Nuvasive (NUVA) 10-Q 4 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 24, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	NUVASIVE INC
Entity Central Index Key	1142596
Document Type	10-Q
Document Period End Date	31-Mar-15
Amendment Flag	FALSE
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	NUVA
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		48,356,489

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$88,494	$142,387
Short-term marketable securities	200,809	220,329
Accounts receivable, net of allowances of $6,119 and $5,844, respectively	111,547	118,959
Inventory, net	163,413	154,638
Deferred and prepaid taxes	59,608	59,233
Prepaid expenses and other current assets	8,992	10,325
Total current assets	632,863	705,871
Property and equipment, net	139,541	128,565
Long-term marketable securities	27,501	43,042
Intangible assets, net	92,640	96,555
Goodwill	154,273	154,443
Deferred tax assets, non-current	65,196	65,330
Restricted cash and investments	156,155	123,233
Other assets	27,439	26,420
Total assets	1,295,608	1,343,459
Current liabilities:
Accounts payable and accrued liabilities	71,507	133,324
Accrued payroll and related expenses	27,702	38,032
Litigation liability	14,000	30,000
Deferred and income tax liabilities	750	13,543
Total current liabilities	113,959	214,899
Senior Convertible Notes	364,588	360,746
Deferred and income tax liabilities, non-current	23,517	12,526
Non-current litigation liability	117,430	93,700
Other long-term liabilities	12,633	13,230
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized, none outstanding
Common stock, $0.001 par value; 120,000,000 shares authorized at March 31, 2015 and December 31, 2014, 49,674,361 and 47,691,744 issued and outstanding at March 31, 2015 and December 31, 2014, respectively	50	48
Additional paid-in capital	884,469	847,145
Accumulated other comprehensive loss	-11,722	-9,670
Accumulated deficit	-155,378	-186,938
Treasury stock at cost; 1,345,606 shares and 233,369 shares at March 31, 2015 and December 31, 2014, respectively	-62,085	-10,537
Total NuVasive, Inc. stockholders’ equity	655,334	640,048
Non-controlling interests	8,147	8,310
Total equity	663,481	648,358
Total liabilities and equity	$1,295,608	$1,343,459

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified
Statement Of Financial Position [Abstract]
Accounts receivable, allowances	$6,119	$5,844
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	49,674,361	47,691,744
Common stock, shares outstanding	49,674,361	47,691,744
Treasury stock at cost, shares	1,345,606	233,369

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Revenue	$192,383	$177,496
Cost of goods sold (excluding below amortization of intangible assets)	45,664	43,294
Gross profit	146,719	134,202
Operating expenses:
Sales, marketing and administrative	116,096	118,104
Research and development	9,264	9,455
Amortization of intangible assets	2,996	3,998
Litigation liability (gain) loss	-42,575	30,000
Business transition costs	5,373
Total operating expenses	91,154	161,557
Interest and other expense, net:
Interest income	419	217
Interest expense	-7,126	-6,865
Other income (expense), net	424	375
Total interest and other expense, net	-6,283	-6,273
Income (loss) before income taxes	49,282	-33,628
Income tax (expense) benefit	-17,885	15,095
Consolidated net income (loss)	31,397	-18,533
Add back net loss attributable to non-controlling interests	-163	-257
Net income (loss) attributable to NuVasive, Inc.	$31,560	($18,276)
Net income (loss) per share attributable to NuVasive, Inc.:
Basic	$0.66	($0.40)
Diluted	$0.61	($0.40)
Weighted average shares outstanding:
Basic	47,989	45,798
Diluted	51,716	45,798

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (Loss) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Consolidated net income (loss)	$31,397	($18,533)
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities, net of tax	133	-12
Translation adjustments, net of tax	-2,185	1,071
Other comprehensive (loss) income:	-2,052	1,059
Total consolidated comprehensive income (loss)	29,345	-17,474
Net loss attributable to non-controlling interests	163	257
Comprehensive income (loss) attributable to NuVasive, Inc.	$29,508	($17,217)

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Operating activities:
Consolidated net income (loss)	$31,397	($18,533)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	16,051	15,363
Amortization of non-cash interest	4,331	4,000
Stock-based compensation	7,611	7,764
Deferred income taxes	11,015
Reserves on current assets	633	1,366
Other non-cash adjustments	6,172	1,661
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable	5,931	-1,194
Inventory	-11,367	-11,743
Prepaid expenses and other current assets	444	-2,807
Accounts payable and accrued liabilities	17,428	17,951
Income taxes	-13,731	-16,751
Accrued royalties	-47,459	3,291
Litigation liability	7,730	30,000
Accrued payroll and related expenses	-10,163	-7,068
Net cash provided by operating activities	26,023	23,300
Investing activities:
Cash paid for acquisitions and investments	-1,357
Purchase of intangible assets	-27,389
Purchases of property and equipment	-30,694	-13,390
Purchases of marketable securities	-71,129	-46,126
Sales of marketable securities	105,794	36,257
Purchases of restricted investments	-32,616
Net cash used in investing activities	-57,391	-23,259
Financing activities:
Incremental tax benefits related to stock-based compensation awards	8,092
Proceeds from the issuance of common stock	1,403	8,749
Payment of contingent consideration	-514	-498
Purchase of treasury stock	-30,944
Other financing activities	-45	-596
Net cash (used in) provided by financing activities	-22,008	7,655
Effect of exchange rate changes on cash	-517	256
(Decrease) increase in cash and cash equivalents	-53,893	7,952
Cash and cash equivalents at beginning of period	142,387	102,825
Cash and cash equivalents at end of period	$88,494	$110,777

Description_of_Business_and_Ba

Description of Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business and Basis of Presentation	1.    Description of Business and Basis of Presentation
	Description of Business
	NuVasive, Inc. (the “Company” or “NuVasive”) was incorporated in Delaware on July 21, 1997, and began commercializing its products in 2001. The Company is focused on developing minimally-disruptive surgical products and procedurally-integrated solutions for the spine. NuVasive’s principal product offering includes a minimally-disruptive surgical platform called Maximum Access Surgery, or MAS®. The MAS platform combines three categories of solutions that collectively minimize soft tissue disruption during spine fusion surgery, provide maximum visualization and are designed to enable safe and reproducible outcomes for the surgeon and the patient. The platform includes proprietary software-driven nerve detection and avoidance systems, NVM5® and NVJJB®, and Intra-Operative Monitoring (“IOM”) services and support; MaXcess®, an integrated split-blade retractor system; and a wide variety of specialized implants and biologics. Many of the Company’s products, including the individual components of NuVasive’s MAS platform, can also be used in open or traditional spine surgery. The Company’s spine surgery product line offerings, which include thoracolumbar product offerings, cervical product offerings, IOM services, and disposables, are primarily used to enable access to the spine and to perform restorative and fusion procedures in a minimally-disruptive fashion.  The Company’s biologic product line offerings used to aid the spinal fusion process or bone healing process include Osteocel® Plus and Osteocel Pro allograft (donated human tissue) which are cellular matrix products containing viable mesenchymal stem cells (“MSCs”), as well as other allograft offerings, FormaGraft®, a collagen synthetic product, and AttraX®, a synthetic bone graft material that is currently available commercially only in select markets outside of the United States. The Company continues to focus significant research and development efforts to expand its MAS product platform and advance the applications of its unique technology into procedurally-integrated surgical solutions. The Company has dedicated and continues to dedicate significant resources toward training spine surgeons around the world; both those who are new to its MAS product platform as well as previously MAS-trained surgeons attending advanced courses.
	The Company’s primary business model is to loan its MAS systems to surgeons and hospitals who use such systems to perform individual procedures, with the hospitals purchasing implants, biologics and disposables in each such case. In addition, for larger customers, the Company’s proprietary nerve monitoring systems, MaXcess and surgical instrument sets are placed with hospitals for an extended period at no up-front cost to them, facilitating the hospital’s purchase of disposables for such machines from the Company. The Company also offers a range of bone allograft in patented saline packaging, disposables and spine implants, which include its branded CoRoent® products and fixation devices such as rods, plates and screws. The Company’s implants, biologics and disposables are currently sold and shipped from its primary distribution and warehousing operations facility located in Memphis, Tennessee. The Company sells MAS instrument sets, MaXcess devices and its proprietary software-driven nerve monitoring systems, however this does not make up a material part of its business.
	Basis of Presentation and Principles of Consolidation
	The accompanying Unaudited Consolidated Financial Statements include the accounts of the Company and its majority-owned or controlled subsidiaries, collectively referred to as either NuVasive or the Company. The Company translates the financial statements of its foreign subsidiaries using end-of-period exchange rates for assets and liabilities and average exchange rates during each reporting period for results of operations. When there is a portion of equity in an acquired subsidiary not attributable, directly or indirectly, to the respective parent entity, the Company records the fair value of the non-controlling interests at the acquisition date and classifies the amounts attributable to non-controlling interests separately in equity in the Company’s Consolidated Financial Statements. Any subsequent changes in a parent’s ownership interest while the parent retains its controlling financial interest in its subsidiary are accounted for as equity transactions. All significant intercompany balances and transactions have been eliminated in consolidation.
	The accompanying Unaudited Consolidated Financial Statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Pursuant to these rules and regulations, the Company has condensed or omitted certain information and footnote disclosures it normally includes in its annual Consolidated Financial Statements prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). Operating results for the three months ended March 31, 2015 are not necessarily indicative of the results that may be expected for any other interim period or for the full year. These Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and notes thereto for the year ended December 31, 2014 included in the Company’s Annual Report on Form 10-K filed with the SEC. In the opinion of management, the Consolidated Financial Statements include all adjustments that are of a normal and recurring nature that are necessary for the fair presentation of the Company’s financial position and of the results of operations and cash flows for the periods presented.
	The Company has reclassified historically presented product offerings revenue to conform to the current year presentation. The reclassification had no impact on previously reported results of operations or financial position.
	Change in Accounting Estimate
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and disclosures of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	Business Transition Costs
	From time to-time, the Company incurs costs related to integration and business transition activities which include severance, relocation, consulting, and other costs directly associated to such activities. The nature of these costs is that of personnel costs that the Company believes arise and warrant specific disclosure. During the three months ended March 31, 2015, the Company incurred $5.4 million of such costs, which included a $3.4 million charge associated with the resignation of the Company’s former Chief Executive Officer and Chairman of the Board, Alex V. Lukianov. Such resignation occurred in the first quarter 2015 and was announced on April 1, 2015 via filing of a Current Report on Form 8-K with the SEC. The $3.4 million charge includes certain severance and compensation-related charges, net of certain forfeitures of previously recognized equity compensation.
	Restructuring Charges
	The Company exited its New Jersey location and terminated the respective lease to reduce its footprint on the east coast of the United States as part of a company-wide efficiency effort in order to match its business needs without adversely impacting its ability to deliver surgeon education and local customer fulfillment. As a result of this undertaking, the Company recognized restructuring and associated impairment charges of $2.3 million during the three months ended March 31, 2015 in addition to the $6.4 million recognized during 2014. The restructuring and impairment charges mainly consist of the future rental payments through 2017, net with estimated future sublease income, and elimination of related leasehold improvements and deferred rent liabilities. These charges are recorded in sales, marketing and administrative expense in the Consolidated Statements of Operations.
	As of March 31, 2015, the total recorded liability associated with this early lease termination was $4.9 million and consists of future rental payments net of estimated sublease income through 2017. The current portion of the liability is recorded within accounts payable and accrued liabilities and the long-term portion is recorded within other long-term liabilities in the Consolidated Balance Sheets at March 31, 2015.
	Comprehensive Income (Loss)
	Comprehensive income (loss) is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources. Comprehensive income (loss) includes unrealized gains or losses on the Company’s marketable securities and foreign currency translation adjustments. The cumulative translation adjustments included in accumulated other comprehensive income (loss) were a net cumulative loss of $11.7 million and $9.5 million at March 31, 2015 and December 31, 2014, respectively.
	Long-Lived Assets
	Long-lived assets include surgical instruments, which are loaned to surgeons and hospitals who purchase implants, biologics and disposables for use in individual procedures, leasehold improvements, software, and intangible assets. The Company periodically re-evaluates the original assumptions and rationale utilized in the establishment of the carrying value and estimated lives of its long-lived assets. The criteria used for these evaluations include management’s estimate of the asset’s continuing ability to generate income from operations and positive cash flow in future periods as well as the strategic significance of any intangible asset to the Company’s business objectives. If assets are considered to be impaired, the impairment recognized is the amount by which the carrying value of the assets exceeds the fair value of the assets, which is determined by applicable market prices when available or other methods by utilizing unobservable inputs including discounted cash flow models. See Note 3, Financial Instruments and Fair Value Measurements for further discussion.
	Inventories
	The Company’s inventory consists primarily of purchased finished goods which includes specialized implants and disposables, and is stated at the lower of cost or market determined by a weighted average cost method. The Company reviews the components of its inventory on a periodic basis for excess, obsolete or impaired inventory, and records a reserve for such identified items. The inventory reserve was $23.0 million and $22.7 million at March 31, 2015 and December 31, 2014, respectively.

