Nuvasive (NUVA) 10-Q30 Oct 192019 Q3 Quarterly reportFinancial data

Company Profile

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2019	Oct. 28, 2019
Document And Entity Information [Abstract]
Entity Registrant Name	NUVASIVE INC
Entity Central Index Key	0001142596
Entity Current Reporting Status	Yes
Document Type	10-Q
Document Period End Date	Sep. 30, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Trading Symbol	NUVA
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		52,073,661
Entity Shell Company	false
Entity File Number	000-50744
Entity Tax Identification Number	33-0768598
Entity Address, Address Line One	7475 Lusk Boulevard
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92121
City Area Code	(858)
Local Phone Number	909-1800
Title of 12(b) Security	Common Stock, par value $0.001 per share
Entity Interactive Data Current	Yes
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 163,399	$ 117,840
Accounts receivable, net of allowances of $16,444 and $16,171, respectively	203,611	196,487
Inventory, net	308,893	273,244
Prepaid income taxes	20,328	16,905
Prepaid expenses and other current assets	14,610	13,733
Total current assets	710,841	618,209
Property and equipment, net	263,135	238,841
Intangible assets, net	214,492	252,048
Goodwill	560,744	561,366
Operating lease right-of-use assets	67,128
Deferred tax assets	4,023	5,263
Restricted cash and investments	2,395	2,395
Other assets	17,094	29,737
Total assets	1,839,852	1,707,859
Current liabilities:
Accounts payable and accrued liabilities	105,944	105,877
Contingent consideration liabilities	7,774	7,560
Accrued payroll and related expenses	66,044	59,960
Operating lease liabilities	5,792
Litigation liabilities	2,065	1,415
Income tax liabilities	5,496	4,648
Total current liabilities	193,115	179,460
Senior convertible notes	617,992	602,526
Deferred and income tax liabilities	13,491	4,964
Operating lease liabilities	72,713
Other long-term liabilities	65,927	86,384
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized, none outstanding
Common stock, $0.001 par value; 120,000,000 shares authorized at September 30, 2019 and December 31, 2018, 57,420,854 and 56,648,077 issued and outstanding at September 30, 2019 and December 31, 2018, respectively	62	61
Additional paid-in capital	1,421,235	1,397,829
Accumulated other comprehensive loss	(11,332)	(8,628)
Retained earnings	52,599	17,241
Treasury stock at cost; 5,354,355 shares and 5,116,496 shares at September 30, 2019 and December 31, 2018, respectively	(585,950)	(571,978)
Total equity	876,614	834,525
Total liabilities and equity	$ 1,839,852	$ 1,707,859

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Accounts receivable, allowances	$ 16,444	$ 16,171
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	57,420,854	56,648,077
Common stock, shares outstanding	57,420,854	56,648,077
Treasury stock at cost, shares	5,354,355	5,116,496

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue
Total revenue	$ 290,835	$ 271,301	$ 857,716	$ 813,387
Cost of revenue (excluding below amortization of intangible assets)
Total cost of revenue	77,028	74,160	229,101	225,030
Gross profit	213,807	197,141	628,615	588,357
Operating expenses:
Sales, marketing and administrative	152,887	141,211	450,816	433,635
Research and development	18,143	15,254	53,271	44,601
Amortization of intangible assets	12,596	12,349	38,498	37,402
Purchase of in-process research and development		8,913		8,913
Litigation liability loss				27,800
Business transition costs	(333)	1,443	5,146	7,694
Total operating expenses	183,293	179,170	547,731	560,045
Interest and other expense, net:
Interest income	620	130	1,356	380
Interest expense	(9,654)	(9,035)	(28,817)	(28,458)
Other (expense) income, net	(5,696)	4,239	(6,053)	(7,843)
Total interest and other expense, net	(14,730)	(4,666)	(33,514)	(35,921)
Income (loss) before income taxes	15,784	13,305	47,370	(7,609)
Income tax (expense) benefit	(4,774)	2,618	(12,012)	7,931
Consolidated net income	$ 11,010	$ 15,923	$ 35,358	$ 322
Net income per share:
Basic	$ 0.21	$ 0.31	$ 0.68	$ 0.01
Diluted	$ 0.21	$ 0.30	$ 0.67	$ 0.01
Weighted average shares outstanding:
Basic	52,057	51,439	51,901	51,341
Diluted	53,056	53,189	52,667	52,296
Product [Member]
Revenue
Total revenue	$ 260,173	$ 242,030	$ 765,377	$ 728,232
Cost of revenue (excluding below amortization of intangible assets)
Total cost of revenue	57,164	54,741	169,263	168,134
Service [Member]
Revenue
Total revenue	30,662	29,271	92,339	85,155
Cost of revenue (excluding below amortization of intangible assets)
Total cost of revenue	$ 19,864	$ 19,419	$ 59,838	$ 56,896

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Consolidated net income	$ 11,010	$ 15,923	$ 35,358	$ 322
Other comprehensive loss:
Translation adjustments, net of tax	(2,780)	(1,318)	(2,704)	(3,261)
Other comprehensive loss	(2,780)	(1,318)	(2,704)	(3,261)
Total consolidated comprehensive income (loss)	$ 8,230	$ 14,605	$ 32,654	$ (2,939)

