Medidata Solutions 10-Q 30 Apr 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014	Apr. 25, 2014
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'Medidata Solutions, Inc.	'
Entity Central Index Key	'0001453814	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	31-Mar-14	'
Document Fiscal Period Focus	'Q1	'
Document Fiscal Year Focus	'2014	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	54,095,546

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Unaudited) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$25,406	$22,328
Marketable securities	196,140	218,892
Accounts receivable, net of allowance for doubtful accounts of $1,089 and $1,055, respectively	66,326	45,534
Prepaid commission expense	4,116	3,615
Prepaid expenses and other current assets	12,434	13,511
Deferred income taxes	2,310	665
Total current assets	306,732	304,545
Restricted cash	5,118	5,118
Marketable securities- long-term	181,947	195,105
Furniture, fixtures and equipment, net	40,482	41,229
Goodwill	15,533	15,487
Intangible assets, net	774	904
Deferred income taxes- long-term	348	345
Other assets	9,804	10,620
Total assets	560,738	573,353
Current liabilities:	'	'
Accounts payable	5,812	7,524
Accrued payroll and other compensation	9,862	27,773
Accrued expenses and other	8,978	12,265
Deferred revenue	57,446	52,628
Total current liabilities	82,098	100,190
Noncurrent liabilities:	'	'
1.00% convertible senior notes, net	232,446	229,705
Deferred revenue, less current portion	3,255	1,430
Deferred tax liabilities	5,654	5,651
Other long-term liabilities	12,085	10,564
Total noncurrent liabilities	253,440	247,350
Total liabilities	335,538	347,540
Commitments and contingencies	'	'
Stockholders' equity:	'	'
Preferred stock, par value $0.01 per share; 5,000 shares authorized, none issued and outstanding	0	0
Common stock, par value $0.01 per share; 100,000 shares authorized, 55,640 and 55,018 shares issued; 54,078 and 53,634 shares outstanding, respectively	556	550
Additional paid-in capital	259,179	248,336
Treasury stock, 1,562 and 1,384 shares, respectively	-36,244	-26,414
Accumulated other comprehensive loss	-16	-199
Retained earnings	1,725	3,540
Total stockholders' equity	225,200	225,813
Total liabilities and stockholders' equity	$560,738	$573,353

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, except Per Share data, unless otherwise specified
Accounts receivable, allowance for doubtful accounts	$1,089	$1,055
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	100,000	100,000
Common stock, shares issued	55,640	55,018
Common stock, shares outstanding	54,078	53,634
Treasury stock, shares	1,562	1,384

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Revenues	'		'
Subscription	$63,811		$50,652
Professional services	12,829		12,607
Total revenues	76,640		63,259
Cost of revenues	'		'
Subscription	11,086		9,025
Professional services	9,713		8,104
Total cost of revenues	20,799	[1],[2]	17,129	[1],[2]
Gross profit	55,841		46,130
Operating costs and expenses:	'		'
Research and development	17,789	[1]	11,905	[1]
Sales and marketing	20,732	[1],[2]	14,489	[1],[2]
General and administrative	17,046	[1]	12,644	[1]
Total operating costs and expenses	55,567		39,038
Operating income	274		7,092
Interest and other (expense) income:	'		'
Interest expense	-3,781		-18
Interest income	395		76
Other income, net	34		154
Total interest and other (expense) income, net	-3,352		212
(Loss) income before income taxes	-3,078		7,304
Provision for income taxes	-1,263		1,604
Net (loss) income	-1,815		5,700
(Loss) earnings per share:	'		'
Basic	($0.03)		$0.11	[3]
Diluted	($0.03)		$0.11	[3]
Weighted average common shares outstanding:	'		'
Basic	52,109		50,240	[3]
Diluted	52,109		52,522	[3]
Total stock-based compensation	9,699	[1]	5,205	[1]
Total amortization of intangible assets	138	[2]	394	[2]
Cost of revenues	'		'
Weighted average common shares outstanding:	'		'
Total stock-based compensation	1,072	[1]	487	[1]
Total amortization of intangible assets	108	[2]	281	[2]
Research and development	'		'
Weighted average common shares outstanding:	'		'
Total stock-based compensation	912	[1]	458	[1]
Sales and marketing	'		'
Weighted average common shares outstanding:	'		'
Total stock-based compensation	2,351	[1]	1,222	[1]
Total amortization of intangible assets	30	[2]	113	[2]
General and administrative	'		'
Weighted average common shares outstanding:	'		'
Total stock-based compensation	$5,364	[1]	$3,038	[1]
[1]	Stock-based compensation expense included in cost of revenues and operating costs and expenses
[2]	Amortization of intangible assets included in cost of revenues and operating costs and expenses
[3]	Prior period results have been adjusted to reflect the two-for-one stock split which was effected in the form of a stock dividend in December 2013.

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net (loss) income	($1,815)	$5,700
Other comprehensive income (loss):	'	'
Foreign currency translation adjustments	182	-986
Unrealized gain (loss) on marketable securities	2	-12
Other comprehensive income (loss):	184	-998
Income tax (expense) benefit related to unrealized gain or loss on marketable securities	-1	5
Other comprehensive income (loss), net of tax	183	-993
Comprehensive (loss) income, net of tax	($1,632)	$4,707

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Cash flows from operating activities:	'		'
Net (loss) income	($1,815)		$5,700
Adjustments to reconcile net (loss) income to net cash (used in) provided by operating activities:	'		'
Depreciation and amortization	2,535		1,851
Stock-based compensation	9,699	[1]	5,205	[1]
Amortization of discounts or premiums on marketable securities	1,431		504
Deferred income taxes	-1,643		718
Amortization of debt issuance costs	319		15
Amortization of debt discount	2,741		0
Excess tax benefit associated with equity awards	-71		-610
Contingent consideration adjustment	0		60
Provision for doubtful accounts	100		657
Changes in operating assets and liabilities:	'		'
Accounts receivable	-25,550		-4,249
Prepaid commission expense	-499		-917
Prepaid expenses and other current assets	1,485		684
Other assets	137		-73
Accounts payable	1,083		-1,558
Accrued payroll and other compensation	-9,260		-6,643
Accrued expenses and other	832		1,518
Deferred revenue	10,653		-287
Other long-term liabilities	1,537		322
Net cash (used in) provided by operating activities	-6,286		2,897
Cash flows from investing activities:	'		'
Purchases of furniture, fixtures and equipment	-7,048		-2,947
Purchases of available-for-sale securities	-46,249		-27,416
Proceeds from sale of available-for-sale securities	80,730		30,030
Decrease in restricted cash	0		388
Net cash provided by investing activities	27,433		55
Cash flows from financing activities:	'		'
Proceeds from exercise of stock options	1,079		1,655
Proceeds from employee stock purchase plan	1,327		0
Excess tax benefit associated with equity awards	71		610
Payment of acquisition-related earn-out	-704		-380
Repayment of obligations under capital leases	-30		-14
Repayments of notes payable	41		38
Acquisition of treasury stock	-19,789		-126
Net cash (used in) provided by financing activities	-18,087		1,707
Effect of exchange rate changes on cash and cash equivalents	18		-51
Net increase in cash and cash equivalents	3,078		4,608
Cash and cash equivalents - Beginning of period	22,328		32,683
Cash and cash equivalents - End of period	25,406		37,291
Cash paid during the period for:	'		'
Interest	1,350		14
Income taxes	296		918
Noncash activities:	'		'
Furniture, fixtures, and equipment acquired but not yet paid for at period-end	2,996		509
Issuance of notes payable in connection with acquisition-related earn-out payments	$97		$341
[1]	Stock-based compensation expense included in cost of revenues and operating costs and expenses