Net_Income_Loss_Per_Share

Net Income (Loss) Per Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	2.    Net Income (Loss) Per Share
	The Company computes basic net income (loss) per share using the weighted-average number of shares of common stock outstanding during the period. Diluted net income (loss) per share assumes the conversion, exercise or issuance of all potential common stock equivalents, unless the effect of inclusion would be anti-dilutive. Common stock equivalents include the Company’s stock options, employee stock purchase plan (ESPP), restricted stock units, including those with performance conditions, warrants, and the shares to be issued upon the conversion of the Senior Convertible Notes (see Note 6 to the Unaudited Consolidated Financial Statements).
	The following table sets forth the computation of basic and diluted earnings or (loss) per share attributable to the Company:
		Three Months Ended March 31,
	(in thousands, except per share data)	2015		2014
	Numerator:
	Net income (loss) available to the Company	$	31,560	$	(18,276	)
	Denominator for basic and diluted net (loss) income per share:
	Weighted average common shares outstanding for basic		47,989		45,798
	Dilutive potential common stock outstanding:
	Stock options and ESPP		1,528		—
	Restricted stock units		1,308		—
	Senior Convertible Notes		891		—
	Weighted average common shares outstanding for diluted		51,716		45,798
	Basic net income (loss) per share attributable to the Company	$	0.66	$	(0.40	)
	Diluted net income (loss) per share attributable to the Company	$	0.61	$	(0.40	)
	The following weighted outstanding common stock equivalents were not included in the calculation of net income (loss) per diluted share because their effects were anti-dilutive:
		Three Months Ended March 31,
	(in thousands)	2015		2014
	Stock Options, ESPP, and RSUs		22		7,870
	Warrants		9,553		9,553
	Senior Convertible Notes		—		9,553
	Total		9,575		26,976

Financial_Instruments_and_Fair

Financial Instruments and Fair Value Measurements	3 Months Ended
	Mar. 31, 2015
Investments Debt And Equity Securities [Abstract]
Financial Instruments and Fair Value Measurements	3.    Financial Instruments and Fair Value Measurements
	The Company invests its excess cash in certificates of deposit, corporate notes, commercial paper, U.S. government treasury securities and securities of government-sponsored entities. The Company classifies all such securities as available-for-sale as the sale of such securities may be required prior to maturity to implement management strategies. These securities are carried at fair value with the unrealized gains and losses reported as a component of other comprehensive income in equity until realized. Realized gains and losses and declines in value judged to be other-than-temporary, if any, on available-for-sale securities are included in other income or expense on the Consolidated Statements of Operations and a new accounting cost basis for the security is established. The Company reviews its investments if there is an indicator of possible other-than-temporary impairment. Factors considered in determining whether a loss is other-than-temporary include the length of time and extent to which fair value has been less than the cost basis, the financial condition and near-term prospects of the investee, and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value. As of March 31, 2015, the Company had no investments that were in a significant unrealized loss position and no impairment charges were recorded during the periods presented. Interest and dividends on securities classified as available-for-sale are also included in interest income on the Consolidated Statements of Operations. Realized gains and losses and interest income related to marketable securities were immaterial during all periods presented.
	According to the Company’s investment policy, the Company maintains a diversified investment portfolio in terms of types, maturities, and credit exposure, and invests with institutions that have high credit quality. The Company does not currently hold financial instruments for speculative purposes.
	The composition of marketable securities is as follows:
	(in thousands, except years)	Contractual		Amortized Cost				Gross				Gross				Fair Value
		Maturity						Unrealized				Unrealized
		(in years)						Gains				Losses
	March 31, 2015:
	Classified as current assets
	Corporate notes	Less than 1		$	121,761			$	37			$	(81	)		$	121,717
	Securities of government-sponsored entities	Less than 1			56,822				12				(2	)			56,832
	Commercial paper	Less than 1			21,979				—				—				21,979
	Certificates of deposit	Less than 1			281				—				—				281
	Short-term marketable securities				200,843				49				(83	)			200,809
	Classified as non-current assets
	Securities of government-sponsored entities	1 to 2			19,498				2				(1	)			19,499
	Corporate notes	1 to 2			7,996				6				—				8,002
	Long-term marketable securities				27,494				8				(1	)			27,501
	Classified as restricted investments
	Securities of government-sponsored entities	Less than 2			71,971				9				(21	)			71,959
	U.S. government treasury securities	Less than 2			52,223				52				—				52,275
	Restricted investments				124,194				61				(21	)			124,234
	Total marketable securities at March 31, 2015			$	352,531			$	118			$	(105	)		$	352,544
	December 31, 2014:
	Classified as current assets
	Certificates of deposit	Less than 1		$	282			$	—			$	—			$	282
	Corporate notes	Less than 1			129,037				8				(105	)			128,940
	Commercial paper	Less than 1			11,290				—				—				11,290
	U.S. government treasury securities	Less than 1			1,500				1				—				1,501
	Securities of government-sponsored entities	Less than 1			78,333				12				(29	)			78,316
	Short-term marketable securities				220,442				21				(134	)			220,329
	Classified as non-current assets
	Corporate notes	1 to 2			14,082				—				(13	)			14,069
	Securities of government-sponsored entities	1 to 2			28,996				—				(23	)			28,973
	Long-term marketable securities				43,078				—				(36	)			43,042
	Classified as restricted investments
	U.S. government treasury securities	Less than 2			51,331				13				(13	)			51,331
	Securities of government-sponsored entities	Less than 2			42,862				2				(54	)			42,810
	Restricted investments				94,193				15				(67	)			94,141
	Total marketable securities at December 31, 2014			$	357,713			$	36			$	(237	)		$	357,512
	Foreign Currency and Derivative Financial Instruments
	The Company translates the financial statements of its foreign subsidiaries using end-of-period exchange rates for assets and liabilities and average exchange rates during each reporting period for results of operations.
	Some of the Company’s reporting entities conduct a portion of their business in currencies other than the entity’s functional currency. These transactions give rise to receivables and payables that are denominated in currencies other than the entity’s functional currency. The value of these receivables and payables is subject to changes in currency exchange rates from the point at which the transactions are originated until the settlement in cash. Both realized and unrealized gains and losses in the value of these receivables and payables are included in the determination of net income. Net currency exchange gains recognized on business transactions were $0.3 million, net with hedging transactions, for the three months ended March 31, 2015, and $0.2 million for the three months ended March 31, 2014, and are included in other income (expense) in the Consolidated Statements of Operations.
	To manage foreign currency exposure risks, the Company uses derivatives for activities in entities that have short term intercompany receivables and payables denominated in a currency other than the entity’s functional currency. Realized and unrealized gains or losses on the value of financial contracts entered into to hedge the exchange rate exposure of these receivables and payables are also included in the determination of net income as they have not been designated for hedge accounting under ASC Topic 815, Derivatives and Hedging. These contracts, which settle monthly, effectively fix the exchange rate at which these specific receivables and payables will be settled in, so that gains or losses on the forward contracts offset the gains or losses from changes in the value of the underlying receivables and payables. As of March 31, 2015 a notional principal amount of $34.4 million in foreign currency forward contracts was outstanding to hedge currency risk relative to our foreign receivables and payables. The Company did not have this program during the three months ended March 31, 2014.
	The Company’s currency exposures vary, but are primarily concentrated in the pound sterling, the euro, the Australian dollar, the Singapore dollar, and the yen. The Company will continuously monitor the costs and the impact of foreign currency risks upon the financial results as part of the Company’s risk management program. The Company does not use derivative financial instruments for speculation or trading purposes or for activities other than risk management. The Company does not require and is not required to pledge collateral for these financial instruments and does not carry any master netting arrangements to mitigate the credit risk.
	The following table summarizes the fair values of derivative instruments at March 31, 2015 and December 31, 2014:
		Asset Derivatives										Liability Derivatives
				Fair Value										Fair Value
		Balance Sheet		March 31,				December 31,				Balance Sheet		March 31,				December 31,
	(in thousands)	Location		2015				2014				Location		2015				2014
	Derivative instruments not designated as cash flow
	hedges
	Forward exchange contracts	Other current		$	268			$	—			Other current		$	—			*
		assets										liabilities
	Total derivatives			$	268			$	—					$	—			*
	*De minimus amount recognized in the hedge relationship.
	The following table summarizes the effect of derivative instruments on the Consolidated Statements of Operations for the three months ended March 31, 2015 and March 31, 2014:
		Three Months Ended						Three Months Ended
		31-Mar-15						31-Mar-14
		Location of		Amount of				Location of		Amount of
		(Gain)/Loss		(Gain)/Loss				(Gain)/Loss		(Gain)/Loss
		Recognized in		Recognized in				Recognized  in		Recognized in
	(in thousands)	Income		Income				Income		Income
	Derivative instruments not designated as cash flow hedges
Forward exchange contracts	Other (income)		$	(2,165	)		Other (income)		$	—
	expense						expense
Total derivatives			$	(2,165	)				$	—
Fair value measurements
The Company measures certain assets and liabilities in accordance with authoritative guidance which requires fair value measurements be classified and disclosed in one of the following three categories:
Level 1: Quoted prices (unadjusted) in active markets that are accessible at the measurement date for assets or liabilities.
Level 2: Observable prices that are based on inputs not quoted on active markets, but corroborated by market data.
Level 3: Unobservable inputs are used when little or no market data is available.
Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. The Company reviews the fair value hierarchy classification on a quarterly basis. Changes in the ability to observe valuation inputs may result in a reclassification of levels for certain assets or liabilities within the fair value hierarchy. The Company did not have any transfers of assets and liabilities between the Levels of the fair value measurement hierarchy during the three months ended March 31, 2015 or March 31, 2014.
The carrying amounts of certain financial instruments such as cash equivalents, accounts receivable, prepaid expenses, other current assets, accounts payable, accrued expenses, and other current liabilities as of March 31, 2015 and December 31, 2014 approximate their related fair values due to the short-term maturities of these instruments. The carrying values of the Company’s capital lease obligations approximate their related fair values as of March 31, 2015 and December 31, 2014.
The fair value, based on a quoted market price (Level 1), of the Company’s outstanding Senior Convertible Notes due 2017 at March 31, 2015 and December 31, 2014 was approximately $503.1 million and $516.1 million, respectively. The carrying value of the Company’s Senior Convertible Notes is discussed in Note 6, Senior Convertible Notes.
The fair values of the Company’s assets and liabilities, including cash equivalents, marketable securities, restricted investments, derivatives, and contingent considerations are measured at fair value on a recurring basis, and are determined using the following inputs:
					Quoted Price in				Significant Other				Significant
					Active Market				Observable Inputs				Unobservable
(in thousands)	Total				(Level 1)				(Level 2)				Inputs (Level 3)
March 31, 2015:
Money market funds	$	30,464			$	30,464			$	—			$	—
Certificates of deposit		281				281				—				—
Corporate notes		129,719				—				129,719				—
Commercial paper		21,979				—				21,979				—
U.S. government treasury securities		52,275				52,275				—				—
Securities of government-sponsored entities		148,290				—				148,290				—
Derivative forward exchange contracts		268				—				268				—
Total assets	$	383,276			$	83,020			$	300,256			$	—
December 31, 2014:
Money market funds	$	39,963			$	39,963			$	—			$	—
Certificates of deposit		282				282				—				—
Corporate notes		143,009				—				143,009				—
Commercial paper		11,290				—				11,290				—
U.S. government treasury securities		52,831				52,831				—				—
Securities of government-sponsored entities		150,101				—				150,101				—
Total assets	$	397,476			$	93,076			$	304,400			$	—
Acquisition-related liabilities, current	$	(644	)		$	—			$	—			$	(644	)
Total liabilities	$	(644	)		$	—			$	—			$	(644	)
Contingent Consideration Liability
The fair value of contingent consideration liabilities assumed by a business combination is determined using a discounted cash flow model, the significant inputs of which are not observable in the market. The fair value of such contingent considerations is recorded as part of the purchase consideration of the acquisition. The key assumptions in applying this approach are the revenue projections, the interest rate and the probabilities assigned to the milestones being achieved.  For those contingent consideration arrangements assumed by an asset purchase will be measured and accrued when contingency is resolved.
The following table sets forth the changes in the estimated fair value of the Company’s liabilities measured on a recurring basis using significant unobservable inputs (Level 3):
	Three Months Ended March 31,
(in thousands)	2015				2014
Fair value measurement at beginning of period	$	644			$	1,212
Change in fair value measurement included in operating expenses		(36	)			—
Contingent consideration paid or settled		(608	)			(608	)
Fair value measurement at end of period	$	—			$	604
The payments made during the three months ended March 31, 2015 and 2014 were related to an immaterial business combination completed in 2012.
Non-financial assets and liabilities measured on a nonrecurring basis
Certain non-financial assets and liabilities are measured at fair value, usually with Level 3 inputs including discounted cash flow method or cost method, on a nonrecurring basis in accordance with authoritative guidance. In general, non-financial assets, including intangible assets and property and equipment, are measured at fair value when there is an indication of impairment and are recorded at fair value only when any impairment is recognized.
The Company exited its New Jersey property and made a decision to terminate the respective lease.  Based on management’s assessment, during the three months ended March 31, 2015 and March 31, 2014, the Company recognized impairment charges of $0.9 million and $2.2 million, respectively, in leasehold improvement write-offs associated with the lease termination.
See Note 1 to the Consolidated Financial Statements included in this Quarterly Report for further discussion on impairment analysis and leasehold related charges.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	4.    Goodwill and Intangible Assets
	Goodwill and intangible assets consisted of the following:
		Weighted-
		Average
		Amortization
	(in thousands, except years)	Period		Gross		Accumulated			Intangible
	March 31, 2015:	(in years)		Amount		Amortization			Assets, net
	Intangible assets subject to amortization:
	Developed technology	9		$	79,008	$	(30,045	)	$	48,963
	Manufacturing know-how and trade secrets	12			21,783		(12,008	)		9,775
	Trade name and trademarks	11			9,500		(4,468	)		5,032
	Customer relationships	8			43,120		(24,890	)		18,230
	Total intangible assets subject to amortization	10		$	153,411	$	(71,411	)	$	82,000
	Intangible assets not subject to amortization:
	In-process research and development								$	10,640
	Goodwill								$	154,273
		Weighted-
		Average
		Amortization
		Period		Gross		Accumulated			Intangible
	December 31, 2014:	(in years)		Amount		Amortization			Assets, net
	Intangible assets subject to amortization:
	Developed technology	9		$	79,008	$	(27,760	)	$	51,248
	Manufacturing know-how and trade secrets	12			21,879		(11,640	)		10,239
	Trade name and trademarks	11			9,500		(4,264	)		5,236
	Customer relationships	8			43,153		(23,961	)		19,192
	Total intangible assets subject to amortization	10		$	153,540	$	(67,625	)	$	85,915
	Intangible assets not subject to amortization:
	In-process research and development								$	10,640
	Goodwill								$	154,443
	Total expense related to the amortization of intangible assets was $3.9 million and $4.0 million for the three months ended March 31, 2015 and March 31, 2014, respectively. Intangible assets acquired in a business combination that are used for in-process research and development activities are considered indefinite lived until the completion or abandonment of the associated research and development efforts. Upon reaching the end of the relevant research and development project, the Company will amortize the acquired in-process research and development over its estimated useful life or expense the acquired in-process research and development should the research and development project be unsuccessful with no future alternative use.
	The Company made a payment of $27.4 million during the three months ended March 31, 2015 associated with the intangible assets which were accrued for as of December 31, 2014 in accounts payable and accrued liabilities.
	Total future amortization expense related to intangible assets subject to amortization at March 31, 2015 is set forth in the table below:
	(in thousands)
	Remaining 2015	$	11,363
	2016		14,802
	2017		12,455
	2018		11,432
	2019		10,078
	2020		9,666
	Thereafter through 2027		12,204
	Total future amortization expense	$	82,000

