Medidata Solutions 10-Q 3 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Oct. 31, 2016
Document and Entity Information [Abstract]
Entity registrant name	Medidata Solutions, Inc.
Entity central index key	1,453,814
Document type	10-Q
Amendment flag	false
Document period end date	Sep. 30, 2016
Document fiscal period focus	Q3
Document fiscal year focus	2,016
Current fiscal year end date	--12-31
Entity filer category	Large Accelerated Filer
Entity common stock, shares outstanding		57,633,313

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 65,165	$ 49,562
Marketable securities	264,903	220,126
Accounts receivable, net of allowance for doubtful accounts	114,886	90,590
Prepaid commission expense	2,830	1,670
Prepaid expenses and other current assets	22,301	21,165
Deferred income taxes	104	88
Total current assets	470,189	383,201
Restricted cash	5,759	5,755
Furniture, fixtures and equipment, net	54,296	51,043
Marketable securities- long-term	154,161	209,041
Goodwill	30,232	18,797
Intangible assets, net	5,489	1,172
Deferred income taxes- long-term	50,668	12,128
Other assets	14,972	3,043
Total assets	785,766	684,180
Current liabilities:
Accounts payable	1,185	6,283
Accrued payroll and other compensation	24,740	23,744
Accrued expenses and other	20,394	15,469
Deferred revenue	77,252	75,582
Total current liabilities	123,571	121,078
Noncurrent liabilities:
1.00% convertible senior notes, net	259,851	249,487
Deferred revenue, less current portion	3,312	2,993
Deferred tax liabilities	446	414
Other long-term liabilities	19,475	26,052
Total noncurrent liabilities	283,084	278,946
Total liabilities	406,655	400,024
Commitments and contingencies
Stockholders' equity:
Preferred stock	0	0
Common stock	612	594
Additional paid-in capital	403,765	364,973
Treasury stock	(113,070)	(100,806)
Accumulated other comprehensive loss	(3,715)	(3,404)
Retained earnings	91,519	22,799
Total stockholders' equity	379,111	284,156
Total liabilities and stockholders' equity	$ 785,766	$ 684,180

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accounts receivable, allowance for doubtful accounts	$ 2,064	$ 1,992
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	61,214	59,455
Common stock, shares outstanding	57,599	56,311
Treasury stock, shares	3,615	3,144

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues
Subscription		$ 101,560	$ 88,878	$ 288,288	$ 251,556
Professional services		18,501	14,235	50,621	42,081
Total revenues		120,061	103,113	338,909	293,637
Cost of revenues
Subscription		16,095	12,489	46,024	36,316
Professional services		13,133	10,304	36,929	31,564
Total cost of revenues	[1],[2]	29,228	22,793	82,953	67,880
Gross profit		90,833	80,320	255,956	225,757
Operating costs and expenses:
Research and development	[2]	28,028	24,192	84,523	68,622
Sales and marketing	[1],[2]	27,789	25,881	80,856	75,923
General and administrative	[2]	20,089	19,143	57,866	61,655
Total operating costs and expenses		75,906	69,216	223,245	206,200
Operating income		14,927	11,104	32,711	19,557
Interest and other income (expense):
Interest expense		(4,220)	(4,038)	(12,530)	(11,993)
Interest income		1,005	739	2,809	1,885
Other income (expense), net		(7)	3	(8)	(65)
Total interest and other expense, net		(3,222)	(3,296)	(9,729)	(10,173)
Income before income taxes		11,705	7,808	22,982	9,384
Provision for income taxes		4,347	3,127	4,839	3,033
Net income		$ 7,358	$ 4,681	$ 18,143	$ 6,351
Earnings per share:
Basic		$ 0.13	$ 0.09	$ 0.33	$ 0.12
Diluted		$ 0.13	$ 0.08	$ 0.32	$ 0.11
Weighted average common shares outstanding:
Basic		55,670	53,933	55,395	53,615
Diluted		57,738	56,687	57,272	55,985
Total stock-based compensation	[2]	$ 10,458	$ 12,102	$ 31,155	$ 37,908
Total amortization of intangible assets	[1]	398	109	900	527
Cost of revenues
Weighted average common shares outstanding:
Total stock-based compensation	[2]	1,154	1,246	3,603	3,805
Total amortization of intangible assets	[1]	314	79	707	438
Research and development
Weighted average common shares outstanding:
Total stock-based compensation	[2]	2,292	2,105	6,809	5,904
Sales and marketing
Weighted average common shares outstanding:
Total stock-based compensation	[2]	1,633	2,343	5,349	7,170
Total amortization of intangible assets	[1]	84	30	193	89
General and administrative
Weighted average common shares outstanding:
Total stock-based compensation	[2]	$ 5,379	$ 6,408	$ 15,394	$ 21,029
[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 Stateme5

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net income	$ 7,358	$ 4,681	$ 18,143	$ 6,351
Other comprehensive income (loss):
Foreign currency translation adjustments	(376)	(564)	(1,028)	(391)
Unrealized gain (loss) on marketable securities	(548)	(389)	1,159	(186)
Other comprehensive income (loss)	(924)	(953)	131	(577)
Income tax effect of unrealized gain or loss on marketable securities	139	155	(442)	87
Other comprehensive income (loss), net of tax	(785)	(798)	(311)	(490)
Comprehensive income (loss), net of tax	$ 6,573	$ 3,883	$ 17,832	$ 5,861