Organization

Organization	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
ORGANIZATION	'
	ORGANIZATION
	Medidata Solutions, Inc. (the “Company”) is the leading global provider of cloud-based solutions for clinical research in life sciences, designed to transform clinical development and increase the value of its customers' research investments. The Company’s solutions allow its customers to more efficiently and effectively design, plan and manage key aspects of the clinical trial process, including study and protocol design, trial planning and budgeting, site negotiation, clinical portal, trial management, randomization and trial supply management, clinical data capture and management, safety events capture, medical coding, clinical business analytics, and data flow and interoperability among multiple trial applications.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	'
	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Except to the extent updated or described below, the Company’s significant accounting policies as of March 31, 2014 are the same as those at December 31, 2013, which are included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on February 24, 2014.
	Basis of Presentation — The accompanying interim condensed consolidated balance sheets as of March 31, 2014 and December 31, 2013, the condensed consolidated statements of operations for the three months ended March 31, 2014 and 2013, the condensed consolidated statements of comprehensive income for the three months ended March 31, 2014 and 2013, and the condensed consolidated statements of cash flows for the three months ended March 31, 2014 and 2013 are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“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 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, 2013 included in the Company’s Annual Report on Form 10-K filed with the SEC on February 24, 2014.
	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 March 31, 2014, results of its operations for the three months ended March 31, 2014 and 2013, comprehensive income for the three months ended March 31, 2014 and 2013, and cash flows for the three months ended March 31, 2014 and 2013. The results of operations for the three months ended March 31, 2014 are not necessarily indicative of the results that may be expected for the year ending December 31, 2014.
	All share and per share data for all periods presented herein reflect the impact of a two-for-one stock split which was effected in the form of a stock dividend in December 2013.
	Stock-Based Compensation — The Company follows Accounting Standards Codification ("ASC") 718, Compensation—Stock Compensation to account for all of its stock-based compensation plans.
	The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes pricing model. The Company uses stock price volatility of its publicly-traded stock as a basis for determining the expected volatility. Management believes this is the best estimate of the expected volatility over the weighted-average expected life of its option grants. As the Company does not have sufficient historical exercise data in the period since its stock began being publicly traded to provide a reasonable basis upon which to estimate the expected life, the Company uses the simplified method as permitted under SEC Staff Accounting Bulletin No. 110 for estimating the expected life of options as all of its options qualify as "plain-vanilla" options. The risk-free interest rate is based on the United States Treasury yield curve in effect at the time of the option grant with a maturity tied to the expected life of the options. No dividends are expected to be declared by the Company at this time. Compensation expense for stock options is recognized, net of estimated forfeitures, on a straight-line basis over the vesting period.
	The fair value of each nonvested restricted stock award ("RSA") is measured as if the nonvested RSA was vested and issued on the grant date. Compensation expense for RSAs is recognized, net of estimated forfeitures, on a straight-line basis over the vesting period.
	The fair value of each performance-based restricted stock unit ("PBRSU") whose vesting is dependent on the achievement of a market price target, or a "market condition," is estimated based upon the results of a Monte Carlo valuation model as of the grant date in accordance with accounting guidelines. Compensation expense related to PBRSUs with a market condition is recognized, net of estimated forfeitures, on a straight-line basis over the vesting period. The fair value of each PBRSU whose vesting is dependent on the satisfaction of a performance target, or a "performance condition," is measured as if the PBRSU was vested and issued on the grant date and adjusted in each reporting period for expected performance relative to the associated goals. Compensation expense related to PBRSUs with a performance condition is recognized when it is probable that the condition will be achieved, net of estimated forfeitures, on a straight-line basis over the vesting period. The compensation expense ultimately recognized will equal the grant date fair value for the number of shares for which the performance condition has been satisfied.
	The fair value of each employee stock purchase plan ("ESPP") share is estimated using the Black-Scholes pricing model. The Company uses stock price volatility of its publicly-traded stock as a basis for determining the expected volatility. Management believes this is the best estimate of the expected volatility over the weighted-average expected life of the ESPP shares. The expected life of each ESPP share is equivalent to the time between the beginning of the offering period and the end of the related purchase period. The risk-free interest rate is based on the United States Treasury yield curve in effect at the beginning of the offering period with a maturity tied to the expected life of the ESPP share. No dividends are expected to be declared by the Company at this time. Compensation expense for ESPP shares is recognized, net of estimated forfeitures, on a straight-line basis over the term of the offering period.
	Income Taxes — The Company uses the asset and liability method of accounting for income taxes, as prescribed by ASC 740, Income Taxes, which recognizes deferred tax assets and liabilities for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are recorded to reduce deferred tax assets when it is more likely than not that a tax benefit will not be realized.
	All of the taxes accrued on the Company's undistributed earnings from its foreign subsidiaries are included in U.S. current income taxes under Internal Revenue Code Section 956. As a result, no deferred income tax liability associated with the Company's undistributed earnings was recorded.
	The Company follows ASC 740-10 for the determination of whether tax benefits claimed or expected to be claimed on a tax return should be recorded in the consolidated financial statements. Under ASC 740-10, the Company may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position.
	For the provision for income taxes at interim periods, the Company follows ASC 740-270, Income Taxes — Interim Reporting, and has developed an estimate of the annual effective tax rate based upon the facts and circumstances known at the time. The Company’s effective tax rate is based on expected income, statutory rates and permanent differences applicable to the Company in the various jurisdictions in which the Company operates.
	Accounts Receivable — Accounts receivable are recorded at original invoice amount less an allowance that management believes will be adequate to absorb estimated losses on existing accounts receivable. The 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 March 31, 2014 and December 31, 2013, unbilled accounts receivable of $6.2 million and $9.5 million, respectively, are included in accounts receivable on the Company's consolidated balance sheets.
	Segment Information — As defined by ASC 280, Segment Reporting, the Company operates as a single segment, as the chief operating decision maker makes operating decisions and assesses performance based on a single operating unit. The Company recorded revenues in the following geographic areas for the three months ended March 31, 2014 and 2013 (in thousands):
		Three Months Ended March 31,
		2014		2013
	Revenues:
	United States of America	$	55,789	$	44,854
	Japan	7,957		7,833
	Switzerland	4,014		2,921
	Other	8,880		7,651
	Total	$	76,640	$	63,259
	Revenues by geographic area are presented based upon the country in which revenues were generated. No individual country other than the United States, Japan and Switzerland represented 5% or more of net revenues for any of the periods presented.
	The following table summarizes long-term assets by geographic area as of March 31, 2014 and December 31, 2013 (in thousands):
		March 31,		December 31,
		2014		2013
	Long-term assets:
	United States of America	$	239,406	$	254,453
	United Kingdom	9,516		10,041
	Japan	5,084		4,314
	Total	$	254,006	$	268,808
	Recently Issued Accounting Pronouncements — In July 2013, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. This ASU amends ASC 740, Income Taxes, to require that an unrecognized tax benefit be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward; to the extent that a net operating loss carry forward, a similar tax loss, or a tax credit carryforward does not exist at the reporting date, the unrecognized tax benefit should be presented in the financial statements as a liability and not combined with deferred tax assets. ASU No. 2013-11 is effective for interim and annual reporting periods beginning after December 15, 2013. The Company adopted ASU No. 2013-11 on January 1, 2014, and the adoption did not have a material impact on its consolidated financial statements.

Stockholders_Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2014
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.
	In December 2013, the Company announced a two-for-one split of its common stock, effected in the form of a stock dividend. The record date for the stock split was December 2, 2013, and the additional shares were distributed on December 16, 2013. Each shareholder of record as of the close of business on the record date received one additional share of common stock for each share held.
	Treasury Stock — From time to time, the Company grants nonvested RSAs and PBRSUs to its employees pursuant to the terms of the 2009 Long-Term Incentive Plan (the “2009 Plan”). Under the provisions of the 2009 Plan, the plan participants are allowed to cover their income tax withholding obligation through net shares upon the vesting of their RSAs or PBRSUs. On the date of vesting, the Company determines the number of shares to be withheld based on their fair value at the closing price of the Company’s common stock on the vesting date, in order to equal the amount of the plan participant's income tax withholding obligation. Those withheld shares are then held in the Company’s treasury stock at cost for future reissuance. During the first three months of 2014, the Company withheld 164,738 shares at an average price of $59.67 in connection with the vesting of its RSAs and PBRSUs.

Marketable_Securities

Marketable Securities	3 Months Ended
	Mar. 31, 2014
Marketable Securities [Abstract]	'
MARKETABLE SECURITIES	'
	MARKETABLE SECURITIES
	The Company manages its cash equivalents and marketable securities as a single investment portfolio that is intended to be available to meet the Company’s current cash requirements. Cash equivalents consist primarily of investments in money market funds. 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 March 31, 2014 and December 31, 2013 (in thousands):
		As of March 31, 2014
		Cost		Gross			Gross			Estimated
				Unrealized			Unrealized			Fair
				Gains			Losses			Value
	Commercial paper and corporate bonds	$	365,157	$	142		$	(217	)	$	365,082
	U.S. government agency debt securities	13,000		5			—			13,005
	Total	$	378,157	$	147		$	(217	)	$	378,087
		As of December 31, 2013
		Cost		Gross			Gross			Estimated
				Unrealized			Unrealized			Fair
				Gains			Losses			Value
	Commercial paper and corporate bonds	$	378,135	$	122		$	(196	)	$	378,061
	U.S. government agency debt securities	35,934		3			(1		)	35,936
	Total	$	414,069	$	125		$	(197	)	$	413,997
	Contractual maturities of the Company’s marketable securities as of March 31, 2014 and December 31, 2013 are summarized as follows (in thousands):
		As of March 31, 2014					As of December 31, 2013
		Cost		Estimated			Cost			Estimated
				Fair						Fair
				Value						Value
	Due in one year or less	$	196,140	$	196,140		$	218,941		$	218,892
	Due in one to five years	182,017		181,947			195,128			195,105
	Total	$	378,157	$	378,087		$	414,069		$	413,997
	The following table provides the fair market value and the gross unrealized losses of the Company’s marketable securities with unrealized losses that are not deemed to be other-than-temporarily impaired, aggregated by security type as of March 31, 2014 and December 31, 2013 (in thousands):
		In Loss Position for Less than 12 Months
		As of March 31, 2014					As of December 31, 2013
		Fair		Gross			Fair			Gross
		Value		Unrealized			Value			Unrealized
				Losses						Losses
	Commercial paper and corporate bonds	$	217,329	$	(217	)	$	241,381		$	(196	)
	U.S. government agency debt securities	—		—			10,910			(1		)
	Total	217,329		(217		)	252,291			(197		)
	None of the Company’s marketable securities has been in a continuous unrealized loss position for more than twelve months as of March 31, 2014 and December 31, 2013.
	The Company regularly reviews its investment portfolio to identify and evaluate investments that have indications of possible impairment. 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 at maturity, the Company has determined that the gross unrealized losses on such investments at March 31, 2014 are temporary in nature. Accordingly, the Company did not consider its investments in marketable securities to be other-than-temporarily impaired as of March 31, 2014.
	During the three months ended March 31, 2014 and 2013, the Company recorded an insignificant amount of net realized gain or loss from the sale of marketable securities.

