Nuvasive (NUVA) 10-Q 30 Apr 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014	Apr. 21, 2014
Document and Entity Information [Abstract]	'	'
Entity Registrant Name	'NUVASIVE INC	'
Entity Central Index Key	'0001142596	'
Document Type	'10-Q	'
Document Period End Date	31-Mar-14	'
Amendment Flag	'false	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	46,598,908

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$110,777	$102,825
Short-term marketable securities	176,608	143,449
Accounts receivable, net of allowances of $3,343 and $3,481, respectively	106,269	104,774
Inventory	147,721	136,937
Deferred tax assets, current	37,091	37,076
Income Taxes Receivable, Current	16,512	0
Prepaid expenses and other current assets	11,273	10,947
Total current assets	606,251	536,008
Property and equipment, net	128,857	128,064
Long-term marketable securities	52,209	79,829
Intangible assets, net	89,593	93,986
Goodwill	154,650	154,944
Deferred tax assets, non-current	42,874	42,863
Restricted cash and investments	123,068	119,195
Other assets	27,586	24,679
Total assets	1,225,088	1,179,568
Current liabilities:	'	'
Accounts payable and accrued liabilities	102,571	86,057
Accrued payroll and related expenses	24,219	31,095
Current Litigation Liability	30,000	0
Total current liabilities	156,790	117,152
Senior Convertible Notes	349,632	346,060
Deferred tax liabilities, non-current	2,933	2,934
Litigation liability	93,700	93,700
Other long-term liabilities	17,545	14,844
Commitments and contingencies	'	'
Stockholders' equity:	'	'
Preferred stock, $0.001 par value; 5,000 shares authorized, none outstanding	0	0
Common stock, $0.001 par value; 120,000 shares authorized at March 31, 2014 and December 31, 2013, 46,540 and 44,943 issued and outstanding at March 31, 2014 and December 31, 2013, respectively	47	45
Additional paid-in capital	786,285	769,203
Accumulated other comprehensive loss	-2,179	-3,238
Accumulated deficit	-188,494	-170,218
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	604,488	604,878
Noncontrolling Interest in Variable Interest Entity	8,829	9,086
Total stockholders' equity	595,659	595,792
Total liabilities and stockholders' equity	$1,225,088	$1,179,568

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, except Per Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Reserves For Accounts Receivable And Sales Returns	$3,343	$3,481
Preferred stock, par value (in usd per share)	$0.00	$0.00
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares outstanding	0	0
Common stock, par value (in usd per share)	$0.00	$0.00
Common stock, shares authorized	120,000	120,000
Common stock, shares issued	46,540	44,943
Common stock, shares outstanding	46,540	44,943

Unaudited_Condensed_Consolidat

Unaudited Condensed Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Revenue	$177,496	$159,504
Cost of goods sold (excluding amortization of purchased technology)	43,294	39,096
Gross profit	134,202	120,408
Operating expenses:	'	'
Sales, marketing and administrative	118,104	99,886
Research and development	9,455	9,694
Amortization of intangible assets	3,998	4,376
Litigation Award	30,000	0
Total operating expenses	161,557	113,956
Interest and other expense, net:	'	'
Interest income	217	172
Interest expense	-6,865	-7,032
Other income, net	375	240
Total interest and other expense, net	-6,273	-6,620
Loss before income taxes	-33,628	-168
Income tax benefit	-15,095	-764
Consolidated net (loss) income	-18,533	596
Net loss attributable to noncontrolling interests	-257	-255
Net (loss) income attributable to NuVasive, Inc.	($18,276)	$851
Net (loss) income per share attributable to NuVasive, Inc.:	'	'
Earnings Per Share, Basic	($0.40)	$0.02
Earnings Per Share, Diluted	($0.40)	$0.02
Weighted average shares outstanding:	'	'
Basic (in shares)	45,798	44,025
Diluted (in shares)	45,798	45,316

Unaudited_Condensed_Consolidat1

Unaudited Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Consolidated net (loss) income	($18,533)	$596
Other comprehensive income (loss):	'	'
Unrealized loss on marketable securities, net of tax	-12	-42
Translation adjustments, net of tax	1,071	-1,787
Other comprehensive income (loss)	1,059	-1,829
Total consolidated comprehensive loss	-17,474	-1,233
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	-257	0
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest	0	255
Comprehensive loss attributable to NuVasive, Inc.	($17,217)	($978)

Unaudited_Condensed_Consolidat2

Unaudited Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Operating activities:	'	'
Consolidated net (loss) income	($18,533)	$596
Adjustments to reconcile net (loss) income to net cash provided by operating activities:	'	'
Depreciation and amortization	15,363	14,581
Amortization of Financing Costs and Discounts	4,000	3,800
Stock-based compensation	7,764	6,787
Valuation Allowances and Reserves, Period Increase (Decrease)	1,366	28
Other non-cash adjustments	1,661	1,410
Changes in operating assets and liabilities, net of effects from acquisitions:	'	'
Accounts receivable	-1,194	-1,619
Inventory	-11,743	-4,098
Prepaid expenses and other current assets	-2,807	-929
Accounts payable and accrued liabilities	4,491	10,373
Increase Decrease In Litigation Liability	-30,000	0
Accrued payroll and related expenses	-7,068	-6,823
Net cash provided by operating activities	23,300	24,106
Investing activities:	'	'
Cash paid for business and asset acquisitions	0	-5,031
Purchases of property and equipment	-13,390	-9,200
Purchases of marketable securities	-46,126	-48,916
Sales of marketable securities	-36,257	-68,621
Net cash (used in) provided by investing activities	-23,259	5,474
Financing activities:	'	'
Principal payment of 2013 Senior Convertible Notes	0	-74,311
Proceeds from the issuance of common stock	8,749	36
Other assets	-1,094	100
Net cash provided by (used in) financing activities	7,655	-74,175
Effect of exchange rate changes on cash	256	-232
Increase (decrease) in cash and cash equivalents	7,952	-44,827
Cash and cash equivalents at beginning of period	102,825	123,299
Cash and cash equivalents at end of period	$110,777	$78,472

Description_of_Business_and_Ba

Description of Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Description of Business and Basis of Presentation	'
	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®", as well as an offering of biologics, cervical and motion preservation products. 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 reproducible outcomes for the surgeon. The platform includes a proprietary software-driven nerve detection and avoidance systems, NVM5 and NVJJB, and Intra-Operative Monitoring ("IOM") support; MaXcess®, an integrated split-blade retractor system; and a wide variety of specialized implants. The individual components of NuVasive's MAS platform, and many of the Company's products, can also be used in open or traditional spine surgery. 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 dedicates significant resources toward training spine surgeons on its unique technology and products.
	The Company’s primary business model is to loan its MAS systems to surgeons and hospitals who purchase implants, biologics and disposables for use in individual procedures. In addition, for larger customers, the Company places its proprietary nerve monitoring systems, MaXcess and surgical instrument sets with hospitals for an extended period at no up-front cost to them. 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. Implants, biologics and disposables are shipped from the Company’s inventories. The Company sells an immaterial quantity of MAS instrument sets, MaXcess and nerve monitoring systems to hospitals.
	Basis of Presentation and Principles of Consolidation.    The accompanying unaudited condensed 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. When there is a portion of equity in an acquired subsidiary not attributable, directly or indirectly, to the parent, the Company records the fair value of the noncontrolling interests at the acquisition date and classifies the amounts attributable to noncontrolling interests separately in equity in the Company’s condensed 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 condensed 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, 2014 are not necessarily indicative of the results that may be expected for any other interim period or for the full year. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2013 included in NuVasive’s Annual Report on Form 10-K filed with the SEC. In the opinion of management, the condensed consolidated financial statements include all adjustments necessary, which are of a normal and recurring nature, for the fair presentation of the Company's financial position and of the results of operations and cash flows for the periods presented.
	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, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	During the three months ended March 31, 2014, the Company completed a review of the estimated useful life of the international surgical instrument sets used in support of its business outside of the United States. Based on historical useful life information, as well as forecasted product life cycles and demand expectations, the useful life of certain international surgical instrument sets was extended from three to four years, which is consistent with the domestic depreciable lives. In accordance with authoritative guidance, this was accounted for as a change in accounting estimate and was made on a prospective basis effective January 1, 2014. For the three months ended March 31, 2014, depreciation expense, which is included in sales, marketing and administrative expenses, was approximately $0.7 million less than it would have been had the useful life of these assets not been extended. The Company expects to have a $2.8 million favorable impact to its consolidated statement of operations, for the full year ended December 31, 2014 due to this change in estimate. The total net impact to the Company's consolidated statement of operations for all four years affected by the change will be zero.
	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 gain of $2.2 million and $3.3 million at March 31, 2014 and December 31, 2013, respectively.
	Long-Lived 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. In connection with certain restructuring activities, as further described in Note 12, Restructuring Charges, the Company wrote-off approximately $2.2 million in leasehold improvements associated with exiting a majority of the leased square footage at its New Jersey location during the three months ended March 31, 2014. Excluding these leasehold improvements write-offs, the Company did not recognize any significant impairment during the three months ended March 31, 2014. The long-lived assets balances as of March 31, 2014 and December 31, 2013 include Company owned surgical instruments, which are loaned to surgeons and hospitals who purchase implants, biologics and disposables for use in individual procedures.
	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 $22.3 million and $21.9 million at March 31, 2014 and December 31, 2013, respectively.