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings (Accumulated Deficit) [Member]	Treasury Stock [Member]	Total Nuvasive, Inc. Stockholders? Equity [Member]	Non-controlling Interest [Member]
Beginning Balance at Dec. 31, 2017	$ 799,416	$ 60	$ 1,363,549	$ (6,933)	$ 4,762	$ (565,867)	$ 795,571	$ 3,845
Beginning Balance, Shares at Dec. 31, 2017		56,164				(5,002)
Issuance of common stock under employee and director equity option and purchase plans	(1,821)		2,012			$ (3,833)	(1,821)
Issuance of common stock under employee and director equity option and purchase plans, Shares		172				(76)
Stock-based compensation expense	5,419		5,419				5,419
Consolidated net income (loss) attributable to NuVasive, Inc.	(27,132)				(27,132)		(27,132)
Consideration paid in excess of non-controlling interests	(12,221)		(12,221)				(12,221)
Net loss attributable to non-controlling interests	(3,845)							(3,845)
Other comprehensive income (loss)	2,579			2,579			2,579
Ending Balance at Mar. 31, 2018	762,395	$ 60	1,358,759	(4,354)	(22,370)	$ (569,700)	762,395
Ending Balance, Shares at Mar. 31, 2018		56,336				(5,078)
Beginning Balance at Dec. 31, 2017	799,416	$ 60	1,363,549	(6,933)	4,762	$ (565,867)	795,571	$ 3,845
Beginning Balance, Shares at Dec. 31, 2017		56,164				(5,002)
Consolidated net income (loss) attributable to NuVasive, Inc.	322
Other comprehensive income (loss)	(3,261)
Ending Balance at Sep. 30, 2018	803,621	$ 61	1,380,519	(10,194)	5,084	$ (571,849)	803,621
Ending Balance, Shares at Sep. 30, 2018		56,567				(5,114)
Beginning Balance at Mar. 31, 2018	762,395	$ 60	1,358,759	(4,354)	(22,370)	$ (569,700)	762,395
Beginning Balance, Shares at Mar. 31, 2018		56,336				(5,078)
Issuance of common stock under employee and director equity option and purchase plans	4,911	$ 1	5,830			$ (920)	4,911
Issuance of common stock under employee and director equity option and purchase plans, Shares		176				(17)
Stock-based compensation expense	6,847		6,847				6,847
Consolidated net income (loss) attributable to NuVasive, Inc.	11,531				11,531		11,531
Other comprehensive income (loss)	(4,522)			(4,522)			(4,522)
Ending Balance at Jun. 30, 2018	781,162	$ 61	1,371,436	(8,876)	(10,839)	$ (570,620)	781,162
Ending Balance, Shares at Jun. 30, 2018		56,512				(5,095)
Issuance of common stock under employee and director equity option and purchase plans	(344)		885			$ (1,229)	(344)
Issuance of common stock under employee and director equity option and purchase plans, Shares		55				(19)
Stock-based compensation expense	7,636		7,636				7,636
Issuance of common stock in connection with royalty milestone achievement	562		562				562
Consolidated net income (loss) attributable to NuVasive, Inc.	15,923				15,923		15,923
Other comprehensive income (loss)	(1,318)			(1,318)			(1,318)
Ending Balance at Sep. 30, 2018	803,621	$ 61	1,380,519	(10,194)	5,084	$ (571,849)	$ 803,621
Ending Balance, Shares at Sep. 30, 2018		56,567				(5,114)
Beginning Balance at Dec. 31, 2018	834,525	$ 61	1,397,829	(8,628)	17,241	$ (571,978)
Beginning Balance, Shares at Dec. 31, 2018		56,648				(5,116)
Issuance of common stock under employee and director equity option and purchase plans	(8,177)		202			$ (8,379)
Issuance of common stock under employee and director equity option and purchase plans, Shares		399				(146)
Stock-based compensation expense	4,766		4,766
Issuance of common stock in connection with royalty milestone achievement, Shares		72
Consolidated net income (loss) attributable to NuVasive, Inc.	9,386				9,386
Other comprehensive income (loss)	(494)			(494)
Ending Balance at Mar. 31, 2019	840,006	$ 61	1,402,797	(9,122)	26,627	$ (580,357)
Ending Balance, Shares at Mar. 31, 2019		57,119				(5,262)
Beginning Balance at Dec. 31, 2018	834,525	$ 61	1,397,829	(8,628)	17,241	$ (571,978)
Beginning Balance, Shares at Dec. 31, 2018		56,648				(5,116)
Consolidated net income (loss) attributable to NuVasive, Inc.	35,358
Other comprehensive income (loss)	(2,704)
Ending Balance at Sep. 30, 2019	876,614	$ 62	1,421,235	(11,332)	52,599	$ (585,950)
Ending Balance, Shares at Sep. 30, 2019		57,421				(5,354)
Beginning Balance at Mar. 31, 2019	840,006	$ 61	1,402,797	(9,122)	26,627	$ (580,357)
Beginning Balance, Shares at Mar. 31, 2019		57,119				(5,262)
Issuance of common stock under employee and director equity option and purchase plans	364	$ 1	4,315			$ (3,952)
Issuance of common stock under employee and director equity option and purchase plans, Shares		238				(66)
Stock-based compensation expense	6,822		6,822
Consolidated net income (loss) attributable to NuVasive, Inc.	14,962				14,962
Other comprehensive income (loss)	570			570
Ending Balance at Jun. 30, 2019	862,724	$ 62	1,413,934	(8,552)	41,589	$ (584,309)
Ending Balance, Shares at Jun. 30, 2019		57,357				(5,328)
Issuance of common stock under employee and director equity option and purchase plans	(1,641)					$ (1,641)
Issuance of common stock under employee and director equity option and purchase plans, Shares		64				(26)
Stock-based compensation expense	7,096		7,096
Consolidated net income (loss) attributable to NuVasive, Inc.	11,010				11,010
Consideration paid in excess of non-controlling interests	205		205
Other comprehensive income (loss)	(2,780)			(2,780)
Ending Balance at Sep. 30, 2019	$ 876,614	$ 62	$ 1,421,235	$ (11,332)	$ 52,599	$ (585,950)
Ending Balance, Shares at Sep. 30, 2019		57,421				(5,354)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities:
Consolidated net income	$ 35,358	$ 322
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	101,245	96,409
Purchase of in-process research and development		8,913
Amortization of non-cash interest	15,853	14,986
Stock-based compensation	20,447	22,062
Reserves on current assets	11,539	11,116
Net loss on strategic investments	4,767	3,867
Other non-cash adjustments	8,733	16,560
Deferred income taxes	9,810	(9,938)
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable	(8,645)	8,622
Inventory	(45,571)	(33,491)
Prepaid expenses and other current assets	(2,499)	(1,047)
Accounts payable and accrued liabilities	7,378	21,400
Accrued payroll and related expenses	4,108	(9,566)
Litigation liability	650	166
Income taxes	(2,588)	108
Net cash provided by operating activities	160,585	150,489
Investing activities:
Acquisitions and investments	(4,100)	(52,555)
Purchases of intangible assets	(7,501)	(7,682)
Purchases of property and equipment	(94,430)	(78,405)
Net cash used in investing activities	(106,031)	(138,642)
Financing activities:
Proceeds from the issuance of common stock	3,888	5,563
Purchases of treasury stock	(13,343)	(2,817)
Payment of contingent consideration	(809)	(18,700)
Proceeds from revolving line of credit		100,000
Repayments on revolving line of credit		(95,000)
Other financing activities	2,283	(236)
Net cash used in financing activities	(7,981)	(11,190)
Effect of exchange rate changes on cash	(1,014)	(1,349)
Increase (decrease) in cash, cash equivalents and restricted cash	45,559	(692)
Cash, cash equivalents and restricted cash at beginning of period	120,235	78,198
Cash, cash equivalents and restricted cash at end of period	$ 165,794	$ 77,506

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Statement Of Cash Flows [Abstract]
Cash and cash equivalents	$ 163,399	$ 75,112
Restricted cash	2,395	2,394
Total cash, cash equivalents and restricted cash shown in the Unaudited Consolidated Statement of Cash Flows	$ 165,794	$ 77,506