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities:
Net income		$ 18,143	$ 6,351
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of intangible assets and depreciation		10,901	7,941
Stock-based compensation	[1]	31,155	37,908
Amortization of discounts or premiums on marketable securities		2,268	3,667
Deferred income taxes		3,768	(1,235)
Amortization of debt issuance costs		959	958
Amortization of debt discount		9,405	8,859
Provision for doubtful accounts		863	539
Loss on fixed asset disposal		15	0
Changes in operating assets and liabilities:
Accounts receivable		(32,414)	(32,284)
Prepaid commission expense		(3,096)	374
Prepaid expenses and other current assets		(1,747)	(5,268)
Other assets		(5,443)	1,814
Accounts payable		(1,883)	(1,235)
Accrued payroll and other compensation		863	3,376
Accrued expenses and other		10,525	1,644
Deferred revenue		10,661	22,842
Other long-term liabilities		(6,577)	1,902
Net cash provided by (used in) operating activities		48,366	58,153	[2]
Cash flows from investing activities:
Purchases of furniture, fixtures and equipment		(15,872)	(11,017)
Purchases of available-for-sale securities		(214,670)	(207,126)
Proceeds from sale of available-for-sale securities		223,664	190,656
Purchase of cost method investment		(4,000)	0
Acquisition of business, net of cash acquired		(17,186)	0
Net (increase) decrease in restricted cash		80	(464)
Net cash provided by (used in) investing activities		(27,984)	(27,951)
Cash flows from financing activities:
Proceeds from exercise of stock options		4,269	5,770
Proceeds from employee stock purchase plan		5,190	4,675
Repayments of notes payable		(100)	(32)
Repayment of obligations under capital leases		0	(26)
Acquisition of treasury stock		(14,437)	(16,915)
Net cash provided by (used in) financing activities		(5,078)	(6,528)	[2]
Effect of exchange rate changes on cash and cash equivalents		299	(12)
Net increase (decrease) in cash and cash equivalents		15,603	23,662
Cash and cash equivalents - Beginning of period		49,562	39,517
Cash and cash equivalents - End of period		65,165	63,179
Cash paid during the period for:
Interest		2,882	2,876
Income taxes		1,514	595
Noncash activities:
Furniture, fixtures, and equipment acquired but not yet paid for at period-end		$ 1,833	$ 2,682
[1]	Stock-based compensation expense included in cost of revenues and operating costs and expenses
[2]	As a result of the Company's early adoption of Accounting Standards Update No. 2016-09, which requires excess tax benefit on equity awards to be presented as an operating activity, the consolidated statement of cash flows for the nine months ended September 30, 2015 has been adjusted to reflect an offsetting increase of $1,706 thousand to net cash provided by operating activities and net cash used in financing activities. Refer to Note 1, "Summary of Significant Accounting Policies — Recently Adopted Accounting Pronouncements" for further information.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES 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 September 30, 2016 are the same as those at December 31, 2015 , which are included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2015 filed with the Securities and Exchange Commission (“SEC”) on February 29, 2016 . Basis of Presentation — The accompanying interim condensed consolidated balance sheets as of September 30, 2016 and December 31, 2015 , the condensed consolidated statements of operations for the three and nine months ended September 30, 2016 and 2015 , the condensed consolidated statements of comprehensive income for the three and nine months ended September 30, 2016 and 2015 , and the condensed consolidated statements of cash flows for the nine months ended September 30, 2016 and 2015 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, 2015 included in the Company’s Annual Report on Form 10-K filed with the SEC on February 29, 2016 . Except for the changes resulting from early adoption of Accounting Standards Update ("ASU") No 2016-09, which is described in the "Recently Adopted Accounting Pronouncements" section of this Note, 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 September 30, 2016 , results of its operations for the three and nine months ended September 30, 2016 and 2015 , comprehensive income for the three and nine months ended September 30, 2016 and 2015 , and cash flows for the nine months ended September 30, 2016 and 2015 . The results of operations for the three and nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 . 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. 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 September 30, 2016 and December 31, 2015 , unbilled accounts receivable of $14.1 million and $10.3 million , respectively, were included in accounts receivable on the Company's consolidated balance sheets. In general, there is a direct relationship between the Company's accounts receivable balance and its transaction volume. Recently Adopted Accounting Pronouncements — In August 2014, the Financial Accounting Standards Board ("FASB") issued ASU No. 2014-15, Presentation of Financial Statements—Going Concern . This new guidance formally establishes management's responsibility to evaluate at each reporting period whether there is substantial doubt about the entity's ability to continue as a going concern for a period of one year after the date the financial statements are issued, and to provide related footnote disclosures. ASU No. 2014-15 is effective for annual reporting periods ending after December 15, 2016, and for interim and annual periods thereafter. The Company will adopt ASU No. 2014-15 for the annual reporting period ending December 31, 2016, and the adoption is not expected to have a material impact on its consolidated financial statements. In April 2015, the FASB issued ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs. ASU No. 2015-03 requires that debt issuance costs be presented not as an asset but as a reduction of the carrying amount of the related debt liability, similar to a debt discount. ASU No. 2015-03 is effective for annual periods beginning after December 15, 2015, and interim periods within those annual periods, with early adoption permitted. The Company adopted ASU No. 2015-03 retrospectively on January 1, 2016, and the adoption did not have a material impact on its consolidated financial statements, aside from a balance sheet reclassification. Refer to Note 6 , "Debt," for details. In April 2015, the FASB issued ASU No. 2015-05, Customer's Accounting for Fees Paid in a Cloud Computing Arrangement , which provides guidance on whether an entity should account for the fees paid as a customer under a cloud computing arrangement as a license of internal-use software or as a service contract. ASU No. 2015-05 is effective for annual periods beginning after December 15, 2015, and interim periods within those annual periods, with early adoption permitted. The Company adopted ASU No. 2015-05 prospectively on January 1, 2016, and the adoption did not have a material impact on its consolidated financial statements as the Company accounts for all subscription fees paid under its cloud computing arrangements as service contracts. In May 2015, the FASB issued ASU No. 2015-07, Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent). ASU No. 2015-07 removes the requirement to categorize within the fair value hierarchy those investments that are measured at fair value using net asset value per share as a practical expedient and requires that sufficient information be provided to permit reconciliation of the fair value of assets categorized within the fair value hierarchy to amounts presented on the balance sheets. ASU No. 2015-07 is effective for annual periods beginning after December 15, 2015, and interim periods within those annual periods, with early adoption permitted. The Company adopted ASU No. 2015-07 retrospectively on January 1, 2016, and the adoption did not have a material impact on its consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting, which simplifies several aspects of the accounting for share-based payment transactions, including income tax consequences, classification of awards as either equity or liability, and classification on the statement of cash flows. ASU No. 2016-09 is effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted in any interim or annual period; if an entity adopts the amendments in an interim period, any adjustments must be reflected as of the beginning of the fiscal year that includes that interim period. The Company's early adoption of ASU No. 2016-09 in the third quarter of 2016 impacted its consolidated financial statements as follows: • The new guidance requires excess tax benefits and tax deficiencies on equity awards, which were formerly recognized in additional paid-in capital, to be recognized in the income statement when the awards vest or are settled; adoption of this portion of ASU No. 2016-09 resulted in recognition of deferred tax assets for all excess tax benefits that had not been previously recognized because the related tax deduction had not reduced income taxes payable. This was effected through a $50.6 million cumulative-effect adjustment to opening retained earnings as of January 1, 2016. • The new guidance requires cash flows related to excess tax benefits, which were formerly classified as a financing activity on the statement of cash flows, to be classified as an operating activity; as a result of the adoption of ASU No. 2016-09, the Company has classified the excess tax benefit for the nine months ended September 30, 2016 as an operating activity on the statement of cash flows. Use of the permitted modified retrospective approach has resulted in an offsetting increase of $1.7 million to cash provided by operating activities and cash used in financing activities for the nine months ended September 30, 2015. 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, except as described below. In January 2016, the FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities, which enhances the reporting model for financial instruments by amending certain aspects of existing guidance on recognition, measurement, presentation, and disclosure to provide financial statement users with more decision-useful information. ASU No. 2016-01 is effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The Company will adopt ASU No. 2016-01 on January 1, 2018, and is presently evaluating the impact of the adoption on its consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases, which replaces previous lease guidance in its entirety with Accounting Standards Codification ("ASC") 842, Leases. The new guidance 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 new guidance also adds quantitative and qualitative disclosure requirements around leasing activities. ASU No. 2016-02 is effective for annual periods beginning after December 15, 2018, including interim periods within those annual periods, and requires a modified retrospective approach. Early adoption is permitted. The Company will adopt ASU No. 2016-02 on January 1, 2019, and is presently evaluating the impact of the adoption on its consolidated financial statements. In August 2015, the FASB issued ASU No. 2016-15, Cash Flows - Classification of Certain Cash Receipts and Cash Payments , which addresses the diversity in practice around presentation of certain cash receipts and payments in the statement of cash flows. ASU No. 2016-15 is effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The Company does not expect the adoption to have a material impact on its consolidated financial statements and may consider early adoption, which is permitted in any interim or annual period.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2016
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 2009 Long-Term Incentive Plan (the “2009 Plan”). Under the provisions of the 2009 Plan, unless otherwise elected, participants fulfill their related income tax withholding 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 for future reissuance. During the nine months ended September 30, 2016 and 2015 , the Company withheld 338,523 shares at an average price of $36.22 and 338,792 shares at an average price of $50.27 , respectively, in connection with the vesting of equity awards. Nonvested RSAs forfeited by plan participants are transferred to the Company's treasury stock at par. During the nine months ended September 30, 2016 and 2015 , 132,626 and 80,752 forfeited shares, respectively, were transferred to treasury stock at their par value of $0.01 .

Investments

Investments	9 Months Ended
	Sep. 30, 2016
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 consolidated balance sheet. The following table provides the Company’s marketable securities by security type as of September 30, 2016 and December 31, 2015 (in thousands): As of September 30, 2016 Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper and corporate bonds $ 386,881 $ 33 $ (471 ) $ 386,443 U.S. government agency debt securities 32,639 — (18 ) 32,621 Total $ 419,520 $ 33 $ (489 ) $ 419,064 As of December 31, 2015 Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper and corporate bonds $ 401,824 $ — $ (1,522 ) $ 400,302 U.S. government agency debt securities 28,958 2 (95 ) 28,865 Total $ 430,782 $ 2 $ (1,617 ) $ 429,167 Contractual maturities of the Company’s marketable securities as of September 30, 2016 and December 31, 2015 are summarized as follows (in thousands): As of September 30, 2016 As of December 31, 2015 Cost Estimated Fair Value Cost Estimated Fair Value Due in one year or less $ 265,154 $ 264,903 $ 220,492 $ 220,126 Due in one to five years 154,366 154,161 210,290 209,041 Total $ 419,520 $ 419,064 $ 430,782 $ 429,167 At September 30, 2016 , the Company had $0.5 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 until maturity, the Company has determined that the gross unrealized losses on such investments at September 30, 2016 are temporary in nature. Accordingly, the Company did not consider its investments in marketable securities to be other-than-temporarily impaired as of September 30, 2016 . The following tables provide the fair market value and the gross unrealized losses of the Company's marketable securities with unrealized losses, aggregated by security type, as of September 30, 2016 and December 31, 2015 (in thousands): In Loss Position for Less than 12 Months As of September 30, 2016 As of December 31, 2015 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Commercial paper and corporate bonds $ 259,180 $ (364 ) $ 359,566 $ (1,443 ) U.S. government agency debt securities 22,824 (15 ) 25,863 (95 ) Total $ 282,004 $ (379 ) $ 385,429 $ (1,538 ) In Loss Position for More than 12 Months As of September 30, 2016 As of December 31, 2015 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Commercial paper and corporate bonds $ 82,509 $ (107 ) $ 38,726 $ (79 ) U.S. government agency debt securities 4,797 (3 ) — — Total $ 87,306 $ (110 ) $ 38,726 $ (79 ) During the three and nine months ended September 30, 2016 and 2015 , the Company recorded an insignificant amount of net realized gains from the sale of marketable securities. Cost Method Investment In August 2016, the Company purchased shares of Series B Preferred Stock of SHYFT Analytics, Inc. ("SHYFT") via a private placement. This investment is accounted for under the cost method and is included in other assets on the Company's consolidated balance sheet as of September 30, 2016 at its purchase price of $4.0 million . The Company's vice chairman, Steven Hirschfeld, has served on the board of directors of SHYFT since 2014 in an individual capacity and not as a representative of the Company.

