value | $ / shares	$ 71.07
Nonvested number of shares/units at end of period | shares	2,076
Nonvested weighted-average grant-date fair value at end of period | $ / shares	$ 66.96

Stock-Based Compensation (Det_5

Stock-Based Compensation (Details 4) - Relative TSR [Member] - Performance-based restricted stock units [Member]	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Assumptions used to estimate fair value of TSR PBRSUs
Expected volatility - Medidata	0.00%	36.00%	35.00%	37.00%
Expected volatility - Comparison index		43.00%	44.00%	42.00%
Expected term		2 years 8 months 8 days	2 years 10 months 17 days	2 years 10 months 6 days
Risk-free interest rate	0.00%	2.58%	2.47%	2.37%
Dividend yield	0.00%	0.00%	0.00%	0.00%

Stock-Based Compensation (Det_6

Stock-Based Compensation (Details 5) - Performance-based restricted stock units [Member] - $ / shares shares in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Summary of performance-based restricted stock units based upon expected performance
Nonvested number of shares/units at beggining of period		1,026
Nonvested weighted-average grant-date fair value at beginning of period		$ 70.80
Granted number of units (based on performance at 100% of targeted levels)		310
Granted weighted-average grant-date fair value		$ 88.56
Adjustment due to expected performance		197
Adjustment due to expected performance weighted average grant date fair value		$ 104.95
Vested number of shares/units		(370)
Vested weighted-average grant-date fair value		$ 47.11
Forfeited number of shares/units		(22)
Forfeited weighted-average grant-date fair value		$ 93.43
Nonvested number of shares/units at end of period		1,141
Nonvested weighted-average grant-date fair value at end of period		$ 88.77
Net income growth [Member]
Summary of performance-based restricted stock units based upon expected performance
Nonvested number of shares/units at beggining of period		210
Granted number of units (based on performance at 100% of targeted levels)	5	0	122
Adjustment due to expected performance		0
Vested number of shares/units		0
Forfeited number of shares/units		0
Nonvested number of shares/units at end of period		210
Relative TSR [Member]
Summary of performance-based restricted stock units based upon expected performance
Nonvested number of shares/units at beggining of period		793
Granted number of units (based on performance at 100% of targeted levels)	6	155	122
Adjustment due to expected performance		197
Vested number of shares/units		(370)
Forfeited number of shares/units		(14)
Nonvested number of shares/units at end of period		761
Revenue [Member]
Summary of performance-based restricted stock units based upon expected performance
Nonvested number of shares/units at beggining of period		0
Granted number of units (based on performance at 100% of targeted levels)		155
Adjustment due to expected performance		0
Vested number of shares/units		0
Forfeited number of shares/units		(7)
Nonvested number of shares/units at end of period		148
Other individual and team goals [Member]
Summary of performance-based restricted stock units based upon expected performance
Nonvested number of shares/units at beggining of period		23
Granted number of units (based on performance at 100% of targeted levels)		0
Adjustment due to expected performance		0
Vested number of shares/units		0
Forfeited number of shares/units		(1)
Nonvested number of shares/units at end of period		22

Stock-Based Compensation (Det_7

Stock-Based Compensation (Details 6) - Employee stock purchase plan [Member]	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Weighted-average Black-Scholes assumptions used to estimate fair value of ESPP shares
Expected volatility	40.00%	37.00%	40.00%	37.00%
Expected term	8 months 15 days	1 year 8 months 12 days	8 months 15 days	1 year 8 months 12 days
Risk-free interest rate	2.39%	1.09%	2.39%	1.09%
Dividend yield	0.00%	0.00%	0.00%	0.00%