Net_Income_Per_Share

Net Income Per Share	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Net Income (Loss) Per Share	'
	Net Income (Loss) Per Share
	The Company computes basic net income (loss) per share using the weighted-average number of common shares 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. For purposes of this calculation, common stock equivalents include the Company’s stock options, employee stock purchase plan shares, restricted stock units, including those with performance conditions, warrants, and the shares to be issued upon the conversion of the Senior Convertible Notes due in 2017 (see Note 6).
	The following table sets forth the computation of basic and diluted earnings or (loss) per share attributable to the Company (in thousands, except per share data):
		Three Months Ended March 31,
		2014				2013
	Numerator:
	Net (loss) income attributable to the Company	$	(18,276	)		$	851
	Denominator for basic and diluted net income per share:
	Weighted average common shares outstanding for basic	45,798				44,025
	Dilutive potential common stock outstanding:
	Stock options and Employee Stock Purchase Plan (ESPP)	—				152
	Restricted stock units	—				1,139
	Weighted average common shares outstanding for diluted	45,798				45,316
	Basic net (loss) income per share attributable to the Company	$	(0.40	)		$	0.02
	Diluted net (loss) income per share attributable to the Company	$	(0.40	)		$	0.02
	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 (in thousands):
		Three Months Ended March 31,
		2014			2013
	Stock options, ESPP shares and restricted stock units	7,870			6,489
	Warrants	9,553			14,694
	Senior Convertible Notes	9,553			10,919
	Total	26,976			32,102

Business_Combinations

Business Combinations	3 Months Ended
	Mar. 31, 2014
Business Combination, Description [Abstract]	'
Business Combinations	'
	Business Combinations
	During its history, the Company has completed acquisitions that were not considered individually or collectively material to the overall consolidated financial statements and 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 noncontrolling interest at fair value at the date of acquisition. Certain acquisitions contain contingent consideration arrangements that require the Company to assess the acquisition date fair value of the contingent consideration liabilities, which is recorded as part of the purchase consideration of the acquisition. The Company continuously assesses and adjusts the fair value of the contingent consideration liabilities, if necessary, until the settlement or expiration of the contingency occurs.
	Contingent Consideration Liabilities
	As a result of contingent consideration arrangements associated with certain asset and/or business acquisitions, the Company may have future payment obligations which are based on certain technological or operational milestones. In accordance with the authoritative guidance, the Company records these obligations at fair value at the time of acquisition with subsequent fair value adjustments to the contingent consideration reflected in the line items of the condensed consolidated statement of operations commensurate with the nature of the contingent consideration. At March 31, 2014, the estimated fair value of existing contingent consideration agreements, individually or collectively, are not considered material to the Company’s consolidated financial statements. Reasonable changes in the unobservable inputs would not be expected to have a significant impact on the Company’s condensed consolidated financial statements.
	Progentix
	In 2009, the Company completed the purchase of forty percent (40%) of the capital stock of Progentix, a company organized under the laws of the Netherlands, from existing shareholders pursuant to a Preferred Stock Purchase Agreement for $10 million in cash (the "Initial Investment"). NuVasive and Progentix also 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. 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.
	Pursuant to authoritative guidance, the equity interests in Progentix not owned by the Company, which includes shares of both common and preferred stock, are reported as noncontrolling interests on the consolidated balance sheet of the Company. The preferred stock represents 18% of the noncontrolling 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 a noncontrolling interest and shares in the allocation of the losses incurred by Progentix. Losses incurred by Progentix are charged to the Company and to the noncontrolling interest holders based on their ownership percentage.
	Total assets and liabilities of Progentix included in the accompanying condensed consolidated balance sheet are as follows (in thousands):
		March 31, 2014		December 31, 2013
	Total current assets	$	619	$	580
	Identifiable intangible assets, net	14,286		14,403
	Goodwill	12,654		12,654
	Other long-term assets	5		7
	Accounts payable & accrued expenses	479		403
	Deferred tax liabilities, net	2,770		2,770
	Noncontrolling interests	8,829		9,086
	The following is a reconciliation of equity (net assets) attributable to the noncontrolling interests (in thousands):
		Three Months Ended March 31,
		2014		2013
	Noncontrolling interests at beginning of period	$	9,086	$	10,003
	Less: Net loss attributable to the noncontrolling interests prior to reclassification from mezzanine to equity	—		255
	Less: Net loss attributable to the noncontrolling interests subsequent to reclassification from mezzanine to equity	257		—
	Noncontrolling interests at end of period	$	8,829	$	9,748
	Impulse Monitoring and Physician Practices
	The Company maintains contractual relationships with several physician practices ("PCs") which were inherited through the acquisition of Impulse Monitoring completed in 2011. Under the contract terms, PCs provide the physician oversight service associated with IOM services. The Company provides management services to the PCs including all non-medical services, management reporting, billing and collections of all charges for medical services provided as well as administrative support. The PCs pay the Company a management fee for these services that is settled on a monthly basis. In accordance with authoritative guidance, the Company has determined that the PCs are variable interest entities as NuVasive has both (1) the power to direct the economically significant activities of the PCs and (2) the obligation to absorb losses of, or the right to receive benefits from, the PCs. Therefore, the accompanying condensed consolidated financial statements include the accounts of the PCs from the date of acquisition. 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.

Financial_Instruments_and_Fair

Financial Instruments and Fair Value Measurements	3 Months Ended
	Mar. 31, 2014
Investments, Debt and Equity Securities [Abstract]	'
Financial Instruments and Fair Value Measurements	'
	Financial Instruments and Fair Value Measurements
	The Company invests a portion of its cash in certificates of deposit, corporate notes, commercial paper, U.S. government treasury securities and securities of government-sponsored entities. The Company classifies all 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 condensed consolidated statements of operations. As of March 31, 2014, the Company had no investments that were in a significant unrealized loss position and no impairment charges were recorded during the periods presented. If an investment is deemed other than temporarily impaired, the impairment is charged to earnings and a new cost basis for the security is established. The Company reviews its investments to identify and evaluate investments that have an indication 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.
	Premiums and discounts are amortized or accreted over the life of the related security as an adjustment to yield using the straight-line method and are included in interest income on the condensed consolidated statements of operations. Interest and dividends on securities classified as available-for-sale are also included in interest income on the condensed consolidated statements of operations. Realized gains and losses and interest income and expense 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 it requires the Company to invest with institutions that have high credit quality. The Company does not currently hold derivative financial investments or speculative investments. The carrying amounts of other 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, 2014 and December 31, 2013 approximate their related fair values due to the short-term maturities of these instruments. The estimated fair value of the Company’s capital lease obligations approximated their carrying values. The fair value and carrying value of the Company’s Senior Convertible Notes is discussed in Note 6.
	The fair value, based on a quoted market price, (Level 1), of the outstanding 2017 Notes at March 31, 2014 and December 31, 2013 was approximately $476.0 million and $439.3 million, respectively.
	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, 2014:
	Classified as current assets
	Certificates of deposit	Less than 1		$	832			$	—			$	—			$	832
	Corporate notes	Less than 1		95,983				32				(23		)		95,992
	Commercial paper	Less than 1		19,985				—				—				19,985
	U.S. government treasury securities	Less than 1		1,500				2				—				1,502
	Securities of government-sponsored entities	Less than 1		58,278				34				(15		)		58,297
	Short-term marketable securities			176,578				68				(38		)		176,608
	Classified as non-current assets
	Certificates of deposit	1 to 2		283				—				—				283
	Corporate notes	1 to 2		32,842				11				(45		)		32,808
	Securities of government-sponsored entities	1 to 2		19,104				18				(4		)		19,118
	Long-term marketable securities			52,229				29				(49		)		52,209
	Classified as restricted investments
	U.S. government treasury securities	Less than 2		40,456				30				(2		)		40,484
	Securities of government-sponsored entities	Less than 2		28,108				5				(18		)		28,095
	Restricted investments			68,564				35				(20		)		68,579
	Total marketable securities at March 31, 2014			$	297,371			$	132			$	(107	)		$	297,396
	December 31, 2013:
	Classified as current assets
	Certificates of deposit	Less than 1		$	833			$	—			$	—			$	833
	Corporate notes	Less than 1		71,611				23				(6		)		71,628
	Commercial paper	Less than 1		19,973				—				—				19,973
	U.S. government treasury securities	Less than 1		7,603				2				—				7,605
	Securities of government-sponsored entities	Less than 1		43,405				14				(9		)		43,410
	Short-term marketable securities			143,425				39				(15		)		143,449
	Classified as non-current assets
	Certificates of deposit	1 to 2		283				—				—				283
	Corporate notes	1 to 2		32,309				23				(14		)		32,318
	U.S. government treasury securities	1 to 2		1,500				1				—				1,501
	Securities of government-sponsored entities	1 to 2		45,722				19				(14		)		45,727
	Long-term marketable securities			79,814				43				(28		)		79,829
	Classified as restricted investments
	U.S. government treasury securities	Less than 2		43,274				16				(6		)		43,284
	Securities of government-sponsored entities	Less than 2		29,125				4				(16		)		29,113
	Restricted investments			72,399				20				(22		)		72,397
	Total marketable securities at December 31, 2013			$	295,638			$	102			$	(65	)		$	295,675
	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 Level 1 and Level 2 of the fair value measurement hierarchy during the three months ended March 31, 2014 and 2013.
	The fair values of the Company’s assets and liabilities, which are measured at fair value on a recurring basis, were determined using the following inputs (in thousands):
		Total				Quoted Price in				Significant Other				Significant
						Active Market				Observable Inputs				Unobservable
						(Level 1)				(Level 2)				Inputs (Level 3)
	March 31, 2014:
	Cash Equivalents, Marketable Securities and Restricted Investments:
	Money market funds	$	59,433			$	59,433			$	—			$	—
	Certificates of deposit	1,115				1,115				—				—
	Corporate notes	128,800				—				128,800				—
	Commercial paper	19,985				—				19,985				—
	U.S. government treasury securities	41,986				41,986				—				—
	Securities of government-sponsored entities	105,510				—				105,510				—
Total cash equivalents, marketable securities and restricted investments	$	356,829			$	102,534			$	254,295			$	—
Contingent Consideration:
Acquisition-related liabilities, current	$	(604	)		$	—			$	—			$	(604	)
Total contingent consideration	$	(604	)		$	—			$	—			$	(604	)
December 31, 2013:
Cash Equivalents, Marketable Securities and Restricted Investments:
Money market funds	$	72,514			$	72,514			$	—			$	—
Certificates of deposit	1,116				1,116				—				—
Corporate notes	103,946				—				103,946				—
Commercial paper	19,973				—				19,973				—
U.S. government treasury securities	52,390				52,390				—				—
Securities of government-sponsored entities	118,250				—				118,250				—
Total cash equivalents, marketable securities and restricted investments	$	368,189			$	126,020			$	242,169			$	—
Contingent Consideration:
Acquisition-related liabilities, current	$	(616	)		$	—			$	—			$	(616	)
Acquisition-related liabilities, non-current	$	(596	)		$	—			$	—			$	(596	)
Total contingent consideration	$	(1,212	)		$	—			$	—			$	(1,212	)
Contingent Consideration Liability
In connection with an immaterial acquisition in 2012, the Company is required to pay an amount not to exceed €2.0 million in the event two specified revenue-based milestones are met. The fair value of the contingent consideration was determined using a discounted cash flow model, the significant inputs of which are not observable in the market. The key assumptions in applying this approach are the revenue projections, the interest rate and the probabilities assigned to the milestones being achieved. Based on these assumptions, the estimated fair value of the contingent consideration totaled $0.6 million at March 31, 2014 and is included in accrued liabilities in the March 31, 2014 condensed consolidated balance sheet. Changes in fair value are recorded in the statements of operations as sales, marketing and administrative expenses.
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) (in thousands):
	Three Months Ended March 31,
	2014				2013
Fair value measurement at beginning of period	$	1,212			$	1,074
Change in fair value measurement included in operating expenses	—				(17		)
Contingent consideration paid or settled	(608		)		—
Fair value measurement at end of period	$	604			$	1,057