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
FAIR VALUE	FAIR VALUE The following table summarizes, as of September 30, 2016 and December 31, 2015 , our financial assets that are measured at fair value on a recurring basis, according to the fair value hierarchy described in our significant accounting policies included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2015 (in thousands): As of September 30, 2016 As of December 31, 2015 Level 1 Level 2 Total Level 1 Level 2 Total Cash 62,867 — 62,867 48,917 — 48,917 Money market funds 2,298 — 2,298 645 — 645 Commercial paper — — — — — — Total cash and cash equivalents 65,165 — 65,165 49,562 — 49,562 Commercial paper and corporate bonds — 386,443 386,443 — 400,302 400,302 U.S. government agency debt securities — 32,621 32,621 — 28,865 28,865 Total marketable securities — 419,064 419,064 — 429,167 429,167 Total financial assets measured at fair value on a recurring basis 65,165 419,064 484,229 49,562 429,167 478,729 As of September 30, 2016 and December 31, 2015 , the Company had no financial liabilities measured at fair value on a recurring basis, and none of its financial assets measured at fair value on a recurring basis relied upon Level 3 inputs. 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 prices for similar instruments if available. During the nine months ended September 30, 2016 and 2015 , there were no transfers of financial assets between Level 1 and Level 2. The carrying amounts of all other current financial assets and current financial liabilities reflected in the consolidated balance sheets approximate fair value due to their short-term nature.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	GOODWILL AND INTANGIBLE ASSETS On April 1, 2016 , the Company acquired Intelemage, LLC ("Intelemage"), a medical image sharing and workflow management company for a net purchase price of $17.2 million , broadening its offerings with the addition of digital image management technology. The acquisition resulted in the recognition of the following intangible assets (in thousands): Acquisition-Date Fair Value Weighted-Average Useful Life Acquired technology $ 3,750 4 years Customer relationships 1,472 6 years Total $ 5,222 The change in the carrying amount of goodwill during the nine months ended September 30, 2016 was as follows (in thousands): Balance as of January 1, 2016 $ 18,797 Additions related to acquisition of Intelemage $ 12,007 Foreign currency translation adjustments (572 ) Balance as of September 30, 2016 $ 30,232 Total intangible assets are summarized as follows (in thousands): As of September 30, 2016 As of December 31, 2015 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Acquired technology $ 8,780 $ (4,851 ) $ 3,929 $ 5,223 $ (4,336 ) $ 887 Customer relationships 3,585 (2,116 ) 1,469 2,165 (1,994 ) 171 Non-competition agreements 150 (59 ) 91 150 (36 ) 114 Total $ 12,515 $ (7,026 ) $ 5,489 $ 7,538 $ (6,366 ) $ 1,172 Amortization of intangible assets for the next five years is expected to be as follows (in thousands): Remainder of year ending December 31, 2016 $ 398 Years ending December 31, 2017 1,569 2018 1,488 2019 1,230 2020 498 2021 245

Debt

Debt	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
DEBT	DEBT The Company's 1.00% convertible senior notes (the "Notes"), issued in August 2013, consisted of the following components as of September 30, 2016 and December 31, 2015 (in thousands): September 30, December 31, Equity component, net of equity issue costs $ 60,222 $ 60,222 Liability component: Principal 287,500 287,500 Less: unamortized debt discount (25,307 ) (34,712 ) Less: unamortized debt issuance costs (2,342 ) (3,301 ) Net carrying amount $ 259,851 $ 249,487 On January 1, 2016, the Company retrospectively adopted ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs, which requires unamortized debt issuance costs to be presented as a reduction of the carrying amount of the related debt liability, similar to a debt discount. This resulted in the reclassification of $3.3 million in unamortized debt issuance costs from other assets to 1.00% convertible senior notes on the Company's consolidated balance sheet as of December 31, 2015 . As of September 30, 2016 and December 31, 2015 , the estimated fair value of the Notes was $332.9 million and $313.0 million , respectively. The Company considers this disclosure to be a Level 2 measurement because it is based upon a recent modeled bid-price quote for the Notes, reflecting activity in a less than active market. As of September 30, 2016 , the Notes are not convertible. Based on the closing price of the Company's common stock on September 30, 2016 of $55.76 , which is less than the Notes' initial conversion price of $58.05 , the if-converted value of the Notes was less than their principal amount. As of September 30, 2016 , the remaining life of the Notes was approximately 22 months . The following table sets forth total interest expense recognized related to the Notes for the three and nine months ended September 30, 2016 and 2015 (in thousands except percentages): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Contractual interest expense $ 718 $ 719 $ 2,156 $ 2,156 Amortization of debt issuance costs 320 319 959 958 Amortization of debt discount 3,181 2,997 9,405 8,859 Total $ 4,219 $ 4,035 $ 12,520 $ 11,973 Effective interest rate 6.5 % 6.5 % 6.5 % 6.5 %