Description of Business and Bas

Description of Business and Basis of Presentation	9 Months Ended
Description of Business and Basis of Presentation	Sep. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business and Basis of Presentation	1. Description of Business and Basis of Presentation Description of Business NuVasive, Inc. (the “Company” or “NuVasive”) was incorporated in Delaware on July 21, 1997, and began commercializing its products in 2001. The Company’s principal product offering includes a minimally disruptive surgical platform called Maximum Access Surgery, or MAS. The MAS platform combines three categories of solutions that collectively minimize soft tissue disruption during spine fusion surgery, provide maximum visualization and are designed to enable safe and reproducible outcomes for the surgeon and the patient. The platform includes the Company’s proprietary software-driven nerve detection and avoidance systems and Intraoperative Monitoring (“IOM”) services and support; MaXcess, an integrated split-blade retractor system; and a wide variety of specialized implants and biologics. To assist with surgical procedures, the Company offers a technology platform called Integrated Global Alignment (“iGA”); in which products and computer assisted technology under the MAS platform help achieve more precise spinal alignment. The individual components of the MAS platform, and many of the Company’s products, can also be used in open or traditional spine surgery. The Company continues to focus 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 procedurally integrated solutions use innovative, technological advancements and the MAS platform to provide surgical efficiency, operative reliability, and procedural versatility. The Company offers a range of implants for spinal surgery, which include its porous titanium and polyetheretherketone (“PEEK”) implants under its Advanced Materials Science portfolio, fixation devices such as customizable rods, plates and screws, bone allograft in patented saline packaging, allogeneic and synthetic biologics, and disposables used in IOM. The Company makes available MAS instrument sets, MaXcess and neuromonitoring systems to hospitals to facilitate surgeon access to the spine to perform restorative and fusion procedures using the Company’s implants and fixation devices. The Company sells MAS instrument sets, MaXcess and neuromonitoring systems to hospitals, however, such sales are immaterial to the Company’s results of operations. The Company also designs and sells expandable growing rod implant systems that can be non-invasively lengthened following implantation with precise, incremental adjustments via an external remote controller using magnetic technology called MAGnetic External Control, or MAGEC, which allows for the minimally invasive treatment of early-onset and adolescent scoliosis. This technology is also the basis for the Company’s Precice limb lengthening system, which allows for the correction of long bone limb length discrepancy, as well as enhanced bone healing in patients that have experienced traumatic injury. In July 2019, the Company commercially launched Pulse, a combined hardware and software technology platform designed to achieve surgical efficiencies via real-time feedback to aid in clinical decision-making and to optimize the procedural workflow in the operating room. Pulse integrates multiple enabling technologies within a single, expandable platform and is engineered to improve workflow, reduce variability, and increase the reproducibility of surgical outcomes. The Pulse platform’s modular architecture incorporates applications for neuromonitoring, iGA surgical planning, patient-specific rod bending, smart imaging with LessRay radiation reduction, 2D and 3D imaging navigation, and integration with robotics and other smart tools. Certain applications of the Pulse platform remain under development. The Company intends to continue development on a wide variety of projects intended to broaden its MAS and other product platforms and advance the applications of its unique technology into procedurally integrated surgical solutions that improve clinical and economic outcomes. Additionally, the Company intends to continue the pursuit of business and technology acquisition targets and strategic relationships. Basis of Presentation and Principles of Consolidation The accompanying Unaudited Consolidated Financial Statements include the accounts of the Company and its majority-owned or controlled subsidiaries, collectively referred to as either NuVasive or the Company. The Company translates the financial statements of its foreign subsidiaries using end-of-period exchange rates for assets and liabilities and average exchange rates during each reporting period for results of operations. When there is a portion of equity in an acquired subsidiary not attributable, directly or indirectly, to the respective parent entity, the Company records the fair value of the non-controlling interest at the acquisition date and classifies the amounts attributable to non-controlling interest separately in equity in the Company's Consolidated Financial Statements. Any subsequent changes in a parent's ownership interest while the parent retains its controlling financial interest in its subsidiary are accounted for as equity transactions. All significant intercompany balances and transactions have been eliminated in consolidation. The accompanying Unaudited Consolidated Financial Statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Pursuant to these rules and regulations, the Company has condensed or omitted certain information and footnote disclosures it normally includes in its annual Consolidated Financial Statements prepared in accordance with generally accepted accounting principles in the United States (“GAAP”). Operating results for the three and nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for any other interim period or for the full year. These Unaudited Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and notes thereto for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the SEC. In the opinion of management, the Unaudited Consolidated Financial Statements and notes thereto include all adjustments that are of a normal and recurring nature that are necessary for the fair presentation of the Company’s financial position and of the results of operations and cash flows for the periods presented. Use of Estimates To prepare financial statements in conformity with GAAP, management must make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Recent Accounting Pronouncements Not Yet Adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2016-13, Financial Instruments – Credit Losses This update is effective for annual periods beginning after December 15, 2019, and interim periods within those periods, and early adoption is permitted and In January 2017, the FASB issued Accounting Standards Update No. 2017-04, Intangibles – Goodwill and Other The Company will adopt ASU 2017-04 on January 1, 2020 and does not expect a material impact to its Consolidated Financial Statements. In August 2018, the FASB issued Accounting Standards Update No. 2018-13, Fair Value Measurement: Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement adds and modifies certain disclosure requirements for fair value measurements entities will no longer be required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, or valuation processes for Level 3 fair value measurements. However, public companies will be required to disclose the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements The Company will adopt ASU 2018-13 on January 1, 2020 and does not expect a material impact to its Consolidated Financial Statements. In September 2018, the FASB issued Accounting Standards Update No. 2018-15, Intangible – Goodwill and Other – Internal-Use Software requires a customer in a cloud computing arrangement to determine which implementation costs to capitalize as assets or expense as incurred capitalized implementation costs related to a hosting arrangement that is a service contract will be amortized over the term of the hosting arrangement, beginning when the module or component of the hosting arrangement is ready for its intended use The Company will adopt ASU 2018-15 on January 1, 2020 and does not expect a material impact to its Consolidated Financial Statements. Recently Adopted Accounting Standards In February 2016, the FASB issued Accounting Standards Update No. 2016-02 – Leases The Company adopted ASC 842 as of January 1, 2019, electing the optional transition method that allows for a cumulative-effect adjustment in the period of adoption and did not restate prior periods. The Company elected the package of practical expedients permitted under the transition guidance. As a result of the adoption, the Company recorded right-of-use assets and liabilities of $62.8 million and $75.1 million, respectively, and their corresponding deferred tax assets and liabilities on its Unaudited Consolidated Balance Sheet as of January 1, 2019. The adoption had no cumulative impact to retained earnings. See Note 10 to the Unaudited Consolidated Financial Statements for further discussion on leases. In July 2017, the FASB issued Accounting Standards Update No. 2017-11, Earnings Per Share, Distinguishing Liabilities from Equity, Derivatives and Hedging . The Company adopted In August 2017, the FASB issued Accounting Standards Update No. 2017-12, Derivatives and Hedging The Company adopted Revenue Recognition In accordance with Accounting Standards Codification 606 Revenue from Contracts with Customers Revenue from IOM services is recognized in the period the service is performed for the amount of consideration expected to be received. Inventory Net inventory as of September 30, 2019 Finished goods primarily consists of specialized implants and disposables and are stated at the lower of cost or market determined by utilizing a standard cost method, which includes capitalized variances, which approximates the weighted average cost. Work in progress and raw materials represent the underlying material, and labor for work in progress, that ultimately yield finished goods upon completion and are subject to lower of cost or market. The Company reviews the components of its inventory on a periodic basis for excess and obsolescence and adjusts inventory to its net realizable value as necessary. Comprehensive Income Comprehensive income is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources. Comprehensive income includes net of tax, unrealized gains or losses on the Company’s marketable securities and foreign currency translation adjustments. The cumulative translation adjustments included in accumulated other comprehensive loss were $11.3 million and $8.6 million at September 30, 2019 and December 31, 2018, respectively. Product Shipment Costs Product shipment costs, included in sales, marketing and administrative expense in the accompanying Unaudited Consolidated Statements of Operations, were $7.3 million and $20.6 million for the three and nine months ended September 30, 2019, respectively, and $6.5 million and $18.9 million for the three and nine months ended September 30, 2018, respectively. The majority of the Company’s shipping costs are related to the distribution of surgical instrument sets, which are not typically sold as part of the Company’s core sales offering. Amounts billed to customers for shipping and handling of products are reflected in revenues and are not material for any period presented . Business Transition Costs The Company incurs certain costs related to acquisition, integration and business transition activities, which include severance, relocation, consulting, leasehold exit costs, third-party merger and acquisition costs, contingent consideration fair value adjustments and other costs directly associated with such activities. The Company incurred $(0.3) million and $5.1 million of such costs during the three and nine months ended September 30, 2019, respectively. For the three months ended September 30, 2019, such costs consisted primarily of $(0.5) million of fair value adjustments on contingent consideration liabilities associated with the Company’s 2017 and 2016 acquisitions. The Company incurred $1.4 million and $7.7 million of such costs during the three and nine months ended September 30, 2018, respectively, which consisted primarily of acquisition, integration and business transition activities, as well as $0.7 million and $1.5 million, respectively, of fair value adjustments on contingent consideration liabilities associated with the Company’s 2017 and 2016 acquisitions.