Fair_Value

Fair Value	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
FAIR VALUE	'
	FAIR VALUE
	ASC 820-10, Fair Value Measurements and Disclosures, establishes a framework for measuring fair value. That framework provides a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value and enhances disclosure requirements for fair value measurements. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy under ASC 820-10 are described as follows:
	Level 1 - Unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date.
	Level 2 - Other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly, including:
	•	quoted prices for similar assets or liabilities in active markets;
	•	quoted prices for identical or similar assets or liabilities in markets that are not active;
	•	inputs other than quoted prices that are observable for the asset or liability;
	•	inputs that are derived principally from or corroborated by observable market data by correlation or other means.
	If the asset or liability has a specified (contractual) term, the Level 2 inputs must be observable for substantially the full term of the asset or liability.
	Level 3 - Unobservable inputs to the valuation methodology that are significant to the fair value measurement for the asset or liability.
	Financial assets (excluding cash balances) measured at fair value on a recurring basis as of March 31, 2014 and December 31, 2013 are summarized as follows (in thousands):
		As of March 31, 2014								As of December 31, 2013
		Fair Value Measurement Using								Fair Value Measurement Using
		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
	Assets:
	Money market funds	$	9,184	$	—	$	—	$	9,184	$	751	$	—	$	—	$	751
	Total cash equivalents	9,184		—		—		9,184		751		—		—		751
	Commercial paper and corporate bonds	—		365,082		—		365,082		—		378,061		—		378,061
	U.S. government agency debt securities	—		13,005		—		13,005		—		35,936		—		35,936
	Total marketable securities	—		378,087		—		378,087		—		413,997		—		413,997
	Total financial assets	$	9,184	$	378,087	$	—	$	387,271	$	751	$	413,997	—		$	414,748
	The Company’s financial assets that are measured at fair value on a recurring basis are generally classified within Level 1 or Level 2 of the fair value hierarchy. Investments in money market funds have been classified as Level 1 since these securities are valued based upon $1.00 net asset value per share or unadjusted quoted prices in active markets. Investments in commercial paper, corporate bonds, and U.S. government agency debt securities have been classified as Level 2 since these securities are valued based on quoted prices in less active markets or significant inputs which are directly or indirectly observable. The valuation techniques used to measure the fair values of corporate bonds and U.S. government agency debt securities were derived from the inputs of market prices from multiple sources at each reporting period. The fair value was then determined based on a consensus price or a weighted average price for each security. For the remaining financial assets classified as Level 2, substantially all of the securities had a short maturity within one year and high credit ratings. Therefore, the valuation techniques used to measure the fair values were primarily derived from accretion of purchase price to its face value over the term of maturity or quoted market prices for similar instruments if available. During the three months ended March 31, 2014 and 2013, 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. The Company does not have non-financial assets or liabilities that have been measured at fair value on a nonrecurring basis as of March 31, 2014.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
GOODWILL AND INTANGIBLE ASSETS	'
	GOODWILL AND INTANGIBLE ASSETS
	The change in the carrying amount of goodwill during the three months ended March 31, 2014 is as follows (in thousands):
	Balance as of January 1, 2014	$	15,487
	Foreign currency translation adjustments	46
	Balance as of March 31, 2014	$	15,533
	Intangible assets are summarized as follows (in thousands):
		As of March 31, 2014							As of December 31, 2013
		Gross		Accumulated			Net		Gross		Accumulated			Net
		Carrying		Amortization			Carrying		Carrying		Amortization			Carrying
		Amount					Amount		Amount					Amount
	Acquired technology	$	4,145	$	(3,599	)	$	546	$	4,129	$	(3,481	)	$	648
	Customer relationships	2,078		(1,850		)	228		2,074		(1,818		)	256
	Total	$	6,223	$	(5,449	)	$	774	$	6,203	$	(5,299	)	$	904
	Annual amortization for the next five years is expected to be as follows (in thousands):
	Remainder of year ending December 31, 2014	$	417
	Years ending December 31,
	2015	290
	2016	48
	2017	19

Debt

Debt	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
DEBT	'
	DEBT
	In August 2013, the Company issued at par value $287.5 million of 1.00% convertible senior notes (the "Notes"). Interest is payable semi-annually in arrears on August 1 and February 1 of each year, beginning on February 1, 2014. The Notes mature on August 1, 2018 unless repurchased or converted in accordance with their terms prior to such date. The Company may not redeem the Notes prior to their maturity date. The Notes are the Company's senior unsecured obligations and are governed by an indenture dated August 12, 2013 between the Company, as issuer, and Wells Fargo Bank, National Association, as trustee.
	Upon conversion of the Notes, the Company may choose to pay or deliver, as applicable, either cash, shares of the Company's common stock, or a combination thereof. If converted, holders of the Notes will receive, at the Company's election, cash and/or shares for the principal amount of the Notes as well as any amounts in excess of principal. The Company intends to settle the principal amount of the Notes in cash if converted.
	The initial conversion rate is 17.2286 shares of the Company's common stock per $1,000 principal amount of Notes, which is equivalent to an initial conversion price of approximately $58.05 per share of common stock. The conversion rate will be subject to adjustment upon occurrence of certain events, including, but not limited to, the issuance of stock dividends or payment of cash dividends on the Company's common stock (unless the holders of the Notes participate at the same time and under the same terms as the holders of common stock), or execution of a share split or share combination. Upon conversion, holders of the Notes will not receive any separate cash payment representing accrued and unpaid interest, unless conversion occurs after close of business on a regular record date and prior to the related interest payment date.
	Holders may convert their Notes at their option at any time prior to the close of business on the business day immediately preceding February 1, 2018 only under the following circumstances:
	•	during any calendar quarter commencing after the calendar quarter ending on December 31, 2013 (and only during such calendar quarter), if the last reported sale price of the common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day;
	•	during the five business day period after any five consecutive trading day period (the "measurement period") in which the trading price per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company's common stock and the conversion rate on such trading day; or
	•	upon the occurrence of certain corporate events described in the indenture governing the Notes.
	On or after February 1, 2018 until close of business on the business day immediately preceding the maturity date, holders may convert their Notes at any time, regardless of the foregoing circumstances. If the Company undergoes a fundamental change as defined in the indenture governing the Notes, holders may require the Company to repurchase for cash all of their Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased plus accrued and unpaid interest.
	In accounting for the issuance of the Notes, the Company separated the Notes into liability and equity components. The carrying amount of the liability component was calculated by measuring the fair value of a similar liability that does not have an associated convertible feature. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the par value of the Notes as a whole. The excess of the par value over the fair value of the debt represents the debt discount, which is amortized to interest expense over the term of the Notes. The equity component is not remeasured as long as it continues to meet the conditions for equity classification.
	In accounting for the $8.1 million in issuance costs related to the Note issuance, the Company allocated the total amount incurred to the liability and equity components based on their relative values. The $6.4 million in issuance costs attributed to the liability component were capitalized and are amortized to interest expense over the term of the Notes. The $1.7 million in issuance costs attributed to the equity component were netted against the equity component in additional paid-in capital.
	As of March 31, 2014, the remaining unamortized debt issuance costs related to the Notes were $5.5 million.
	The components of the Notes are summarized as follows (in thousands):
		March 31,			December 31,
		2014			2013
	Equity component, net of equity issue costs	$	60,222		$	60,222
	Liability component:
	Principal	287,500			287,500
	Less: unamortized debt discount	(55,054		)	(57,795		)
	Net carrying amount	$	232,446		$	229,705
	The Notes are carried at face value less any unamortized discount, but require a disclosure of an estimate of fair value. As of March 31, 2014 and December 31, 2013, the estimated fair value of the Notes was $345.7 million and $365.1 million, respectively, which the Company considers to be a Level 2 measurement because it is based upon a recent quoted bid price for the Notes, reflecting market activity in a less than active market. As of March 31, 2014, the Notes are not convertible. Based on the closing price of the Company's common stock on March 31, 2014 of $54.34, 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 March 31, 2014, the remaining life of the Notes is approximately 52 months.
	The following table sets forth total interest expense recognized related to the Notes for the three months ended March 31, 2014 (in thousands except percentages):
	Contractual interest expense	$	711
	Amortization of debt issuance costs	319
	Amortization of debt discount	2,741
	Total	$	3,771
	Effective interest rate	6.5		%