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION For the three and nine months ended September 30, 2016 and 2015 , the components of stock-based compensation expense were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Stock options $ 947 $ 1,070 $ 3,000 $ 3,906 Restricted stock awards and units 6,571 5,031 18,312 14,334 Performance-based restricted stock units 2,264 4,964 7,133 16,546 Employee stock purchase plan 676 1,037 2,710 3,122 Total stock-based compensation $ 10,458 $ 12,102 $ 31,155 $ 37,908 Stock Options The fair value of each stock option granted during the three and nine months ended September 30, 2016 and 2015 was estimated on the date of grant using a Black-Scholes pricing model with the following weighted-average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Expected volatility 44 % 43 % 43 % 43 % Expected life 6 years 6 years 6 years 6 years Risk-free interest rate 1.20 % 1.69 % 1.42 % 1.69 % Dividend yield — — — — The following table summarizes the status of the Company's stock options as of September 30, 2016 , and changes during the nine 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, 2016 1,940 $21.73 Granted 134 41.33 Exercised (238 ) 17.89 Forfeited (6 ) 40.54 Expired (22 ) 58.09 Outstanding at September 30, 2016 1,808 $23.18 5.37 $59,233 Exercisable at September 30, 2016 1,413 $17.13 4.48 $54,809 Vested and expected to vest at September 30, 2016 1,759 $22.59 5.27 $58,682 The weighted-average grant-date fair value of stock options granted during the three months ended September 30, 2016 and 2015 was $23.15 and $19.99 , respectively. The weighted-average grant-date fair value of stock options granted during the nine months ended September 30, 2016 and 2015 was $17.92 and $21.81 , respectively. The total intrinsic value of stock options exercised during the three months ended September 30, 2016 and 2015 was $4.4 million and $1.7 million , respectively. The total intrinsic value of stock options exercised during the nine months ended September 30, 2016 and 2015 was $7.4 million and $14.1 million , respectively. The total fair value of stock options vested during the three months ended September 30, 2016 and 2015 was $1.7 million and $1.1 million , respectively. The total fair value of stock options vested during the nine months ended September 30, 2016 and 2015 was $3.8 million and $3.5 million , respectively. As of September 30, 2016 , there was $6.8 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 2.55 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 September 30, 2016 , and changes during the nine months then ended (in thousands, except per share data): Number of Shares Weighted- Average Grant-Date Fair Value Nonvested at January 1, 2016 1,355 $40.82 Granted 1,138 37.90 Vested (481 ) 33.94 Forfeited (138 ) 41.76 Nonvested at September 30, 2016 1,874 $40.75 The total fair value of RSAs and RSUs vested during the three months ended September 30, 2016 and 2015 was $1.5 million and $2.1 million , respectively. The total fair value of RSAs and RSUs vested during the nine months ended September 30, 2016 and 2015 was $18.4 million and $29.3 million , respectively. As of September 30, 2016 , there was $60.4 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 2.72 years . Performance-Based Restricted Stock Units No PBRSUs were granted during the three months ended September 30, 2016 and 2015 . During the nine months ended September 30, 2016 , the Company granted 223 thousand PBRSUs ("2016 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, 2018, vesting in full in three years with the number of PBRSUs ultimately earned ranging from zero to 200% of the target number of shares . The Company also granted an insignificant number of other PBRSUs with performance conditions based on achievement of certain individual performance objectives. During the nine months ended September 30, 2015 , the Company granted 242 thousand PBRSUs ("2015 TSR PBRSUs") with market conditions based on the Company's TSR relative to that of the Russell 2000 Index over the one-, two-, and three-year periods ending December 31, 2015, 2016, and 2017, respectively, vesting in equal parts over three years with the number of PBRSUs ultimately earned ranging from zero to 200% of the target number of shares . The fair value of PBRSUs with market conditions granted during the nine months ended September 30, 2016 and 2015 was estimated as of the date of grant using a Monte Carlo valuation model with the following weighted average assumptions: 2016 TSR PBRSUs 2015 TSR PBRSUs Expected volatility - Medidata 48 % 46 % Expected volatility - comparison index 43 % 41 % Expected life 2.84 years 2.88 years Risk-free interest rate 0.91 % 0.99 % Dividend yield — — The following table summarizes the status of the Company’s PBRSUs based upon expected performance as of September 30, 2016 , and changes during the nine months then ended (in thousands, except per share data): Revenue TSR Other Total Number of Shares Weighted-Average Grant Date Fair Value Nonvested at January 1, 2016 136 347 7 490 $ 49.86 Granted (based on performance at 100% of targeted levels) — 223 16 239 46.45 Adjustment related to expected performance — 215 — 215 56.48 Vested (136 ) (164 ) (2 ) (302 ) 38.50 Forfeited — (6 ) (1 ) (7 ) 65.23 Nonvested at September 30, 2016 — 615 20 635 $ 56.05 The total fair value of PBRSUs vested during the three months ended September 30, 2016 and 2015 was $0.1 million and $0.1 million , respectively. The total fair value of PBRSUs vested during the nine months ended September 30, 2016 and 2015 was $10.1 million and $10.7 million , respectively. As of September 30, 2016 , there was $12.6 million in unrecognized compensation cost related to all nonvested PBRSUs. This cost is expected to be recognized over a weighted-average remaining period of 1.60 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 September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Expected volatility 41 % 49 % 42 % 49 % Expected life 1.35 years 1.45 years 1.46 years 1.49 years Risk-free interest rate 0.54 % 0.35 % 0.53 % 0.34 % Dividend yield — — — — During the nine months ended September 30, 2016 , 89 thousand shares were purchased under the ESPP at a weighted-average price of $38.35 . During the nine months ended September 30, 2015 , 86 thousand shares were purchased under the ESPP at a weighted-average price of $37.93 . No shares were purchased under the ESPP during the three months ended September 30, 2016 and 2015 . As of September 30, 2016 , there was $5.4 million in unrecognized compensation cost related to ESPP shares. This cost is expected to be recognized over a weighted-average remaining period of 1.59 years . During the second quarter of 2016, the Company increased the number of shares reserved under the ESPP from 0.3 million to 0.8 million . Modifications Net incremental expense associated with modifications to stock options, RSAs, RSUs, and PBRSUs during the three and nine months ended September 30, 2016 was $0.1 million and $0.5 million in the aggregate, respectively, and immaterial on an individual basis. No equity awards were modified during the three months ended September 30, 2015 . During the nine months ended September 30, 2015 , net incremental expense associated with modifications was $1.3 million as a result of the Company's CFO transition in the second quarter of 2015.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
ACCUMULATED OTHER COMPREHENSIVE INCOME	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) The changes in the balances of each component of accumulated other comprehensive loss during the nine months ended September 30, 2016 are as follows (in thousands): Foreign currency translation adjustments Unrealized gains (losses) on marketable securities Total Balance as of January 1, 2016 $ (2,405 ) $ (999 ) $ (3,404 ) Other comprehensive income, net of tax (1,028 ) 717 (311 ) Balance as of September 30, 2016 $ (3,433 ) $ (282 ) $ (3,715 ) For the nine months ended September 30, 2016 and 2015 , reclassifications of items from accumulated other comprehensive loss to net income were insignificant.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2016
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 unvested 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 antidilutive. As the Company intends to settle the principal amount of the Notes (see Note 6 , "Debt") in cash upon conversion, their dilutive effect, if any, will be reflected in diluted earnings per share using the treasury stock method, which considers the number of shares that would be required to settle any premium above principal at the average stock price for the period. During the three and nine months ended September 30, 2016 and 2015 , the average price of the Company's stock was below the conversion price of the Notes; as a result the Notes were not dilutive for these periods. A reconciliation of the numerator and denominator of basic earnings per share and diluted earnings per share for the three and nine months ended September 30, 2016 and 2015 is shown in the following table (in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Numerator Net income $ 7,358 $ 4,681 $ 18,143 $ 6,351 Denominator Denominator for basic earnings per share: Weighted average common shares outstanding 55,670 53,933 55,395 53,615 Denominator for diluted earnings per share: Dilutive potential common shares: Stock options 976 856 977 921 Restricted stock awards and units 681 361 570 496 Performance-based restricted stock units 386 1,532 330 951 Employee stock purchase plan 25 5 — 2 Weighted average common shares outstanding with assumed conversion 57,738 56,687 57,272 55,985 Basic earnings per share 0.13 $ 0.09 $ 0.33 $ 0.12 Diluted earnings per share 0.13 $ 0.08 $ 0.32 $ 0.11 Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share for the three and nine months ended September 30, 2016 and 2015 are shown in the following table (in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Stock options 458 411 627 355 Restricted stock awards and units 20 13 30 5 Performance-based restricted stock units — — — 1 Employee stock purchase plan — 243 262 243 Total 478 667 919 604

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company had approximately $3.7 million and $8.1 million of gross unrecognized tax benefits as of September 30, 2016 and December 31, 2015 , respectively. The $4.4 million decrease in gross unrecognized tax benefits during the nine months ended September 30, 2016 was primarily the result of the Internal Revenue Service ("IRS") concluding its examination of the Company's 2012 federal income tax return. The Company redetermined its unrecognized tax benefits, including similar items in open tax years, based on the agreed adjustments with the IRS and other associated information and analysis, resulting in a discrete item in the period.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2016
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 the 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. On March 4, 2011, DataTrak International, Inc. ("DataTrak") filed a complaint for alleged patent infringement against the Company in DataTrak International v. Medidata Solutions, C.A. No. 1:11-cv-00458 in the U.S. District Court for the Northern District of Ohio (the "NDOH District Court"). The complaint asserted infringement of U.S. Patent No. 7,464,087 (the “'087 Patent”). On November 6, 2015, the NDOH District Court granted the Company's motion to dismiss DataTrak's complaint on the grounds that the '087 Patent is invalid for lack of patentable subject matter under 35 U.S.C. §101. On January 5, 2016, the Company entered into a settlement agreement resolving all related aspects of its litigation with DataTrak. No monies were exchanged. 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 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 Accoun18