Net Income Per Share

Net Income Per Share	9 Months Ended
Net Income Per Share	Sep. 30, 2019
Earnings Per Share [Abstract]
Net Income Per Share	2. Net Income Per Share The following table sets forth the computation of basic and diluted consolidated net income per share: Three Months Ended September 30, Nine Months Ended September 30, ( in thousands, except per share data 2019 2018 2019 2018 Numerator: Net income $ 11,010 $ 15,923 $ 35,358 $ 322 Denominator for basic and diluted net income per share: Weighted average common shares outstanding for basic 52,057 51,439 51,901 51,341 Dilutive potential common stock outstanding: Stock options and employee stock purchase plan 17 41 15 37 Restricted stock units 516 1,059 596 701 Senior Convertible Notes 466 650 155 217 Weighted average common shares outstanding for diluted 53,056 53,189 52,667 52,296 Basic net income per share $ 0.21 $ 0.31 $ 0.68 $ 0.01 Diluted net income per share $ 0.21 $ 0.30 $ 0.67 $ 0.01 The following weighted-average outstanding common stock equivalents were not included in the calculation of net income per diluted share because their effects were anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, ( in thousands 2019 2018 2019 2018 Stock options, employee stock purchase plan, and restricted stock units 10 11 111 198 Warrants 10,865 10,865 10,865 10,865 Senior Convertible Notes — — 7,244 7,244 Total 10,875 10,876 18,220 18,307

Financial Instruments and Fair

Financial Instruments and Fair Value Measurements	9 Months Ended
Financial Instruments and Fair Value Measurements	Sep. 30, 2019
Investments Debt And Equity Securities [Abstract]
Financial Instruments and Fair Value Measurements	3. Financial Instruments and Fair Value Measurements Foreign Currency and Derivative Financial Instruments The Company translates the financial statements of its foreign subsidiaries using end-of-period exchange rates for assets and liabilities and average exchange rates during each reporting period for results of operations. Some of the Company’s reporting entities conduct a portion of their business in currencies other than the entity’s functional currency. These transactions give rise to receivables and payables that are denominated in currencies other than the entity’s functional currency. The value of these receivables and payables is subject to changes in currency exchange rates from the point at which the transactions are originated until the settlement in cash. Both realized and unrealized gains and losses in the value of these receivables and payables are included in the determination of net income. Net currency exchange (losses) gains, which include gains and losses from derivative instruments, were $(0.8) million and $(1.0) million for the three and nine months ended September 30, 2019, respectively, and $(0.9) million and $(3.4) million for the three and nine months ended September 30, 2018, respectively, and are included in other (expense) income, net in the Unaudited Consolidated Statements of Operations. To manage foreign currency exposure risks, the Company uses derivatives for activities in entities that have short-term intercompany receivables and payables denominated in a currency other than the entity’s functional currency. A s of September 30, 2019 and December 31, 2018 a notional principal amount of $34.5 million and $ 26.8 was outstanding to hedge currency risk relative to the Company’s foreign receivables and payables . Derivative instrument net gains on the Company’s forward exchange contracts were $0.7 million for both the three and nine months ended September 30, 2019 and $0.2 million and $0.5 million for the three and nine months ended September 30, 2018, respectively, and are included in other (expense) income, net in the Unaudited Consolidated Statements of Operations. The fair value of the forward contract exchange derivative instrument asset (liability) was and $(0.3) million as of September 30, 2019 and December 31, 2018, respectively. The derivative instruments are recorded in other current assets or other current liabilities in the Unaudited Consolidated Balance Sheets commensurate with the nature of the instrument at period end. Fair Value Measurements The Company measures certain assets and liabilities in accordance with authoritative guidance, which requires fair value measurements be classified and disclosed in one of the following three categories: Level 1: Quoted prices (unadjusted) in active markets that are accessible at the measurement date for assets or liabilities. Level 2: Observable prices that are based on inputs not quoted on active markets, but corroborated by market data. Level 3: Unobservable inputs are used when little or no market data is available. Assets and liabilities are classified based on the lowest level of input that is significant to the fair value measurements. The Company reviews the fair value hierarchy classification on a quarterly basis. Changes in the ability to observe valuation inputs may result in a reclassification of levels for certain assets or liabilities within the fair value hierarchy. The Company did not have any transfers of assets and liabilities between the levels of the fair value measurement hierarchy during the periods presented. The fair values of the Company’s assets and liabilities, including cash equivalents, marketable securities, restricted investments, derivatives, and contingent obligations are measured at fair value on a recurring basis. As of September 30, 2019 Quoted Price in Significant Other Significant Active Market Observable Inputs Unobservable ( in thousands Total (Level 1) (Level 2) Inputs (Level 3) September 30, 2019: Cash equivalents: Money market funds $ 100,983 $ 100,983 $ — $ — Total cash equivalents $ 100,983 $ 100,983 $ — $ — December 31, 2018: Cash equivalents: Money market funds $ 56,000 $ 56,000 $ — $ — Total cash equivalents $ 56,000 $ 56,000 $ — $ — The carrying amounts of certain financial instruments such as cash equivalents, accounts receivable, prepaid expenses, other current assets, accounts payable, accrued expenses, and other current liabilities as of September 30, 2019 and December 31, 2018 approximate their related fair values due to the short-term maturities of these instruments. The fair value of certain financial instruments was measured and classified within Level 1 of the fair value hierarchy based on quoted prices. Fair Value of Senior Convertible Notes The fair value, based on a quoted market price (Level 1), of the Company’s outstanding Senior Convertible Notes due 2021 at September 30, 2019 and December 31, 2018, was $767.4 million and $684.8 million, respectively. See Note 6 to the Unaudited Consolidated Financial Statements for further discussion on the carrying value of the notes. Contingent Consideration Liabilities The fair value of contingent consideration liabilities assumed in business combinations is recorded as part of the purchase price consideration of the acquisition, and is determined using a discounted cash flow model or probability simulation model. The significant inputs of such models are not observable in the market, such as certain financial metric growth rates, volatility rates, projections associated with the applicable milestone, the interest rate, and the related probabilities and payment structure in the contingent consideration arrangement. Fair value adjustments to contingent consideration liabilities are recorded through operating expenses in the Unaudited Contingent consideration liabilities were $50.4 million as of September 30, 2019 and December 31, 2018 and were recorded in the Unaudited Consolidated Balance Sheet commensurate with the respective payment terms. 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): Nine Months Ended September 30, ( in thousands 2019 2018 Fair value measurement at beginning of period $ 50,410 $ 67,941 Contingent consideration liability recorded upon acquisition — 6,663 Change in fair value measurement 1,435 1,539 Changes resulting from foreign currency fluctuations (60 ) 17 Contingent consideration paid or settled (1,435 ) (19,000 ) Fair value measurement at end of period $ 50,350 $ 57,160 During the nine months ended September 30, 2018, the Company paid $19.0 million in outstanding milestone obligations associated with the LessRay acquisition, of which $9.0 million related to the achievement of a commercial milestone, and $10.0 million related to the achievement of a regulatory approval milestone. Of the $19.0 million, $18.7 million represented the initial purchase price allocation and is presented as a cash outflow for financing activities on the Unaudited Consolidated Statement of Cash Flows, and the remaining $0.3 million represented fair value adjustments and is presented as a cash outflow for operating activities. Non-financial assets and liabilities measured on a nonrecurring basis Certain non-financial assets and liabilities are measured at fair value, usually with Level 3 inputs including the discounted cash flow method or cost method, on a nonrecurring basis in accordance with authoritative guidance. These include items such as non-financial assets and liabilities initially measured at fair value in a business combination and non-financial long-lived assets measured at fair value for an impairment assessment. In general, non-financial assets, including goodwill, intangible assets and property and equipment, are measured at fair value when there is an indication of impairment and are recorded at fair value only when any impairment is recognized. The carrying values of the Company’s financing lease obligations approximated their estimated fair value as of September 30, 2019 and December 31, 2018. During the three months ended September 30, 2018, the Company expensed $8.9 million for a purchased in-process research and development asset which had no future alternative use. During the nine months ended September 30, 2018, the Company recorded an impairment charge of $9.0 million on a strategic investment. The impairment was recorded in other (expense) income, net in the Unaudited Consolidated Statement of Operations