Business_Combinations

Business Combinations	3 Months Ended
	Mar. 31, 2015
Business Combination Description [Abstract]
Business Combinations	5.    Business Combinations
	The Company has completed acquisitions that were not considered individually or collectively material to the overall Consolidated Financial Statements and/or the results of the Company’s operations. These acquisitions have been included in the Consolidated Financial Statements from the respective dates of the acquisitions. The Company recognizes the assets acquired, liabilities assumed, and any non-controlling interest at fair value at the date of acquisition. Certain acquisitions contained contingent consideration arrangements that required the Company to assess the acquisition date fair value of the contingent consideration liabilities, which was recorded as part of the purchase consideration of the acquisition with subsequent fair value adjustments to the contingent consideration reflected in the line items of the Consolidated Statements of Operations commensurate with the nature of the contingent consideration.
	Investment in Progentix Orthobiology B.V.
	In 2009, the Company completed the purchase of 40% of the capital stock of Progentix Orthobiology B.V. (“Progentix”), a company organized under the laws of the Netherlands, from existing shareholders (the Progentix Shareholders) pursuant to a Preferred Stock Purchase Agreement for $10.0 million in cash (the Initial Investment). As of March 31, 2015, NuVasive has loaned Progentix cumulatively $5.3 million at an interest at a rate of 6% per year. NuVasive is not obligated to provide additional funding.
	Concurrently with the Preferred Stock Purchase Agreement, NuVasive, Progentix and the Progentix Shareholders entered into an Option Purchase Agreement (as amended the “Option Agreement”), whereby NuVasive was obligated under certain circumstances, and had the option under other circumstances, to purchase the remaining 60% of capital stock of Progentix (the “Remaining Shares”) from its shareholders for an amount up to $35.0 million, subject to certain reductions. The Option Agreement expired unexercised in 2013. Also, concurrently with the Preferred Stock Purchase Agreement, NuVasive and Progentix entered into a Distribution Agreement, as amended, whereby Progentix appointed NuVasive as its exclusive distributor for certain Progentix products. The Distribution Agreement is in effect for a term of ten years unless terminated earlier in accordance with its terms.
	In accordance with authoritative guidance, the Company has determined that Progentix is a variable interest entity, (“VIE”) as it does not have the ability to finance its activities without additional subordinated financial support and its equity investors will not absorb their proportionate share of expected losses and will be limited in the receipt of the potential residual returns of Progentix. Additionally, pursuant to this guidance, NuVasive is considered a primary beneficiary as NuVasive has both the power to direct the economically significant activities of Progentix and the obligation to absorb losses of, or the right to receive benefits from, Progentix. Accordingly, the financial position and results of operations of Progentix have been included in the Company’s consolidated financial statements from the date of the Initial Investment. The liabilities recognized as a result of consolidating Progentix do not represent additional claims on the Company’s general assets. The creditors of Progentix have claims only on the assets of Progentix, which are not material, and the assets of Progentix are not available to NuVasive.
	The equity interests in Progentix not owned by the Company, which includes shares of both common and preferred stock, are reported as non-controlling interests on the consolidated balance sheet of the Company. The preferred stock represents 18% of the non-controlling equity interests and provides for a cumulative 8% dividend, if and when declared by Progentix’s Board of Directors. As the rights of the preferred stock are substantially the same as those of the common stock, the preferred stock is classified as non-controlling interest and shares in the allocation of the losses incurred by Progentix. Losses incurred by Progentix are charged to the Company and to the non-controlling interest holders based on their ownership percentage.
	Total assets and liabilities of Progentix included in the accompanying Consolidated Balance Sheet are as follows:
	(in thousands)	31-Mar-15		31-Dec-14
	Total current assets	$	639	$	839
	Identifiable intangible assets, net		13,819		13,935
	Goodwill		12,654		12,654
	Other long-term assets		1		1
	Accounts payable and accrued expenses		453		542
	Deferred tax liabilities, net		2,770		2,770
	Non-controlling interests		8,147		8,310
	The following is a reconciliation of equity (net assets) attributable to the non-controlling interests:
		Three Months Ended March 31,
	(in thousands)	2015		2014
	Non-controlling interests at beginning of period	$	8,310	$	9,086
	Less: Net loss attributable to the non-controlling interests		163		257
	Non-controlling interests at end of period	$	8,147	$	8,829
	Impulse Monitoring Inc. and Physician Practices
	The Company maintains contractual relationships with several physician practices (“PCs”) which were inherited through the 2011 acquisition of Impulse Monitoring Inc. Under the respective contracts’ terms, respective PCs provide physician oversight services associated with the IOM service offerings. The Company provides management services to these PCs including all non-medical services, management reporting, billing and collections of all charges for medical services provided as well as administrative support. In turn, the PCs pay the Company a monthly management fee for these services. In accordance with authoritative guidance, the Company has determined that the PCs are VIEs and the Company has controlling financial interests in the PCs as it has both the power to direct the economically significant activities of the PCs, and the obligation to absorb losses of, or the right to receive benefits from, the PCs. Therefore, the accompanying Consolidated Financial Statements include the accounts of the PCs from the date of acquisition. During the periods presented, the result of PCs was immaterial to our financials. The creditors of the PCs have claims only on the assets of the PCs, which are not material, and the assets of the PCs are not available to the Company.

Senior_Convertible_Notes

Senior Convertible Notes	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Senior Convertible Notes	6.    Senior Convertible Notes
	The carrying values of the Company’s Senior Convertible Notes are as follows:
	(in thousands)	31-Mar-15			31-Dec-14
	2.75% Senior Convertible Notes due 2017:
	Principal amount	$	402,500		$	402,500
	Unamortized debt discount		(37,912	)		(41,754	)
	Total Senior Convertible Notes	$	364,588		$	360,746
	2.75% Senior Convertible Notes due 2017
	In June 2011, the Company issued $402.5 million principal amount of Senior Convertible Notes with a stated interest rate of 2.75% and a maturity date of July 1, 2017 (the “2017 Notes”). The net proceeds from the offering, after deducting initial purchasers’ discounts and costs directly related to the offering, were approximately $359.2 million. The 2017 Notes may be settled in cash, stock, or a combination thereof, solely at the Company’s discretion. It is the Company’s current intent and policy to settle all conversions through combination settlement, which involves satisfying the principal amount outstanding with cash and any note conversion value over the principal amount in shares of the Company’s common stock. The initial conversion rate of the 2017 Notes is 23.7344 shares per $1,000 principal amount, which is equivalent to a conversion price of approximately $42.13 per share, subject to adjustments.  The Company also entered into transactions for convertible note hedge (the “2017 Hedge”) and warrants (the “2017 Warrants”) concurrently with the issuance of the 2017 Notes.
	The cash conversion feature of the 2017 Notes (the “Embedded Conversion Derivative”) required bifurcation from the 2017 Notes and was initially accounted for as a derivative liability and debt discount of $88.9 million upon issuance of the 2017 Notes without authorization of issuing additional common stock for the conversion.  Upon obtaining stockholder approval for the additional authorized shares of the Company’s common stock, the derivative liability was reclassified to stockholders’ equity, which resulted in recognizing cumulatively $39.5 million in other income for change in fair value measurement and $49.4 million in additional paid-in-capital during 2011. The debt discount of $88.9 million is recognized as interest expense using an effective interest rate of 8.0% over the term of the 2017 Notes. The interest expense recognized on the 2017 Notes during the three months ended March 31, 2015 includes $2.8 million and $3.8 million for the contractual coupon interest and the accretion of the debt discount, respectively. The interest expense recognized on the 2017 Notes during the three months ended March 31, 2014 includes $2.8 million and $3.6 million for the contractual coupon interest and the accretion of the debt discount, respectively. Interest on the 2017 Notes began accruing upon issuance and is payable semi-annually. The Company uses the treasury share method for assumed conversion of the 2017 Notes to compute the weighted average common shares outstanding for diluted earnings per share.
	Prior to January 1, 2017, holders may convert their 2017 Notes only under the following conditions: (a) during any calendar quarter beginning October 1, 2011, if the reported sale price of the Company’s common stock for at least 20 days out of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than 130% of the conversion price on each applicable trading day; (b) during the five business day period in which the trading price of the 2017 Notes falls below 98% of the product of (i) the last reported sale price of the Company’s common stock and (ii) the conversion rate on that date; and (c) upon the occurrence of specified corporate events, as defined in the 2017 Notes. From January 1, 2017 and until the close of business on the second scheduled trading day immediately preceding July 1, 2017, holders may convert their 2017 Notes at any time (regardless of the foregoing circumstances). The Company may not redeem the 2017 Notes prior to maturity. Other than restrictions relating to certain fundamental changes and consolidations, mergers or asset sales and customary anti-dilution adjustments, the 2017 Notes do not contain any financial covenants and do not restrict the Company from paying dividends or issuing or repurchasing any of its other securities.
	2017 Hedge
	In connection with the offering of the 2017 Notes, the Company entered into the 2017 Hedge with the initial purchasers and/or their affiliates (the “2017 Counterparties”) entitling the Company to purchase up to 9,553,096 shares of the Company’s common stock at an initial stock price of $42.13 per share, each of which is subject to adjustment. The cost of the 2017 Hedge was $80.1 million and accounted for as derivative assets upon issuance of the 2017 Notes. Upon obtaining stockholder approval for the additional authorized shares of the Company’s common stock, the derivative asset was reclassified to stockholders’ equity, resulted in recognizing cumulatively $37.1 million in other expense for the change in fair value measurement and $43.0 million in additional paid-in-capital during 2011. The 2017 Hedge will expire on July 1, 2017. The 2017 Hedge is expected to reduce the potential equity dilution upon conversion of the 2017 Notes if the daily volume-weighted average price per share of the Company’s common stock exceeds the strike price of the 2017 Hedge. An assumed exercise of the 2017 Hedge by the Company is considered anti-dilutive since the effect of inclusion would always be anti-dilutive with respect to the calculation of diluted earnings per share.
	2017 Warrant
	The Company sold warrants to the 2017 Counterparties to acquire up to 477,654 shares of the Company’s Series A Participating Preferred Stock at an initial strike price of $988.51 per share, subject to adjustment. Each share of Series A Participating Preferred Stock is convertible into 20 shares of the Company’s common stock, or up to 9,553,080 common shares in total. The 2017 Warrants will expire on various dates from September 2017 through January 2018 and may be settled in cash or net shares. It is the Company’s current intent and policy to settle all conversions in shares of the Company’s common stock. The Company received $47.9 million in cash proceeds from the sale of the 2017 Warrants, which was recorded in additional paid-in-capital. The 2017 Warrants could have a dilutive effect on the Company’s earnings per share to the extent that the price of the Company’s common stock during a given measurement period exceeds the strike price of the 2017 Warrants. The Company uses the treasury share method for assumed conversion of its 2017 Warrants to compute the weighted average common shares outstanding for diluted earnings per share.