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Basis of presentation	Basis of Presentation — The accompanying interim condensed consolidated balance sheets as of September 30, 2016 and December 31, 2015 , the condensed consolidated statements of operations for the three and nine months ended September 30, 2016 and 2015 , the condensed consolidated statements of comprehensive income for the three and nine months ended September 30, 2016 and 2015 , and the condensed consolidated statements of cash flows for the nine months ended September 30, 2016 and 2015 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, 2015 included in the Company’s Annual Report on Form 10-K filed with the SEC on February 29, 2016 . Except for the changes resulting from early adoption of Accounting Standards Update ("ASU") No 2016-09, which is described in the "Recently Adopted Accounting Pronouncements" section of this Note, 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 September 30, 2016 , results of its operations for the three and nine months ended September 30, 2016 and 2015 , comprehensive income for the three and nine months ended September 30, 2016 and 2015 , and cash flows for the nine months ended September 30, 2016 and 2015 . The results of operations for the three and nine months ended September 30, 2016 are not necessarily indicative of the results that may be expected for the year ending December 31, 2016 .
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.
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 September 30, 2016 and December 31, 2015 , unbilled accounts receivable of $14.1 million and $10.3 million , respectively, were included in accounts receivable on the Company's consolidated balance sheets. In general, there is a direct relationship between the Company's accounts receivable balance and its transaction volume.
Recently issued accounting pronouncements	Recently Adopted Accounting Pronouncements — In August 2014, the Financial Accounting Standards Board ("FASB") issued ASU No. 2014-15, Presentation of Financial Statements—Going Concern . This new guidance formally establishes management's responsibility to evaluate at each reporting period whether there is substantial doubt about the entity's ability to continue as a going concern for a period of one year after the date the financial statements are issued, and to provide related footnote disclosures. ASU No. 2014-15 is effective for annual reporting periods ending after December 15, 2016, and for interim and annual periods thereafter. The Company will adopt ASU No. 2014-15 for the annual reporting period ending December 31, 2016, and the adoption is not expected to have a material impact on its consolidated financial statements. In April 2015, the FASB issued ASU No. 2015-03, Simplifying the Presentation of Debt Issuance Costs. ASU No. 2015-03 requires that debt issuance costs be presented not as an asset but as a reduction of the carrying amount of the related debt liability, similar to a debt discount. ASU No. 2015-03 is effective for annual periods beginning after December 15, 2015, and interim periods within those annual periods, with early adoption permitted. The Company adopted ASU No. 2015-03 retrospectively on January 1, 2016, and the adoption did not have a material impact on its consolidated financial statements, aside from a balance sheet reclassification. Refer to Note 6 , "Debt," for details. In April 2015, the FASB issued ASU No. 2015-05, Customer's Accounting for Fees Paid in a Cloud Computing Arrangement , which provides guidance on whether an entity should account for the fees paid as a customer under a cloud computing arrangement as a license of internal-use software or as a service contract. ASU No. 2015-05 is effective for annual periods beginning after December 15, 2015, and interim periods within those annual periods, with early adoption permitted. The Company adopted ASU No. 2015-05 prospectively on January 1, 2016, and the adoption did not have a material impact on its consolidated financial statements as the Company accounts for all subscription fees paid under its cloud computing arrangements as service contracts. In May 2015, the FASB issued ASU No. 2015-07, Disclosures for Investments in Certain Entities That Calculate Net Asset Value per Share (or Its Equivalent). ASU No. 2015-07 removes the requirement to categorize within the fair value hierarchy those investments that are measured at fair value using net asset value per share as a practical expedient and requires that sufficient information be provided to permit reconciliation of the fair value of assets categorized within the fair value hierarchy to amounts presented on the balance sheets. ASU No. 2015-07 is effective for annual periods beginning after December 15, 2015, and interim periods within those annual periods, with early adoption permitted. The Company adopted ASU No. 2015-07 retrospectively on January 1, 2016, and the adoption did not have a material impact on its consolidated financial statements. In March 2016, the FASB issued ASU No. 2016-09, Improvements to Employee Share-Based Payment Accounting, which simplifies several aspects of the accounting for share-based payment transactions, including income tax consequences, classification of awards as either equity or liability, and classification on the statement of cash flows. ASU No. 2016-09 is effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted in any interim or annual period; if an entity adopts the amendments in an interim period, any adjustments must be reflected as of the beginning of the fiscal year that includes that interim period. The Company's early adoption of ASU No. 2016-09 in the third quarter of 2016 impacted its consolidated financial statements as follows: • The new guidance requires excess tax benefits and tax deficiencies on equity awards, which were formerly recognized in additional paid-in capital, to be recognized in the income statement when the awards vest or are settled; adoption of this portion of ASU No. 2016-09 resulted in recognition of deferred tax assets for all excess tax benefits that had not been previously recognized because the related tax deduction had not reduced income taxes payable. This was effected through a $50.6 million cumulative-effect adjustment to opening retained earnings as of January 1, 2016. • The new guidance requires cash flows related to excess tax benefits, which were formerly classified as a financing activity on the statement of cash flows, to be classified as an operating activity; as a result of the adoption of ASU No. 2016-09, the Company has classified the excess tax benefit for the nine months ended September 30, 2016 as an operating activity on the statement of cash flows. Use of the permitted modified retrospective approach has resulted in an offsetting increase of $1.7 million to cash provided by operating activities and cash used in financing activities for the nine months ended September 30, 2015. 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, except as described below. In January 2016, the FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities, which enhances the reporting model for financial instruments by amending certain aspects of existing guidance on recognition, measurement, presentation, and disclosure to provide financial statement users with more decision-useful information. ASU No. 2016-01 is effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The Company will adopt ASU No. 2016-01 on January 1, 2018, and is presently evaluating the impact of the adoption on its consolidated financial statements. In February 2016, the FASB issued ASU No. 2016-02, Leases, which replaces previous lease guidance in its entirety with Accounting Standards Codification ("ASC") 842, Leases. The new guidance 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 new guidance also adds quantitative and qualitative disclosure requirements around leasing activities. ASU No. 2016-02 is effective for annual periods beginning after December 15, 2018, including interim periods within those annual periods, and requires a modified retrospective approach. Early adoption is permitted. The Company will adopt ASU No. 2016-02 on January 1, 2019, and is presently evaluating the impact of the adoption on its consolidated financial statements. In August 2015, the FASB issued ASU No. 2016-15, Cash Flows - Classification of Certain Cash Receipts and Cash Payments , which addresses the diversity in practice around presentation of certain cash receipts and payments in the statement of cash flows. ASU No. 2016-15 is effective for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The Company does not expect the adoption to have a material impact on its consolidated financial statements and may consider early adoption, which is permitted in any interim or annual period.
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 unvested 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 antidilutive. As the Company intends to settle the principal amount of the Notes (see Note 6 , "Debt") in cash upon conversion, their dilutive effect, if any, will be reflected in diluted earnings per share using the treasury stock method, which considers the number of shares that would be required to settle any premium above principal at the average stock price for the period. During the three and nine months ended September 30, 2016 and 2015 , the average price of the Company's stock was below the conversion price of the Notes; as a result the Notes were not dilutive for these periods.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2016
Investments [Abstract]
Marketable securities by security type	The following table provides the Company’s marketable securities by security type as of September 30, 2016 and December 31, 2015 (in thousands): As of September 30, 2016 Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper and corporate bonds $ 386,881 $ 33 $ (471 ) $ 386,443 U.S. government agency debt securities 32,639 — (18 ) 32,621 Total $ 419,520 $ 33 $ (489 ) $ 419,064 As of December 31, 2015 Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper and corporate bonds $ 401,824 $ — $ (1,522 ) $ 400,302 U.S. government agency debt securities 28,958 2 (95 ) 28,865 Total $ 430,782 $ 2 $ (1,617 ) $ 429,167
Contractual maturities of marketable securities	Contractual maturities of the Company’s marketable securities as of September 30, 2016 and December 31, 2015 are summarized as follows (in thousands): As of September 30, 2016 As of December 31, 2015 Cost Estimated Fair Value Cost Estimated Fair Value Due in one year or less $ 265,154 $ 264,903 $ 220,492 $ 220,126 Due in one to five years 154,366 154,161 210,290 209,041 Total $ 419,520 $ 419,064 $ 430,782 $ 429,167
Fair market value and gross unrealized losses of marketable securities	The following tables provide the fair market value and the gross unrealized losses of the Company's marketable securities with unrealized losses, aggregated by security type, as of September 30, 2016 and December 31, 2015 (in thousands): In Loss Position for Less than 12 Months As of September 30, 2016 As of December 31, 2015 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Commercial paper and corporate bonds $ 259,180 $ (364 ) $ 359,566 $ (1,443 ) U.S. government agency debt securities 22,824 (15 ) 25,863 (95 ) Total $ 282,004 $ (379 ) $ 385,429 $ (1,538 ) In Loss Position for More than 12 Months As of September 30, 2016 As of December 31, 2015 Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Commercial paper and corporate bonds $ 82,509 $ (107 ) $ 38,726 $ (79 ) U.S. government agency debt securities 4,797 (3 ) — — Total $ 87,306 $ (110 ) $ 38,726 $ (79 )

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Financial assets measured at fair value on a recurring basis	The following table summarizes, as of September 30, 2016 and December 31, 2015 , our financial assets that are measured at fair value on a recurring basis, according to the fair value hierarchy described in our significant accounting policies included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2015 (in thousands): As of September 30, 2016 As of December 31, 2015 Level 1 Level 2 Total Level 1 Level 2 Total Cash 62,867 — 62,867 48,917 — 48,917 Money market funds 2,298 — 2,298 645 — 645 Commercial paper — — — — — — Total cash and cash equivalents 65,165 — 65,165 49,562 — 49,562 Commercial paper and corporate bonds — 386,443 386,443 — 400,302 400,302 U.S. government agency debt securities — 32,621 32,621 — 28,865 28,865 Total marketable securities — 419,064 419,064 — 429,167 429,167 Total financial assets measured at fair value on a recurring basis 65,165 419,064 484,229 49,562 429,167 478,729

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Finite-lived intangible assets acquired during period	On April 1, 2016 , the Company acquired Intelemage, LLC ("Intelemage"), a medical image sharing and workflow management company for a net purchase price of $17.2 million , broadening its offerings with the addition of digital image management technology. The acquisition resulted in the recognition of the following intangible assets (in thousands): Acquisition-Date Fair Value Weighted-Average Useful Life Acquired technology $ 3,750 4 years Customer relationships 1,472 6 years Total $ 5,222
Changes in the carrying amount of goodwill	The change in the carrying amount of goodwill during the nine months ended September 30, 2016 was as follows (in thousands): Balance as of January 1, 2016 $ 18,797 Additions related to acquisition of Intelemage $ 12,007 Foreign currency translation adjustments (572 ) Balance as of September 30, 2016 $ 30,232
Intangible assets	Total intangible assets are summarized as follows (in thousands): As of September 30, 2016 As of December 31, 2015 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Acquired technology $ 8,780 $ (4,851 ) $ 3,929 $ 5,223 $ (4,336 ) $ 887 Customer relationships 3,585 (2,116 ) 1,469 2,165 (1,994 ) 171 Non-competition agreements 150 (59 ) 91 150 (36 ) 114 Total $ 12,515 $ (7,026 ) $ 5,489 $ 7,538 $ (6,366 ) $ 1,172
Annual amortization for the next five years	Amortization of intangible assets for the next five years is expected to be as follows (in thousands): Remainder of year ending December 31, 2016 $ 398 Years ending December 31, 2017 1,569 2018 1,488 2019 1,230 2020 498 2021 245