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
STOCK-BASED COMPENSATION	'
	STOCK-BASED COMPENSATION
	The Company accounts for stock-based compensation in accordance with ASC 718, Compensation — Stock Compensation. For the three months ended March 31, 2014 and 2013, the components of stock-based compensation expense are summarized in the following table (in thousands):
		Three Months Ended March 31,
		2014			2013
	Stock options	$	1,214		$	962
	Restricted stock awards	3,169			3,182
	Performance-based restricted stock units	4,750			1,061
	Employee stock purchase plan	566			—
	Total stock-based compensation	$	9,699		$	5,205
	Stock Options
	The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes pricing model with the following weighted-average assumptions:
		Three Months Ended March 31,
		2014		2013
	Expected volatility	42	%	—
	Expected life	6 years		—
	Risk-free interest rate	1.76	%	—
	Dividend yield	—		—
	The following table summarizes the activity under the stock option plans as of March 31, 2014, and changes during the three months then ended (in thousands, except per share data):
		Number of		Weighted-				Weighted-	Aggregate
		Shares		Average				Average	Intrinsic
				Exercise				Remaining	Value
				Price				Contractual
								Term
								(years)
	Outstanding at January 1, 2014	2,670		$	16
	Granted	60		62.95
	Exercised	(125	)	8.65
	Forfeited	(23	)	34.17
	Expired	—		—
	Outstanding at March 31, 2014	2,582		$	17.28			7.14	$	96,571
	Exercisable at March 31, 2014	1,366		$	9.25			5.95	$	61,598
	Vested and expected to vest at March 31, 2014	2,532		$	16.92			7.11	$	95,571
	The weighted-average grant-date fair value of stock options granted during the three months ended March 31, 2014 and 2013 was $26.79 and none, respectively. The total intrinsic value of stock options exercised during the three months ended March 31, 2014 and 2013 was $6.8 million and $4.4 million, respectively. As of March 31, 2014, there was a total of $12.5 million of unrecognized compensation cost related to all non-vested stock options granted, as recorded in accordance with ASC 718. This cost is expected to be recognized over a weighted-average remaining period of 2.48 years. The total fair value of stock options vested during the three months ended March 31, 2014 and 2013 was $0.7 million and $0.9 million, respectively.
	Restricted Stock Awards
	The following table summarizes the status of the Company’s nonvested RSAs as of March 31, 2014, and changes during the three months then ended (in thousands, except per share data):
		Number of		Weighted-
		Shares		Average
				Grant-Date
				Fair Value
	Nonvested at January 1, 2014	1,672		$	18.06
	Granted	270		54.7
	Vested	(134	)	24.22
	Forfeited	(13	)	15.34
	Nonvested at March 31, 2014	1,795		$	23.14
	As of March 31, 2014, there was a total of $34.5 million of unrecognized compensation cost related to all nonvested RSAs granted, as recorded in accordance with ASC 718. This cost is expected to be recognized over a weighted-average remaining period of 2.19 years. The total fair value of RSAs vested during the three months ended March 31, 2014 and 2013 was $8.4 million and $0.2 million, respectively.
	Performance-Based Restricted Stock Units
	During the three months ended March 31, 2014 the Company granted PBRSUs to certain employees including executives. Of the number of PBRSUs granted during the three months ended March 31, 2014, which assumes performance at 100% of targeted levels, (1) 149 thousand PBRSUs ("Revenue PBRSUs") have performance conditions based on revenue for the year ending December 31, 2014 relative to the Company's revenue guidance and a minimum profitability condition, vesting annually over three years commencing on the first anniversary of the grant date, with the number of PBRSUs ultimately earned ranging from zero to 200% of the original award; and (2) 74 thousand PBRSUs ("TSR PBRSUs") have market conditions based on the Company's total stockholder return ("TSR") relative to that of the NASDAQ Composite Index for the year ending December 31, 2014, vesting annually over three years commencing on the first anniversary of the grant date, with the number of PBRSUs ultimately earned ranging from zero to 200% of the original award. The Company also granted an insignificant number of other PBRSUs with performance conditions based on achievement of certain predetermined objectives.
	The fair value of each TSR PBRSU is estimated as of the date of grant based upon evaluation of expected performance relative to the associated market condition using a Monte Carlo valuation model with the following weighted-average assumptions:
		Three Months Ended March 31,
		2014		2013
	Expected volatility - Medidata	52	%	39	%
	Expected volatility - NASDAQ Composite Index	13	%	15	%
	Risk-free interest rate	0.12	%	0.16	%
	Expected term	0.89 years		1.00 year
	The following table summarizes the status of the Company’s PBRSUs based upon expected performance as of March 31, 2014, and changes during the three months then ended (in thousands, except per share data):
		Revenue		TSR			Long-Term		Other		Total Number of Shares		Weighted-Average Grant Date Fair Value
	Nonvested at January 1, 2014	454		227			1,012		9		1,702		$	29.18
	Granted (based on performance at 100% of targeted levels)	149		74			—		5		228		54.01
	Adjustment related to expected performance	—		—			—		(5	)	(5	)	67.01
	Vested	(151	)	(76	)		—		—		(227	)	26.33
	Forfeited	—		—			—		—		—		—
	Nonvested at March 31, 2014	452		225			1,012		9		1,698		$	32.79
	As of March 31, 2014, there was a total of $40.6 million of unrecognized compensation cost related to all nonvested PBRSUs, as recorded in accordance with ASC 718. This cost is expected to be recognized over a weighted-average remaining period of 2.04 years. The total fair value of PBRSUs vested during the three months ended March 31, 2014 and 2013 was $13.3 million and none, respectively.
Employee Stock Purchase Plan
The Company's Board of Directors has adopted the Amended and Restated 2014 Employee Stock Purchase Plan, which will be effective as of January 1, 2014 if approved by the Company's stockholders at the 2014 Annual Meeting of Stockholders. The ESPP allows eligible employees to purchase shares of the Company's common stock at a discount though payroll deductions, and consists of a 24-month offering period with four six-month purchase periods in each offering period. Employees purchase shares at the lesser of (1) 85% of the fair market value (“FMV”) per share on the first day of the offering period, or (2) 85% of the FMV per share at the end of the relevant purchase period. As such, the ESPP is considered to be a compensatory plan under ASC 718. A total of 0.3 million shares of common stock is reserved for issuance under the ESPP, pending approval of the Company's stockholders at the 2014 Annual Meeting of Stockholders.
The fair value of ESPP shares is estimated using the Black-Scholes pricing model with the following weighted-average assumptions:
	Three Months Ended March 31,
	2014		2013
Expected volatility	49	%	—
Expected life	1.22 years		—
Risk-free interest rate	0.21	%	—
Dividend yield	—		—
As of March 31, 2014, there was $4.0 million in unrecognized compensation cost related to ESPP shares, expected to be recognized over a weighted-average remaining period of 1.75 years.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
ACCUMULATED OTHER COMPREHENSIVE LOSS	'
	ACCUMULATED OTHER COMPREHENSIVE LOSS
	The changes in the balances of each component of accumulated other comprehensive loss during the three months ended March 31, 2014 are as follows (in thousands):
		Foreign Currency Translation Adjustments			Unrealized Losses On Available-For-Sale Securities			Total
	Balance as of January 1, 2014	$	(127	)	$	(72	)	$	(199	)
	Other comprehensive income, net of tax	182			1			183
	Balance as of March 31, 2014	$	55		$	(71	)	$	(16	)
	For the three months ended March 31, 2014, reclassifications of items from accumulated other comprehensive loss to net loss were insignificant.

Earnings_Loss_Per_Share

Earnings (Loss) Per Share	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
EARNINGS (LOSS) PER SHARE	'
	EARNINGS PER SHARE
	The Company follows ASC 260, Earnings Per Share, in calculating 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. The effect of the Notes, if any, is reflected in diluted earnings per share using the treasury stock method as the Company intends to settle the principal amount of the Notes in cash upon conversion.
	All share and per share data for all periods presented reflect the impact of a two-for-one stock split which was effected in the form of a stock dividend in December 2013. A reconciliation of the numerators and denominators of basic (loss) earnings per share and diluted (loss) earnings per share for the three months ended March 31, 2014 and 2013 are shown in the following table (in thousands, except per share data):
		Three Months Ended March 31,
		2014				2013
	Numerator
	Net (loss) income	$	(1,815	)		$	5,700
	Denominator
	Denominator for basic earnings (loss) per share:
	Weighted average common shares outstanding	52,109				50,240
	Denominator for diluted earnings (loss) per share:
	Dilutive potential common shares:
	Stock options	—				1,442
	Restricted stock awards	—				830
	Performance-based restricted stock units	—				10
	Weighted average common shares outstanding with assumed conversion	52,109				52,522
	Basic (loss) earnings per share	$	(0.03	)		$	0.11
	Diluted (loss) earnings per share	$	(0.03	)		$	0.11
	Antidilutive common stock equivalents excluded from the calculation of dilutive (loss) earnings per share for the three months ended March 31, 2014 and 2013 are shown in the following table (in thousands, except per share data):
		Three Months Ended March 31,
		2014			2013
	Stock options	2,625			126
	Restricted stock awards	1,759			6
	Performance-based restricted stock units	1,713			2
	Employee stock purchase plan	243			—
	Convertible notes	234			—
	Total	6,574			134