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
Goodwill and Intangible Assets	Sep. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	4. Goodwill and Intangible Assets Goodwill and intangible assets consisted of the following: Weighted- Average Amortization ( in thousands, except years Period Gross Accumulated Intangible September 30, 2019: (in years) Amount Amortization Assets, net Intangible assets subject to amortization: Developed technology 8 $ 271,748 $ (155,527 ) $ 116,221 Manufacturing know-how and trade secrets 13 30,774 (19,710 ) 11,064 Trade name and trademarks 9 25,500 (16,198 ) 9,302 Customer relationships 9 150,512 (72,607 ) 77,905 Total intangible assets subject to amortization 9 $ 478,534 $ (264,042 ) $ 214,492 Intangible assets not subject to amortization: Goodwill $ 560,744 Total goodwill and intangible assets, net $ 775,236 Weighted- Average Amortization Period Gross Accumulated Intangible December 31, 2018: (in years) Amount Amortization Assets, net Intangible assets subject to amortization: Developed technology 8 $ 271,748 $ (131,730 ) $ 140,018 Manufacturing know-how and trade secrets 13 30,814 (17,926 ) 12,888 Trade name and trademarks 9 25,500 (13,901 ) 11,599 Customer relationships 9 147,021 (59,478 ) 87,543 Total intangible assets subject to amortization 9 $ 475,083 $ (223,035 ) $ 252,048 Intangible assets not subject to amortization: Goodwill $ 561,366 Total goodwill and intangible assets, net $ 813,414 The following table summarizes the changes in the carrying value of the Company’s goodwill: ( in thousands December 31, 2018 Gross goodwill $ 569,666 Accumulated impairment loss (8,300 ) 561,366 Changes to gross goodwill Changes resulting from foreign currency fluctuations (622) (622) September 30, 2019 Gross goodwill 569,044 Accumulated impairment loss (8,300 ) $ 560,744 Total expense related to the amortization of intangible assets, which is recorded in both cost of revenue and operating expenses in the Unaudited Consolidated Statements of Operations depending on the functional nature of the intangible asset, was $13.5 million and $41.2 million for the three and nine months ended September 30, 2019, respectively, and $13.3 million and $40.2 million for the three and nine months ended September 30, 2018, respectively. Total future amortization expense related to intangible assets subject to amortization at September 30, 2019 is set forth in the table below: ( in thousands Remaining 2019 $ 13,515 2020 52,085 2021 50,198 2022 41,441 2023 17,684 Thereafter through 2031 39,569 Total future amortization expense $ 214,492

Business Combinations

Business Combinations	9 Months Ended
Business Combinations	Sep. 30, 2019
Business Combination Description [Abstract]
Business Combinations	5. Business Combinations The Company recognizes the assets acquired, liabilities assumed, and any non-controlling interest at fair value at the date of acquisition. Certain acquisitions contained contingent consideration arrangements that required the Company to assess the acquisition date fair value of the contingent consideration liabilities, which was recorded as part of the purchase price allocation of the acquisition, with subsequent fair value adjustments to the contingent consideration recorded in the Unaudited Consolidated Statements of Operations. See Note 3 Acquisitions The Company has completed acquisitions that were not considered material, individually or collectively, to the overall Unaudited Consolidated Financial Statements during the periods presented. These acquisitions have been included in the Unaudited Consolidated Financial Statements from the respective dates of acquisition. The Company does not believe that collectively the acquisitions made during the periods presented are material to the overall financial statements. The Company finalizes the purchase price allocation of the assets and liabilities subject to valuation obtained in business combinations within one year from the acquisition date. While the Company does not expect material changes from the initial outcome of the valuation, certain assumptions and findings made at the date of acquisition could result in changes in the purchase price allocation. Variable Interest Entities The Company provides IOM services through various subsidiaries, which conduct business as NuVasive Clinical Services. In providing IOM services to surgeons and healthcare facilities across the United States, the Company maintains contractual relationships with several physician practices (“PCs”). In accordance with authoritative guidance, the Company has determined that the PCs are variable interest entities and therefore, the accompanying Unaudited Consolidated Financial Statements include the accounts of the PCs from the date of acquisition. During the periods presented, the results of the PCs were immaterial to the Company’s financial statements. The creditors of the PCs have claims only to the assets of the PCs, which are not material, and the assets of the PCs are not available to the Company .