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Intangible Assets	'
	Goodwill and Intangible Assets
	Goodwill and intangible assets consisted of the following (in thousands, except years):
		Weighted-		Gross		Accumulated			Intangible
		Average		Amount		Amortization			Assets, net
		Amortization
		Period
		(in years)
	March 31, 2014:
	Intangible Assets Subject to Amortization:
	Purchased technology:
	Developed technology	10		$	62,328	$	(23,142	)	$	39,186
	Manufacturing know-how and trade secrets	12		21,997		(10,352		)	11,645
	Trade name and trademarks	11		9,500		(3,564		)	5,936
	Customer relationships	8		43,871		(21,685		)	22,186
	Total intangible assets subject to amortization	10		$	137,696	$	(58,743	)	$	78,953
	Intangible Assets Not Subject to Amortization:
	In-process research and development								10,640
	Goodwill								154,650
	Total goodwill and intangible assets, net								$	244,243
		Weighted-		Gross		Accumulated			Intangible
		Average		Amount		Amortization			Assets, net
		Amortization
		Period
		(in years)
	December 31, 2013:
	Intangible Assets Subject to Amortization:
	Purchased technology:
	Developed technology	10		$	62,328	$	(21,359	)	$	40,969
	Manufacturing know-how and trade secrets	12		21,997		(9,890		)	12,107
	Trade name and trademarks	11		9,500		(3,317		)	6,183
	Customer relationships	8		43,871		(19,784		)	24,087
	Total intangible assets subject to amortization	10		$	137,696	$	(54,350	)	$	83,346
	Intangible Assets Not Subject to Amortization:
	In-process research and development								10,640
	Goodwill								154,944
	Total goodwill and intangible assets, net								$	248,930
	Total expense related to the amortization of intangible assets was $4.0 million and $4.4 million for the three months ended March 31, 2014 and 2013, respectively. In-process research and development will be amortized beginning on the regulatory approval date of the respective acquired products and will be amortized over the estimated useful life determined at that time.
	Total future amortization expense related to intangible assets subject to amortization at March 31, 2014 is set forth in the table below (in thousands):
	Remaining 2014	$	10,292
	2015	13,182
	2016	12,705
	2017	10,352
	2018	9,834
	2019	8,480
	Thereafter through 2026	14,108
	Total future amortization expense	$	78,953

Senior_Convertible_Notes

Senior Convertible Notes	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Senior Convertible Notes	'
	Senior Convertible Notes
	The carrying values of the Company’s Senior Convertible Notes are as follows (in thousands):
		March 31, 2014			December 31, 2013
	2.75% Senior Convertible Notes due 2017:
	Principal amount	$	402,500		$	402,500
	Unamortized debt discount	(52,868		)	(56,440		)
	Senior Convertible Notes due 2017, net of unamortized discount	$	349,632		$	346,060
	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 repayment of an amount of cash equal to the principal amount and any excess of the conversion value over the principal amount in shares of 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. Interest on the 2017 Notes began accruing upon issuance and is payable semi-annually on January 1st and July 1st, beginning January 1, 2012.
	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 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.
	As of March 31, 2014, the "if-converted" value of the 2017 Notes did not exceed the principal amount and none of the conditions allowing holders of the 2017 Notes to convert had been met.
	In accordance with authoritative guidance, $49.3 million was recorded in stockholders' equity, and $88.9 million of debt discount was recorded during 2011. The debt discount is being 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, 2014 includes $2.8 million and $3.6 million for the contractual coupon interest and the accretion of the debt discount, respectively. During the three months ended March 31, 2013, interest expense recognized on the 2017 Notes includes $2.8 million and $3.3 million for the contractual coupon interest and the accretion of the debt discount, respectively.
	In connection with the offering of the 2017 Notes, the Company entered into a convertible note hedge transaction (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. In accordance with authoritative guidance, the derivative asset was assessed at a fair value and recorded in stockholders’ equity since the financial instruments were indexed to the Company's own stock. The 2017 Hedge expires 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.
	In addition, the Company sold warrants to the 2017 Counterparties to acquire up to 477,654 shares of the Company’s Series A Participating Preferred Stock (the "2017 Warrants"), 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. The 2017 Warrants expire on various dates from September 2017 through January 2018 and may be settled in cash or net shares. The Company received $47.9 million in cash proceeds from the sale of the 2017 Warrants, which has been recorded as an increase 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.

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation	'
	Stock-Based Compensation
	Under the 2004 Amended and Restated Equity Incentive Plan, as amended (the "2004 EIP"), the Company had the ability to grant stock options, stock appreciation rights, restricted stock units, restricted stock awards, performance awards, and deferred stock awards. The 2004 EIP terminated in accordance with its terms on February 20, 2014. Since it has terminated, no further awards may be granted under the 2004 EIP, however, that plan continues to govern grants made under it. In March 2014, the Compensation Committee (the "Compensation Committee") of the Board of Directors of the Company adopted the 2014 Equity Incentive Plan of NuVasive, Inc. subject to stockholder approval, which, if approved, would also provide the Company with the ability to grant equity awards to its workforce. Additionally, the NuVasive, Inc. 2004 Employee Stock Purchase Plan, as amended (the "ESPP") provides eligible employees with a means of acquiring equity in the Company through accumulated payroll deductions and at a discounted purchase price.
	The Company uses the Black-Scholes option-pricing model (the "Black-Scholes model") to value share-based employee stock option and purchase right awards and Monte Carlo simulations (the "Monte Carlo model") to value performance-based restricted stock units. The Company uses the stock price on the date of grant to value time-based restricted stock units. The determination of fair value of stock-based payment awards using the Black-Scholes model and the Monte Carlo model requires the use of certain estimates and assumptions that affect the reported amount of share-based compensation cost recognized in the condensed consolidated statements of operations. Among these cost-affecting estimates are the expected term of awards, estimated forfeitures, expected volatility of the Company’s stock price, expected dividends and the risk-free interest rate. In addition to these assumptions, performance-based conditions require the assessment of probability of achievement and correlation coefficients. The fair value of equity instruments that are expected to vest are recognized and amortized on an accelerated basis over the requisite service periods.
	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,
		2014		2013
	ESPP
	Volatility	47	%	58	%
	Expected term (years)	1.1		1.5
	Risk free interest rate	0.2	%	0.2	%
	Expected dividend yield	—	%	—	%
	The Company did not grant any stock options during the three months ended March 31, 2014 or 2013.
	The Company issued approximately 405,000 shares of common stock upon the exercise of stock options during the three months ended March 31, 2014 and issued approximately 177,000 shares of common stock upon the exercise of stock options during the year ended December 31, 2013.
	Restricted Stock Units
	Time-based restricted stock units ("RSUs") represent a right to receive shares of common stock at a future date determined in accordance with the participant’s award agreement. An exercise price and monetary payment are not required for receipt of RSUs or the shares issued in settlement of the respective awards. Instead, consideration is furnished in the form of the participant’s services to the Company. Time-based RSUs have graded vesting terms of up to four years. Total compensation cost for these awards is based on the fair value of the award on the date of grant. Performance-based restricted stock units ("PRSUs") are granted to certain senior Company executives and are earned based on the achievement of pre-defined performance criteria. The Compensation Committee has granted PRSUs annually since 2012, of which shares were earned in 2012 and 2013 pursuant to such types of awards. During February 2014, the Compensation Committee granted PRSUs (the "2014 PRSUs") with performance criteria measured by the Company’s two-year total shareholder return ("TSR") and total revenue growth, each as measured over the two-year performance period spanning 2014 and 2015. Each performance metric is also weighted equally and determined independently. The Company’s two-year TSR is measured as the change in the Company’s stock price between the opening stock price for 2014 and December 31, 2015, with the latter price being measured as the fifteen trading-day trailing average of the Company's stock price as of December 31, 2015. The target TSR is the median TSR of the companies comprising the Dow Jones Medical Devices Index. Achievement of a Company two-year TSR in excess of the 90th percentile of the index will result in shares equal to 250% of the target amount of PRSUs being awarded for this goal. Conversely, no shares would be awarded if the Company’s two-year TSR is below the 30th percentile of the index; provided, however, that, if the Company’s TSR during the two-year performance period is more than 5%, then, notwithstanding the Company’s percentile ranking, the minimum PRSU multiplier will be 25%. Revenue growth performance is measured as total revenue growth against the target revenue growth as determined by the Compensation Committee, measured over the two-year performance period spanning fiscal years 2014 and 2015. Achievement of 185.7% of the target revenue growth goal would result in shares equal to 250% of the target amount of PRSUs being awarded for this goal. Conversely, no shares would be awarded upon achievement of less than 28.6% of the target revenue growth goal. The number of shares achieved with respect to the 2014 PRSUs will be determined in or around January 2016, upon determination of the Company’s two-year TSR and total revenue growth over the two-fiscal year performance period as compared to the respective targets. Once the number of shares are determined pursuant to the formula, half of any such shares will vest on a date shortly after the date of such determination, as determined by the Compensation Committee, and the remaining half will vest on the one-year anniversary of such date, subject to continuous employment through each of the vesting dates.
	The fair value of the 2014 PRSUs based on the TSR performance metric is measured on the date of grant using a Monte Carlo model and the associated expense is amortized over the three-year period from the date of grant. The fair value of the PRSUs based on the revenue growth performance metric is measured on the date of grant, considering a probability of achieving the specific goals, and expense is amortized over the three-year vesting period.
	The Company is required to estimate forfeitures at the time of grant and revise those estimates in subsequent periods on a cumulative basis in the period the estimated forfeiture rate changes. The Company considered its historical experience of pre-vesting forfeitures on RSUs by employee ("shareowner") rank as the basis to arrive at its estimated annual pre-vesting forfeiture rate of 0% to 8% per year for the three months ended March 31, 2014.
	At March 31, 2014, there was $44.2 million of unamortized compensation expense for RSUs and PRSUs to be recognized over the remaining vesting periods.
	The Company issued approximately 1,210,000 shares of common stock upon the vesting of RSUs and PRSUs during the three months ended March 31, 2014 and issued approximately 665,000 shares of common stock upon the vesting of RSUs and PRSUs during the year ended December 31, 2013.
	The compensation cost that has been included in the statement of operations for all stock-based compensation arrangements was as follows (in thousands):
		Three Months Ended March 31,
		2014			2013
	Sales, marketing and administrative expense	$	7,186		$	6,424
	Research and development expense	465			342
	Cost of goods sold	113			21
	Total stock-based compensation expense	$	7,764		$	6,787