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	7.   Stock-Based Compensation
	The Company estimates the fair value of stock options and shares issued to shareowners under the NuVasive, Inc. 2004 Amended and Restated Employee Stock Purchase Plan (the “ESPP”) using a Black-Scholes option-pricing model on the date of grant. The Black-Scholes option-pricing model incorporates various and highly sensitive assumptions including expected volatility, expected term and risk-free interest rates. The expected volatility is based on the historical volatility of the Company’s common stock over the most recent period commensurate with the estimated expected term of the Company’s stock options and ESPP which is derived from historical experience. The risk-free interest rate for periods within the contractual life of the option is based on the U.S. Treasury yield in effect at the time of grant. The Company has never declared or paid dividends and has no plans to do so in the foreseeable future. The fair value of restricted stock units (“RSUs”) including performance RSU (“PRSUs”) with pre-defined performance criteria is based on the stock price on the date of grant whereas the expense for PRSU with pre-defined performance criteria is adjusted with probability of achievements at each period end. The fair value of the PRSUs that are earned based on the achievement of pre-defined market conditions for total shareholder return (“TSR PRSUs”) is estimated on the date of grant using a Monte Carlo valuation model. The key assumptions in applying this model are an expected volatility and a risk free interest rate. The fair value of equity instruments that are expected to vest are recognized and amortized on an accelerated basis over the requisite service period.
	The Company is required to estimate at the grant date the value of awards that are anticipated to be forfeited prior to their vesting, and thereafter, adjusts the forfeiture rate estimates as necessary through the vesting date so that full compensation cost is recognized only for awards that vest. The Company assesses the reasonableness of the estimated forfeiture rate at least annually, with any change to be made on a cumulative basis in the period the estimated forfeiture rates change. The Company considered its historical experience of pre-vesting forfeitures on awards by each homogenous group of shareowners as the basis to arrive at its estimated annual pre-vesting forfeiture rates for RSUs.
	The compensation cost that has been included in the Consolidated Statements of Operations for all stock-based compensation arrangements was as follows:
		Three Months Ended March 31,
	(in thousands)	2015			2014
	Sales, marketing and administrative expense	$	7,277		$	7,186
	Research and development expense		259			465
	Cost of goods sold		75			113
	Stock-based compensation expense before taxes		7,611			7,764
	Related income tax benefits		(3,044	)		(3,106	)
	Stock-based compensation expense, net of taxes	$	4,567		$	4,658
	At March 31, 2015, there was $30.7 million of unamortized compensation expense for stock options, restricted stock units and performance-based restricted stock units to be recognized over a weighted average period of 2.1 years.
	Stock Options and Purchase Rights
	The weighted average assumptions used to estimate the fair value of stock purchase rights under the ESPP are as follows:
		Three Months Ended March 31,
		2015			2014
	ESPP
	Volatility		44	%		47	%
	Expected term (years)		1.4			1.1
	Risk free interest rate		0.2	%		0.2	%
	Expected dividend yield		—	%		—	%
	Under the terms of ESPP, employees can elect to have up to 15% of their annual compensation, up to a maximum of $21,250 per year withheld to purchase shares of NuVasive common stock at a discount. The purchase price of the common stock is equal to 85% of the lower of the fair market value per share of the common stock on the commencement date of the two-year or six-month offering period (depending on the purchase period enrolled) or the end of each semi-annual purchase period. The Company has not granted any options since 2011.
	The Company issued approximately 692,000 shares of common stock, before net share settlement, upon the exercise of outstanding stock options during the three months ended March 31, 2015 and approximately 1,030,000 shares of common stock upon the exercise of outstanding stock options during the year ended December 31, 2014.
	Restricted Stock Units
	RSUs represent a right to receive shares of common stock at a future date determined in accordance with the terms and conditions of a participant’s award agreement (issued under either our 2004 Amended and Restated Equity Incentive Plan (as previously amended “the 2004 EIP”) or the 2014 Equity Incentive Plan of NuVasive, Inc. (the “2014 EIP”)). No exercise price or other monetary payment is required for receipt of RSUs or the shares issued in settlement of the respective award; instead, consideration is furnished in the form of the participant’s service to the Company. The Company has granted time-based RSUs with graded vesting terms of up to four years. The Company has also granted PRSUs with up to three year graded or cliff vesting terms (in each case, with service through the date of vesting being required) and for which the ultimate issuance amount is determined by the Company’s Compensation Committee upon its certification of Company performance against a pre-determined matrix, including revenue targets, total shareholder return, or earnings per share over pre-determined periods of time. Share payout levels range from 0 to 250% depending on the respective terms of an award.
	The Company issued approximately 1,291,000 shares of common stock, before net share settlement, upon vesting of RSUs (including PRSUs) during the three months ended March 31, 2015, and issued approximately 1,361,000 shares of common stock in settlement of RSUs (including PRSUs) upon their vesting during the year ended December 31, 2014.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	8.    Income Taxes
	The Company recorded an income tax expense of $17.9 million for the three months ended March 31, 2015 and an income tax benefit of $15.1 million for the three months ended March 31, 2014. The effective income tax rate for the three months ended March 31, 2015 was 36% and reflects a negative impact from our globalization initiative project, change in mix of earnings between high tax and low tax jurisdictions, reduced by an unexpected benefit relating to executive stock-based compensation. The effective income tax rate for the three months ended March 31, 2014 was 45% and reflected a negative impact from our globalization initiative project and non-deductible expenses primarily relating to stock-based compensation. The globalization initiative which started during 2013 and became effective in January 2014 involved establishing new international operations and entering into new intercompany transfer pricing arrangements, including the licensing of intangibles. As part of the initiative the Company expects a negative impact on the tax rate in the implementation years with longer term benefits as international operations expand.
	In accordance with the disclosure requirements as described in ASC Topic 740, Income Taxes, the Company has classified unrecognized tax benefits as non-current income tax liabilities, or a reduction in non-current deferred tax assets, unless expected to be paid within one year. The Company’s continuing practice is to recognize interest and/or penalties related to income tax matters in income tax expense. There were no material changes to the Company’s unrecognized tax benefits and interest accrued related to unrecognized tax benefits during the three months ended March 31, 2015 and 2014.

Business_Segment_Product_and_G

Business Segment, Product, and Geographic Information	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Business Segment, Product and Geographic Information	9.    Business Segment, Product and Geographic Information
	The Company operates in one segment based upon the Company’s organizational structure, the way in which the operations are managed and evaluated by the chief operating decision maker (“CODM”) and the lack of availability of discrete financial information.  The Company’s CODM reviews revenue at the product line offering level, and manufacturing, operating income and expenses, and net income at the Company wide level to allocate resources and assess the Company’s overall performance. The Company shares common, centralized support functions, including finance, human resources, legal, information technology, and corporate marketing, all of which report directly to the CODM. Accordingly, decisions regarding the Company’s overall operating performance and allocation of Company resources are assessed on a consolidated basis. The Company believes it is appropriate to operate as one reporting segment. The Company has disclosed the revenues for each of its product line offerings to allow the reader of the financial statements the ability to gain some transparency into the operations of the Company.
	The Company operates under two distinct product line offerings for revenue; spine surgery products, and biologics. The Company’s spine surgery products line offerings, which include thoracolumbar product offerings, cervical product offerings, IOM services, and disposables, are primarily used to enable access to the spine and to perform restorative and fusion procedures in a minimally-disruptive fashion. The Company’s biologics product line offerings includes allograft (donated human tissue), FormaGraft (a collagen synthetic product), Osteocel Plus and Osteocel Pro (each an allograft cellular matrix containing viable mesenchymal stem cells, or MSCs), and AttraX (a synthetic bone graft material), all of which are used to aid the spinal fusion or bone healing process.
	Revenue by product line offerings was as follows:
		Three Months Ended March 31,
	(in thousands)	2015		2014
	Spine surgery products	$	159,054	$	148,007
	Biologics		33,329		29,489
	Total Revenue	$	192,383	$	177,496
	Revenue and property and equipment, net, by geographic area were as follows:
		Revenue				Property and Equipment, Net
		Three Months Ended March 31,				March 31,		December 31,
	(in thousands)	2015		2014		2015		2014
	United States	$	169,926	$	158,394	$	116,229	$	105,022
	International (excludes Puerto Rico)		22,457		19,102		23,312		23,543
	Total	$	192,383	$	177,496	$	139,541	$	128,565

Commitments

Commitments	3 Months Ended
	Mar. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Commitments	10.    Commitments
	Licensing and Purchasing Agreements
	As of March 31, 2015, the Company has obligations under certain consultancy arrangements to pay up to approximately $22.7 million in the aggregate in the event that specified revenue-based milestones are achieved prior to 2024.  Any such payment will be made in a combination of cash and the Company’s common shares as provided in the agreements.  Any payments in satisfaction of theses contingent obligations are considered a cost of goods sold and are recognized as and if milestones are achieved.  In early 2014, the Company paid $6.2 million in aggregate – $3.0 million in cash and $3.2 million in common shares - in connection with these agreements.  There was no accrual recognized as of March 31, 2015 and December 31, 2014 related to these payments.
	Executive Severance Plans
	The Company is party to certain agreements with its key executives that provide for certain payments if an executive is terminated for reasons other than cause, as defined in those agreements. At March 31, 2015, future contractual commitments for such key executives were approximately $15.3 million, excluding the acceleration of equity vesting, which is called for in certain circumstances by the applicable agreements.