Stock-Based Compensation (Det_8

Stock-Based Compensation (Details Textual) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
[Line Items]
Shares originally authorized for issuance under 2019 Plan					2,500
Shares available for issuance under 2017 Plan	4,800		4,800
Incremental expense associated with equity modifications	$ 0.2	$ 0.2	$ 0.3	$ 0.4
Stock options [Member]
[Line Items]
Weighted-average grant-date fair value of stock options granted	$ 0	$ 28.93	$ 0	$ 28.93
Total intrinsic value of stock options exercised	$ 23.9	$ 3.8	$ 25.8	$ 11.4
Unrecognized compensation cost related to non-vested stock-based compensation awards granted	2.1		$ 2.1
Weighted-average remaining period over which cost is expected to be recognized			1 year 10 months 17 days
Restricted stock awards and units [Member]
[Line Items]
Total fair value of shares vested	15.2	5.7	$ 53.4	37.3
Unrecognized compensation cost related to non-vested stock-based compensation awards granted	119.4		$ 119.4
Weighted-average remaining period over which cost is expected to be recognized			2 years 8 months 1 day
Granted number of units (based on performance at 100% of targeted levels)			958
Performance-based restricted stock units [Member]
[Line Items]
Total fair value of shares vested	0	$ 0	$ 26.6	$ 8.1
Unrecognized compensation cost related to non-vested stock-based compensation awards granted	38		$ 38
Weighted-average remaining period over which cost is expected to be recognized			1 year 8 months 1 day
Granted number of units (based on performance at 100% of targeted levels)			310
Employee stock purchase plan [Member]
[Line Items]
Unrecognized compensation cost related to non-vested stock-based compensation awards granted	$ 7.7		$ 7.7
Weighted-average remaining period over which cost is expected to be recognized			1 year 5 months 8 days
Shares issued during period under employee stock purchase plan	135	150	135	150
Weighted-average purchase price of shares issued during period under employee stock purchase plan	$ 56.60	$ 43.04	$ 56.60	$ 43.04
Revenue [Member] | Performance-based restricted stock units [Member]
[Line Items]
Granted number of units (based on performance at 100% of targeted levels)			155
Award terms			performance conditions based on the compound annual growth rate of revenue over the three-year period ending December 31, 2021, vesting in full in three years with the number of shares ultimately earned ranging from zero to 250% of the target number of shares
Relative TSR [Member] | Performance-based restricted stock units [Member]
[Line Items]
Granted number of units (based on performance at 100% of targeted levels)		6	155	122
Award terms		market conditions based on the Company's total stockholder return ("TSR") relative to that of the Russell 2000 Index over the three-year period ending December 31, 2020, vesting in full in three years with the number of shares ultimately earned ranging from zero to 200% of the target number of shares	market conditions based on the Company's TSR relative to that of the Russell 2000 Index over the three-year period ending December 31, 2021, vesting in full in three years with the number of shares ultimately earned ranging from zero to 200% of the target number of shares
Net income growth [Member] | Performance-based restricted stock units [Member]
[Line Items]
Granted number of units (based on performance at 100% of targeted levels)		5	0	122
Award terms		performance conditions based on the compound annual growth rate of net income over the three-year period ending December 31, 2020, vesting in full in three years with the number of shares ultimately earned ranging from zero to 200% of the target number of shares
Other individual and team goals [Member] | Performance-based restricted stock units [Member]
[Line Items]
Granted number of units (based on performance at 100% of targeted levels)			0

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Reconciliation of the numerators and denominators of basic and diluted earnings per share
Net income	$ 7,893	$ 16,589	$ 19,038	$ 26,914
Denominator for basic earnings per share:
Weighted average common shares outstanding	60,081	57,448	59,888	57,252
Dilutive potential common shares:
Stock options	740	866	762	897
Restricted stock awards and units	764	612	811	752
Performance-based restricted stock units	685	610	664	586
Employee stock purchase plan	102	220	66	181
Convertible senior notes	0	1,118	0	896
Weighted average common shares outstanding with assumed conversion	62,372	60,874	62,191	60,564
Basic earnings per share	$ 0.13	$ 0.29	$ 0.32	$ 0.47
Diluted earnings per share	$ 0.13	$ 0.27	$ 0.31	$ 0.44

Earnings Per Share (Details 1)