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	The Company recorded an income tax benefit of $15.1 million for the three months ended March 31, 2014 and an income tax benefit of $0.8 million for the three months ended March 31, 2013. The effective income tax benefit rate for the three months ended March 31, 2014 was 45% and reflects an expected statutory tax benefit associated with the trademark litigation accrual, reduced by U.S. permanent tax items primarily relating to stock-based compensation and non-deductible expenses. The effective income tax benefit rate for the three months ended March 31, 2013 was 455% and reflected a discrete tax benefit of $0.9 million, or 536% of pre-tax loss, related to the 2012 federal research and development credit which was retrospectively reinstated in the three months ended March 31, 2013. The Company updates its annual effective income tax rate each quarter and if the estimated effective income tax rate changes, a cumulative adjustment is made.
	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, 2014.
	The Globalization Initiative, which involved establishing new international operations and entering into new intercompany transfer pricing arrangements, including the licensing of intangibles, was implemented in January 2014. The results for the three months ended March 31, 2014 reflect the impacts of implementing this initiative.

Business_Segment_Product_and_G

Business Segment, Product, and Geographic Information	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Business Segment, Product and Geographic Information	'
	Business Segment, Product and Geographic Information
	The Company’s business 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 and the lack of availability of discrete financial information.
	The company operates under three products lines for revenues; Spine Surgery Products, Biologics and a Monitoring Service. The Company’s Spine Surgery Product line offerings, which include thoracolumbar product offerings, cervical offerings, and a set of motion preservation products still under development, 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 includes allograft (donated human tissue), FormaGraft®, a collagen synthetic product, Osteocel Plus®, an allograft cellular matrix containing viable mesenchymal stem cells, or MSCs, and AttraX®, a synthetic bone graft material, all used to aid the spinal fusion process. The Company’s Monitoring Service offering includes IOM services. Revenue by product line offerings was as follows (in thousands):
		Three Months Ended March 31,
		2014		2013
	Spine Surgery Products	$	137,308	$	122,667
	Biologics	29,489		27,156
	Monitoring Service	10,699		9,681
	Total Revenue	$	177,496	$	159,504
	Revenue and property and equipment, net, by geographic area were as follows (in thousands):
		Revenue				Property and Equipment, Net
		Three Months Ended March 31,				March 31,		December 31,
		2014		2013		2014		2013
	United States	$	158,394	$	146,222	$	108,924	$	109,458
	International (excludes Puerto Rico)	19,102		13,282		19,933		18,606
	Total	$	177,496	$	159,504	$	128,857	$	128,064

Contingencies

Contingencies	3 Months Ended
	Mar. 31, 2014
Contingencies [Abstract]	'
Contingencies	'
	Contingencies
	We are subject to potential liabilities under government regulations and various claims and legal actions that are pending or may be asserted. These matters arise in the ordinary course and conduct of our business. They include, for example, commercial, intellectual property, environmental, securities and employment matters. We intend to continue to defend ourselves vigorously in such matters. We regularly assess contingencies to determine the degree of probability and range of possible loss for potential accrual in our financial statements. An estimated loss contingency is accrued in our financial statements if it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Based on our assessment, we have adequately accrued an amount in our financial position for such contingent liabilities, and except for those that are specifically addressed below, that the Company 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 our current accruals, and it is possible that our 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 suit against NuVasive in the U.S. District Court for the Southern District of California (the "Medtronic Litigation"), alleging that certain of NuVasive’s products 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 patents. NuVasive brought counterclaims against Medtronic alleging infringement of certain of NuVasive’s patents. The case has been administratively broken into serial phases. The first phase of the case included three Medtronic patents and one NuVasive patent and on September 20, 2011, a jury from the U.S. District Court delivered an unfavorable verdict against NuVasive with respect to the three Medtronic patents and a favorable verdict with respect to the one NuVasive patent. The jury awarded monetary damages of approximately $101.2 million to Medtronic, which includes lost profits and back royalties (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, and on June 11, 2013, the District Court ruled on the ongoing royalty rates (the "June 2013 ruling"). On August 20, 2013, NuVasive and Medtronic filed their respective notices of appeal, and the appeal is now proceeding before the U.S. Court of Appeals for the Federal Circuit. In addition, on March 19, 2012, 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, 2014 condensed 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, on sales subsequent to the 2011 verdict and through March 31, 2013, the Company accrued royalties at the royalty rates stated in the 2011 verdict. Upon receiving the District Court ruling in June 2013, the Company began accruing ongoing royalties on sales at the royalty rates stated in the June 2013 ruling, and 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. As a result of the June 2013 ruling, the Company will be required to escrow funds to secure accrued royalties, estimated at $23 million to date, and ongoing royalties. The Company is also accruing post-judgment interest. With respect to the prejudgment interest award, the Company, based on its own assessment, as well as that of outside counsel, believes a reversal of the prejudgment interest award on appeal is probable, and therefore, in accordance with authoritative guidance on the evaluation of loss contingencies, the Company has not recorded an accrual for this amount, which is estimated to approximate $13 million. Additional damages, including interest may still be awarded, and at March 31, 2014, the Company cannot estimate a range of additional potential loss.
	With respect to the favorable verdict delivered regarding the one NuVasive patent, 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, 2014. 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 NuVasive patent. Consistent with the treatment afforded the $0.7 million damage award, no amount has been recorded for royalty revenue as of March 31, 2014.
	The second phase of the case pending in the Southern District of California involved one Medtronic cervical plate patent. On April 25, 2013, NuVasive and Medtronic entered into a settlement agreement fully resolving the second phase of the case. The settlement also removes from the case the cervical plate patent that was part of the first phase. As part of the settlement, NuVasive 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 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, NuVasive 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 NuVasive 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 NuVasive, 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 NuVasive spinal implants (including its CoRoent® XL family of spinal implants) infringe U.S. Patent No. 8,021,430, that NuVasive's Osteocel® Plus bone graft product infringes U.S. Patent No. 5,676,146, and that NuVasive's XLIF® procedure and use of MaXcess IV retractor during the XLIF procedure infringe methodology claims of U.S. Patent No. 8,251,997. The case was later transferred to the Southern District of California and on March 7, 2013, NuVasive counterclaimed to allege infringement by Medtronic of 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 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 June 27, 2013, NuVasive filed an inter partes review petition with the U.S. Patent Office challenging U.S. Patent No. 8,444,696 ("the '696 Patent"), which issued to Medtronic on May 21, 2013. On July 25, 2013, Medtronic amended its complaint to add a charge of infringement of the '696 Patent. The District Court has yet to determine which patents are to be tried in this phase of the case and has stayed litigation of a number of Medtronic and NuVasive patents currently subject to inter partes reexamination proceedings conducted by the Patent Office. Trial on this third phase of the case is anticipated to begin in early 2015. At March 31, 2014, 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
	In September 2009, Neurovision Medical Products, Inc. ("NMP") filed suit against NuVasive in the U.S. District Court for the Central District of California (Case No. 2:9-cv-6988-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. On November 23, 2009, the Company denied the allegations in NMP’s complaint. After trial of the matter on October 25, 2010, an unfavorable jury verdict was delivered against the Company relating to its use of the NeuroVision trade name. The verdict awarded damages to NMP of $60.0 million. The Company appealed the judgment and on September 10, 2012, the Ninth Circuit 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. On October 5, 2012, the case was reassigned to a new District Court judge for re-trial of the matter. During pendency of the appeal, the Company was required to escrow funds totaling $62.5 million to secure the amount of the judgment, plus interest, attorneys’ fees and costs. As a result of the reversal of the judgment at the conclusion of the appeal, the full $62.5 million was released from escrow and returned to the Company. Re-trial of this matter began on March 25, 2014. On April 3, 2014, the jury returned a verdict in favor of NMP on its claims against NuVasive in the amount of $30 million. Judgment has not been entered, and a hearing on NuVasive's affirmative defenses and motions for judgment as a matter of law and for a new trial, as well as NMP's motions for cancellation of trademark and a permanent injunction is anticipated to occur in June 2014. At March 31, 2014, the jury verdict represents a probable loss that can reasonably be determined. In accordance with the authoritative guidance on the evaluation of loss contingencies, the Company has recorded a $30 million liability related to this litigation.
	Securities Litigation
	On August 28, 2013, a purported securities class action lawsuit was filed by Danny Popov in the United States District Court for the Southern District of California naming NuVasive 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 filed an Amended Class Action Complaint for Violations of the Federal Securities Laws. On March 28, 2014, the Company filed a motion to dismiss the Amended Class Action Complaint for Violations of the Federal Securities Laws, which is scheduled to be heard by the court on July 14, 2014. The Company intends to vigorously defend against this action. At March 31, 2014, 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_Notes