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
INCOME TAXES	'
	INCOME TAXES
	The Company’s effective tax rate for the three months ended March 31, 2014 was 41% and differed from the federal statutory rate of 35% primarily due to state and local income taxes, investment in U.S. property under Internal Revenue Code Section 956 and stock-based compensation, partially offset by benefit associated with domestic production activities deduction.
	The Company’s effective tax rate for the three months ended March 31, 2013 was 22% and differed from the federal statutory rate of 35% primarily due to state and local income taxes, stock-based compensation, research and development tax credits, and limitations on officers' compensation. The Company recognized as a favorable discrete item a research and development tax credit of $1.2 million, resulting from the retroactive reinstatement of the research and development tax credit for 2012 during the first quarter of 2013.
	The Company had approximately $4.1 million of gross unrecognized tax benefits as of December 31, 2013. For the three months ended March 31, 2014, there was no change relating to the Company’s tax positions. In April 2014, the Company was informed by the Internal Revenue Service that its 2012 federal income tax return has been selected for examination.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2014
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. From time to time, third parties have asserted and may in the future assert intellectual property rights to technologies that are important to the Company’s business and have demanded and may in the future demand that the Company license their technology. The Company 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 complaint asserts infringement of U.S. Patent No. 7,464,087 (the “’087 Patent”), which claims a method and system for unifying data from a variety of sources. The complaint asserts that the Company infringes upon the patent owned without providing any details concerning the alleged infringement, and it seeks unspecified damages and injunctive relief. On October 28, 2011, the Company filed an application for ex parte reexamination of the ’087 Patent with the U.S. Patent and Trademark Office (the “PTO”). On December 16, 2011, the PTO issued a non-final rejection of the validity of all claims of the ’087 Patent. On the same date, the district court granted the Company’s motion to stay the case pending reexamination of the patent-in-suit. On April 6, 2012, the PTO issued its final office action rejecting all asserted claims of the ’087 Patent. In July 2012, DataTrak filed a notice of appeal to the Board of Patent Appeals and Interferences (the "BPAI"). The BPAI rendered a decision on March 4, 2014, affirming the rejection of some claims of the '087 Patent and reversing the rejection of other claims. The PTO has not yet issued a notice of intent to issue ex parte reexamination certificate, which is expected to confirm patentability of the remaining claims and will close the current reexamination proceeding.
	The Company believes that it has valid defenses to the lawsuit and intends to defend itself vigorously in the event the reexamination certificate issues and the stay of the case is lifted. The probability of a favorable or unfavorable outcome to the Company should the lawsuit resume is not known nor can the liability that could potentially result from a negative outcome be reasonably estimated. As a result, the Company has not recorded an accrual associated with this litigation. Additionally, given the early stage of the proceedings, the complexities of the facts in dispute and the multiple claims involved, the Company is unable to estimate a range of loss related to this litigation.
	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 officer’s base salary plus target bonus amount; (b) continuation of health benefits for 12 months; and (c) immediate vesting of any remaining unvested equity awards, unless otherwise specified in the equity award agreements.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation — The accompanying interim condensed consolidated balance sheets as of March 31, 2014 and December 31, 2013, the condensed consolidated statements of operations for the three months ended March 31, 2014 and 2013, the condensed consolidated statements of comprehensive income for the three months ended March 31, 2014 and 2013, and the condensed consolidated statements of cash flows for the three months ended March 31, 2014 and 2013 are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“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 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, 2013 included in the Company’s Annual Report on Form 10-K filed with the SEC on February 24, 2014.
	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 March 31, 2014, results of its operations for the three months ended March 31, 2014 and 2013, comprehensive income for the three months ended March 31, 2014 and 2013, and cash flows for the three months ended March 31, 2014 and 2013. The results of operations for the three months ended March 31, 2014 are not necessarily indicative of the results that may be expected for the year ending December 31, 2014.
	All share and per share data for all periods presented herein reflect the impact of a two-for-one stock split which was effected in the form of a stock dividend in December 2013.
Stock-Based Compensation	'
	Stock-Based Compensation — The Company follows Accounting Standards Codification ("ASC") 718, Compensation—Stock Compensation to account for all of its stock-based compensation plans.
	The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes pricing model. The Company uses stock price volatility of its publicly-traded stock as a basis for determining the expected volatility. Management believes this is the best estimate of the expected volatility over the weighted-average expected life of its option grants. As the Company does not have sufficient historical exercise data in the period since its stock began being publicly traded to provide a reasonable basis upon which to estimate the expected life, the Company uses the simplified method as permitted under SEC Staff Accounting Bulletin No. 110 for estimating the expected life of options as all of its options qualify as "plain-vanilla" options. The risk-free interest rate is based on the United States Treasury yield curve in effect at the time of the option grant with a maturity tied to the expected life of the options. No dividends are expected to be declared by the Company at this time. Compensation expense for stock options is recognized, net of estimated forfeitures, on a straight-line basis over the vesting period.
	The fair value of each nonvested restricted stock award ("RSA") is measured as if the nonvested RSA was vested and issued on the grant date. Compensation expense for RSAs is recognized, net of estimated forfeitures, on a straight-line basis over the vesting period.
	The fair value of each performance-based restricted stock unit ("PBRSU") whose vesting is dependent on the achievement of a market price target, or a "market condition," is estimated based upon the results of a Monte Carlo valuation model as of the grant date in accordance with accounting guidelines. Compensation expense related to PBRSUs with a market condition is recognized, net of estimated forfeitures, on a straight-line basis over the vesting period. The fair value of each PBRSU whose vesting is dependent on the satisfaction of a performance target, or a "performance condition," is measured as if the PBRSU was vested and issued on the grant date and adjusted in each reporting period for expected performance relative to the associated goals. Compensation expense related to PBRSUs with a performance condition is recognized when it is probable that the condition will be achieved, net of estimated forfeitures, on a straight-line basis over the vesting period. The compensation expense ultimately recognized will equal the grant date fair value for the number of shares for which the performance condition has been satisfied.
	The fair value of each employee stock purchase plan ("ESPP") share is estimated using the Black-Scholes pricing model. The Company uses stock price volatility of its publicly-traded stock as a basis for determining the expected volatility. Management believes this is the best estimate of the expected volatility over the weighted-average expected life of the ESPP shares. The expected life of each ESPP share is equivalent to the time between the beginning of the offering period and the end of the related purchase period. The risk-free interest rate is based on the United States Treasury yield curve in effect at the beginning of the offering period with a maturity tied to the expected life of the ESPP share. No dividends are expected to be declared by the Company at this time. Compensation expense for ESPP shares is recognized, net of estimated forfeitures, on a straight-line basis over the term of the offering period.
Income Taxes	'
	Income Taxes — The Company uses the asset and liability method of accounting for income taxes, as prescribed by ASC 740, Income Taxes, which recognizes deferred tax assets and liabilities for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Valuation allowances are recorded to reduce deferred tax assets when it is more likely than not that a tax benefit will not be realized.
	All of the taxes accrued on the Company's undistributed earnings from its foreign subsidiaries are included in U.S. current income taxes under Internal Revenue Code Section 956. As a result, no deferred income tax liability associated with the Company's undistributed earnings was recorded.
	The Company follows ASC 740-10 for the determination of whether tax benefits claimed or expected to be claimed on a tax return should be recorded in the consolidated financial statements. Under ASC 740-10, the Company may recognize the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained on examination by the taxing authorities, based on the technical merits of the position.
	For the provision for income taxes at interim periods, the Company follows ASC 740-270, Income Taxes — Interim Reporting, and has developed an estimate of the annual effective tax rate based upon the facts and circumstances known at the time. The Company’s effective tax rate is based on expected income, statutory rates and permanent differences applicable to the Company in the various jurisdictions in which the Company operates.
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 existing accounts receivable. The 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 March 31, 2014 and December 31, 2013, unbilled accounts receivable of $6.2 million and $9.5 million, respectively, are included in accounts receivable on the Company's consolidated balance sheets.
Segment Information	'
	Segment Information — As defined by ASC 280, Segment Reporting, the Company operates as a single segment, as the chief operating decision maker makes operating decisions and assesses performance based on a single operating unit. The Company recorded revenues in the following geographic areas for the three months ended March 31, 2014 and 2013 (in thousands):
		Three Months Ended March 31,
		2014		2013
	Revenues:
	United States of America	$	55,789	$	44,854
	Japan	7,957		7,833
	Switzerland	4,014		2,921
	Other	8,880		7,651
	Total	$	76,640	$	63,259
	Revenues by geographic area are presented based upon the country in which revenues were generated. No individual country other than the United States, Japan and Switzerland represented 5% or more of net revenues for any of the periods presented.
	The following table summarizes long-term assets by geographic area as of March 31, 2014 and December 31, 2013 (in thousands):
		March 31,		December 31,
		2014		2013
	Long-term assets:
	United States of America	$	239,406	$	254,453
	United Kingdom	9,516		10,041
	Japan	5,084		4,314
	Total	$	254,006	$	268,808
Recently Issued Accounting Pronouncements	'
	Recently Issued Accounting Pronouncements — In July 2013, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2013-11, Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. This ASU amends ASC 740, Income Taxes, to require that an unrecognized tax benefit be presented in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward; to the extent that a net operating loss carry forward, a similar tax loss, or a tax credit carryforward does not exist at the reporting date, the unrecognized tax benefit should be presented in the financial statements as a liability and not combined with deferred tax assets. ASU No. 2013-11 is effective for interim and annual reporting periods beginning after December 15, 2013. The Company adopted ASU No. 2013-11 on January 1, 2014, and the adoption did not have a material impact on its consolidated financial statements.
Earnings Per Share	'
	The Company follows ASC 260, Earnings Per Share, in calculating 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. The effect of the Notes, if any, is reflected in diluted earnings per share using the treasury stock method as the Company intends to settle the principal amount of the Notes in cash upon conversion.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Geographic segment and long-term assets geographic segment	'
	The following table summarizes long-term assets by geographic area as of March 31, 2014 and December 31, 2013 (in thousands):
		March 31,		December 31,
		2014		2013
	Long-term assets:
	United States of America	$	239,406	$	254,453
	United Kingdom	9,516		10,041
	Japan	5,084		4,314
	Total	$	254,006	$	268,808
	The Company recorded revenues in the following geographic areas for the three months ended March 31, 2014 and 2013 (in thousands):
		Three Months Ended March 31,
		2014		2013
	Revenues:
	United States of America	$	55,789	$	44,854
	Japan	7,957		7,833
	Switzerland	4,014		2,921
	Other	8,880		7,651
	Total	$	76,640	$	63,259

Marketable_Securities_Tables

Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2014
Marketable Securities [Abstract]	'
Marketable securities by security type	'
	The following table provides the Company’s marketable securities by security type as of March 31, 2014 and December 31, 2013 (in thousands):
		As of March 31, 2014
		Cost		Gross			Gross			Estimated
				Unrealized			Unrealized			Fair
				Gains			Losses			Value
	Commercial paper and corporate bonds	$	365,157	$	142		$	(217	)	$	365,082
	U.S. government agency debt securities	13,000		5			—			13,005
	Total	$	378,157	$	147		$	(217	)	$	378,087
		As of December 31, 2013
		Cost		Gross			Gross			Estimated
				Unrealized			Unrealized			Fair
				Gains			Losses			Value
	Commercial paper and corporate bonds	$	378,135	$	122		$	(196	)	$	378,061
	U.S. government agency debt securities	35,934		3			(1		)	35,936
	Total	$	414,069	$	125		$	(197	)	$	413,997
Contractual maturities of marketable securities	'
	Contractual maturities of the Company’s marketable securities as of March 31, 2014 and December 31, 2013 are summarized as follows (in thousands):
		As of March 31, 2014					As of December 31, 2013
		Cost		Estimated			Cost			Estimated
				Fair						Fair
				Value						Value
	Due in one year or less	$	196,140	$	196,140		$	218,941		$	218,892
	Due in one to five years	182,017		181,947			195,128			195,105
	Total	$	378,157	$	378,087		$	414,069		$	413,997
Fair market value and gross unrealized losses of marketable securities	'
	The following table provides the fair market value and the gross unrealized losses of the Company’s marketable securities with unrealized losses that are not deemed to be other-than-temporarily impaired, aggregated by security type as of March 31, 2014 and December 31, 2013 (in thousands):
		In Loss Position for Less than 12 Months
		As of March 31, 2014					As of December 31, 2013
		Fair		Gross			Fair			Gross
		Value		Unrealized			Value			Unrealized
				Losses						Losses
	Commercial paper and corporate bonds	$	217,329	$	(217	)	$	241,381		$	(196	)
	U.S. government agency debt securities	—		—			10,910			(1		)
	Total	217,329		(217		)	252,291			(197		)

Fair_Value_Tables

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Financial assets measured at fair value on a recurring basis	'
	Financial assets (excluding cash balances) measured at fair value on a recurring basis as of March 31, 2014 and December 31, 2013 are summarized as follows (in thousands):
		As of March 31, 2014								As of December 31, 2013
		Fair Value Measurement Using								Fair Value Measurement Using
		Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
	Assets:
	Money market funds	$	9,184	$	—	$	—	$	9,184	$	751	$	—	$	—	$	751
	Total cash equivalents	9,184		—		—		9,184		751		—		—		751
	Commercial paper and corporate bonds	—		365,082		—		365,082		—		378,061		—		378,061
	U.S. government agency debt securities	—		13,005		—		13,005		—		35,936		—		35,936
	Total marketable securities	—		378,087		—		378,087		—		413,997		—		413,997
	Total financial assets	$	9,184	$	378,087	$	—	$	387,271	$	751	$	413,997	—		$	414,748