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Components of convertible senior notes	The Company's 1.00% convertible senior notes (the "Notes"), issued in August 2013, consisted of the following components as of September 30, 2016 and December 31, 2015 (in thousands): September 30, December 31, Equity component, net of equity issue costs $ 60,222 $ 60,222 Liability component: Principal 287,500 287,500 Less: unamortized debt discount (25,307 ) (34,712 ) Less: unamortized debt issuance costs (2,342 ) (3,301 ) Net carrying amount $ 259,851 $ 249,487
Interest expense related to convertible senior notes	The following table sets forth total interest expense recognized related to the Notes for the three and nine months ended September 30, 2016 and 2015 (in thousands except percentages): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Contractual interest expense $ 718 $ 719 $ 2,156 $ 2,156 Amortization of debt issuance costs 320 319 959 958 Amortization of debt discount 3,181 2,997 9,405 8,859 Total $ 4,219 $ 4,035 $ 12,520 $ 11,973 Effective interest rate 6.5 % 6.5 % 6.5 % 6.5 %

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Components of stock-based compensation expense	For the three and nine months ended September 30, 2016 and 2015 , the components of stock-based compensation expense were as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Stock options $ 947 $ 1,070 $ 3,000 $ 3,906 Restricted stock awards and units 6,571 5,031 18,312 14,334 Performance-based restricted stock units 2,264 4,964 7,133 16,546 Employee stock purchase plan 676 1,037 2,710 3,122 Total stock-based compensation $ 10,458 $ 12,102 $ 31,155 $ 37,908
Fair value of stock option grants	The fair value of each stock option granted during the three and nine months ended September 30, 2016 and 2015 was estimated on the date of grant using a Black-Scholes pricing model with the following weighted-average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Expected volatility 44 % 43 % 43 % 43 % Expected life 6 years 6 years 6 years 6 years Risk-free interest rate 1.20 % 1.69 % 1.42 % 1.69 % 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 September 30, 2016 , and changes during the nine 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, 2016 1,940 $21.73 Granted 134 41.33 Exercised (238 ) 17.89 Forfeited (6 ) 40.54 Expired (22 ) 58.09 Outstanding at September 30, 2016 1,808 $23.18 5.37 $59,233 Exercisable at September 30, 2016 1,413 $17.13 4.48 $54,809 Vested and expected to vest at September 30, 2016 1,759 $22.59 5.27 $58,682
Summary of nonvested restricted stock awards	The following table summarizes the status of the Company’s nonvested time-based RSAs and RSUs as of September 30, 2016 , and changes during the nine months then ended (in thousands, except per share data): Number of Shares Weighted- Average Grant-Date Fair Value Nonvested at January 1, 2016 1,355 $40.82 Granted 1,138 37.90 Vested (481 ) 33.94 Forfeited (138 ) 41.76 Nonvested at September 30, 2016 1,874 $40.75
Fair value of TSR PBRSUs	The fair value of PBRSUs with market conditions granted during the nine months ended September 30, 2016 and 2015 was estimated as of the date of grant using a Monte Carlo valuation model with the following weighted average assumptions: 2016 TSR PBRSUs 2015 TSR PBRSUs Expected volatility - Medidata 48 % 46 % Expected volatility - comparison index 43 % 41 % Expected life 2.84 years 2.88 years Risk-free interest rate 0.91 % 0.99 % 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 September 30, 2016 , and changes during the nine months then ended (in thousands, except per share data): Revenue TSR Other Total Number of Shares Weighted-Average Grant Date Fair Value Nonvested at January 1, 2016 136 347 7 490 $ 49.86 Granted (based on performance at 100% of targeted levels) — 223 16 239 46.45 Adjustment related to expected performance — 215 — 215 56.48 Vested (136 ) (164 ) (2 ) (302 ) 38.50 Forfeited — (6 ) (1 ) (7 ) 65.23 Nonvested at September 30, 2016 — 615 20 635 $ 56.05
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 September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Expected volatility 41 % 49 % 42 % 49 % Expected life 1.35 years 1.45 years 1.46 years 1.49 years Risk-free interest rate 0.54 % 0.35 % 0.53 % 0.34 % Dividend yield — — — —

Accumulated Other Comprehensi24

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of accumulated other comprehensive loss	The changes in the balances of each component of accumulated other comprehensive loss during the nine months ended September 30, 2016 are as follows (in thousands): Foreign currency translation adjustments Unrealized gains (losses) on marketable securities Total Balance as of January 1, 2016 $ (2,405 ) $ (999 ) $ (3,404 ) Other comprehensive income, net of tax (1,028 ) 717 (311 ) Balance as of September 30, 2016 $ (3,433 ) $ (282 ) $ (3,715 )

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2016
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 nine months ended September 30, 2016 and 2015 is shown in the following table (in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Numerator Net income $ 7,358 $ 4,681 $ 18,143 $ 6,351 Denominator Denominator for basic earnings per share: Weighted average common shares outstanding 55,670 53,933 55,395 53,615 Denominator for diluted earnings per share: Dilutive potential common shares: Stock options 976 856 977 921 Restricted stock awards and units 681 361 570 496 Performance-based restricted stock units 386 1,532 330 951 Employee stock purchase plan 25 5 — 2 Weighted average common shares outstanding with assumed conversion 57,738 56,687 57,272 55,985 Basic earnings per share 0.13 $ 0.09 $ 0.33 $ 0.12 Diluted earnings per share 0.13 $ 0.08 $ 0.32 $ 0.11
Schedule of antidilutive securities excluded from computation of earnings per share	Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share for the three and nine months ended September 30, 2016 and 2015 are shown in the following table (in thousands, except per share data): Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Stock options 458 411 627 355 Restricted stock awards and units 20 13 30 5 Performance-based restricted stock units — — — 1 Employee stock purchase plan — 243 262 243 Total 478 667 919 604

Summary of Significant Accoun26

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Unbilled receivables	$ 14.1	$ 10.3
Cumulative effect on retained earnings of adoption of Accounting Standards Update No. 2016-09	$ 50.6
Effect on cash flows of adoption of Accounting Standards Update No. 2016-09	The new guidance requires cash flows related to excess tax benefits, which were formerly classified as a financing activity on the statement of cash flows, to be classified as an operating activity; as a result of the adoption of ASU No. 2016-09, the Company has classified the excess tax benefit for the nine months ended September 30, 2016 as an operating activity on the statement of cash flows. Use of the permitted modified retrospective approach has resulted in an offsetting increase of $1.7 million to cash provided by operating activities and cash used in financing activities for the nine months ended September 30, 2015.

Stockholders' Equity (Details)

Stockholders' Equity (Details) - $ / shares	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Equity [Abstract]
Shares paid for tax withholding for share based compensation	338,523	338,792
Shares paid for tax withholding for share based compensation, average price	$ 36.22	$ 50.27
Forfeited restricted stock awards transferred to treasury stock	132,626	80,752
Par value of treasury stock	$ 0.01		$ 0.01

Investments (Details)

Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Marketable securities by security type
Cost	$ 419,520	$ 430,782
Gross unrealized gains	33	2
Gross unrealized losses	(489)	(1,617)
Estimated fair value	419,064	429,167
Commercial paper and corporate bonds [Member]
Marketable securities by security type
Cost	386,881	401,824
Gross unrealized gains	33	0
Gross unrealized losses	(471)	(1,522)
Estimated fair value	386,443	400,302
U.S. government agency debt securities [Member]
Marketable securities by security type
Cost	32,639	28,958
Gross unrealized gains	0	2
Gross unrealized losses	(18)	(95)
Estimated fair value	$ 32,621	$ 28,865

Investments (Details 1)

Investments (Details 1) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Marketable securities by contractual maturity
Cost	$ 419,520	$ 430,782
Estimated fair value	419,064	429,167
One year or less [Member]
Marketable securities by contractual maturity
Cost	265,154	220,492
Estimated fair value	264,903	220,126
One to five years [Member]
Marketable securities by contractual maturity
Cost	154,366	210,290
Estimated fair value	$ 154,161	$ 209,041

Investments (Details 2)

Investments (Details 2) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair market value and gross unrealized losses of marketable securities
Less than 12 months in unrealized loss position - fair value	$ 282,004	$ 385,429
Less than 12 months in unrealized loss position - gross unrealized losses	(379)	(1,538)
12 months or more in unrealized loss position - fair value	87,306	38,726
12 months or more in unrealized loss position - gross unrealized losses	(110)	(79)
Commercial paper and corporate bonds [Member]
Fair market value and gross unrealized losses of marketable securities
Less than 12 months in unrealized loss position - fair value	259,180	359,566
Less than 12 months in unrealized loss position - gross unrealized losses	(364)	(1,443)
12 months or more in unrealized loss position - fair value	82,509	38,726
12 months or more in unrealized loss position - gross unrealized losses	(107)	(79)
U.S. government agency debt securities [Member]
Fair market value and gross unrealized losses of marketable securities
Less than 12 months in unrealized loss position - fair value	22,824	25,863
Less than 12 months in unrealized loss position - gross unrealized losses	(15)	(95)
12 months or more in unrealized loss position - fair value	4,797	0
12 months or more in unrealized loss position - gross unrealized losses	$ (3)	$ 0

Investments (Details Textual)

Investments (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Investments (Textual)
Net realized gains (losses) from the sale of marketable securities	$ 3	$ 3	$ 6	$ 23
Cost method investment, description			In August 2016, the Company purchased shares of Series B Preferred Stock of SHYFT Analytics, Inc. ("SHYFT") via a private placement. This investment is accounted for under the cost method and is included in other assets on the Company's consolidated balance sheet
Cost method investment, original cost	$ 4,000		$ 4,000
Cost method investment, independence			The Company's vice chairman, Steven Hirschfeld, has served on the board of directors of SHYFT since 2014 in an individual capacity and not as a representative of the Company.