Regulatory Matter (Notes)	3 Months Ended
	Mar. 31, 2014
Regulatory Matter [Abstract]	'
Regulatory Matter [Text Block]	'
	Regulatory Matter
	During the three months ended June 30, 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 seeks discovery of documents for the period January 2007 through April 2013. The Company is working with the OIG to understand the scope of the subpoena and to provide the requested documents. The Company intends to fully cooperate with the OIG's request. At March 31, 2014, the Company is unable to determine the potential financial impact, if any, that will result from this investigation.

Restructuring_Charges_Notes

Restructuring Charges (Notes)	3 Months Ended
	Mar. 31, 2014
Restructuring and Related Activities [Abstract]	'
Restructuring and Related Activities Disclosure [Text Block]	'
	Restructuring Charges
	During the three months ended March 31, 2014, as part of a company-wide efficiency effort, the Company reduced its footprint on the east coast of the United States in order to match its current and projected business needs without adversely impacting its ability to deliver surgeon education and local customer fulfillment. At March 31, 2014, the Company exited a majority of the leased square footage at its New Jersey location and made a decision to terminate the lease early at December 2017. As a result of the reduction in space, the Company recorded restructuring and associated impairment charges in the three months ended March 31, 2014 of approximately $6.4 million. Of the total restructuring and associated impairment charges, an approximately $0.1 million gain was related to the write-off of deferred rent offset by the noncash impairment of assets. The remaining $6.5 million loss was related to cash payments made during the current period as well as those anticipated to occur during subsequent periods, primarily associated with future rental payments through December 31, 2017 and lease termination charges, offset by estimated future sublease income. As of March 31, 2014, the total recorded liability associated with this early lease termination was $6.4 million. The charge is recorded within sales, marketing and administrative expense in the Condensed, Consolidated Statements of Operations for the three months ended March 31, 2014. 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 Condensed Consolidated Balance Sheets for the three months ended March 31, 2014.

Subsequent_Events_Notes

Subsequent Events (Notes)	3 Months Ended
	Mar. 31, 2014
Subsequent Events [Abstract]	'
Subsequent Events [Text Block]	'
	Subsequent Events
	As previously discussed in the Form 8-K filed with the SEC, an unfavorable jury verdict was delivered against NuVasive on April 3, 2014 relating to the Company's use of the trade name "NeuroVision" in the amount of $30 million. The Company strongly disagrees with the verdict and intends to vigorously defend its right to use the "NeuroVision" trademark. The Company intends to file post-trial motions in the U.S. District Court for the Central District of California (the "District Court") seeking judgment as a matter of law, and, in the alternative, a new trial. If necessary, the Company intends to appeal the verdict to the Ninth Circuit Court of Appeals. In the event NuVasive’s post-trial motions are denied and judgment is ultimately entered by the District Court, any payment of damages per the judgment will be stayed pending resolution of the appeals process (which could take up to two years). In accordance with authoritative guidance, the jury verdict is considered a recognizable subsequent event. The amount of the jury verdict represents a probable loss that can be reasonably estimated. Accordingly, the Company recorded a liability of $30 million as of March 31, 2014 for this anticipated cost. This additional expense, net of tax, lowered basic and diluted income per share by $0.41.

Description_of_Business_and_Ba1

Description of Business and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2014
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®", as well as an offering of biologics, cervical and motion preservation products. 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 reproducible outcomes for the surgeon. The platform includes a proprietary software-driven nerve detection and avoidance systems, NVM5 and NVJJB, and Intra-Operative Monitoring ("IOM") support; MaXcess®, an integrated split-blade retractor system; and a wide variety of specialized implants. The individual components of NuVasive's MAS platform, and many of the Company's products, can also be used in open or traditional spine surgery. 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 dedicates significant resources toward training spine surgeons on its unique technology and products.
	The Company’s primary business model is to loan its MAS systems to surgeons and hospitals who purchase implants, biologics and disposables for use in individual procedures. In addition, for larger customers, the Company places its proprietary nerve monitoring systems, MaXcess and surgical instrument sets with hospitals for an extended period at no up-front cost to them. 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. Implants, biologics and disposables are shipped from the Company’s inventories. The Company sells an immaterial quantity of MAS instrument sets, MaXcess and nerve monitoring systems to hospitals.
Basis of Presentation and Principles of Consolidation	'
	Basis of Presentation and Principles of Consolidation.    The accompanying unaudited condensed 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. When there is a portion of equity in an acquired subsidiary not attributable, directly or indirectly, to the parent, the Company records the fair value of the noncontrolling interests at the acquisition date and classifies the amounts attributable to noncontrolling interests separately in equity in the Company’s condensed 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 condensed 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, 2014 are not necessarily indicative of the results that may be expected for any other interim period or for the full year. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2013 included in NuVasive’s Annual Report on Form 10-K filed with the SEC. In the opinion of management, the condensed consolidated financial statements include all adjustments necessary, which are of a normal and recurring nature, for the fair presentation of the Company's financial position and of the results of operations and cash flows for the periods presented.

Net_Income_Per_Share_Tables

Net Income Per Share (Tables)	3 Months Ended
	Mar. 31, 2014
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 (in thousands, except per share data):
		Three Months Ended March 31,
		2014				2013
	Numerator:
	Net (loss) income attributable to the Company	$	(18,276	)		$	851
	Denominator for basic and diluted net income per share:
	Weighted average common shares outstanding for basic	45,798				44,025
	Dilutive potential common stock outstanding:
	Stock options and Employee Stock Purchase Plan (ESPP)	—				152
	Restricted stock units	—				1,139
	Weighted average common shares outstanding for diluted	45,798				45,316
	Basic net (loss) income per share attributable to the Company	$	(0.40	)		$	0.02
	Diluted net (loss) income per share attributable to the Company	$	(0.40	)		$	0.02
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 (in thousands):
		Three Months Ended March 31,
		2014			2013
	Stock options, ESPP shares and restricted stock units	7,870			6,489
	Warrants	9,553			14,694
	Senior Convertible Notes	9,553			10,919
	Total	26,976			32,102

Business_Combinations_Tables

Business Combinations (Tables)	3 Months Ended
	Mar. 31, 2014
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 condensed consolidated balance sheet are as follows (in thousands):
		March 31, 2014		December 31, 2013
	Total current assets	$	619	$	580
	Identifiable intangible assets, net	14,286		14,403
	Goodwill	12,654		12,654
	Other long-term assets	5		7
	Accounts payable & accrued expenses	479		403
	Deferred tax liabilities, net	2,770		2,770
	Noncontrolling interests	8,829		9,086
Reconciliation of equity (net assets) attributable to the noncontrolling interests	'
	The following is a reconciliation of equity (net assets) attributable to the noncontrolling interests (in thousands):
		Three Months Ended March 31,
		2014		2013
	Noncontrolling interests at beginning of period	$	9,086	$	10,003
	Less: Net loss attributable to the noncontrolling interests prior to reclassification from mezzanine to equity	—		255
	Less: Net loss attributable to the noncontrolling interests subsequent to reclassification from mezzanine to equity	257		—
	Noncontrolling interests at end of period	$	8,829	$	9,748

Financial_Instruments_and_Fair1

Financial Instruments and Fair Value Measurements Fair Value Table (Tables)	3 Months Ended
	Mar. 31, 2014
Fair Value Table [Abstract]	'
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	'
	The fair values of the Company’s assets and liabilities, which are measured at fair value on a recurring basis, were determined using the following inputs (in thousands):
		Total			Quoted Price in			Significant Other		Significant
					Active Market			Observable Inputs		Unobservable
					(Level 1)			(Level 2)		Inputs (Level 3)
	March 31, 2014:
	Cash Equivalents, Marketable Securities and Restricted Investments:
	Money market funds	$	59,433		$	59,433		$	—	$	—
	Certificates of deposit	1,115			1,115			—		—
	Corporate notes	128,800			—			128,800		—
	Commercial paper	19,985			—			19,985		—
	U.S. government treasury securities	41,986			41,986			—		—
	Securities of government-sponsored entities	105,510			—			105,510		—
	Total cash equivalents, marketable securities and restricted investments	$	356,829		$	102,534		$	254,295	$	—
	Contingent Consideration:
	Acquisition-related liabilities, current	$	(604	)	$	—		$	—	$	(604	)
	Total contingent consideration	$	(604	)	$	—		$	—	$	(604	)
	December 31, 2013:
	Cash Equivalents, Marketable Securities and Restricted Investments:
	Money market funds	$	72,514		$	72,514		$	—	$	—
	Certificates of deposit	1,116			1,116			—		—
	Corporate notes	103,946			—			103,946		—
	Commercial paper	19,973			—			19,973		—
	U.S. government treasury securities	52,390			52,390			—		—
	Securities of government-sponsored entities	118,250			—			118,250		—
	Total cash equivalents, marketable securities and restricted investments	$	368,189		$	126,020		$	242,169	$	—
	Contingent Consideration:
	Acquisition-related liabilities, current	$	(616	)	$	—		$	—	$	(616	)
	Acquisition-related liabilities, non-current	$	(596	)	$	—		$	—	$	(596	)
	Total contingent consideration	$	(1,212	)	$	—		$	—	$	(1,212	)
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Table Text Block]	'
	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) (in thousands):
		Three Months Ended March 31,
		2014			2013
	Fair value measurement at beginning of period	$	1,212		$	1,074
	Change in fair value measurement included in operating expenses	—			(17		)
	Contingent consideration paid or settled	(608		)	—
	Fair value measurement at end of period	$	604		$	1,057