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Changes in the carrying amount of goodwill	'
	The change in the carrying amount of goodwill during the three months ended March 31, 2014 is as follows (in thousands):
	Balance as of January 1, 2014	$	15,487
	Foreign currency translation adjustments	46
	Balance as of March 31, 2014	$	15,533
Intangible assets	'
	Intangible assets are summarized as follows (in thousands):
		As of March 31, 2014							As of December 31, 2013
		Gross		Accumulated			Net		Gross		Accumulated			Net
		Carrying		Amortization			Carrying		Carrying		Amortization			Carrying
		Amount					Amount		Amount					Amount
	Acquired technology	$	4,145	$	(3,599	)	$	546	$	4,129	$	(3,481	)	$	648
	Customer relationships	2,078		(1,850		)	228		2,074		(1,818		)	256
	Total	$	6,223	$	(5,449	)	$	774	$	6,203	$	(5,299	)	$	904
Annual amortization for the next five years	'
	Annual amortization for the next five years is expected to be as follows (in thousands):
	Remainder of year ending December 31, 2014	$	417
	Years ending December 31,
	2015	290
	2016	48
	2017	19

Debt_Tables

Debt (Tables)	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Components of convertible senior notes	'
	The components of the Notes are summarized as follows (in thousands):
		March 31,			December 31,
		2014			2013
	Equity component, net of equity issue costs	$	60,222		$	60,222
	Liability component:
	Principal	287,500			287,500
	Less: unamortized debt discount	(55,054		)	(57,795		)
	Net carrying amount	$	232,446		$	229,705
Interest expense related to convertible senior notes	'
	The following table sets forth total interest expense recognized related to the Notes for the three months ended March 31, 2014 (in thousands except percentages):
	Contractual interest expense	$	711
	Amortization of debt issuance costs	319
	Amortization of debt discount	2,741
	Total	$	3,771
	Effective interest rate	6.5		%

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Components of stock-based compensation expense	'
	For the three months ended March 31, 2014 and 2013, the components of stock-based compensation expense are summarized in the following table (in thousands):
		Three Months Ended March 31,
		2014			2013
	Stock options	$	1,214		$	962
	Restricted stock awards	3,169			3,182
	Performance-based restricted stock units	4,750			1,061
	Employee stock purchase plan	566			—
	Total stock-based compensation	$	9,699		$	5,205
Fair value of stock option grants	'
	The fair value of each stock option grant is estimated on the date of grant using the Black-Scholes pricing model with the following weighted-average assumptions:
		Three Months Ended March 31,
		2014		2013
	Expected volatility	42	%	—
	Expected life	6 years		—
	Risk-free interest rate	1.76	%	—
	Dividend yield	—		—
Summary of activities and changes in stock option plans	'
	The following table summarizes the activity under the stock option plans as of March 31, 2014, and changes during the three months then ended (in thousands, except per share data):
		Number of		Weighted-				Weighted-	Aggregate
		Shares		Average				Average	Intrinsic
				Exercise				Remaining	Value
				Price				Contractual
								Term
								(years)
	Outstanding at January 1, 2014	2,670		$	16
	Granted	60		62.95
	Exercised	(125	)	8.65
	Forfeited	(23	)	34.17
	Expired	—		—
	Outstanding at March 31, 2014	2,582		$	17.28			7.14	$	96,571
	Exercisable at March 31, 2014	1,366		$	9.25			5.95	$	61,598
	Vested and expected to vest at March 31, 2014	2,532		$	16.92			7.11	$	95,571
Summary of nonvested restricted stock awards	'
	The following table summarizes the status of the Company’s nonvested RSAs as of March 31, 2014, and changes during the three months then ended (in thousands, except per share data):
		Number of		Weighted-
		Shares		Average
				Grant-Date
				Fair Value
	Nonvested at January 1, 2014	1,672		$	18.06
	Granted	270		54.7
	Vested	(134	)	24.22
	Forfeited	(13	)	15.34
	Nonvested at March 31, 2014	1,795		$	23.14
Fair value of TSR PBRSUs	'
	The fair value of each TSR PBRSU is estimated as of the date of grant based upon evaluation of expected performance relative to the associated market condition using a Monte Carlo valuation model with the following weighted-average assumptions:
		Three Months Ended March 31,
		2014		2013
	Expected volatility - Medidata	52	%	39	%
	Expected volatility - NASDAQ Composite Index	13	%	15	%
	Risk-free interest rate	0.12	%	0.16	%
	Expected term	0.89 years		1.00 year
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 March 31, 2014, and changes during the three months then ended (in thousands, except per share data):
		Revenue		TSR			Long-Term		Other		Total Number of Shares		Weighted-Average Grant Date Fair Value
	Nonvested at January 1, 2014	454		227			1,012		9		1,702		$	29.18
	Granted (based on performance at 100% of targeted levels)	149		74			—		5		228		54.01
	Adjustment related to expected performance	—		—			—		(5	)	(5	)	67.01
	Vested	(151	)	(76	)		—		—		(227	)	26.33
	Forfeited	—		—			—		—		—		—
	Nonvested at March 31, 2014	452		225			1,012		9		1,698		$	32.79
Fair value of employee stock purchase plan shares	'
	The fair value of ESPP shares is estimated using the Black-Scholes pricing model with the following weighted-average assumptions:
		Three Months Ended March 31,
		2014		2013
	Expected volatility	49	%	—
	Expected life	1.22 years		—
	Risk-free interest rate	0.21	%	—
	Dividend yield	—		—

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2014
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 three months ended March 31, 2014 are as follows (in thousands):
		Foreign Currency Translation Adjustments			Unrealized Losses On Available-For-Sale Securities			Total
	Balance as of January 1, 2014	$	(127	)	$	(72	)	$	(199	)
	Other comprehensive income, net of tax	182			1			183
	Balance as of March 31, 2014	$	55		$	(71	)	$	(16	)

Earnings_Loss_Per_Share_Tables

Earnings (Loss) Per Share (Tables)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Reconciliation of the numerators and denominators of basic and diluted (loss) earnings per share	'
	All share and per share data for all periods presented reflect the impact of a two-for-one stock split which was effected in the form of a stock dividend in December 2013. A reconciliation of the numerators and denominators of basic (loss) earnings per share and diluted (loss) earnings per share for the three months ended March 31, 2014 and 2013 are shown in the following table (in thousands, except per share data):
		Three Months Ended March 31,
		2014				2013
	Numerator
	Net (loss) income	$	(1,815	)		$	5,700
	Denominator
	Denominator for basic earnings (loss) per share:
	Weighted average common shares outstanding	52,109				50,240
	Denominator for diluted earnings (loss) per share:
	Dilutive potential common shares:
	Stock options	—				1,442
	Restricted stock awards	—				830
	Performance-based restricted stock units	—				10
	Weighted average common shares outstanding with assumed conversion	52,109				52,522
	Basic (loss) earnings per share	$	(0.03	)		$	0.11
	Diluted (loss) earnings per share	$	(0.03	)		$	0.11
Schedule of antidilutive securities excluded from computation of earnings per share	'
	Antidilutive common stock equivalents excluded from the calculation of dilutive (loss) earnings per share for the three months ended March 31, 2014 and 2013 are shown in the following table (in thousands, except per share data):
		Three Months Ended March 31,
		2014			2013
	Stock options	2,625			126
	Restricted stock awards	1,759			6
	Performance-based restricted stock units	1,713			2
	Employee stock purchase plan	243			—
	Convertible notes	234			—
	Total	6,574			134

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Revenues and long-term assets by geographic segment	'	'	'
Revenues	$76,640	$63,259	'
Long-term assets	254,006	'	268,808
Specified percentage of net revenue required for separate reporting of countries' revenue	5.00%	'	'
United States of America [Member]	'	'	'
Revenues and long-term assets by geographic segment	'	'	'
Revenues	55,789	44,854	'
Long-term assets	239,406	'	254,453
United Kingdom [Member]	'	'	'
Revenues and long-term assets by geographic segment	'	'	'
Long-term assets	9,516	'	10,041
Japan [Member]	'	'	'
Revenues and long-term assets by geographic segment	'	'	'
Revenues	7,957	7,833	'
Long-term assets	5,084	'	4,314
Switzerland [Member]	'	'	'
Revenues and long-term assets by geographic segment	'	'	'
Revenues	4,014	2,921	'
Other countries [Member]	'	'	'
Revenues and long-term assets by geographic segment	'	'	'
Revenues	$8,880	$7,651	'

Summary_of_Significant_Account4

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details Textual) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Accounting Policies [Abstract]	'	'
Unbilled receivables	$6.20	$9.50

Stockholders_Equity_Details

Stockholders' Equity (Details) (USD $)	3 Months Ended
	Mar. 31, 2014
Equity [Abstract]	'
Stock split ratio	2
Description of stock split	'effected in the form of a stock dividend. The record date for the stock split was December 2, 2013, and the additional shares were distributed on December 16, 2013. Each shareholder of record as of the close of business on the record date received one additional share of common stock for each share held.
Shares paid for tax withholding for share based compensation	164,738
Shares paid for tax withholding for share based compensation, average price	$59.67

Marketable_Securities_Details

Marketable Securities (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Marketable securities by security type	'	'
Cost	$378,157	$414,069
Gross unrealized gains	147	125
Gross unrealized losses	-217	-197
Estimated fair value	378,087	413,997
Commercial paper and corporate bonds [Member]	'	'
Marketable securities by security type	'	'
Cost	365,157	378,135
Gross unrealized gains	142	122
Gross unrealized losses	-217	-196
Estimated fair value	365,082	378,061
U.S. government agency debt securities [Member]	'	'
Marketable securities by security type	'	'
Cost	13,000	35,934
Gross unrealized gains	5	3
Gross unrealized losses	0	-1
Estimated fair value	$13,005	$35,936

Marketable_Securities_Details_

Marketable Securities (Details 1) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Marketable securities by contractual maturity	'	'
Cost	$378,157	$414,069
Estimated fair value	378,087	413,997
One year or less [Member]	'	'
Marketable securities by contractual maturity	'	'
Cost	196,140	218,941
Estimated fair value	196,140	218,892
One to five years [Member]	'	'
Marketable securities by contractual maturity	'	'
Cost	182,017	195,128
Estimated fair value	$181,947	$195,105