Fair Value (Details)

Fair Value (Details) - Fair value, recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Assets
Total cash and cash equivalents	$ 65,165	$ 49,562
Total marketable securities	419,064	429,167
Total financial assets	484,229	478,729
Cash [Member]
Assets
Total cash and cash equivalents	62,867	48,917
Money market funds [Member]
Assets
Total cash and cash equivalents	2,298	645
Commercial paper [Member]
Assets
Total cash and cash equivalents	0	0
Commercial paper and corporate bonds [Member]
Assets
Total marketable securities	386,443	400,302
U.S. government agency debt securities [Member]
Assets
Total marketable securities	32,621	28,865
Level 1 [Member]
Assets
Total cash and cash equivalents	65,165	49,562
Total marketable securities	0	0
Total financial assets	65,165	49,562
Level 1 [Member] | Cash [Member]
Assets
Total cash and cash equivalents	62,867	48,917
Level 1 [Member] | Money market funds [Member]
Assets
Total cash and cash equivalents	2,298	645
Level 1 [Member] | Commercial paper [Member]
Assets
Total cash and cash equivalents	0	0
Level 1 [Member] | Commercial paper and corporate bonds [Member]
Assets
Total marketable securities	0	0
Level 1 [Member] | U.S. government agency debt securities [Member]
Assets
Total marketable securities	0	0
Level 2 [Member]
Assets
Total cash and cash equivalents	0	0
Total marketable securities	419,064	429,167
Total financial assets	419,064	429,167
Level 2 [Member] | Cash [Member]
Assets
Total cash and cash equivalents	0	0
Level 2 [Member] | Money market funds [Member]
Assets
Total cash and cash equivalents	0	0
Level 2 [Member] | Commercial paper [Member]
Assets
Total cash and cash equivalents	0	0
Level 2 [Member] | Commercial paper and corporate bonds [Member]
Assets
Total marketable securities	386,443	400,302
Level 2 [Member] | U.S. government agency debt securities [Member]
Assets
Total marketable securities	$ 32,621	$ 28,865

Fair Value (Details Textual)

Fair Value (Details Textual) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 30, 2015
Fair value (Textual) [Abstract]
Transfers of financial assets between Level 1 and Level 2	$ 0	$ 0

Goodwill and Intangible Asset34

Goodwill and Intangible Assets (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 5,222
Acquired technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 3,750
Acquired finite-lived intangible assets, weighted-average useful life	4 years
Customer relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 1,472
Acquired finite-lived intangible assets, weighted-average useful life	6 years

Goodwill and Intangible Asset35

Goodwill and Intangible Assets (Details 1) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
Changes in the carrying amount of goodwill
Balance as of beginning of period	$ 18,797
Additions related to acquisition	12,007
Foreign currency translation adjustments	(572)
Balance as of end of period	$ 30,232

Goodwill and Intangible Asset36

Goodwill and Intangible Assets (Details 2) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Intangible assets
Gross carrying amount	$ 12,515	$ 7,538
Accumulated amortization	(7,026)	(6,366)
Net carrying amount	5,489	1,172
Acquired technology [Member]
Intangible assets
Gross carrying amount	8,780	5,223
Accumulated amortization	(4,851)	(4,336)
Net carrying amount	3,929	887
Customer relationships [Member]
Intangible assets
Gross carrying amount	3,585	2,165
Accumulated amortization	(2,116)	(1,994)
Net carrying amount	1,469	171
Non-competition agreements [Member]
Intangible assets
Gross carrying amount	150	150
Accumulated amortization	(59)	(36)
Net carrying amount	$ 91	$ 114

Goodwill and Intangible Asset37

Goodwill and Intangible Assets (Details 3) $ in Thousands	Sep. 30, 2016USD ($)
Annual amortization for the next five years
Remainder of year current year	$ 398
Next twelve months	1,569
Year two	1,488
Year three	1,230
Year four	498
Year five	$ 245

Goodwill and Intangible Asset38

Goodwill and Intangible Assets (Details Textual)	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Acquisition date	Apr. 1, 2016

Debt (Details)

Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Components of convertible senior notes
Equity component net of equity issue costs	$ 60,222	$ 60,222
Principal amount	287,500	287,500
Unamortized discount	(25,307)	(34,712)
Unamortized debt issuance costs	(2,342)	(3,301)
Convertible senior notes, net carrying amount	$ 259,851	$ 249,487

Debt (Details 1)

Debt (Details 1) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Interest expense on convertible senior notes
Convertible senior notes, contractual interest expense	$ 718	$ 719	$ 2,156	$ 2,156
Amortization of debt issuance costs	320	319	959	958
Amortization of debt discount	3,181	2,997	9,405	8,859
Convertible senior notes, total interest expense	$ 4,219	$ 4,035	$ 12,520	$ 11,973
Convertible senior notes, effective interest rate during period	6.50%	6.50%	6.50%	6.50%

Debt (Details Textual)

Debt (Details Textual) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015	Aug. 12, 2013
Convertible senior notes
Conversion price			$ 58.05
Closing price of the Company's common stock	$ 55.76
Approximate remaining life	22 months
Convertible Debt [Member] | Fair Value, Inputs, Level 2 [Member]
Convertible senior notes
Approximate fair value	$ 332.9	$ 313

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Components of stock-based compensation expense
Total stock-based compensation	$ 10,458	$ 12,102	$ 31,155	$ 37,908
Stock options [Member]
Components of stock-based compensation expense
Total stock-based compensation	947	1,070	3,000	3,906
Restricted stock awards and units [Member]
Components of stock-based compensation expense
Total stock-based compensation	6,571	5,031	18,312	14,334
Performance-based restricted stock units [Member]
Components of stock-based compensation expense
Total stock-based compensation	2,264	4,964	7,133	16,546
Employee stock purchase plan [Member]
Components of stock-based compensation expense
Total stock-based compensation	$ 676	$ 1,037	$ 2,710	$ 3,122

Stock-Based Compensation (Det43

Stock-Based Compensation (Details 1) - Stock options [Member]	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Weighted-average Black-Scholes assumptions used to estimate fair value of stock options granted
Expected volatility	44.00%	43.00%	43.00%	43.00%
Expected term	6 years	6 years	6 years	6 years
Risk-free interest rate	1.20%	1.69%	1.42%	1.69%
Dividend yield	0.00%	0.00%	0.00%	0.00%

Stock-Based Compensation (Det44

Stock-Based Compensation (Details 2) - Stock options [Member] $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)$ / sharesshares
Summary of activities and changes in stock option plans
Number of shares outstanding at beginning of period | shares	1,940
Weighted-average exercise price outstanding at beginning of period | $ / shares	$ 21.73
Number of shares granted | shares	134
Weighted-average exercise price granted | $ / shares	$ 41.33
Number of shares exercised | shares	(238)
Weighted-average exercise price exercised | $ / shares	$ 17.89
Number of shares forfeited | shares	(6)
Weighted-average exercise price forfeited | $ / shares	$ 40.54
Number of shares expired | shares	(22)
Weighted-average exercise price expired | $ / shares	$ 58.09
Number of shares outstanding at end of period | shares	1,808
Weighted-average exercise price outstanding at end of period | $ / shares	$ 23.18
Weighted average remaining contractual term outstanding at end of period	5 years 4 months 13 days
Aggregate intrinsic value outstanding at end of period | $	$ 59,233
Number of shares exercisable at end of period | shares	1,413
Weighted-average exercise price exercisable at end of period | $ / shares	$ 17.13
Weighted average remaining contractual term exercisable at end of period	4 years 5 months 22 days
Aggregate intrinsic value exercisable at end of period | $	$ 54,809
Number of shares vested and expected to vest at end of period | shares	1,759
Weighted-average exercise price vested and expected to vest at end of period | $ / shares	$ 22.59
Weighted average remaining contractual term vested and expected to vest at end of period	5 years 3 months 8 days
Aggregate intrinsic value vested and expected to vest at end of period | $	$ 58,682