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	3 Months Ended										12 Months Ended
	Mar. 31, 2014										Dec. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'										'
Goodwill and intangible assets	'										'
	Goodwill and intangible assets consisted of the following (in thousands, except years):
												Weighted-	Gross		Accumulated			Intangible
		Weighted-		Gross		Accumulated			Intangible			Average	Amount		Amortization			Assets, net
		Average		Amount		Amortization			Assets, net			Amortization
		Amortization										Period
		Period										(in years)
		(in years)									December 31, 2013:
	March 31, 2014:										Intangible Assets Subject to Amortization:
	Intangible Assets Subject to Amortization:										Purchased technology:
	Purchased technology:										Developed technology	10	$	62,328	$	(21,359	)	$	40,969
	Developed technology	10		$	62,328	$	(23,142	)	$	39,186
											Manufacturing know-how and trade secrets	12	21,997		(9,890		)	12,107
	Manufacturing know-how and trade secrets	12		21,997		(10,352		)	11,645
											Trade name and trademarks	11	9,500		(3,317		)	6,183
	Trade name and trademarks	11		9,500		(3,564		)	5,936
											Customer relationships	8	43,871		(19,784		)	24,087
	Customer relationships	8		43,871		(21,685		)	22,186
											Total intangible assets subject to amortization	10	$	137,696	$	(54,350	)	$	83,346
	Total intangible assets subject to amortization	10		$	137,696	$	(58,743	)	$	78,953
											Intangible Assets Not Subject to Amortization:
	Intangible Assets Not Subject to Amortization:										In-process research and development							10,640
	In-process research and development								10,640
											Goodwill							154,944
	Goodwill								154,650
											Total goodwill and intangible assets, net							$	248,930
	Total goodwill and intangible assets, net								$	244,243
Future amortization expense related to intangible assets	'										'
	Total future amortization expense related to intangible assets subject to amortization at March 31, 2014 is set forth in the table below (in thousands):
	Remaining 2014	$	10,292
	2015	13,182
	2016	12,705
	2017	10,352
	2018	9,834
	2019	8,480
	Thereafter through 2026	14,108
	Total future amortization expense	$	78,953

Senior_Convertible_Notes_Table

Senior Convertible Notes (Tables)	3 Months Ended
	Mar. 31, 2014
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):
		March 31, 2014			December 31, 2013
	2.75% Senior Convertible Notes due 2017:
	Principal amount	$	402,500		$	402,500
	Unamortized debt discount	(52,868		)	(56,440		)
	Senior Convertible Notes due 2017, net of unamortized discount	$	349,632		$	346,060

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based 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,
		2014		2013
	ESPP
	Volatility	47	%	58	%
	Expected term (years)	1.1		1.5
	Risk free interest rate	0.2	%	0.2	%
	Expected dividend yield	—	%	—	%
Compensation costs included in statement of income for all stock-based compensation arrangements	'
	The compensation cost that has been included in the statement of operations for all stock-based compensation arrangements was as follows (in thousands):
		Three Months Ended March 31,
		2014			2013
	Sales, marketing and administrative expense	$	7,186		$	6,424
	Research and development expense	465			342
	Cost of goods sold	113			21
	Total stock-based compensation expense	$	7,764		$	6,787

Business_Segment_Product_and_G1

Business Segment, Product, and Geographic Information (Tables)	3 Months Ended
	Mar. 31, 2014
Segment Reporting [Abstract]	'
Revenue from External Customers by Products and Services	'
	The Company’s Monitoring Service offering includes IOM services. Revenue by product line offerings was as follows (in thousands):
		Three Months Ended March 31,
		2014		2013
	Spine Surgery Products	$	137,308	$	122,667
	Biologics	29,489		27,156
	Monitoring Service	10,699		9,681
	Total Revenue	$	177,496	$	159,504
Schedule of Revenue and Net Property and Equipment by Geographical Areas [Table Text Block]	'
	Revenue and property and equipment, net, by geographic area were as follows (in thousands):
		Revenue				Property and Equipment, Net
		Three Months Ended March 31,				March 31,		December 31,
		2014		2013		2014		2013
	United States	$	158,394	$	146,222	$	108,924	$	109,458
	International (excludes Puerto Rico)	19,102		13,282		19,933		18,606
	Total	$	177,496	$	159,504	$	128,857	$	128,064

Description_of_Business_and_Ba2

Description of Business and Basis of Presentation Change in Accounting Estimate (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Change in Accounting Estimate [Line Items]	'
Document Period End Date	31-Mar-14
Depreciation Affect of Change in Estimate	$0.70
Depreciation Affect of Change in Estimate - Full Year Impact	$2.80

Description_of_Business_and_Ba3

Description of Business and Basis of Presentation Comprehensive Income (Loss) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Cumulative Translation Adjustments [Abstract]	'	'
Translation Adjustment Functional to Reporting Currency, Net of Tax	$2.20	$3.30

Description_of_Business_and_Ba4

Description of Business and Basis of Presentation Exit or Disposal Costs (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Restructuring and Related Activities [Abstract]	'
Asset Impairment Charges	$2.20

Description_of_Business_and_Ba5

Description of Business and Basis of Presentation Inventory Reserves (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Inventory Valuation Reserves	$22.30	$21.90

Net_Income_Per_Share_Computati

Net Income Per Share Computation of Basic and Diluted Earnings Per Share (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Numerator:	'	'
Net (loss) income attributable to the Company	($18,276)	$851
Denominator for basic and diluted net income per share:	'	'
Weighted average common shares outstanding for basic (in shares)	45,798	44,025
Dilutive potential common stock outstanding:	'	'
Weighted average common shares outstanding for diluted (in shares)	45,798	45,316
Earnings Per Share, Basic	($0.40)	$0.02
Earnings Per Share, Diluted	($0.40)	$0.02
Stock Options and ESPP [Member]	'	'
Dilutive potential common stock outstanding:	'	'
Stock options and ESPP (in shares)	0	152
Restricted Stock Units (RSUs) [Member]	'	'
Dilutive potential common stock outstanding:	'	'
Stock options and ESPP (in shares)	0	1,139

Net_Income_Per_Share_Antidilut

Net Income 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, 2014	Mar. 31, 2013
Computation of basic and diluted earnings per share	'	'
Anti-dilutive securities excluded from computation of earnings per share	26,976	32,102
Stock Options and RSUs [Member]	'	'
Computation of basic and diluted earnings per share	'	'
Anti-dilutive securities excluded from computation of earnings per share	7,870	6,489
Warrants [Member]	'	'
Computation of basic and diluted earnings per share	'	'
Anti-dilutive securities excluded from computation of earnings per share	9,553	14,694
Senior Convertible Notes [Member]	'	'
Computation of basic and diluted earnings per share	'	'
Anti-dilutive securities excluded from computation of earnings per share	9,553	10,919

Business_Combinations_Details

Business Combinations (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Components of total assets and liabilities of Progentix	'	'
Noncontrolling Interest in Variable Interest Entity	$8,829	$9,086
Progentix Orthobiology [Member]	'	'
Components of total assets and liabilities of Progentix	'	'
Variable Interest Entity Consolidated Carrying Amount Current Assets Net	619	580
Variable Interest Entity Consolidated Carrying Amount Finite And Indefinite Lived Intangible Assets Net	14,286	14,403
Variable Interest Entity Consolidated Carrying Amount Goodwill	12,654	12,654
Variable Interest Entity Consolidated Carrying Amount Other Long Term Assets Net	5	7
Variable Interest Entity Consolidated Carrying Amount Current Liabilities Net	479	403
Variable Interest Entity Consolidated Carrying Amount Deferred Tax Liabilities Net	$2,770	$2,770

Reconciliation_of_Equity_Net_A

Reconciliation of Equity (Net Assets) Attributable to the Noncontrolling Interests (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Reconciliation of equity (net assets) attributable to the noncontrolling interests	'	'
Noncontrolling interests at beginning of period	'	$10,003
Non-redeembable Noncontrolling Interest in Variable Interest Entity	8,829	'
Net Income (Loss) Attributable to Redeemable Noncontrolling Interest	0	255
Net Income (Loss) Attributable to Nonredeemable Noncontrolling Interest	257	0
Noncontrolling interests at end of period	'	9,748
Non-redeembable Noncontrolling Interest in Variable Interest Entity	$9,086	'

Business_Combinations_Details_

Business Combinations (Details Textual) (Progentix Orthobiology [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2009
Preferred Stock Purchase Agreement [Member]	'
Business Combinations (Textual) [Abstract]	'
Percentage of ownership Interests acquired	40.00%
Cash payment on purchase of outstanding shares	$10
Percentage of minority interest represented by preferred stock	18.00%
Percentage of cumulative dividend	'cumulative 8% dividend
Percentage of cumulative dividend, percent	8.00%
Option Purchase Agreement [Member]	'
Business Combinations (Textual) [Abstract]	'
Term of distribution agreement years	'10 years