Contingencies

Contingencies	3 Months Ended
	Mar. 31, 2015
Contingencies [Abstract]
Contingencies	11.    Contingencies
	The Company is subject to potential liabilities under government regulations and various claims and legal actions that are pending or may be asserted from time-to-time. These matters arise in the ordinary course and conduct of the Company’s business and include, for example, commercial, intellectual property, environmental, securities and employment matters. The Company intends to continue to defend itself vigorously in such matters. Furthermore, the Company regularly assesses contingencies to determine the degree of probability and range of possible loss for potential accrual in its financial statements. During the period ended March 31, 2015, the Company had a litigation accrual change gain of $56.4 million related to the legal proceedings in the Medtronic Sofamor Danek USA, Inc. litigation whereby the damages award by the jury was overturned. Refer to the subsequent section herein titled “Legal Proceedings” for further information.
	An estimated loss contingency is accrued in the Company’s financial statements if it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Based on the Company’s assessment, it has adequately accrued an amount for contingent liabilities currently in existence. The Company does not accrue amounts for liabilities that it does not believe are probable or that it considers immaterial to its overall financial position. Litigation is inherently unpredictable, and unfavorable resolutions could occur. As a result, assessing contingencies is highly subjective and requires judgment about future events. The amount of ultimate loss may exceed the Company’s current accruals, and it is possible that its cash flows or results of operations could be materially affected in any particular period by the unfavorable resolution of one or more of these contingencies.
	Legal Proceedings
	Medtronic Sofamor Danek USA, Inc. Litigation
	In August 2008, Warsaw Orthopedic, Inc., Medtronic Sofamor Danek USA, Inc. and other Medtronic related entities (collectively, “Medtronic”) filed a patent infringement lawsuit against the Company in the United States District Court for the Southern District of California (the “Medtronic Litigation”), alleging that certain of the Company’s products or methods, including the XLIF® procedure, infringe, or contribute to the infringement of, twelve U.S. patents assigned or licensed to Medtronic. Three of the patents were later withdrawn by Medtronic, leaving nine purportedly infringed patents. The Company brought counterclaims against Medtronic alleging infringement of certain of the Company’s patents.
	The case has been administratively broken into several phases.
	The first phase of the case included three Medtronic patents and one Company patent. The initial trial on the first phase of the case concluded on September 20, 2011 and a jury delivered an unfavorable verdict against the Company with respect to the three Medtronic patents and a favorable verdict with respect to the one Company patent at hand, including a monetary damages award of approximately $101.2 million to Medtronic (the “2011 verdict”). Medtronic’s subsequent motion for a permanent injunction was denied by the District Court on January 26, 2012. On March 19, 2012, the District Court issued an order granting prejudgment interest with respect to the patent infringements determined in the 2011 verdict. On May 15, 2013, the District Court granted the parties’ joint motion to dismiss claims relating to one of the three Medtronic patents pursuant to a settlement agreement. On June 11, 2013, the District Court granted the parties ongoing royalties with respect to the two Medtronic patents and the one Company patent remaining in the first phase of the case (the “June 2013 ruling”).
	On August 20, 2013, the Company and Medtronic filed their respective notices of appeal to the U.S. Court of Appeals for the Federal Circuit. On March 2, 2015, the Court of Appeals issued a decision upholding the jury’s findings of liability as to all patents, but overturning the damage award against the Company as improper (“March 2nd Court of Appeals Decision”). The case has been transferred back to the District Court for further proceedings to determine a proper damage award, and no trial date has been set. As a result of the affirmation of the infringement and remand for a new trial on damages, the Company assessed the existing liability under the loss contingency framework and – in accordance with applicable accounting guidance – believes the most appropriate accrual estimate within the possible range dictated by such guidance is $87.4 million. This amount represents a liability for the infringement of patents for infringing products at historically supplied rates from the date of infringement to the current period. The liability does not include an accrual for lost profits or convoyed products. A liability associated with this matter has been recorded in non-current litigation liabilities. In prior periods, the Company recorded the respective liabilities (as estimated) in non-current litigation liabilities and the accrued royalties in accrued liabilities. The Company does not agree with the previously-ruled royalty rates, and intends to rigorously pursue appropriate rates during the new trial on damages. Nonetheless, in the interim, the Company has applied the previously-ruled royalty rates when calculating the appropriate estimate. As a result of the adjustment, the Company has recorded an adjustment of $56.4 million as a gain in its Consolidated Statements of Operations.
	On March 19, 2012, in connection with these proceedings, the Company entered into an escrow arrangement and transferred $113.3 million of cash into a restricted escrow account to secure the amount of judgment, plus prejudgment interest, during pendency of the appeal. These funds are included in restricted cash and investments on the Company’s March 31, 2015 Consolidated Balance Sheet.
	In accordance with the authoritative guidance on the evaluation of loss contingencies, during the year ended December 31, 2011, the Company recorded an accrual of $101.2 million for the 2011 verdict. In addition, the Company accrued royalties at the royalty rates stated in the 2011 verdict on sales subsequent to the 2011 verdict and through March 31, 2013. After the June 2013 ruling, the Company (i) began accruing ongoing royalties on sales at the royalty rates stated in the June 2013 ruling, and (ii) recorded a charge of approximately $7.9 million to account for the difference between using the royalty rates stated in the 2011 verdict and those in the June 2013 ruling on sales through March 31, 2013. Based on the June 2013 ruling, the Company agreed to escrow funds to secure accrued royalties as well as future ongoing royalties. However, in light of the Court of Appeals ruling, absent a court order the Company will no longer escrow such funds until damages are ultimately determined. Additionally, the Company has modified its accrual from the 2011 verdict as a result of the March 2, 2015 Court of Appeals ruling as previously discussed.
	With respect to the favorable verdict delivered regarding the one Company patent litigated to verdict, the jury awarded the Company monetary damages of approximately $0.7 million for reasonable royalty damages. In accordance with the authoritative guidance on the evaluation of gain contingencies, this amount has not been recorded at March 31, 2015. Additionally, the June 2013 ruling determined the ongoing royalty rate to be paid to the Company by Medtronic for its post-verdict sales of the one Company patent. Consistent with the treatment afforded the $0.7 million damage award, no amount has been recorded for royalty revenue as of March 31, 2015.
	The second phase of the case involved one Medtronic cervical plate patent. On April 25, 2013, the Company and Medtronic entered into a settlement agreement fully resolving the second phase of the case. The settlement also removed from the case the cervical plate patent that was part of the first phase. As part of the settlement, the Company received a broad license to practice (i) the Medtronic patent that was the sole subject of the second phase of the litigation, (ii) the Medtronic cervical plate patent that was part of the first phase of the litigation, and (iii) each of the Medtronic patent families that collectively represent the vast majority of Medtronic’s patent rights related to cervical plate technology. In exchange for these license rights, the Company made a one-time payment to Medtronic of $7.5 million, which amount will be fully offset against any damage award ultimately determined to be owed by the Company in connection with a final resolution of the first phase of the litigation. In addition, Medtronic will receive a royalty on certain cervical plate products sold by the Company, including the Helix® and Gradient® lines of products. As a result of this settlement, all current patent disputes between the parties related to cervical plate technology have been resolved.
	In August 2012, Medtronic filed additional patent claims in the U.S. District Court for the Northern District of Indiana alleging that various Company spinal implants (including its CoRoent® XL family of spinal implants) infringe Medtronic’s U.S. Patent No. 8,021,430, that the Company’s Osteocel® Plus bone graft product infringes Medtronic’s U.S. Patent No. 5,676,146, (‘146 Patent) and that the Company’s XLIF® procedure and use of MaXcess IV retractor during the XLIF procedure infringe methodology claims of Medtronic’s U.S. Patent No. 8,251,997. The case, which is referred to herein as the third phase of the Medtronic litigation, was later transferred to the Southern District of California, and, on March 7, 2013, the Company counterclaimed alleging infringement by Medtronic of the Company’s U.S. Patent Nos. 8,000,782 (systems and related methods for performing surgical procedures), 8,005,535 (systems and related methods for performing surgical procedures), 8,016,767 (a surgical access system including a tissue distraction assembly and a tissue retraction assembly), 8,192,356 (a system for accessing a surgical target site and related methods, involving an initial distraction system, among other things), 8,187,334 (spinal fusion implant), 8,361,156 (spinal fusion implant), D652,922 (dilator design), and D666,294 (dilator design). On July 25, 2013, Medtronic amended its complaint to add a charge of infringement of its U.S. Patent No. 8,444,696. The District Court has stayed litigation of a number of Medtronic and Company patents currently subject to reexamination or review proceedings conducted by the Patent Office. Both parties brought motions for summary judgment addressing the remaining patents, Medtronic’s ‘146 Patent and the Company’s ‘922 Patent but the District Court has not yet issued a final decision regarding summary judgment. No trial date has been set in this third phase of the litigation for the ‘146 Patent or ‘922 Patent. At March 31, 2015, the probable outcome of this litigation cannot be determined, nor can the Company estimate a range of potential loss. In accordance with the authoritative guidance on the evaluation of loss contingencies, the Company has not recorded an accrual related to this litigation.
	Trademark Infringement Litigation
	On September 25, 2009, Neurovision Medical Products, Inc. (NMP) filed suit against the Company in the U.S. District Court for the Central District of California (Case No. 2:09-cv-06988-R-JEM) alleging trademark infringement and unfair competition. NMP sought cancellation of NuVasive’s “NeuroVision” trademark registrations, injunctive relief and damages based on NMP’s common law use of the “NeuroVision” mark. The matter was tried in October 2010 and an unfavorable jury verdict was delivered against the Company. The verdict awarded damages to NMP of $60.0 million, which was upheld in a January 2011 judgment ordered by the District Court. NuVasive appealed the judgment, and during pendency of the appeal, NuVasive was required to escrow funds totaling $62.5 million. In September 2012, the Court of Appeals reversed and vacated the District Court judgment and ordered the case back to the District Court for a new trial before a different judge.  As a result, the full $62.5 million was released from escrow and returned to the Company.  Retrial of the matter began on March 25, 2014, and on April 3, 2014, a jury returned a verdict in favor of NMP on its claims against the Company in the amount of $30.0 million.  The Court affirmed the jury’s verdict, and on September 4, 2014, the Company filed a notice of appeal.  The Court entered judgment and ordered a permanent injunction on September 24, 2014, enjoining the Company’s future use of the NeuroVision trademark to market or promote its products. The Court also entered an order canceling the Company’s NeuroVision trademark registrations, but that order is stayed pending the appeal process. On December 2, 2014, the Court denied NMP’s motion for attorneys’ fees, costs, and prejudgment interest, and NMP filed a notice of appeal on December 17, 2014.  The appeals were consolidated on February 2, 2015, and resolution of the appeals may take up to two years.  During pendency of the appeal, the Company escrowed funds totaling $32.5 million to secure the amount of judgment, and cover potential attorney’s fees and costs. Those funds accrue interest and are included in restricted cash and investments in the Consolidated Balance Sheets. At March 31, 2015 the jury verdict represents a probable loss that can reasonably be determined. Accordingly, in accordance with the authoritative guidance on the evaluation of loss contingencies, the Company has a litigation accrual of $30.0 million related to this litigation at period end, which was reclassified from current liabilities to long-term liabilities to coincide with the establishment of restricted assets during the three months ended March 31, 2015.
	Securities Litigation
	On August 28, 2013, a purported securities class action lawsuit was filed in the United States District Court for the Southern District of California naming the Company and certain of its current and former executive officers for allegedly making false and materially misleading statements regarding the Company’s business and financial results, specifically relating to the purported improper submission of false claims to Medicare and Medicaid. The complaint asserts a putative class period stemming from October 22, 2008 to July 30, 2013. The complaint alleges violations of Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended, and Rule 10b-5 promulgated thereunder and seeks unspecified monetary relief, interest, and attorneys’ fees. On February 13, 2014, the lead plaintiff (“Plaintiff”) filed an Amended Class Action Complaint for Violations of the Federal Securities Laws. In March 2014, the Company filed a motion to dismiss the Amended Class Action Complaint for Violations of the Federal Securities Laws. On August 19, 2014, the Court granted the Company’s motion to dismiss and ordered Plaintiff to amend its complaint. Plaintiff filed a Second Amended Complaint on September 8, 2014. The Company once again moved to dismiss the complaint on September 22, 2014 and that motion was granted on December 9, 2014.  On December 23, 2014 Plaintiff filed a Third Amended Complaint.  The Company filed a motion to dismiss the Third Amended Complaint on January 9, 2015. While the Company’s motion was pending, Plaintiff sought leave to file a Fourth Amended Complaint. The Company moved to dismiss the Fourth Amended Complaint and the motion is pending. At March 31, 2015, the probable outcome of this litigation cannot be determined, nor can the Company estimate a range of potential loss. In accordance with authoritative guidance on the evaluation of loss contingencies, the Company has not recorded an accrual related to this litigation.

Regulatory_Matter

Regulatory Matter	3 Months Ended
	Mar. 31, 2015
Regulatory Matter [Abstract]
Regulatory Matter	12.    Regulatory Matter
	In 2013, the Company received a federal administrative subpoena from the Office of the Inspector General of the U.S. Department of Health and Human Services (OIG) in connection with an investigation into possible false or otherwise improper claims submitted to Medicare and Medicaid. The subpoena sought discovery of documents for the period January 2007 through April 2013. The Company has been working with the OIG to understand the scope of their investigation and has reached an agreement in principle with the U.S. Department of Justice (“DOJ”), as further detailed in the Company’s Current Report on Form 8-K filed with the SEC on April 30, 2015. Subject to completion of a written settlement agreement, the Company has agreed to pay $13.8 million to resolve this matter. The Company does not currently anticipate entering into a corporate integrity agreement with the OIG as part of the settlement. Finalizing the written settlement agreement could take several months. In accordance with the authoritative guidance on the evaluation of loss contingencies, the Company recorded a $13.8 million liability related to this matter, which is included in the Consolidated Statements of Operations during the three months ending March 31, 2015.

Description_of_Business_and_Ba1

Description of Business and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business	Description of Business
	NuVasive, Inc. (the “Company” or “NuVasive”) was incorporated in Delaware on July 21, 1997, and began commercializing its products in 2001. The Company is focused on developing minimally-disruptive surgical products and procedurally-integrated solutions for the spine. NuVasive’s principal product offering includes a minimally-disruptive surgical platform called Maximum Access Surgery, or MAS®. The MAS platform combines three categories of solutions that collectively minimize soft tissue disruption during spine fusion surgery, provide maximum visualization and are designed to enable safe and reproducible outcomes for the surgeon and the patient. The platform includes proprietary software-driven nerve detection and avoidance systems, NVM5® and NVJJB®, and Intra-Operative Monitoring (“IOM”) services and support; MaXcess®, an integrated split-blade retractor system; and a wide variety of specialized implants and biologics. Many of the Company’s products, including the individual components of NuVasive’s MAS platform, can also be used in open or traditional spine surgery. The Company’s spine surgery product line offerings, which include thoracolumbar product offerings, cervical product offerings, IOM services, and disposables, are primarily used to enable access to the spine and to perform restorative and fusion procedures in a minimally-disruptive fashion.  The Company’s biologic product line offerings used to aid the spinal fusion process or bone healing process include Osteocel® Plus and Osteocel Pro allograft (donated human tissue) which are cellular matrix products containing viable mesenchymal stem cells (“MSCs”), as well as other allograft offerings, FormaGraft®, a collagen synthetic product, and AttraX®, a synthetic bone graft material that is currently available commercially only in select markets outside of the United States. The Company continues to focus significant research and development efforts to expand its MAS product platform and advance the applications of its unique technology into procedurally-integrated surgical solutions. The Company has dedicated and continues to dedicate significant resources toward training spine surgeons around the world; both those who are new to its MAS product platform as well as previously MAS-trained surgeons attending advanced courses.
	The Company’s primary business model is to loan its MAS systems to surgeons and hospitals who use such systems to perform individual procedures, with the hospitals purchasing implants, biologics and disposables in each such case. In addition, for larger customers, the Company’s proprietary nerve monitoring systems, MaXcess and surgical instrument sets are placed with hospitals for an extended period at no up-front cost to them, facilitating the hospital’s purchase of disposables for such machines from the Company. The Company also offers a range of bone allograft in patented saline packaging, disposables and spine implants, which include its branded CoRoent® products and fixation devices such as rods, plates and screws. The Company’s implants, biologics and disposables are currently sold and shipped from its primary distribution and warehousing operations facility located in Memphis, Tennessee. The Company sells MAS instrument sets, MaXcess devices and its proprietary software-driven nerve monitoring systems, however this does not make up a material part of its business.
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation
	The accompanying Unaudited Consolidated Financial Statements include the accounts of the Company and its majority-owned or controlled subsidiaries, collectively referred to as either NuVasive or the Company. The Company translates the financial statements of its foreign subsidiaries using end-of-period exchange rates for assets and liabilities and average exchange rates during each reporting period for results of operations. When there is a portion of equity in an acquired subsidiary not attributable, directly or indirectly, to the respective parent entity, the Company records the fair value of the non-controlling interests at the acquisition date and classifies the amounts attributable to non-controlling interests separately in equity in the Company’s Consolidated Financial Statements. Any subsequent changes in a parent’s ownership interest while the parent retains its controlling financial interest in its subsidiary are accounted for as equity transactions. All significant intercompany balances and transactions have been eliminated in consolidation.
	The accompanying Unaudited Consolidated Financial Statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Pursuant to these rules and regulations, the Company has condensed or omitted certain information and footnote disclosures it normally includes in its annual Consolidated Financial Statements prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). Operating results for the three months ended March 31, 2015 are not necessarily indicative of the results that may be expected for any other interim period or for the full year. These Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and notes thereto for the year ended December 31, 2014 included in the Company’s Annual Report on Form 10-K filed with the SEC. In the opinion of management, the Consolidated Financial Statements include all adjustments that are of a normal and recurring nature that are necessary for the fair presentation of the Company’s financial position and of the results of operations and cash flows for the periods presented.
	The Company has reclassified historically presented product offerings revenue to conform to the current year presentation. The reclassification had no impact on previously reported results of operations or financial position.
Change in Accounting Estimate	Change in Accounting Estimate
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities and disclosures of contingent assets and liabilities at the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Business Transition Costs	From time to-time, the Company incurs costs related to integration and business transition activities which include severance, relocation, consulting, and other costs directly associated to such activities. The nature of these costs is that of personnel costs that the Company believes arise and warrant specific disclosure. During the three months ended March 31, 2015, the Company incurred $5.4 million of such costs, which included a $3.4 million charge associated with the resignation of the Company’s former Chief Executive Officer and Chairman of the Board, Alex V. Lukianov. Such resignation occurred in the first quarter 2015 and was announced on April 1, 2015 via filing of a Current Report on Form 8-K with the SEC. The $3.4 million charge includes certain severance and compensation-related charges, net of certain forfeitures of previously recognized equity compensation.
Restructuring Charges	Restructuring Charges
	The Company exited its New Jersey location and terminated the respective lease to reduce its footprint on the east coast of the United States as part of a company-wide efficiency effort in order to match its business needs without adversely impacting its ability to deliver surgeon education and local customer fulfillment. As a result of this undertaking, the Company recognized restructuring and associated impairment charges of $2.3 million during the three months ended March 31, 2015 in addition to the $6.4 million recognized during 2014. The restructuring and impairment charges mainly consist of the future rental payments through 2017, net with estimated future sublease income, and elimination of related leasehold improvements and deferred rent liabilities. These charges are recorded in sales, marketing and administrative expense in the Consolidated Statements of Operations.
	As of March 31, 2015, the total recorded liability associated with this early lease termination was $4.9 million and consists of future rental payments net of estimated sublease income through 2017. The current portion of the liability is recorded within accounts payable and accrued liabilities and the long-term portion is recorded within other long-term liabilities in the Consolidated Balance Sheets at March 31, 2015.
Comprehensive Income (Loss)	Comprehensive Income (Loss)
	Comprehensive income (loss) is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources. Comprehensive income (loss) includes unrealized gains or losses on the Company’s marketable securities and foreign currency translation adjustments. The cumulative translation adjustments included in accumulated other comprehensive income (loss) were a net cumulative loss of $11.7 million and $9.5 million at March 31, 2015 and December 31, 2014, respectively.
Long-Lived Assets	Long-Lived Assets
	Long-lived assets include surgical instruments, which are loaned to surgeons and hospitals who purchase implants, biologics and disposables for use in individual procedures, leasehold improvements, software, and intangible assets. The Company periodically re-evaluates the original assumptions and rationale utilized in the establishment of the carrying value and estimated lives of its long-lived assets. The criteria used for these evaluations include management’s estimate of the asset’s continuing ability to generate income from operations and positive cash flow in future periods as well as the strategic significance of any intangible asset to the Company’s business objectives. If assets are considered to be impaired, the impairment recognized is the amount by which the carrying value of the assets exceeds the fair value of the assets, which is determined by applicable market prices when available or other methods by utilizing unobservable inputs including discounted cash flow models. See Note 3, Financial Instruments and Fair Value Measurements for further discussion.
Inventories	Inventories
	The Company’s inventory consists primarily of purchased finished goods which includes specialized implants and disposables, and is stated at the lower of cost or market determined by a weighted average cost method. The Company reviews the components of its inventory on a periodic basis for excess, obsolete or impaired inventory, and records a reserve for such identified items. The inventory reserve was $23.0 million and $22.7 million at March 31, 2015 and December 31, 2014, respectively.