Indebtedness

Indebtedness	9 Months Ended
Indebtedness	Sep. 30, 2019
Debt Disclosure [Abstract]
Indebtedness	6. Indebtedness The carrying values of the Company’s Senior Convertible Notes due 2021 are as follows: ( in thousands September 30, 2019 December 31, 2018 2.25% Senior Convertible Notes due 2021: Principal amount $ 650,000 $ 650,000 Unamortized debt discount (26,992 ) (40,117 ) Unamortized debt issuance costs (5,016 ) (7,357 ) Total Senior Convertible Notes $ 617,992 $ 602,526 2.25% Senior Convertible Notes due 2021 In March 2016, the Company issued $650.0 million principal amount of unsecured Senior Convertible Notes with a stated interest rate of 2.25% and a maturity date of March 15, 2021 (the "2021 Notes"). The net proceeds from the offering, after deducting initial purchasers' discounts and costs directly related to the offering, were approximately $634.1 million. The 2021 Notes may be settled in cash, stock, or a combination thereof, solely at the Company's discretion. It is the Company's current intent and policy to settle all conversions through combination settlement, which involves satisfying the principal amount outstanding with cash and any note conversion value over the principal amount in shares of the Company's common stock. The initial conversion rate of the 2021 Notes is 16.7158 shares per $1,000 principal amount, which is equivalent to a conversion price of approximately $59.82 per share, subject to adjustments. The Company uses the treasury share method for assumed conversion of the 2021 Notes to compute the weighted average shares of common stock outstanding for diluted earnings per share. The Company also entered into transactions for a convertible notes hedge (the "2021 Hedge") and warrants (the "2021 Warrants") concurrently with the issuance of the 2021 Notes. The cash conversion feature of the 2021 Notes required bifurcation from the notes and was initially accounted for as an equity instrument classified to stockholders’ equity, which resulted in recognizing $84.8 million in additional paid-in-capital during 2016. The interest expense recognized on the 2021 Notes during the three months ended September 30, 2019 includes $3.7 million, $4.4 million and $0.8 million for the contractual coupon interest, the accretion of the debt discount and the amortization of the debt issuance costs, respectively. The interest expense recognized on the 2021 Notes during the nine months ended September 30, 2019 includes $11.0 million, $13.1 million and $2.3 million for the contractual coupon interest, the accretion of the debt discount and the amortization of the debt issuance costs, respectively. The interest expense recognized on the 2021 Notes during the three months ended September 30, 2018 includes $3.7 million, $4.2 million and $0.7 million for the contractual coupon interest, the accretion of the debt discount and the amortization of the debt issuance costs, respectively. The interest expense recognized on the 2021 Notes during the nine months ended September 30, 2018 includes $11.0 million, $12.5 million and $2.1 million for the contractual coupon interest, the accretion of the debt discount and the amortization of the debt issuance costs, respectively. The effective interest rate on the 2021 Notes is 5.8%, which includes the interest on the notes, amortization of the debt discount and debt issuance costs. Interest on the 2021 Notes began accruing upon issuance and is payable semi-annually. Prior to September 15, 2020, holders may convert their 2021 Notes only under the following conditions: (a) during any calendar quarter beginning June 30, 2016, if the reported sale price of the Company's common stock for at least 20 days out of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is greater than 130% of the conversion price on each applicable trading day; (b) during the five business day period in which the trading price of the 2021 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 2021 Notes. From September 15, 2020 and until the close of business on the second scheduled trading day immediately preceding March 15, 2021, holders may convert their 2021 Notes at any time (regardless of the foregoing circumstances). The Company may not redeem the 2021 Notes prior to March 20, 2019. The Company may redeem the 2021 Notes, at its option, in whole or in part on or after March 20, 2019 until the close of business on the business day immediately preceding September 15, 2020 if the last reported sale price of the Company’s common stock has been at least 130% of the conversion price then in effect for at least 20 trading days during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which the Company delivers written notice of a redemption. The redemption price will be equal to 100% of the principal amount of such 2021 Notes to be redeemed plus accrued and unpaid interest to, but excluding, the redemption date 2021 Hedge In connection with the offering of the 2021 Notes, the Company entered into the hedge transaction with the initial purchasers of the 2021 Notes and/or their affiliates (the "2021 Counterparties") entitling the Company to purchase up to 10,865,270 shares of the Company's common stock at an initial stock price of $59.82 per share, each of which is subject to adjustment. The cost of the 2021 Hedge was $111.2 million and accounted for as an equity instrument by recognizing $111.2 million in additional paid-in-capital during 2016. The 2021 Hedge will expire on March 15, 2021. The 2021 Hedge is expected to reduce the potential equity dilution upon conversion of the 2021 Notes if the daily volume-weighted average price per share of the Company's common stock exceeds the strike price of the 2021 Hedge. An assumed exercise of the 2021 Hedge by the Company is considered anti-dilutive since the effect of the inclusion would always be anti-dilutive with respect to the calculation of diluted earnings per share. 2021 Warrants The Company sold warrants to the 2021 Counterparties to acquire up to 10,865,270 shares of the Company’s common stock. The 2021 Warrants will expire on various dates from June 2021 through December 2021 and may be settled in cash or net shares. It is the Company's current intent and policy to settle all conversions in shares of the Company’s common stock. The Company received $44.9 million in cash proceeds from the sale of the 2021 Warrants, which was recorded in additional paid-in-capital. The 2021 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 2021 Warrants, which is $80.00 per share. The Company uses the treasury share method for assumed conversion of its 2021 Warrants to compute the weighted average common shares outstanding for diluted earnings per share. Revolving Senior Credit Facility In April 2017, the Company entered into an Amended and Restated Credit Agreement (the “2017 Credit Agreement”) for a revolving senior credit facility (the “2017 Facility”), which replaced the previous Credit Agreement the Company had entered into in February 2016. The 2017 Credit Agreement provides for secured revolving loans, multicurrency loan options and letters of credit in an aggregate amount of up to $500.0 million. The 2017 Credit Agreement also contains an expansion feature, which allows the Company to increase the aggregate principal amount of the 2017 Facility provided the Company remains in compliance with the underlying financial covenants, including but not limited to, compliance with the consolidated interest coverage ratio and certain consolidated leverage ratios. The 2017 Facility matures in April 2022 (subject to an earlier springing maturity date), and includes a sublimit of $100.0 million for multicurrency borrowings, a sublimit of $50.0 million for the issuance of standby letters of credit, and a sublimit of $5.0 million for swingline loans. All assets of the Company and its material domestic subsidiaries are pledged as collateral under the 2017 Facility (subject to customary exceptions) pursuant to the term set forth in the Amended and Restated Security and Pledge Agreement (the “2017 Security Agreement”) executed in favor of the administrative agent by the Company. Each of the Company’s material domestic subsidiaries guarantees the 2017 Facility. In connection with the 2017 Facility, the Company incurred issuance costs which will be amortized over the term of the 2017 Facility. Borrowings under the 2017 Facility are used by the Company to provide financing for working capital and other general corporate purposes, including potential mergers and acquisitions. Borrowings under the 2017 Facility bear interest, at the Company’s option, at a rate equal to an applicable margin plus: (a) the applicable Eurocurrency Rate (as defined in the 2017 Credit Agreement), or (b) a base rate determined by reference to the highest of (1) the federal funds effective rate plus 0.50%, (2) the Bank of America prime rate, and (3) LIBOR for an interest period of one month plus 1.00%. The margin for the 2017 Facility ranges, based on the Company’s consolidated leverage ratio, from 0.00% to 1.00% in the case of base rate loans and from 1.00% to 2.00% in the case of Eurocurrency Rate loans. The 2017 Facility includes an unused line fee ranging, based on the Company’s consolidated leverage ratio, from 0.20% to 0.35% per annum on the revolving commitment. The 2017 Credit Agreement contains affirmative, negative, permitted acquisition and financial covenants, and events of default customary for financings of this type. The financial covenants require the Company to maintain ratios of consolidated earnings before interest, taxes, depreciation and amortization (EBITDA) in relation to consolidated interest expense and consolidated debt, respectively, as defined in the 2017 Credit Agreement. The 2017 Facility grants the lenders preferred first priority liens and security interests in capital stock, intercompany debt and all of the present and future property and assets of the Company and each guarantor. The Company is currently in compliance with the 2017 Credit Agreement covenants.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
Stock-Based Compensation	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	7. Stock-Based Compensation The compensation cost that has been included in the Unaudited Consolidated Statements of Operations for all stock-based compensation arrangements was as follows: Three Months Ended September 30, Nine Months Ended September 30, ( in thousands 2019 2018 2019 2018 Sales, marketing and administrative expense $ 6,627 $ 10,095 $ 17,317 $ 19,539 Research and development expense 1,064 863 2,716 2,201 Cost of revenue 138 110 414 322 Stock-based compensation expense before taxes 7,829 11,068 20,447 22,062 Related income tax benefits (1,957 ) (2,767 ) (5,112 ) (5,516 ) Stock-based compensation expense, net of taxes $ 5,872 $ 8,301 $ 15,335 $ 16,546 At September 30, 2019, there was $46.4 million of unamortized compensation expense for restricted stock units (“RSUs”) and performance-based restricted stock units (“PRSUs”) to be recognized over a weighted average period of 2.3 years Restricted Stock Units and Performance-Based Restricted Stock Units The Company issued approximately 64,000 and 675,000 shares of common stock, before net share settlement, upon vesting of RSUs and PRSUs during the three and nine months ended September 30, 2019, respectively, and issued approximately 190,000 shares of common stock, before net share settlement, upon vesting of RSUs and PRSUs during the year ended December 31, 2018. Stock Options and Purchase Rights The weighted average assumptions used to estimate the fair value of stock purchase rights under the employee stock purchase plan (“ESPP”) are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 ESPP Volatility 37 % 28 % 37 % 32 % Expected term (years) 0.5 0.5 0.5 0.5 Risk free interest rate 2.4 % 2.1 % 2.5 % 1.6 % Expected dividend yield — % — % — % — % Under the terms of the ESPP, the Company’s employees (referred to as “shareowners”) can elect to have up to 15% of their annual compensation, up to a maximum of $21,250 per year, withheld to purchase shares of the Company’s common stock for a purchase price equal to 85% of the lower of the fair market value per share (at closing) of the Company’s common stock on (i) the commencement date of the six-month offering period, or (ii) the respective purchase date. The Company has not granted any options since 2011. There were no options exercised during the three months ended September 30, 2019. The Company issued approximately 18,000 shares of common stock, before net share settlement, upon the exercise of outstanding stock options during the nine months ended September 30, 2019 and issued approximately 128,000 shares of common stock, before net share settlement, upon the exercise of outstanding stock options during the year ended December 31, 2018.