Financial_Instruments_and_Fair2

Financial Instruments and Fair Value Measurements - Composition of Marketable Securities (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	$297,371	$295,638
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	132	102
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	107	65
Available-for-sale Securities, Fair Value	297,396	295,675
Restricted Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	68,564	72,399
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	35	20
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	20	22
Available-for-sale Securities, Fair Value	68,579	72,397
Short-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	176,578	143,425
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	68	39
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	38	15
Available-for-sale Securities, Fair Value	176,608	143,449
Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	52,229	79,814
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	29	43
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	49	28
Available-for-sale Securities, Fair Value	52,209	79,829
Certificates of deposit [Member] | Short-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	832	833
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	0	0
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	0	0
Available-for-sale Securities, Fair Value	832	833
Certificates of deposit [Member] | Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	283	283
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	0	0
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	0	0
Available-for-sale Securities, Fair Value	283	283
Corporate notes [Member] | Short-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	95,983	71,611
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	32	23
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	23	6
Available-for-sale Securities, Fair Value	95,992	71,628
Corporate notes [Member] | Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	32,842	32,309
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	11	23
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	45	14
Available-for-sale Securities, Fair Value	32,808	32,318
Commercial paper [Member] | Short-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	19,985	19,973
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	0	0
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	0	0
Available-for-sale Securities, Fair Value	19,985	19,973
U.S. government treasury securities [Member] | Restricted Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	40,456	43,274
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	30	16
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	2	6
Available-for-sale Securities, Fair Value	40,484	43,284
U.S. government treasury securities [Member] | Short-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	1,500	7,603
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	2	2
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	0	0
Available-for-sale Securities, Fair Value	1,502	7,605
U.S. government treasury securities [Member] | Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	'	1,500
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	'	1
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	'	0
Available-for-sale Securities, Fair Value	'	1,501
Securities of government-sponsored entities [Member] | Restricted Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	28,108	29,125
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	5	4
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	18	16
Available-for-sale Securities, Fair Value	28,095	29,113
Securities of government-sponsored entities [Member] | Short-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	58,278	43,405
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	34	14
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	15	9
Available-for-sale Securities, Fair Value	58,297	43,410
Securities of government-sponsored entities [Member] | Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities, Cost	19,104	45,722
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax	18	19
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax	4	14
Available-for-sale Securities, Fair Value	$19,118	$45,727
Minimum [Member] | Certificates of deposit [Member] | Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'1 year	'
Minimum [Member] | Corporate notes [Member] | Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'1 year	'
Minimum [Member] | U.S. government treasury securities [Member] | Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'1 year	'
Minimum [Member] | Securities of government-sponsored entities [Member] | Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'	'1 year
Maximum [Member] | Certificates of deposit [Member] | Short-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'1 year	'1 year
Maximum [Member] | Certificates of deposit [Member] | Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'2 years	'
Maximum [Member] | Corporate notes [Member] | Short-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'1 year	'1 year
Maximum [Member] | Corporate notes [Member] | Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'2 years	'
Maximum [Member] | Commercial paper [Member] | Short-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'1 year	'1 year
Maximum [Member] | U.S. government treasury securities [Member] | Restricted Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'2 years	'2 years
Maximum [Member] | U.S. government treasury securities [Member] | Short-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'1 year	'1 year
Maximum [Member] | U.S. government treasury securities [Member] | Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'2 years	'
Maximum [Member] | Securities of government-sponsored entities [Member] | Restricted Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'2 years	'2 years
Maximum [Member] | Securities of government-sponsored entities [Member] | Short-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'1 year	'1 year
Maximum [Member] | Securities of government-sponsored entities [Member] | Long-term Investments [Member]	'	'
Composition of marketable securities	'	'
Available-for-sale Securities Contractual Maturity	'	'2 years

Financial_Instruments_and_Fair3

Financial Instruments and Fair Value Measurements - Fair Value of Assets and Liabilities (Details) (Fair value measurements on recurring basis [Member], USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	$356,829	$368,189
Contingent Consideration Fair Value Disclosure, Current	-604	-616
Acquisition-related liabilities, non-current	'	-596
Contingent Consideration:	'	'
Acquisition-related liabilities	-604	-1,212
Money Market Funds [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	59,433	72,514
Certificates of deposit [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	1,115	1,116
Corporate notes [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	128,800	103,946
Commercial paper [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	19,985	19,973
U.S. government treasury securities [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	41,986	52,390
Securities of government-sponsored entities [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	105,510	118,250
Quoted price in active market (Level 1) [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	102,534	126,020
Contingent Consideration Fair Value Disclosure, Current	0	0
Acquisition-related liabilities, non-current	'	0
Contingent Consideration:	'	'
Acquisition-related liabilities	0	0
Quoted price in active market (Level 1) [Member] | Money Market Funds [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	59,433	72,514
Quoted price in active market (Level 1) [Member] | Certificates of deposit [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	1,115	1,116
Quoted price in active market (Level 1) [Member] | Corporate notes [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	0	0
Quoted price in active market (Level 1) [Member] | Commercial paper [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	0	0
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	41,986	52,390
Quoted price in active market (Level 1) [Member] | Securities of government-sponsored entities [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	0	0
Significant other observable inputs (Level 2) [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	254,295	242,169
Contingent Consideration Fair Value Disclosure, Current	0	0
Acquisition-related liabilities, non-current	'	0
Contingent Consideration:	'	'
Acquisition-related liabilities	0	0
Significant other observable inputs (Level 2) [Member] | Money Market Funds [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	0	0
Significant other observable inputs (Level 2) [Member] | Certificates of deposit [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	0	0
Significant other observable inputs (Level 2) [Member] | Corporate notes [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	128,800	103,946
Significant other observable inputs (Level 2) [Member] | Commercial paper [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	19,985	19,973
Significant other observable inputs (Level 2) [Member] | U.S. government treasury securities [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	0	0
Significant other observable inputs (Level 2) [Member] | Securities of government-sponsored entities [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	105,510	118,250
Significant unobservable inputs (Level 3) [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	0	0
Contingent Consideration Fair Value Disclosure, Current	-604	-616
Acquisition-related liabilities, non-current	'	-596
Contingent Consideration:	'	'
Acquisition-related liabilities	-604	-1,212
Significant unobservable inputs (Level 3) [Member] | Money Market Funds [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	0	0
Significant unobservable inputs (Level 3) [Member] | Certificates of deposit [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	0	0
Significant unobservable inputs (Level 3) [Member] | Corporate notes [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	0	0
Significant unobservable inputs (Level 3) [Member] | Commercial paper [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	0	0
Significant unobservable inputs (Level 3) [Member] | U.S. government treasury securities [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	0	0
Significant unobservable inputs (Level 3) [Member] | Securities of government-sponsored entities [Member]	'	'
Marketable Securities and Restricted Investments	'	'
Total marketable securities and restricted investments	$0	$0

Financial_Instruments_and_Fair4

Financial Instruments and Fair Value Measurements (Details Textual)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014
	USD ($)	Immaterial Acquisition 2012 [Member]	Immaterial Acquisition 2012 [Member]
	Milestone	USD ($)	EUR (€)
Investments, Debt and Equity Securities [Abstract]	'	'	'
Impairment charges recorded for earnings	$0	'	'
Business Acquisition [Line Items]	'	'	'
Maximum additional payment the Company is contingently obligated to make due to Cervitech acquisition	'	'	2,000,000
Acquisition-related liabilities	'	$600,000	'
Number of milestone	2	'	'

Financial_Instruments_and_Fair5

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, 2014	Mar. 31, 2013
Fair Value Disclosures [Abstract]	'	'
Fair value measurement at beginning of period	$1,212	$1,074
Change in fair value measurement included in operating expenses	0	-17
Contingent consideration paid or settled	-608	0
Fair value measurement at end of period	$604	$1,057

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets (Details 1) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Intangible Assets Subject to Amortization:	'	'
Weighted Average Amortization Period	'10 years	'10 years
Gross Amount	$137,696	$137,696
Accumulated Amortization	-58,743	-54,350
Intangible Assets, net	78,953	83,346
Intangible Assets Not Subject to Amortization:	'	'
In-process research and development	10,640	10,640
Goodwill	154,650	154,944
Total intangible assets, net	244,243	248,930
Developed technology [Member]	'	'
Intangible Assets Subject to Amortization:	'	'
Weighted Average Amortization Period	'10 years	'10 years
Gross Amount	62,328	62,328
Accumulated Amortization	-23,142	-21,359
Intangible Assets, net	39,186	40,969
Manufacturing know-how and trade secrets [Member]	'	'
Intangible Assets Subject to Amortization:	'	'
Weighted Average Amortization Period	'12 years	'12 years
Gross Amount	21,997	21,997
Accumulated Amortization	-10,352	-9,890
Intangible Assets, net	11,645	12,107
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	-3,564	-3,317
Intangible Assets, net	5,936	6,183
Customer relationships [Member]	'	'
Intangible Assets Subject to Amortization:	'	'
Weighted Average Amortization Period	'8 years	'8 years
Gross Amount	43,871	43,871
Accumulated Amortization	-21,685	-19,784
Intangible Assets, net	$22,186	$24,087

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets (Details 2) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]	'	'
Remaining 2014	$10,292	'
Future amortization expense related to intangible assets	'	'
2013	13,182	'
2014	12,705	'
2015	10,352	'
2016	9,834	'
2017	8,480	'
Thereafter through 2026	14,108	'
Intangible Assets, net	$78,953	$83,346

Goodwill_and_Intangible_Assets4

Goodwill and Intangible Assets (Details Textual) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Goodwill and Intangible Assets Disclosure [Abstract]	'	'
Amortization expense related to intangible assets	$3,998	$4,376