Net_Income_Loss_Per_Share_Tabl

Net Income (Loss) Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Computation of basic and diluted earnings per share	The following table sets forth the computation of basic and diluted earnings or (loss) per share attributable to the Company:
		Three Months Ended March 31,
	(in thousands, except per share data)	2015		2014
	Numerator:
	Net income (loss) available to the Company	$	31,560	$	(18,276	)
	Denominator for basic and diluted net (loss) income per share:
	Weighted average common shares outstanding for basic		47,989		45,798
	Dilutive potential common stock outstanding:
	Stock options and ESPP		1,528		—
	Restricted stock units		1,308		—
	Senior Convertible Notes		891		—
	Weighted average common shares outstanding for diluted		51,716		45,798
	Basic net income (loss) per share attributable to the Company	$	0.66	$	(0.40	)
	Diluted net income (loss) per share attributable to the Company	$	0.61	$	(0.40	)
Anti-dilutive common stock equivalents not included in calculation of net income per diluted share	The following weighted outstanding common stock equivalents were not included in the calculation of net income (loss) per diluted share because their effects were anti-dilutive:
		Three Months Ended March 31,
	(in thousands)	2015		2014
	Stock Options, ESPP, and RSUs		22		7,870
	Warrants		9,553		9,553
	Senior Convertible Notes		—		9,553
	Total		9,575		26,976

Financial_Instruments_and_Fair1

Financial Instruments and Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Table [Abstract]
Composition of Marketable Securities	The composition of marketable securities is as follows:
	(in thousands, except years)	Contractual		Amortized Cost				Gross				Gross				Fair Value
		Maturity						Unrealized				Unrealized
		(in years)						Gains				Losses
	March 31, 2015:
	Classified as current assets
	Corporate notes	Less than 1		$	121,761			$	37			$	(81	)		$	121,717
	Securities of government-sponsored entities	Less than 1			56,822				12				(2	)			56,832
	Commercial paper	Less than 1			21,979				—				—				21,979
	Certificates of deposit	Less than 1			281				—				—				281
	Short-term marketable securities				200,843				49				(83	)			200,809
	Classified as non-current assets
	Securities of government-sponsored entities	1 to 2			19,498				2				(1	)			19,499
	Corporate notes	1 to 2			7,996				6				—				8,002
	Long-term marketable securities				27,494				8				(1	)			27,501
	Classified as restricted investments
	Securities of government-sponsored entities	Less than 2			71,971				9				(21	)			71,959
	U.S. government treasury securities	Less than 2			52,223				52				—				52,275
	Restricted investments				124,194				61				(21	)			124,234
	Total marketable securities at March 31, 2015			$	352,531			$	118			$	(105	)		$	352,544
	December 31, 2014:
	Classified as current assets
	Certificates of deposit	Less than 1		$	282			$	—			$	—			$	282
	Corporate notes	Less than 1			129,037				8				(105	)			128,940
	Commercial paper	Less than 1			11,290				—				—				11,290
	U.S. government treasury securities	Less than 1			1,500				1				—				1,501
	Securities of government-sponsored entities	Less than 1			78,333				12				(29	)			78,316
	Short-term marketable securities				220,442				21				(134	)			220,329
	Classified as non-current assets
	Corporate notes	1 to 2			14,082				—				(13	)			14,069
	Securities of government-sponsored entities	1 to 2			28,996				—				(23	)			28,973
	Long-term marketable securities				43,078				—				(36	)			43,042
	Classified as restricted investments
	U.S. government treasury securities	Less than 2			51,331				13				(13	)			51,331
	Securities of government-sponsored entities	Less than 2			42,862				2				(54	)			42,810
	Restricted investments				94,193				15				(67	)			94,141
	Total marketable securities at December 31, 2014			$	357,713			$	36			$	(237	)		$	357,512
Schedule of Derivatives Not Designated as Cash Flow Hedges	The following table summarizes the fair values of derivative instruments at March 31, 2015 and December 31, 2014:
		Asset Derivatives										Liability Derivatives
				Fair Value										Fair Value
		Balance Sheet		March 31,				December 31,				Balance Sheet		March 31,				December 31,
	(in thousands)	Location		2015				2014				Location		2015				2014
	Derivative instruments not designated as cash flow
	hedges
	Forward exchange contracts	Other current		$	268			$	—			Other current		$	—			*
		assets										liabilities
	Total derivatives			$	268			$	—					$	—			*
	*De minimus amount recognized in the hedge relationship.
Schedule of Derivative Instruments Effect on Statements of Operations	The following table summarizes the effect of derivative instruments on the Consolidated Statements of Operations for the three months ended March 31, 2015 and March 31, 2014:
		Three Months Ended						Three Months Ended
		31-Mar-15						31-Mar-14
		Location of		Amount of				Location of		Amount of
		(Gain)/Loss		(Gain)/Loss				(Gain)/Loss		(Gain)/Loss
		Recognized in		Recognized in				Recognized  in		Recognized in
	(in thousands)	Income		Income				Income		Income
	Derivative instruments not designated as cash flow hedges
	Forward exchange contracts	Other (income)		$	(2,165	)		Other (income)		$	—
		expense						expense
	Total derivatives			$	(2,165	)				$	—
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The fair values of the Company’s assets and liabilities, including cash equivalents, marketable securities, restricted investments, derivatives, and contingent considerations are measured at fair value on a recurring basis, and are determined using the following inputs:
						Quoted Price in				Significant Other				Significant
						Active Market				Observable Inputs				Unobservable
	(in thousands)	Total				(Level 1)				(Level 2)				Inputs (Level 3)
	March 31, 2015:
	Money market funds	$	30,464			$	30,464			$	—			$	—
	Certificates of deposit		281				281				—				—
	Corporate notes		129,719				—				129,719				—
	Commercial paper		21,979				—				21,979				—
	U.S. government treasury securities		52,275				52,275				—				—
	Securities of government-sponsored entities		148,290				—				148,290				—
	Derivative forward exchange contracts		268				—				268				—
	Total assets	$	383,276			$	83,020			$	300,256			$	—
	December 31, 2014:
	Money market funds	$	39,963			$	39,963			$	—			$	—
	Certificates of deposit		282				282				—				—
	Corporate notes		143,009				—				143,009				—
	Commercial paper		11,290				—				11,290				—
	U.S. government treasury securities		52,831				52,831				—				—
	Securities of government-sponsored entities		150,101				—				150,101				—
	Total assets	$	397,476			$	93,076			$	304,400			$	—
	Acquisition-related liabilities, current	$	(644	)		$	—			$	—			$	(644	)
	Total liabilities	$	(644	)		$	—			$	—			$	(644	)
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation	The following table sets forth the changes in the estimated fair value of the Company’s liabilities measured on a recurring basis using significant unobservable inputs (Level 3):
		Three Months Ended March 31,
	(in thousands)	2015				2014
	Fair value measurement at beginning of period	$	644			$	1,212
	Change in fair value measurement included in operating expenses		(36	)			—
	Contingent consideration paid or settled		(608	)			(608	)
	Fair value measurement at end of period	$	—			$	604
	The payments made during the three months ended March 31, 2015 and 2014 were related to an immaterial business combination completed in 2012.

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and intangible assets	Goodwill and intangible assets consisted of the following:
		Weighted-
		Average
		Amortization
	(in thousands, except years)	Period		Gross		Accumulated			Intangible
	March 31, 2015:	(in years)		Amount		Amortization			Assets, net
	Intangible assets subject to amortization:
	Developed technology	9		$	79,008	$	(30,045	)	$	48,963
	Manufacturing know-how and trade secrets	12			21,783		(12,008	)		9,775
	Trade name and trademarks	11			9,500		(4,468	)		5,032
	Customer relationships	8			43,120		(24,890	)		18,230
	Total intangible assets subject to amortization	10		$	153,411	$	(71,411	)	$	82,000
	Intangible assets not subject to amortization:
	In-process research and development								$	10,640
	Goodwill								$	154,273
		Weighted-
		Average
		Amortization
		Period		Gross		Accumulated			Intangible
	December 31, 2014:	(in years)		Amount		Amortization			Assets, net
	Intangible assets subject to amortization:
	Developed technology	9		$	79,008	$	(27,760	)	$	51,248
	Manufacturing know-how and trade secrets	12			21,879		(11,640	)		10,239
	Trade name and trademarks	11			9,500		(4,264	)		5,236
	Customer relationships	8			43,153		(23,961	)		19,192
	Total intangible assets subject to amortization	10		$	153,540	$	(67,625	)	$	85,915
	Intangible assets not subject to amortization:
	In-process research and development								$	10,640
	Goodwill								$	154,443
Future amortization expense related to intangible assets	Total future amortization expense related to intangible assets subject to amortization at March 31, 2015 is set forth in the table below:
	(in thousands)
	Remaining 2015	$	11,363
	2016		14,802
	2017		12,455
	2018		11,432
	2019		10,078
	2020		9,666
	Thereafter through 2027		12,204
	Total future amortization expense	$	82,000

Business_Combinations_Tables

Business Combinations (Tables)	3 Months Ended
	Mar. 31, 2015
Business Combination Description [Abstract]
Summary of assets and liabilities included in the accompanying consolidated balance sheet	Total assets and liabilities of Progentix included in the accompanying Consolidated Balance Sheet are as follows:
	(in thousands)	31-Mar-15		31-Dec-14
	Total current assets	$	639	$	839
	Identifiable intangible assets, net		13,819		13,935
	Goodwill		12,654		12,654
	Other long-term assets		1		1
	Accounts payable and accrued expenses		453		542
	Deferred tax liabilities, net		2,770		2,770
	Non-controlling interests		8,147		8,310
Reconciliation of equity (net assets) attributable to the non-controlling interests	The following is a reconciliation of equity (net assets) attributable to the non-controlling interests:
		Three Months Ended March 31,
	(in thousands)	2015		2014
	Non-controlling interests at beginning of period	$	8,310	$	9,086
	Less: Net loss attributable to the non-controlling interests		163		257
	Non-controlling interests at end of period	$	8,147	$	8,829