Income Taxes

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	8. Income Taxes Income taxes are determined using an estimated annual effective tax rate applied against income, and then adjusted for the tax impacts of certain significant and discrete items. For the nine months ended September 30, 2019, the Company treated the tax impact of the following as discrete events for which the tax effect was recognized separately from the application of the annual effective tax rate: net windfalls on share-based payments, return to provision adjustments and the revaluation of deferred taxes based on changes in tax rates. The Company’s effective tax rate recorded for the nine months ended September 30, 2019 was 25%. In accordance with the disclosure requirements as described in ASC Topic 740, Income Taxes, the Company has classified unrecognized tax benefits as non-current income tax liabilities, or a reduction in deferred tax assets, unless expected to be paid within one year. The Company’s continuing practice is to recognize interest and/or penalties related to income tax matters in income tax expense. The Company had an increase in gross unrecognized tax benefits of approximately $1.0 million during the nine months ended September 30, 2019, primarily related to research and development credits. The Company believes it is reasonably possible that approximately $0.6 million of its remaining unrecognized tax positions may be recognized within the next twelve months due to potential tax settlements and as certain statute of limitations expire, the amount of which is primarily attributable to tax positions involving the valuation of intercompany transactions. The Company is subject to routine compliance reviews on various tax matters around the world in the ordinary course of business. Currently, the only income tax audits being conducted are in the United States and Germany. The United States and most foreign jurisdictions remain subject to examination for tax years 2015 and forward with the exception of California due to research and development credit carryforwards.

Business Segment, Product, and

Business Segment, Product, and Geographic Information	9 Months Ended
Business Segment, Product, and Geographic Information	Sep. 30, 2019
Segment Reporting [Abstract]
Business Segment, Product and Geographic Information	9. Business Segment, Product and Geographic Information The Company operates in one segment based upon the Company’s organizational structure, the way in which the operations and investments are managed and evaluated by the chief operating decision maker (“CODM”) as well as the lack of availability of discrete financial information at a lower level. The Company’s CODM reviews revenue at the product line offering level, and manufacturing, operating income and expenses, and net income at the Company wide level to allocate resources and assess the Company’s overall performance. The Company shares common, centralized support functions, including finance, human resources, legal, information technology, and corporate marketing, all of which report directly to the CODM. Accordingly, decision-making regarding the Company’s overall operating performance and allocation of Company resources is assessed on a consolidated basis. As such, the Company operates as one reporting segment. The Company has disclosed the revenues for each of its product line offerings to provide the reader of the financial statements transparency into the operations of the Company. The Company reports under two distinct product lines; spinal hardware and surgical support. The Company’s spinal hardware product line offerings include implants and fixation products. The Company’s surgical support product offerings include IOM services, disposables and biologics, all of which are used to aid spinal surgery. Revenue by product line was as follows: Three Months Ended September 30, Nine Months Ended September 30, ( in thousands 2019 2018 2019 2018 Spinal hardware $ 214,190 $ 193,626 $ 623,962 $ 581,587 Surgical support 76,645 77,675 233,754 231,800 Total revenue $ 290,835 $ 271,301 $ 857,716 $ 813,387 Revenue and property and equipment, net, by geographic area were as follows: Revenue Property and Equipment, Net Three Months Ended September 30, Nine Months Ended September 30, September 30, December 31, ( in thousands 2019 2018 2019 2018 2019 2018 United States $ 233,676 $ 221,318 $ 692,617 $ 661,570 $ 217,545 $ 200,404 International (excludes Puerto Rico) 57,159 49,983 165,099 151,817 45,590 38,437 Total $ 290,835 $ 271,301 $ 857,716 $ 813,387 $ 263,135 $ 238,841