Senior_Convertible_Notes_Detai

Senior Convertible Notes (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Jun. 30, 2011
Net carrying amount of the debt component	'	'	'	'
Senior Convertible Notes	$349,632,000	'	$346,060,000	'
2.75% Senior Convertible Notes due 2017 [Member]	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'
Amortization of Debt Discount (Premium)	3,600,000	3,300,000	'	'
Contractual Coupon Interest Expense	2,800,000	2,800,000	'	'
Net carrying amount of the debt component	'	'	'	'
Principal amount	402,500,000	'	402,500,000	402,500,000
Unamortized debt discount	($52,868,000)	'	($56,440,000)	'

Senior_Convertible_Notes_Detai1

Senior Convertible Notes (Details Textual) (USD $)	3 Months Ended		6 Months Ended	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Jun. 30, 2011	Dec. 31, 2011	Dec. 31, 2013
Senior Convertible Notes (Textual) [Abstract]	'	'	'	'	'
Debt Instrument, convertible carrying amount	$49,300,000	'	'	$49,300,000	'
2.75% Senior Convertible Notes due 2017 [Member]	'	'	'	'	'
Senior Convertible Notes (Textual) [Abstract]	'	'	'	'	'
Interest rate on convertible notes	'	'	2.75%	'	'
Principal amount of senior convertible notes	402,500,000	'	402,500,000	'	402,500,000
Net proceeds of unsecured senior convertible notes	'	'	359,200,000	'	'
Debt instrument, maturity date	'	'	1-Jul-17	'	'
Initial conversion rate adjustment Shares	'	'	23.7344	'	'
Base principal amount per note	'	'	1,000	'	'
Initial conversion price of convertible notes	'	'	$42.13	'	'
Business day period	'	'	'	'5 days	'
Fair value of debt conversion cost	'	'	'	88,900,000	'
Debt discount, interest rate	'	'	'	8.00%	'
Contractual Coupon Interest Expense	2,800,000	2,800,000	'	'	'
Amortization of Debt Discount (Premium)	3,600,000	3,300,000	'	'	'
Number of common stock to be purchased	'	'	'	9,553,096	'
Initial stock price at which shares to be purchased	'	'	'	$42.13	'
Cost of hedge transaction	'	'	'	80,100,000	'
Number of warrants to be acquired	'	'	'	477,654	'
Initial strike price at which Warrants to be acquired	'	'	'	988.51	'
Number of common stock shares preferred stock convertible into	'	'	'	20	'
Number Of Securities Called By Warrant Transaction	'	'	'	9,553,080	'
Cash proceeds from the sale of warrants	'	'	'	$47,900,000	'
Minimum [Member] | 2.75% Senior Convertible Notes due 2017 [Member]	'	'	'	'	'
Senior Convertible Notes (Textual) [Abstract]	'	'	'	'	'
Consecutive trading days immediately preceding calendar quarter	'	'	'	'20 days	'
Percentage of conversion price	'	'	'	130.00%	'
Maximum [Member] | 2.75% Senior Convertible Notes due 2017 [Member]	'	'	'	'	'
Senior Convertible Notes (Textual) [Abstract]	'	'	'	'	'
Consecutive trading days immediately preceding calendar quarter	'	'	'	'30 days	'
Percentage of conversion price	'	'	'	98.00%	'

StockBased_Compensation_Assump

Stock-Based Compensation Assumptions Table (Details 1) (ESPP [Member])	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
ESPP [Member]	'	'
Weighted average assumptions used to estimate fair value of stock options granted and stock purchase rights under ESPP	'	'
Volatility	47.00%	58.00%
Expected term (years)	'1 year 1 month	'1 year 6 months
Risk free interest rate	0.20%	0.20%
Expected dividend yield	0.00%	0.00%

StockBased_Compensation_Detail

Stock-Based Compensation (Details Textuals 1) (USD $)	3 Months Ended	12 Months Ended	3 Months Ended	12 Months Ended	0 Months Ended	3 Months Ended
In Millions, except Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014	Dec. 31, 2013	Mar. 01, 2013	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014
			Restricted Stock Units (RSUs) [Member]	Restricted Stock Units (RSUs) [Member]	Performance-Based Restricted Stock Units [Member]	Vesting in One Year [Member]	Vesting in One Year [Member]	Vesting in Two Years [Member]	Vesting in Two Years [Member]	Maximum [Member]
						Performance-Based Restricted Stock Units [Member]	Total Stockholder Return Performance-Based Restricted Stock Units [Member]	Performance-Based Restricted Stock Units [Member]	Total Stockholder Return Performance-Based Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'	'	'	'	'	'
Number of common stock issued to exercise stock options	405,000	177,000	'	'	'	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	'	'	'	'	'	'	'	'	'	'4 years 0 months
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Percentage Of Target Number Of Shares Eligible To Receive	'	'	'	'	'	'	'	'	'	250.00%
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$44.20	'	'	'	'	'	'	'	'	'
Document Period End Date	31-Mar-14	'	'	'	'	'	'	'	'	'
Number of shares of common stock issued upon vesting of RSUs	'	'	1,210,000	665,000	'	'	'	'	'	'
Current Fiscal Year End Date	'--12-31	'	'	'	'	'	'	'	'	'
Vesting percentage	'	'	'	'	33.33%	33.33%	50.00%	33.33%	50.00%	'

StockBased_Compensation_Expens

Stock-Based Compensation Expense Table (Details 2) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Compensation cost included in statement of income for all stock-based compensation arrangements	'	'
Stock based compensation expense	$7,764	$6,787
Sales, marketing and administrative expense [Member]	'	'
Compensation cost included in statement of income for all stock-based compensation arrangements	'	'
Stock based compensation expense	7,186	6,424
Research and development expense [Member]	'	'
Compensation cost included in statement of income for all stock-based compensation arrangements	'	'
Stock based compensation expense	465	342
Cost of goods sold [Member]	'	'
Compensation cost included in statement of income for all stock-based compensation arrangements	'	'
Stock based compensation expense	$113	$21

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]	'	'
Income tax benefit	($15,095,000)	($764,000)
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent	0.00%	500.00%
Tax benefit related to federal research and development credit	'	$900,000
Tax benefit related to federal research and development credit, percentage	'	-536.00%

Business_Segment_Product_and_G2

Business Segment, Product, and Geographic Information (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
	segment
Segment Reporting [Abstract]	'	'
Number of Reportable Segments	1	'
Revenue from spine surgery product line offerings	'	'
Total revenues	$177,496	$159,504
Spine Surgery Products [Member]	'	'
Revenue from spine surgery product line offerings	'	'
Total revenues	137,308	122,667
Biologics [Member]	'	'
Revenue from spine surgery product line offerings	'	'
Total revenues	29,489	27,156
Monitoring Service [Member]	'	'
Revenue from spine surgery product line offerings	'	'
Total revenues	$10,699	$9,681

Business_Segment_Product_and_G3

Business Segment, Product, and Geographic Information Geographic Information (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Revenues and Net Property and Equipment by Geographical Areas [Line Items]	'	'	'
Total revenues	$177,496	$159,504	'
Property, Plant and Equipment, Net	128,857	'	128,064
UNITED STATES	'	'	'
Revenues and Net Property and Equipment by Geographical Areas [Line Items]	'	'	'
Total revenues	158,394	146,222	'
Property, Plant and Equipment, Net	108,924	'	109,458
International [Member]	'	'	'
Revenues and Net Property and Equipment by Geographical Areas [Line Items]	'	'	'
Total revenues	19,102	13,282	'
Property, Plant and Equipment, Net	$19,933	'	$18,606

Contingencies_Details

Contingencies (Details) (USD $)

3 Months Ended

6 Months Ended

9 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Jun. 30, 2013

Sep. 30, 2012

Dec. 31, 2013

Dec. 31, 2011

Mar. 31, 2013

Mar. 31, 2014

Dec. 31, 2010

Dec. 31, 2011

Dec. 10, 2012

Medtronic Litigation [Member]

Medtronic Litigation [Member]

Medtronic Litigation [Member]

Medtronic Litigation [Member]

Medtronic Litigation [Member]

Medtronic Litigation [Member]

Trademark Infringement [Member]

Trademark Infringement [Member]

Trademark Infringement [Member]

Trademark Infringement [Member]

patent

Legal Proceedings (Textual) [Abstract]

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'

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'

'

'

'

'

'

'

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'

Number of patents assigned or licensed

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12

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'

'

'

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'

Number of patents withdrawn

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3

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'

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'

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'

Number of patents remaining

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9

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Company's Patents in Initial Phase of Litigation

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1

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'

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'

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Number of Patents Selected for Litigation

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3

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Other Company's Patents in Initial Phase of Litigation

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3

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'

Litigation award

$30,000,000

$0

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($101,200,000)

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($101,200,000)

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RoyaltyAccrualCharge

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7,900,000

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TransferOfFundsNotAvailableForWithdrawalOrUse

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23,000,000

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Company's cash and investment in escrow

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113,300,000

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62,500,000

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Approximate loss contingency

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13,000,000

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Unrecorded royalty damages

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700,000

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Loss Contingency, Settlement Agreement, Consideration

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7,500,000

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Jury award

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30,000,000

60,000,000

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Release of funds from escrow

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$62,500,000

Restructuring_Charges_Details

Restructuring Charges (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014
Q1 2014 Restructuring Charge [Line Items]	'
Q1 2014 Net Restructuring Charge	$6.40
Q1 2014 Gain on Restructuring Writeoffs	-0.1
Q1 2014 Gross Restructuring Charge	6.5
Q1 2014 Restructuring Liability	$6.40

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Subsequent Events [Abstract]	'	'
Litigation Award	$30,000	$0
Earnings Per Share Basic and Dilutive Effect of Litigation Award	$0.41	'