Senior_Convertible_Notes_Table

Senior Convertible Notes (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Net carrying amount of the debt component	The carrying values of the Company’s Senior Convertible Notes are as follows:
	(in thousands)	31-Mar-15			31-Dec-14
	2.75% Senior Convertible Notes due 2017:
	Principal amount	$	402,500		$	402,500
	Unamortized debt discount		(37,912	)		(41,754	)
	Total Senior Convertible Notes	$	364,588		$	360,746

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Weighted average assumptions used to estimate fair value of stock options granted and stock purchase rights under ESPP	The weighted average assumptions used to estimate the fair value of stock purchase rights under the ESPP are as follows:
		Three Months Ended March 31,
		2015			2014
	ESPP
	Volatility		44	%		47	%
	Expected term (years)		1.4			1.1
	Risk free interest rate		0.2	%		0.2	%
	Expected dividend yield		—	%		—	%
Equity [Abstract]
Compensation costs included in statement of income for all stock-based compensation arrangements	The compensation cost that has been included in the Consolidated Statements of Operations for all stock-based compensation arrangements was as follows:
		Three Months Ended March 31,
	(in thousands)	2015			2014
	Sales, marketing and administrative expense	$	7,277		$	7,186
	Research and development expense		259			465
	Cost of goods sold		75			113
	Stock-based compensation expense before taxes		7,611			7,764
	Related income tax benefits		(3,044	)		(3,106	)
	Stock-based compensation expense, net of taxes	$	4,567		$	4,658

Business_Segment_Product_and_G1

Business Segment, Product and Geographical Information (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Revenue from External Customers by Products and Services	Revenue by product line offerings was as follows:
		Three Months Ended March 31,
	(in thousands)	2015		2014
	Spine surgery products	$	159,054	$	148,007
	Biologics		33,329		29,489
	Total Revenue	$	192,383	$	177,496
Schedule of Revenue from Net Property and Equipment by Geographical Areas	Revenue and property and equipment, net, by geographic area were as follows:
		Revenue				Property and Equipment, Net
		Three Months Ended March 31,				March 31,		December 31,
	(in thousands)	2015		2014		2015		2014
	United States	$	169,926	$	158,394	$	116,229	$	105,022
	International (excludes Puerto Rico)		22,457		19,102		23,312		23,543
	Total	$	192,383	$	177,496	$	139,541	$	128,565

Description_of_Business_and_Ba2

Description of Business and Basis of Presentation (Details Textual) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule Of Description Of Business And Basis Of Presentation [Line Items]
Relocation, consulting, and other costs	$5.40
Severance Costs	3.4
Total recorded liability associated with early lease termination	4.9
Translation Adjustment Functional to Reporting Currency, Net of Tax	11.7	9.5
Inventory Valuation Reserves	23	22.7
Sales, Marketing and Administrative Expense [Member]
Schedule Of Description Of Business And Basis Of Presentation [Line Items]
Restructuring and associated impairment charges	2.3	6.4
Chief Executive Officer and Chairman of the Board [Member]
Schedule Of Description Of Business And Basis Of Presentation [Line Items]
Severance Costs	$3.40

Net_Income_Loss_Per_Share_Comp

Net Income (Loss) Per Share - Computation of Basic and Diluted Earnings Per Share (Details) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Numerator:
Net income (loss) available to the Company	$31,560	($18,276)
Denominator for basic and diluted net (loss) income per share:
Weighted average common shares outstanding for basic	47,989	45,798
Dilutive potential common stock outstanding:
Weighted average common shares outstanding for diluted	51,716	45,798
Basic net income (loss) per share attributable to the Company	$0.66	($0.40)
Diluted net income (loss) per share attributable to the Company	$0.61	($0.40)
Senior Convertible Notes [Member]
Dilutive potential common stock outstanding:
Incremental common shares attributable to dilutive effect of share-based payment arrangements	891
Stock Options and ESPP [Member]
Dilutive potential common stock outstanding:
Incremental common shares attributable to dilutive effect of share-based payment arrangements	1,528
Restricted Stock Units (RSUs) [Member]
Dilutive potential common stock outstanding:
Incremental common shares attributable to dilutive effect of share-based payment arrangements	1,308

Net_Income_Loss_Per_Share_Anti

Net Income (Loss) Per Share - Anti-dilutive Common Stock Equivalents Not Included in Calculation of Net Income Per Diluted Share (Details)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share	9,575	26,976
Stock Options and RSUs [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share	22	7,870
Warrants [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share	9,553	9,553
Senior Convertible Notes [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share		9,553

Financial_Instruments_and_Fair2

Financial Instruments and Fair Value Measurements (Details Textual) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
	investment
Business Acquisition [Line Items]
Impairment charges recorded for earnings	$0
Unrealized loss position investment	0
Net currency exchange gains (losses)	300,000	200,000
Leasehold improvement impairment	900,000	2,200,000
Quoted price in active market (Level 1) [Member]
Business Acquisition [Line Items]
Debt instrument, fair value disclosure	503,100,000		516,100,000
Foreign Exchange Forward [Member]
Business Acquisition [Line Items]
Notional principal amount	$34,400,000

Financial_Instruments_and_Fair3

Financial Instruments and Fair Value Measurements - Composition of Marketable Securities (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost	352,531	357,713
Available-for-sale Securities, Gross Unrealized Gains, Before Tax	118	36
Available-for-sale Securities, Gross Unrealized Losses, Before Tax	-105	-237
Available-for-sale Securities, Fair Value	352,544	357,512
Short-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost	200,843	220,442
Available-for-sale Securities, Gross Unrealized Gains, Before Tax	49	21
Available-for-sale Securities, Gross Unrealized Losses, Before Tax	-83	-134
Available-for-sale Securities, Fair Value	200,809	220,329
Long-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost	27,494	43,078
Available-for-sale Securities, Gross Unrealized Gains, Before Tax	8
Available-for-sale Securities, Gross Unrealized Losses, Before Tax	-1	-36
Available-for-sale Securities, Fair Value	27,501	43,042
Commercial paper [Member] | Short-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost	21,979	11,290
Available-for-sale Securities, Fair Value	21,979	11,290
Commercial paper [Member] | Maximum [Member] | Short-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities Contractual Maturity	1 year	1 year
Certificates of deposit [Member] | Short-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost	281	282
Available-for-sale Securities, Fair Value	281	282
Certificates of deposit [Member] | Maximum [Member] | Short-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities Contractual Maturity	1 year	1 year
Restricted Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost	124,194	94,193
Available-for-sale Securities, Gross Unrealized Gains, Before Tax	61	15
Available-for-sale Securities, Gross Unrealized Losses, Before Tax	-21	-67
Available-for-sale Securities, Fair Value	124,234	94,141
Corporate notes [Member] | Short-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost	121,761	129,037
Available-for-sale Securities, Gross Unrealized Gains, Before Tax	37	8
Available-for-sale Securities, Gross Unrealized Losses, Before Tax	-81	-105
Available-for-sale Securities, Fair Value	121,717	128,940
Corporate notes [Member] | Long-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost	7,996	14,082
Available-for-sale Securities, Gross Unrealized Gains, Before Tax	6
Available-for-sale Securities, Gross Unrealized Losses, Before Tax		-13
Available-for-sale Securities, Fair Value	8,002	14,069
Corporate notes [Member] | Maximum [Member] | Short-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities Contractual Maturity	1 year	1 year
Corporate notes [Member] | Maximum [Member] | Long-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities Contractual Maturity	2 years	2 years
Corporate notes [Member] | Minimum [Member] | Long-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities Contractual Maturity	1 year	1 year
Securities of government-sponsored entities [Member] | Short-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost	56,822	78,333
Available-for-sale Securities, Gross Unrealized Gains, Before Tax	12	12
Available-for-sale Securities, Gross Unrealized Losses, Before Tax	-2	-29
Available-for-sale Securities, Fair Value	56,832	78,316
Securities of government-sponsored entities [Member] | Long-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost	19,498	28,996
Available-for-sale Securities, Gross Unrealized Gains, Before Tax	2
Available-for-sale Securities, Gross Unrealized Losses, Before Tax	-1	-23
Available-for-sale Securities, Fair Value	19,499	28,973
Securities of government-sponsored entities [Member] | Maximum [Member] | Short-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities Contractual Maturity	1 year	1 year
Securities of government-sponsored entities [Member] | Maximum [Member] | Long-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities Contractual Maturity	2 years	2 years
Securities of government-sponsored entities [Member] | Minimum [Member] | Long-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities Contractual Maturity	1 year	1 year
Securities of government-sponsored entities [Member] | Restricted Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost	71,971	42,862
Available-for-sale Securities, Gross Unrealized Gains, Before Tax	9	2
Available-for-sale Securities, Gross Unrealized Losses, Before Tax	-21	-54
Available-for-sale Securities, Fair Value	71,959	42,810
Securities of government-sponsored entities [Member] | Restricted Investments [Member] | Maximum [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities Contractual Maturity	2 years	2 years
U.S. government treasury securities [Member] | Short-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost		1,500
Available-for-sale Securities, Gross Unrealized Gains, Before Tax		1
Available-for-sale Securities, Fair Value		1,501
U.S. government treasury securities [Member] | Maximum [Member] | Short-term Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities Contractual Maturity		1 year
U.S. government treasury securities [Member] | Restricted Investments [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities, Cost	52,223	51,331
Available-for-sale Securities, Gross Unrealized Gains, Before Tax	52	13
Available-for-sale Securities, Gross Unrealized Losses, Before Tax		-13
Available-for-sale Securities, Fair Value	52,275	51,331
U.S. government treasury securities [Member] | Restricted Investments [Member] | Maximum [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale Securities Contractual Maturity	2 years	2 years

Financial_Instruments_and_Fair4

Financial Instruments and Fair Value Measurements - Schedule of Derivatives Not Designated as Cash Flow Hedges (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Derivative [Line Items]
Asset Derivatives	$0	$0
Liability Derivatives	0	0
Cash Flow Hedges [Member] | Not Designated As Hedging Instrument [Member]
Derivative [Line Items]
Asset Derivatives	268	0
Cash Flow Hedges [Member] | Not Designated As Hedging Instrument [Member] | Other Current Liabilities [Member]
Derivative [Line Items]
Liability Derivatives	0	0
Cash Flow Hedges [Member] | Not Designated As Hedging Instrument [Member] | Foreign Exchange Forward [Member] | Other Current Assets [Member]
Derivative [Line Items]
Asset Derivatives	268	0
Cash Flow Hedges [Member] | Not Designated As Hedging Instrument [Member] | Foreign Exchange Forward [Member] | Other Current Liabilities [Member]
Derivative [Line Items]
Liability Derivatives	$0	$0

Financial_Instruments_and_Fair5

Financial Instruments and Fair Value Measurements - Schedule of Derivative Instruments Effect on Statements of Operations (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Derivative Instruments Gain Loss [Line Items]
Amount of (Gain)/Loss Recognized in Income	$0	$0
Cash Flow Hedges [Member] | Not Designated As Hedging Instrument [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of (Gain)/Loss Recognized in Income	-2,165	0
Cash Flow Hedges [Member] | Not Designated As Hedging Instrument [Member] | Foreign Exchange Forward [Member] | Other (Income) Expense [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of (Gain)/Loss Recognized in Income	($2,165)	$0

Financial_Instruments_and_Fair6

Financial Instruments and Fair Value Measurements - Fair Value of Assets and Liabilities (Details) (Fair value measurements on recurring basis [Member], USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	$383,276	$397,476
Contingent Consideration:
Acquisition-related liabilities, current		-644
Acquisition-related liabilities		-644
Foreign Exchange Forward [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	268
Money Market Funds [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	30,464	39,963
Certificates of deposit [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	281	282
Corporate notes [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	129,719	143,009
Commercial paper [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	21,979	11,290
U.S. government treasury securities [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	52,275	52,831
Securities of government-sponsored entities [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	148,290	150,101
Quoted price in active market (Level 1) [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	83,020	93,076
Quoted price in active market (Level 1) [Member] | Money Market Funds [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	30,464	39,963
Quoted price in active market (Level 1) [Member] | Certificates of deposit [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	281	282
Quoted price in active market (Level 1) [Member] | U.S. government treasury securities [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	52,275	52,831
Significant other observable inputs (Level 2) [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	300,256	304,400
Significant other observable inputs (Level 2) [Member] | Foreign Exchange Forward [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	268
Significant other observable inputs (Level 2) [Member] | Corporate notes [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	129,719	143,009
Significant other observable inputs (Level 2) [Member] | Commercial paper [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	21,979	11,290
Significant other observable inputs (Level 2) [Member] | Securities of government-sponsored entities [Member]
Marketable Securities and Restricted Investments
Total marketable securities and restricted investments	148,290	150,101
Significant unobservable inputs (Level 3) [Member]
Contingent Consideration:
Acquisition-related liabilities, current		-644
Acquisition-related liabilities		($644)

Financial_Instruments_and_Fair7

Financial Instruments and Fair Value Measurements - Estimated Fair Value of Liabilities Measured on a Recurring Basis Using Significant Unobservable Inputs (Level 3) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Fair Value Disclosures [Abstract]
Fair value measurement at beginning of period	$644	$1,212
Change in fair value measurement included in operating expenses	-36
Contingent consideration paid or settled	-608	-608
Fair value measurement at end of period		$604