Marketable_Securities_Details_1

Marketable Securities (Details 2) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair market value and gross unrealized losses of marketable securities	'	'
Fair value	$217,329	$252,291
Gross unrealized losses	-217	-197
Commercial paper and corporate bonds [Member]	'	'
Fair market value and gross unrealized losses of marketable securities	'	'
Fair value	217,329	241,381
Gross unrealized losses	-217	-196
U.S. government agency debt securities [Member]	'	'
Fair market value and gross unrealized losses of marketable securities	'	'
Fair value	0	10,910
Gross unrealized losses	$0	($1)

Marketable_Securities_Details_2

Marketable Securities (Details Textual) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Marketable Securities (Textual)	'	'	'
Marketable securities in a continuous unrealized loss position for more than 12 months	$0	'	$0
Net realized gains (losses) from the sale of marketable securities	$1	$0	'

Fair_Value_Details

Fair Value (Details) (Fair value, recurring [Member], USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets	'	'
Cash equivalents	$9,184	$751
Total marketable securities	378,087	413,997
Total financial assets	387,271	414,748
Level 1 [Member]	'	'
Assets	'	'
Cash equivalents	9,184	751
Total marketable securities	0	0
Total financial assets	9,184	751
Level 1 [Member] | Money market funds [Member]	'	'
Assets	'	'
Cash equivalents	9,184	751
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	'	'
Cash equivalents	0	0
Total marketable securities	378,087	413,997
Total financial assets	378,087	413,997
Level 2 [Member] | Money market funds [Member]	'	'
Assets	'	'
Cash equivalents	0	0
Level 2 [Member] | Commercial paper and corporate bonds [Member]	'	'
Assets	'	'
Total marketable securities	365,082	378,061
Level 2 [Member] | U.S. government agency debt securities [Member]	'	'
Assets	'	'
Total marketable securities	13,005	35,936
Level 3 [Member]	'	'
Assets	'	'
Cash equivalents	0	0
Total marketable securities	0	0
Total financial assets	0	0
Level 3 [Member] | Money market funds [Member]	'	'
Assets	'	'
Cash equivalents	0	0
Level 3 [Member] | Commercial paper and corporate bonds [Member]	'	'
Assets	'	'
Total marketable securities	0	0
Level 3 [Member] | U.S. government agency debt securities [Member]	'	'
Assets	'	'
Total marketable securities	$0	$0

Fair_Value_Details_Textual

Fair Value (Details Textual) (USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Fair value (Textual) [Abstract]	'	'
Net asset value per share used to value money market and U.S. Treasury debt securities	$1	'
Transfers of financial assets between Level 1 and Level 2	$0	$0

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014
Changes in the carrying amount of goodwill	'
Balance as of January 1, 2014	$15,487
Foreign currency translation adjustments	46
Balance as of March 31, 2014	$15,533

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets (Details 1) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Intangible assets	'	'
Gross carrying amount	$6,223	$6,203
Accumulated amortization	-5,449	-5,299
Net carrying amount	774	904
Acquired technology [Member]	'	'
Intangible assets	'	'
Gross carrying amount	4,145	4,129
Accumulated amortization	-3,599	-3,481
Net carrying amount	546	648
Customer relationships [Member]	'	'
Intangible assets	'	'
Gross carrying amount	2,078	2,074
Accumulated amortization	-1,850	-1,818
Net carrying amount	$228	$256

Goodwill_and_Intangible_Assets4

Goodwill and Intangible Assets (Details 2) (USD $)	Mar. 31, 2014
In Thousands, unless otherwise specified
Annual amortization for the next five years	'
Remainder of year ending December 31, 2014	$417
Year ending December 31, 2015	290
Year ending December 31, 2016	48
Year ending December 31, 2017	$19

Debt_Details

Debt (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Aug. 12, 2013
In Thousands, unless otherwise specified
Components of convertible senior notes	'	'	'
Equity component net of equity issue costs	$60,222	$60,222	'
Principal amount	287,500	287,500	287,500
Unamortized discount	-55,054	-57,795	'
Convertible senior notes, net carrying amount	$232,446	$229,705	'

Debt_Details_1

Debt (Details 1) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Interest expense on convertible senior notes	'	'
Convertible senior notes, contractual interest expense	$711	'
Amortization of debt issuance costs	319	'
Amortization of debt discount	2,741	0
Convertible senior notes, total interest expense	$3,771	'
Convertible senior notes, effective interest rate during period	6.50%	'

Debt_Details_Textual

Debt (Details Textual) (USD $)	3 Months Ended
	Mar. 31, 2014		Dec. 31, 2013	Aug. 12, 2013
Convertible senior notes	'		'	'
Principal amount	$287,500,000		$287,500,000	$287,500,000
Stated interest rate	'		'	1.00%
Interest payment terms	'Interest is payable semi-annually in arrears on August 1 and February 1 of each year, beginning on February 1, 2014.		'	'
Maturity	'The Notes mature on August 1, 2018 unless repurchased or converted in accordance with their terms prior to such date. The Company may not redeem the Notes prior to their maturity date.		'	'
Settlement terms	'Upon conversion of the Notes, the Company may choose to pay or deliver, as applicable, either cash, shares of the Company's common stock, or a combination thereof. If converted, holders of the Notes will receive, at the Company's election, cash and/or shares for the principal amount of the Notes as well as any amounts in excess of principal. The Company intends to settle the principal amount of the Notes in cash if converted.		'	'
Conversion ratio	17.2286	[1]	'	'
Face amount	'		'	1,000
Conversion price	'		'	$58.05	[1]
Terms of conversion feature	'The initial conversion rate is 17.2286 shares of the Company's common stock per $1,000 principal amount of Notes, which is equivalent to an initial conversion price of approximately $58.05 per share of common stock. The conversion rate will be subject to adjustment upon occurrence of certain events, including, but not limited to, the issuance of stock dividends or payment of cash dividends on the Company's common stock (unless the holders of the Notes participate at the same time and under the same terms as the holders of common stock), or execution of a share split or share combination. Upon conversion, holders of the Notes will not receive any separate cash payment representing accrued and unpaid interest, unless conversion occurs after close of business on a regular record date and prior to the related interest payment date. Holders may convert their Notes at their option at any time prior to the close of business on the business day immediately preceding February 1, 2018 only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on December 31, 2013 (and only during such calendar quarter), if the last reported sale price of the common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five business day period after any five consecutive trading day period (the "measurement period") in which the trading price per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company's common stock and the conversion rate on such trading day; or (3) upon the occurrence of certain corporate events described in the indenture governing the Notes. On or after February 1, 2018 until close of business on the business day immediately preceding the maturity date, holders may convert their Notes at any time, regardless of the foregoing circumstances. If the Company undergoes a fundamental change as defined in the indenture governing the Notes, holders may require the Company to repurchase for cash all of their Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased plus accrued and unpaid interest.		'	'
Issuance costs	8,100,000		'	'
Issuance costs related to debt component	6,400,000		'	'
Issuance costs related to equity component	1,700,000		'	'
Unamortized debt issuance costs	5,500,000		'	'
Closing price of the Company's common stock	$54.34		'	'
Approximate remaining life	'52 months		'	'
Convertible Debt [Member] | Fair Value, Inputs, Level 2 [Member]	'		'	'
Convertible senior notes	'		'	'
Approximate fair value	$345,700,000		$365,100,000	'
[1]	Prior period results have been adjusted to reflect the two-for-one stock split which was effected in the form of a stock dividend in December 2013.

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Components of stock-based compensation expense	'	'
Total stock-based compensation	$9,699	$5,205
Stock options [Member]	'	'
Components of stock-based compensation expense	'	'
Total stock-based compensation	1,214	962
Restricted stock awards [Member]	'	'
Components of stock-based compensation expense	'	'
Total stock-based compensation	3,169	3,182
Performance-based restricted stock units [Member]	'	'
Components of stock-based compensation expense	'	'
Total stock-based compensation	4,750	1,061
Employee stock purchase plan [Member]	'	'
Components of stock-based compensation expense	'	'
Total stock-based compensation	$566	$0

StockBased_Compensation_Detail1

Stock-Based Compensation (Details 1) (Stock options [Member])	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Stock options [Member]	'	'
Weighted-average Black-Scholes assumptions used to estimate fair value of stock options granted	'	'
Expected volatility	42.00%	0.00%
Expected life	'6 years	'0 years
Risk-free interest rate	1.76%	0.00%
Dividend yield	0.00%	0.00%

StockBased_Compensation_Detail2

Stock-Based Compensation (Details 2) (Stock options [Member], USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014
Stock options [Member]	'
Summary of activities and changes in stock option plans	'
Number of shares outstanding at beginning of period	2,670
Weighted-average exercise price outstanding at beginning of period	$16
Number of shares granted	60
Weighted-average exercise price granted	$62.95
Number of shares exercised	-125
Weighted-average exercise price exercised	$8.65
Number of shares forfeited	-23
Weighted-average exercise price forfeited	$34.17
Number of shares expired	0
Weighted-average exercise price expired	$0
Number of shares outstanding at end of period	2,582
Weighted-average exercise price outstanding at end of period	$17.28
Weighted average remaining contractual term outstanding at end of period	'7 years 1 month 21 days
Aggregate intrinsic value outstanding at end of period	$96,571
Number of shares exercisable at end of period	1,366
Weighted-average exercise price exercisable at end of period	$9.25
Weighted average remaining contractual term exercisable at end of period	'5 years 11 months 12 days
Aggregate intrinsic value exercisable at end of period	61,598
Number of shares vested and expected to vest at end of period	2,532
Weighted-average exercise price vested and expected to vest at end of period	$16.92
Weighted average remaining contractual term vested and expected to vest at end of period	'7 years 1 month 10 days
Aggregate intrinsic value vested and expected to vest at end of period	$95,571

StockBased_Compensation_Detail3

Stock-Based Compensation (Details 3) (Restricted stock awards [Member], USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014
Restricted stock awards [Member]	'
Summary of nonvested restricted stock awards	'
Nonvested number of shares/units at beggining of period	1,672
Nonvested weighted-average grant-date fair value at beginning of period	$18.06
Granted number of shares	270
Granted weighted-average grant-date fair value	$54.70
Vested number of shares/units	-134
Vested weighted-average grant-date fair value	$24.22
Forfeited number of shares/units	-13
Forfeited weighted-average grant-date fair value	$15.34
Nonvested number of shares/units at end of period	1,795
Nonvested weighted-average grant-date fair value at end of period	$23.14