Stock-Based Compensation (Det45

Stock-Based Compensation (Details 3) - Restricted stock awards and units [Member] shares in Thousands	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Summary of time-based nonvested restricted stock awards and units
Nonvested number of shares/units at beggining of period | shares	1,355
Nonvested weighted-average grant-date fair value at beginning of period | $ / shares	$ 40.82
Granted number of shares | shares	1,138
Granted weighted-average grant-date fair value | $ / shares	$ 37.90
Vested number of shares/units | shares	(481)
Vested weighted-average grant-date fair value | $ / shares	$ 33.94
Forfeited number of shares/units | shares	(138)
Forfeited weighted-average grant-date fair value | $ / shares	$ 41.76
Nonvested number of shares/units at end of period | shares	1,874
Nonvested weighted-average grant-date fair value at end of period | $ / shares	$ 40.75

Stock-Based Compensation (Det46

Stock-Based Compensation (Details 4) - Performance-based restricted stock units [Member] - TSR [Member]	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Assumptions used to estimate fair value of TSR PBRSUs
Expected volatility - Medidata	48.00%	46.00%
Expected volatility - Comparison index	43.00%	41.00%
Expected term	2 years 10 months 2 days	2 years 10 months 16 days
Risk-free interest rate	0.91%	0.99%
Dividend yield	0.00%	0.00%

Stock-Based Compensation (Det47

Stock-Based Compensation (Details 5) - Performance-based restricted stock units [Member] shares in Thousands	9 Months Ended
	Sep. 30, 2016$ / sharesshares
Summary of performance-based restricted stock units based upon expected performance
Nonvested number of shares/units at beggining of period	490
Nonvested weighted-average grant-date fair value at beginning of period | $ / shares	$ 49.86
Granted number of units (based on performance at 100% of targeted levels)	239
Granted weighted-average grant-date fair value | $ / shares	$ 46.45
Adjustment due to expected performance	215
Adjustment due to expected performance weighted average grant date fair value | $ / shares	$ 56.48
Vested number of shares/units	(302)
Vested weighted-average grant-date fair value | $ / shares	$ 38.50
Forfeited number of shares/units	(7)
Forfeited weighted-average grant-date fair value | $ / shares	$ 65.23
Nonvested number of shares/units at end of period	635
Nonvested weighted-average grant-date fair value at end of period | $ / shares	$ 56.05
Revenue [Member]
Summary of performance-based restricted stock units based upon expected performance
Nonvested number of shares/units at beggining of period	136
Granted number of units (based on performance at 100% of targeted levels)	0
Adjustment due to expected performance	0
Vested number of shares/units	(136)
Forfeited number of shares/units	0
Nonvested number of shares/units at end of period	0
TSR [Member]
Summary of performance-based restricted stock units based upon expected performance
Nonvested number of shares/units at beggining of period	347
Granted number of units (based on performance at 100% of targeted levels)	223
Adjustment due to expected performance	215
Vested number of shares/units	(164)
Forfeited number of shares/units	(6)
Nonvested number of shares/units at end of period	615
Other [Member]
Summary of performance-based restricted stock units based upon expected performance
Nonvested number of shares/units at beggining of period	7
Granted number of units (based on performance at 100% of targeted levels)	16
Adjustment due to expected performance	0
Vested number of shares/units	(2)
Forfeited number of shares/units	(1)
Nonvested number of shares/units at end of period	20

Stock-Based Compensation (Det48

Stock-Based Compensation (Details 6) - Employee stock purchase plan [Member]	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Weighted-average Black-Scholes assumptions used to estimate fair value of ESPP shares
Expected volatility	41.00%	49.00%	42.00%	49.00%
Expected term	1 year 4 months 6 days	1 year 5 months 13 days	1 year 5 months 16 days	1 year 5 months 26 days
Risk-free interest rate	0.54%	0.35%	0.53%	0.34%
Dividend yield	0.00%	0.00%	0.00%	0.00%

Stock-Based Compensation (Det49

Stock-Based Compensation (Details Textual) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Stock based compensation (Textual) [Abstract]
Incremental expense associated with equity modifications	$ 0.1	$ 0	$ 0.5	$ 1.3
Stock options [Member]
Stock based compensation (Textual) [Abstract]
Weighted-average grant-date fair value of stock options granted	$ 23.15	$ 19.99	$ 17.92	$ 21.81
Total intrinsic value of stock options exercised	$ 4.4	$ 1.7	$ 7.4	$ 14.1
Total fair value of shares vested	1.7	1.1	3.8	3.5
Unrecognized compensation cost related to non-vested stock-based compensation awards granted	6.8		$ 6.8
Weighted-average remaining period over which cost is expected to be recognized			2 years 6 months 17 days
Restricted stock awards and units [Member]
Stock based compensation (Textual) [Abstract]
Total fair value of shares vested	1.5	2.1	$ 18.4	29.3
Unrecognized compensation cost related to non-vested stock-based compensation awards granted	60.4		$ 60.4
Weighted-average remaining period over which cost is expected to be recognized			2 years 8 months 20 days
Performance-based restricted stock units [Member]
Stock based compensation (Textual) [Abstract]
Total fair value of shares vested	0.1	$ 0.1	$ 10.1	$ 10.7
Unrecognized compensation cost related to non-vested stock-based compensation awards granted	$ 12.6		$ 12.6
Weighted-average remaining period over which cost is expected to be recognized			1 year 7 months 6 days
Performance-based restricted stock units [Member] | TSR [Member]
Stock based compensation (Textual) [Abstract]
Target number of performance-based restricted stock units granted during the period	0	0	223	242
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, 2018, vesting in full in three years with the number of PBRSUs 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 one-, two-, and three-year periods ending December 31, 2015, 2016, and 2017, respectively, vesting in equal parts over three years with the number of PBRSUs ultimately earned ranging from zero to 200% of the target number of shares
Employee stock purchase plan [Member]
Stock based compensation (Textual) [Abstract]
Unrecognized compensation cost related to non-vested stock-based compensation awards granted	$ 5.4		$ 5.4
Weighted-average remaining period over which cost is expected to be recognized			1 year 7 months 2 days
Shares issued during period under employee stock purchase plan	0	0	89	86
Weighted-average purchase price of shares issued during period under employee stock purchase plan			$ 38.35	$ 37.93
Number of shares of common stock issuable under ESPP, original			300
Number of shares of common stock issuable under ESPP, amended			800

Accumulated Other Comprehensi50

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated other comprehensive income
Balance as of beginning of period			$ (3,404)
Other comprehensive income (loss), net of tax	$ (785)	$ (798)	(311)	$ (490)
Balance as of end of period	(3,715)		(3,715)
Unrealized gains (losses) on available for sale securities
Accumulated other comprehensive income
Balance as of beginning of period			(999)
Other comprehensive income (loss), net of tax			717
Balance as of end of period	(282)		(282)
Foreign currency translation adjustments
Accumulated other comprehensive income
Balance as of beginning of period			(2,405)
Other comprehensive income (loss), net of tax			(1,028)
Balance as of end of period	$ (3,433)		$ (3,433)

Accumulated Other Comprehensi51

Accumulated Other Comprehensive Income (Details Textual) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Reclassifications from accumulated other comprehensive income	$ 6	$ 23

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator
Net income	$ 7,358	$ 4,681	$ 18,143	$ 6,351
Denominator for basic earnings per share:
Weighted average common shares outstanding	55,670	53,933	55,395	53,615
Dilutive potential common shares:
Stock options	976	856	977	921
Restricted stock awards and units	681	361	570	496
Performance-based restricted stock units	386	1,532	330	951
Employee stock purchase plan	25	5	0	2
Weighted average common shares outstanding with assumed conversion	57,738	56,687	57,272	55,985
Basic earnings per share	$ 0.13	$ 0.09	$ 0.33	$ 0.12
Diluted earnings per share	$ 0.13	$ 0.08	$ 0.32	$ 0.11

Earnings Per Share (Details 1)

Earnings Per Share (Details 1) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Antidilutive common stock equivalents excluded from the calculation of diluted earnings per share
Antidilutive shares excluded from calculation of diluted earnings (loss) per share	478	667	919	604
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	458	411	627	355
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	20	13	30	5
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	1
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	243	262	243

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Income Taxes (Textual) [Abstract]
Gross unrecognized tax benefits	$ 3.7	$ 8.1
Changes in tax position	$ (4.4)

Commitments and Contingencies (

Commitments and Contingencies (Details)	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies (Textual) [Abstract]
Description settlement of legal proceedings	On March 4, 2011, DataTrak International, Inc. ("DataTrak") filed a complaint for alleged patent infringement against the Company in DataTrak International v. Medidata Solutions, C.A. No. 1:11-cv-00458 in the U.S. District Court for the Northern District of Ohio (the "NDOH District Court"). The complaint asserted infringement of U.S. Patent No. 7,464,087 (the “'087 Patent”). On November 6, 2015, the NDOH District Court granted the Company's motion to dismiss DataTrak's complaint on the grounds that the '087 Patent is invalid for lack of patentable subject matter under 35 U.S.C. §101. On January 5, 2016, the Company entered into a settlement agreement resolving all related aspects of its litigation with DataTrak. No monies were exchanged.
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 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.