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets (Details 1) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Intangible assets subject to amortization:
Weighted Average Amortization Period	10 years	10 years
Gross Amount	$153,411	$153,540
Accumulated Amortization	-71,411	-67,625
Intangible Assets, net	82,000	85,915
Intangible assets not subject to amortization:
In-process research and development	10,640	10,640
Goodwill	154,273	154,443
Developed technology [Member]
Intangible assets subject to amortization:
Weighted Average Amortization Period	9 years	9 years
Gross Amount	79,008	79,008
Accumulated Amortization	-30,045	-27,760
Intangible Assets, net	48,963	51,248
Manufacturing know-how and trade secrets [Member]
Intangible assets subject to amortization:
Weighted Average Amortization Period	12 years	12 years
Gross Amount	21,783	21,879
Accumulated Amortization	-12,008	-11,640
Intangible Assets, net	9,775	10,239
Trade name and trademarks [Member]
Intangible assets subject to amortization:
Weighted Average Amortization Period	11 years	11 years
Gross Amount	9,500	9,500
Accumulated Amortization	-4,468	-4,264
Intangible Assets, net	5,032	5,236
Customer relationships [Member]
Intangible assets subject to amortization:
Weighted Average Amortization Period	8 years	8 years
Gross Amount	43,120	43,153
Accumulated Amortization	-24,890	-23,961
Intangible Assets, net	$18,230	$19,192

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets (Details Textual) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense related to intangible assets	$3,900,000	$4,000,000
Purchase of intangible assets	$27,389,000

Goodwill_and_Intangible_Assets4

Goodwill and Intangible Assets (Details 2) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Future amortization expense related to intangible assets
Remaining 2015	$11,363
2016	14,802
2017	12,455
2018	11,432
2019	10,078
2020	9,666
Thereafter through 2027	12,204
Intangible Assets, net	$82,000	$85,915

Business_Combinations_Details_

Business Combinations (Details Textual) (Progentix Orthobiology [Member], USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2009
Senior Secured Facility [Member]
Business Acquisition [Line Items]
Advanced loan accordance to loan agreement	5.3
Accrued interest rate of loan	6.00%
Preferred Stock Purchase Agreement [Member]
Business Acquisition [Line Items]
Percentage of ownership Interests acquired		40.00%
Cash payment on purchase of outstanding shares		10
Percentage of cumulative dividend, description	cumulative 8% dividend
Preferred Stock Purchase Agreement [Member] | Cumulative Preferred Stock [Member]
Business Acquisition [Line Items]
Percentage of minority interest represented by preferred stock		18.00%
Percentage of cumulative dividend		8.00%
Option Purchase Agreement
Business Acquisition [Line Items]
Call option remaining variable interest entity ownership percentage		60.00%
Amount of remaining shares		$35
Term of distribution agreement years		10 years

Business_Combinations_Details

Business Combinations (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Total current assets	$632,863	$705,871
Identifiable intangible assets, net	92,640	96,555
Goodwill	154,273	154,443
Other long-term assets	27,439	26,420
Non-controlling interests	8,147	8,310
Variable Interest Entity [Member]
Business Acquisition [Line Items]
Non-controlling interests	8,147		8,829
Variable Interest Entity [Member] | Progentix Orthobiology [Member]
Business Acquisition [Line Items]
Total current assets	639	839
Identifiable intangible assets, net	13,819	13,935
Goodwill	12,654	12,654
Other long-term assets	1	1
Accounts payable and accrued expenses	453	542
Deferred tax liabilities, net	2,770	2,770
Non-controlling interests	$8,147	$8,310

Reconciliation_of_Equity_Net_A

Reconciliation of Equity (Net Assets) Attributable to the Non-controlling Interests (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Reconciliation of equity (net assets) attributable to the non-controlling interests
Non-controlling interests at end of period	$8,147		$8,310
Variable Interest Entity [Member]
Reconciliation of equity (net assets) attributable to the non-controlling interests
Non-controlling interests at beginning of period	8,310	9,086
Less: Net loss attributable to the non-controlling interests	163	257
Non-controlling interests at end of period	$8,147	$8,829

Senior_Convertible_Notes_Detai

Senior Convertible Notes (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2011	Jun. 30, 2011
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Total Senior Convertible Notes	$364,588	$360,746
2.75% Senior Convertible Notes due 2017 [Member]
Debt Instrument [Line Items]
Principal amount	402,500	402,500		402,500
Unamortized debt discount	-37,912	-41,754	-88,900
Total Senior Convertible Notes	$364,588	$360,746

Senior_Convertible_Notes_Paren

Senior Convertible Notes (Parenthetical) (Details) (2.75% Senior Convertible Notes due 2017 [Member])	Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2011
2.75% Senior Convertible Notes due 2017 [Member]
Debt Instrument [Line Items]
Interest rate on convertible notes	2.75%	2.75%	2.75%

Senior_Convertible_Notes_Detai1

Senior Convertible Notes (Details Textual) (USD $)	3 Months Ended		12 Months Ended	1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2014
Debt Instrument [Line Items]
Contractual Coupon Interest Expense	$2,800,000	$2,800,000
Amortization of Debt Discount (Premium)	3,800,000	3,600,000
Derivative, maturity date			1-Jul-17
Initial strike price at which Warrants to be acquired			$988.51
Number of common stock shares preferred stock convertible into			20
Cash proceeds from the sale of warrants			47,900,000
2017 Hedge [Member]
Debt Instrument [Line Items]
Number of common stock to be purchased			9,553,096
Cost of hedge transaction			80,100,000
Minimum [Member]
Debt Instrument [Line Items]
Class of warrant or rights expiry month and year			2017-09
Maximum [Member]
Debt Instrument [Line Items]
Class of warrant or rights expiry month and year			2018-01
Maximum [Member] | Series A Convertible Participating Preferred Stock [Member]
Debt Instrument [Line Items]
Number of preferred or common stock into which the warrants is converted			477,654
Maximum [Member] | Common Shares [Member]
Debt Instrument [Line Items]
Number of preferred or common stock into which the warrants is converted			9,553,080
Other Expense [Member] | 2017 Hedge [Member]
Debt Instrument [Line Items]
Embedded derivative, gain (loss) reclassified to earnings			37,100,000
Additional Paid-in Capital [Member] | 2017 Hedge [Member]
Debt Instrument [Line Items]
Embedded derivative, amount reclassified to stockholders' equity			43,000,000
2.75% Senior Convertible Notes due 2017 [Member]
Debt Instrument [Line Items]
Principal amount	402,500,000			402,500,000	402,500,000
Net proceeds of unsecured senior convertible notes				359,200,000
Interest rate on convertible notes	2.75%			2.75%	2.75%
Debt instrument, maturity date				1-Jul-17
Initial conversion rate adjustment Shares				23.7344
Principal amount of debt considered for conversion rate				1,000
Initial conversion price of convertible notes				$42.13
Fair value of debt conversion cost	37,912,000		88,900,000		41,754,000
Effective interest rate			8.00%
2.75% Senior Convertible Notes due 2017 [Member] | Scenario Two [Member]
Debt Instrument [Line Items]
Consecutive trading days considered for debt conversion			5 days
2.75% Senior Convertible Notes due 2017 [Member] | Minimum [Member]
Debt Instrument [Line Items]
Percentage of conversion price			130.00%
2.75% Senior Convertible Notes due 2017 [Member] | Minimum [Member] | Scenario One [Member]
Debt Instrument [Line Items]
Consecutive trading days considered for debt conversion			20 days
2.75% Senior Convertible Notes due 2017 [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage of conversion price			98.00%
2.75% Senior Convertible Notes due 2017 [Member] | Maximum [Member] | Scenario One [Member]
Debt Instrument [Line Items]
Trading days considered for debt conversion			30
2.75% Senior Convertible Notes due 2017 [Member] | Other Income [Member]
Debt Instrument [Line Items]
Embedded derivative, gain (loss) reclassified to earnings			39,500,000
2.75% Senior Convertible Notes due 2017 [Member] | Additional Paid-in Capital [Member]
Debt Instrument [Line Items]
Embedded derivative, amount reclassified to stockholders' equity			$49,400,000

StockBased_Compensation_Stock_

Stock-Based Compensation, Stock Compensation Expense (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	$7,611	$7,764
Related income tax benefits	-3,044	-3,106
Stock-based compensation expense, net of taxes	4,567	4,658
Sales, Marketing and Administrative Expense [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	7,277	7,186
Research and development expense [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	259	465
Cost of goods sold [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	$75	$113

StockBased_Compensation_Detail

Stock-Based Compensation (Details Textual) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unamortized cost related to share-based compensation	$30,700,000
Weighted average contractual term	2 years 1 month 6 days
Stock options granted	0	0
Number of common stock issued to exercise stock options	692,000		1,030,000
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period for the award	4 years
Number of shares of common stock issued upon vesting of RSUs	1,291,000		1,361,000
Restricted Stock Units (RSUs) [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share payout levels	0.00%
Restricted Stock Units (RSUs) [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share payout levels	250.00%
Performance Based Restricted Stock Units (PRSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period for the award	3 years
Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of issuance price of stock under the stock issuance program	85.00%
Maximum percentage of annual compensation	15.00%
Maximum amount withheld to purchase shares of the company	$21,250
Employee Stock Purchase Plan Offering Period	2 years

StockBased_Compensation_Assump

Stock-Based Compensation, Assumptions Table (Details) (ESPP [Member])	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
ESPP [Member]
Weighted average assumptions used to estimate fair value of stock options granted and stock purchase rights under ESPP
Volatility	44.00%	47.00%
Expected term (years)	1 year 4 months 24 days	1 year 1 month 6 days
Risk free interest rate	0.20%	0.20%

Income_Taxes_Details_Textual

Income Taxes (Details Textual) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Tax Disclosure [Abstract]
Income Tax Expense (Benefit)	$17,885,000	($15,095,000)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent	36.00%	45.00%
Unrecognized tax benefit	0	0
Accrued interest related to unrecognized tax benefit	$0	$0

Business_Segment_Product_and_G2

Business Segment, Product and Geographic Information (Details Textual)	3 Months Ended
	Mar. 31, 2015
	segment
Segment Reporting [Abstract]
Number of reportable segments	1

Business_Segment_Product_and_G3

Business Segment, Product and Geographic Information (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Entity Wide Information Revenue From External Customer [Line Items]
Total Revenue	$192,383	$177,496
Spine surgery products [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Total Revenue	159,054	148,007
Biologics [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Total Revenue	$33,329	$29,489

Business_Segment_Product_and_G4

Business Segment, Product and Geographic Information (Details 2) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Revenues and Net Property and Equipment by Geographical Areas [Line Items]
Revenue	$192,383	$177,496
Property and equipment, net	139,541		128,565
UNITED STATES
Revenues and Net Property and Equipment by Geographical Areas [Line Items]
Revenue	169,926	158,394
Property and equipment, net	116,229		105,022
International [Member]
Revenues and Net Property and Equipment by Geographical Areas [Line Items]
Revenue	22,457	19,102
Property and equipment, net	$23,312		$23,543

Commitments_Details_Textual

Commitments (Details Textual) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Licensing and Purchasing Agreements [Member]
Business Acquisition [Line Items]
Obligation under consultancy arrangements	$22,700,000
Revenue based milestone period	achieved prior to 2024
Total payment for arrangements	6,200,000
Cash payment on purchase of outstanding shares	3,000,000
Payment in shares	3,200,000
Accrual recognized	0	0
Executive Severance Plans [Member]
Business Acquisition [Line Items]
Other Commitments, Future Minimum Payments, Remainder of Fiscal Year	$15,300,000

Contingencies_Details

Contingencies (Details) (USD $)	3 Months Ended		0 Months Ended		1 Months Ended	12 Months Ended	0 Months Ended	1 Months Ended	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Apr. 25, 2013	Sep. 20, 2011	Aug. 31, 2008	Dec. 31, 2011	Dec. 02, 2014	Oct. 31, 2010	Dec. 31, 2014	Mar. 02, 2015	Sep. 30, 2012
				patent	patent
Loss Contingencies [Line Items]
Gain related to litigation	$42,575,000	($30,000,000)
Loss Contingency, Estimate of Possible Loss										87,400,000
Legal Proceedings (Textual) [Abstract]
Unrecorded royalty damages	0
Medtronic Litigation
Loss Contingencies [Line Items]
Gain related to litigation	56,400,000
Number of patents assigned or licensed	9				12
Number of patents withdrawn	3
Number of patents selected for litigation				3
Company's patents in initial phase of litigation				1
Litigation liability				101,200,000		101,200,000
Loss contingency, settlement agreement, court	On May 15, 2013, the District Court granted the parties’ joint motion to dismiss claims relating to one of the three Medtronic patents pursuant to a settlement agreement. On June 11, 2013, the District Court granted the parties ongoing royalties with respect to the two Medtronic patents and the one Company patent remaining in the first phase of the case (the “June 2013 ruling”).
Company's cash and investment in escrow	113,300,000
Royalty accrual charge	7,900,000
Legal Proceedings (Textual) [Abstract]
Unrecorded royalty damages	700,000
Loss contingency, settlement agreement, consideration			7,500,000
Trademark Infringement [Member]
Loss Contingencies [Line Items]
Company's cash and investment in escrow							32,500,000		62,500,000
Legal Proceedings (Textual) [Abstract]
Jury award								60,000,000
Release of funds from escrow											62,500,000
Litigation Liability	$30,000,000

Regulatory_Matter_Details_Text

Regulatory Matter (Details Textual) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Regulatory Asset [Line Items]
Liability related to settlement with OIG	$42,575	($30,000)
OIG [Member]
Regulatory Asset [Line Items]
Liability related to settlement with OIG	$13,800