StockBased_Compensation_Detail4

Stock-Based Compensation (Details 4) (Performance-based restricted stock units [Member], TSR [Member])	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Performance-based restricted stock units [Member] | TSR [Member]	'	'
Assumptions used to estimate fair value of TSR PBRSUs	'	'
Expected volatility - Medidata	52.00%	39.00%
Expected volatility - NASDAQ	13.00%	15.00%
Risk-free interest rate	0.12%	0.16%
Expected term	'10 months 21 days	'1 year

StockBased_Compensation_Detail5

Stock-Based Compensation (Details 5) (Performance-based restricted stock units [Member], USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014
Summary of performance-based restricted stock units based upon expected performance	'
Nonvested number of shares/units at beggining of period	1,702
Nonvested weighted-average grant-date fair value at beginning of period	$29.18
Granted number of units (based on performance at 100% of targeted levels)	228
Granted weighted-average grant-date fair value	$54.01
Adjustment due to expected performance	-5
Adjustment due to expected performance weighted average grant date fair value	$67.01
Vested number of shares/units	-227
Vested weighted-average grant-date fair value	$26.33
Forfeited number of shares/units	0
Forfeited weighted-average grant-date fair value	$0
Nonvested number of shares/units at end of period	1,698
Nonvested weighted-average grant-date fair value at end of period	$32.79
Revenue [Member]	'
Summary of performance-based restricted stock units based upon expected performance	'
Nonvested number of shares/units at beggining of period	454
Granted number of units (based on performance at 100% of targeted levels)	149
Adjustment due to expected performance	0
Vested number of shares/units	-151
Forfeited number of shares/units	0
Nonvested number of shares/units at end of period	452
TSR [Member]	'
Summary of performance-based restricted stock units based upon expected performance	'
Nonvested number of shares/units at beggining of period	227
Granted number of units (based on performance at 100% of targeted levels)	74
Adjustment due to expected performance	0
Vested number of shares/units	-76
Forfeited number of shares/units	0
Nonvested number of shares/units at end of period	225
Long-term [Member]	'
Summary of performance-based restricted stock units based upon expected performance	'
Nonvested number of shares/units at beggining of period	1,012
Granted number of units (based on performance at 100% of targeted levels)	0
Adjustment due to expected performance	0
Vested number of shares/units	0
Forfeited number of shares/units	0
Nonvested number of shares/units at end of period	1,012
Other [Member]	'
Summary of performance-based restricted stock units based upon expected performance	'
Nonvested number of shares/units at beggining of period	9
Granted number of units (based on performance at 100% of targeted levels)	5
Adjustment due to expected performance	-5
Vested number of shares/units	0
Forfeited number of shares/units	0
Nonvested number of shares/units at end of period	9

StockBased_Compensation_Detail6

Stock-Based Compensation (Details 6) (Employee stock purchase plan [Member])	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Employee stock purchase plan [Member]	'	'
Weighted-average Black-Scholes assumptions used to estimate fair value of ESPP shares	'	'
Expected volatility	49.00%	0.00%
Expected life	'1 year 2 months 19 days	'0 years
Risk-free interest rate	0.21%	0.00%
Dividend yield	0.00%	0.00%

StockBased_Compensation_Detail7

Stock-Based Compensation (Details Textual) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Stock based compensation (Textual) [Abstract]	'	'
Total stock-based compensation	$9,699,000	$5,205,000
Stock options [Member]	'	'
Stock based compensation (Textual) [Abstract]	'	'
Weighted-average grant-date fair value of stock options granted	$26.79	$0
Total intrinsic value of stock options exercised	6,800,000	4,400,000
Unrecognized compensation cost related to non-vested stock-based compensation awards granted	12,500,000	'
Weighted-average remaining period over which cost is expected to be recognized	'2 years 5 months 23 days	'
Total fair value of shares vested	700,000	900,000
Total stock-based compensation	1,214,000	962,000
Restricted stock awards [Member]	'	'
Stock based compensation (Textual) [Abstract]	'	'
Unrecognized compensation cost related to non-vested stock-based compensation awards granted	34,500,000	'
Weighted-average remaining period over which cost is expected to be recognized	'2 years 2 months 9 days	'
Total fair value of shares vested	8,400,000	200,000
Total stock-based compensation	3,169,000	3,182,000
Performance-based restricted stock units [Member]	'	'
Stock based compensation (Textual) [Abstract]	'	'
Unrecognized compensation cost related to non-vested stock-based compensation awards granted	40,600,000	'
Weighted-average remaining period over which cost is expected to be recognized	'2 years 0 months 15 days	'
Total fair value of shares vested	13,300,000	0
Total stock-based compensation	4,750,000	1,061,000
Performance-based restricted stock units [Member] | Revenue [Member]	'	'
Stock based compensation (Textual) [Abstract]	'	'
Target number of performance-based restricted stock units granted during the period	149,000	'
Award terms	'performance conditions based on revenue for the year ending December 31, 2014 relative to the Company's revenue guidance and a minimum profitability condition, vesting annually over three years commencing on the first anniversary of the grant date, with the number of PBRSUs ultimately earned ranging from zero to 200% of the original award	'
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	74,000	'
Award terms	'market conditions based on the Company's total stockholder return ("TSR") relative to that of the NASDAQ Composite Index for the year ending December 31, 2014, vesting annually over three years commencing on the first anniversary of the grant date, with the number of PBRSUs ultimately earned ranging from zero to 200% of the original award	'
Employee stock purchase plan [Member]	'	'
Stock based compensation (Textual) [Abstract]	'	'
Unrecognized compensation cost related to non-vested stock-based compensation awards granted	4,000,000	'
Weighted-average remaining period over which cost is expected to be recognized	'1 year 9 months	'
Description of employee stock purchase plan	'The ESPP allows eligible employees to purchase shares of the Company's common stock at a discount though payroll deductions, and consists of a 24-month offering period with four six-month purchase periods in each offering period. Employees purchase shares at the lesser of (1) 85% of the fair market value (bFMVb) per share on the first day of the offering period, or (2) 85% of the FMV per share at the end of the relevant purchase period.	'
Shares reserved under employee stock purchase plan	300,000	'
Total stock-based compensation	$566,000	$0

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Loss (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Accumulated other comprehensive loss	'	'
Balance as of January 1, 2014	($199)	'
Other comprehensive income (loss), net of tax	183	-993
Balance as of March 31, 2014	-16	'
Unrealized gains (losses) on available for sale securities	'	'
Accumulated other comprehensive loss	'	'
Balance as of January 1, 2014	-72	'
Other comprehensive income (loss), net of tax	1	'
Balance as of March 31, 2014	-71	'
Foreign currency translation adjustments	'	'
Accumulated other comprehensive loss	'	'
Balance as of January 1, 2014	-127	'
Other comprehensive income (loss), net of tax	182	'
Balance as of March 31, 2014	$55	'

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Loss (Details Textual) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]	'
Reclassifications from accumulated other comprehensive income (loss)	$0

Earnings_Loss_Per_Share_Detail

Earnings (Loss) Per Share (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Numerator	'	'
Net (loss) income	($1,815)	$5,700
Denominator for basic (loss) earnings per share:	'	'
Weighted average common shares outstanding	52,109	50,240	[1]
Dilutive potential common shares:	'	'
Stock based compensation	0	1,442	[1]
Restricted stock awards	0	830	[1]
Performance-based restricted stock units	0	10	[1]
Weighted average common shares outstanding with assumed conversion	52,109	52,522	[1]
Basic (loss) earnings per share	($0.03)	$0.11	[1]
Diluted (loss) earnings per share	($0.03)	$0.11	[1]
[1]	Prior period results have been adjusted to reflect the two-for-one stock split which was effected in the form of a stock dividend in December 2013.

Earnings_Loss_Per_Share_Detail1

Earnings (Loss) Per Share (Details 1)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Antidilutive common stock equivalents excluded from the calculation of diluted earnings (loss) per share	'	'
Antidilutive shares excluded from calculation of diluted (loss) earnings per share	6,574	134	[1]
Stock options [Member]	'	'
Antidilutive common stock equivalents excluded from the calculation of diluted earnings (loss) per share	'	'
Antidilutive shares excluded from calculation of diluted (loss) earnings per share	2,625	126	[1]
Restricted stock awards [Member]	'	'
Antidilutive common stock equivalents excluded from the calculation of diluted earnings (loss) per share	'	'
Antidilutive shares excluded from calculation of diluted (loss) earnings per share	1,759	6	[1]
Performance-based restricted stock units [Member]	'	'
Antidilutive common stock equivalents excluded from the calculation of diluted earnings (loss) per share	'	'
Antidilutive shares excluded from calculation of diluted (loss) earnings per share	1,713	2	[1]
Employee stock purchase plan [Member]	'	'
Antidilutive common stock equivalents excluded from the calculation of diluted earnings (loss) per share	'	'
Antidilutive shares excluded from calculation of diluted (loss) earnings per share	243	0	[1]
Convertible notes [Member]	'	'
Antidilutive common stock equivalents excluded from the calculation of diluted earnings (loss) per share	'	'
Antidilutive shares excluded from calculation of diluted (loss) earnings per share	234	0	[1]
[1]	Prior period results have been adjusted to reflect the two-for-one stock split which was effected in the form of a stock dividend in December 2013.

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Income Taxes (Textual) [Abstract]	'	'	'
Effective tax rate	41.00%	22.00%	'
Federal statutory income tax rate	35.00%	35.00%	'
R&D tax credit recognized during period	'	$1.20	'
Gross unrecognized tax benefits	'	'	4.1
Changes in tax position	$0	'	'

Commitments_and_Contingencies_

Commitments and Contingencies (Details)	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies (Textual) [Abstract]	'
Period following change in control for payments to be made upon involuntary termination of employment	'2 years
Period following change in control for continuation of health benefits	'12 months