Earnings Per Share (Details 1) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share
Antidilutive shares excluded from calculation of diluted earnings (loss) per share	55	197	543	192
Stock options [Member]
Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share
Antidilutive shares excluded from calculation of diluted earnings (loss) per share	49	79	62	78
Restricted stock awards and units [Member]
Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share
Antidilutive shares excluded from calculation of diluted earnings (loss) per share	6	34	7	30
Performance-based restricted stock units [Member]
Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share
Antidilutive shares excluded from calculation of diluted earnings (loss) per share	0	0	0	0
Employee stock purchase plan [Member]
Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share
Antidilutive shares excluded from calculation of diluted earnings (loss) per share	0	84	474	84

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Gross unrecognized tax benefits	$ 6.4	$ 6.4
Changes in tax position	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details)	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Legal matters	The Company is subject to legal proceedings and claims that arise in the ordinary course of business and records an estimated liability for these matters when an adverse outcome is considered to be probable and can be reasonably estimated. Although the outcome of this routine litigation cannot be predicted with certainty and some lawsuits, claims, or proceedings may be disposed of unfavorably to the Company, which could materially and adversely affect its financial condition or results of operations, the Company does not believe that it is currently a party to any material legal proceedings in the ordinary course of business. In addition, four complaints were filed against the Company and its board of directors relating to the Merger with Dassault Systèmes announced on June 12, 2019. As of August 5, 2019, the Company had received the following complaints. On July 22, 2019, a putative class action lawsuit, Kent v. Medidata Solutions, Inc., et al., 1:19-cv-01361-RGA, was filed by purported shareholder Michael Kent against the Company and its board of directors in the United States District Court for the District of Delaware. On July 25, 2019, a complaint, Stein v. Medidata Solutions, Inc., et al., 1:19-cv-06933, was filed as an individual action by purported shareholder Shiva Stein against the Company and its board of directors in the United States District Court for the Southern District of New York. On July 30, 2019, a complaint, Sivigny v. Medidata Solutions, Inc., et al., 2:19-cv-16113, was filed as an individual action by purported shareholder Robert Sivigny against the Company and its board of directors in the United States District Court for the District of New Jersey. On July 31, 2019, a complaint, Borodin v. Medidata Solutions, Inc., et al., 1:19-cv-07176, was filed as an individual action by purported shareholder Suvi Borodin against the Company and its board of directors in the United States District Court for the Southern District of New York. The Company refers to the Kent, Stein, and Sivigny, and Borodin cases as the “merger actions.” The merger actions generally allege that the Company’s proxy statement filed on July 19, 2019 misrepresents and/or omits certain purportedly material information and assert violations of Sections 14(a) of the Securities Exchange Act of 1934 (the “Exchange Act”) and Rule 14a-9 promulgated thereunder against all defendants and violations of Section 20(a) of the Exchange Act against the directors. The merger actions seek, among other things, an injunction enjoining consummation of the merger, costs of the action, including plaintiff’s attorneys’ fees and experts’ fees, declaratory relief, and any other relief the court may deem just and proper.
Standard product warranty description	The Company typically provides contractual warranties to its customers covering its solutions and services. To date, any refunds provided to customers have been immaterial.
Description of executive change in control agreements	The Company has change in control agreements with its chief executive officer and certain other executive officers. These agreements provide for payments to be made to such officers upon involuntary termination of their employment by the Company without cause or by such officers for good reason as defined in the agreements, within a period of 1 year following a change in control. For purposes of any equity or equity-based awards granted by the Company prior to the closing of the Merger that are converted into Dassault Systèmes restricted stock units in accordance with the terms of the Merger Agreement, such converted equity awards will vest upon a termination of employment by the Company without cause or by the officer for good reason, in either case within a period of 2 years following a change in control. The agreements provide that, upon a qualifying termination event, such officers will be entitled to (a) a severance payment equal to the sum of the officer’s base salary and target bonus amount (except that such payment for the Company's chief executive officer and president would be two times such sum); (b) continuation of health benefits for one year (except that such continuation for the Company's chief executive officer and president would be for two years); and (c) immediate vesting of remaining unvested equity awards, unless otherwise specified in the equity award agreements.