Commitments

Commitments	9 Months Ended
Commitments	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments	10. Commitments Leases At the inception of a contractual arrangement, the Company determines whether the contract contains a lease by assessing whether there is an identified asset and whether the contract conveys the right to control the use of the identified asset in exchange for consideration over a period of time. If both criteria are met, the Company records the associated lease liability and corresponding right-of-use asset upon commencement of the lease using a discount rate based on a credit-adjusted secured borrowing rate commensurate with the term of the lease. The Company records lease liabilities within current liabilities or long-term liabilities based upon the length of time associated with the lease payments. The Company records its operating lease right-of-use assets as long-term assets. Right-of-use assets for financing leases are recorded within property and equipment, net in the Unaudited Consolidated Balance Sheet. Leases with an initial term of 12 months or less are not recorded on the Unaudited Consolidated Balance Sheet. Instead, the Company recognizes lease expense for these leases on a straight-line basis over the lease term. In connection with certain operating leases, the Company has security deposits recorded and maintained as restricted cash totaling $2.4 million as of September 30, 2019. The Company leases office and storage facilities and equipment under various operating and financing lease agreements. The initial terms of these leases range from 1 to 17 years and generally provide for periodic rent increases, and renewal and termination options. The Company’s lease agreements do not contain any material variable lease payments, residual value guarantees or material restrictive covenants. Certain leases require the Company to pay taxes, insurance, and maintenance. Payments for the transfer of goods or services such as common area maintenance and utilities represent non-lease components. The Company elected the package of practical expedients and therefore does not separate non-lease components from lease components. The Company has future lease payment obligations of approximately $59.9 million related to corporate office facilities that are in the process of being built-out prior to being leased. The lease liabilities and the corresponding right-of-use assets associated with these lease obligations will be recorded upon the commencement date of the lease. The table below summarizes the Company’s right-of-use assets and lease liabilities as of September 30, 2019 (in thousands) September 30, 2019 Assets Operating $ 67,128 Financing 1,074 Total leased assets $ 68,202 Liabilities Current: Operating $ 5,792 Financing 508 Long-term: Operating 72,713 Financing 684 Total lease liabilities $ 79,697 Supplemental non-cash information: Weighted-average remaining lease term (years) - operating leases 12.6 Weighted-average remaining lease term (years) - finance leases 2.2 Weighted-average discount rate - operating leases 7.3 % Weighted-average discount rate - finance leases 5.2 % The table below summarizes the Company’s lease costs, cash payments, and operating lease liabilities arising from obtaining right-of-use assets under its operating and financing lease obligations during the three and nine months ended September 30, 2019: Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except years and rates) 2019 2019 Lease expense: Operating lease expense $ 3,043 $ 8,829 Finance lease expense: Depreciation of right-of-use assets 99 296 Interest expense on lease liabilities 12 38 Total lease expense $ 3,154 $ 9,163 Consolidated Statements of Cash Flows information: Operating cash flows used for operating leases $ 3,132 $ 9,304 Operating cash flows used for financing leases 12 38 Financing cash flows used for financing leases 96 281 Total cash paid for amounts included in the measurement of lease liabilities $ 3,240 $ 9,623 Supplemental non-cash information: Operating lease liabilities arising from obtaining right-of-use assets $ 6,757 $ 84,362 The Company’s future minimum annual lease payments under operating and financing leases at September 30, 2019 are as follows: Financing Operating (in thousands) Leases Leases Remaining 2019 $ 140 $ 2,851 2020 561 10,750 2021 462 10,231 2022 114 9,767 2023 — 9,511 Thereafter — 82,511 Total minimum lease payments $ 1,277 $ 125,621 Less: amount representing interest (85 ) (47,116 ) Present value of obligations under leases 1,192 78,505 Less: current portion (508 ) (5,792 ) Long-term lease obligations $ 684 $ 72,713 Executive Severance Plans The Company has employment contracts with key executives and maintains severance plans that provide for the payment of severance and other benefits if such executives are terminated for reasons other than cause, as defined in those agreements and plans. Certain agreements call for payments that are based on historical compensation, and accordingly, the amount of the contractual commitment will change over time commensurate with the executive’s applicable earnings. At September 30, 2019, future commitments for such key executives were approximately $16.2 million. In certain circumstances, the agreements call for the acceleration of equity vesting. Those figures are not reflected in the above information.

Contingencies

Contingencies	9 Months Ended
Contingencies	Sep. 30, 2019
Contingencies [Abstract]
Contingencies	11. Contingencies The Company is subject to potential liabilities under government regulations and various claims and legal actions that are pending or may be asserted from time-to-time. These matters arise in the ordinary course and conduct of the Company’s business and include, for example, commercial, intellectual property, environmental, securities and employment matters. The Company intends to continue to defend itself vigorously in such matters and when warranted, take legal action against others. Furthermore, the Company regularly assesses contingencies to determine the degree of probability and range of possible loss for potential accrual in its financial statements. An estimated loss contingency is accrued in the Company’s financial statements if it is probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Based on the Company’s assessment, it has adequately accrued an amount for contingent liabilities currently in existence. The Company does not accrue amounts for liabilities that it does not believe are probable. Litigation is inherently unpredictable, and unfavorable resolutions could occur. As a result, assessing contingencies is highly subjective and requires judgment about future events. The amount of ultimate loss may exceed the Company’s current accruals, and it is possible that its cash flows or results of operations could be materially affected in any particular period by the unfavorable resolution of one or more of these contingencies. Legal Proceedings Securities Litigation On August 28, 2013, a purported securities class action lawsuit was filed in the U.S. District Court for the Southern District of California naming the Company and certain of its current and former executive officers for allegedly making false and materially misleading statements regarding the Company’s business and financial results, specifically relating to the purported improper submission of false claims to Medicare and Medicaid. The operative 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, Brad Mauss, the lead plaintiff in the case, filed an Amended Class Action Complaint for Violations of the Federal Securities Laws. The Company answered the complaint on August 25, 2016, and discovery commenced. The plaintiffs filed motions for class certification on October 28, 2016 and the Company’s opposition papers were filed on January 9, 2017. On March 22, 2017, the court issued an order granting class certification. The Company filed a petition to appeal the order granting class certification with the U.S. Court of Appeals for the Ninth Circuit (the “Ninth Circuit”) on April 5, 2017 and the plaintiffs filed an opposition to the petition. On August 15, 2017, the Ninth Circuit denied the Company’s petition. The Company filed a motion for summary judgment on September 8, 2017. On February 1, 2018, the court entered an order denying the Company’s motion for summary judgment. On February 13, 2018, the Company entered into a memorandum of understanding with the plaintiffs to settle the case for $7.9 million. On March 23, 2018, the parties executed a stipulation of settlement, which was preliminarily approved by the court on June 11, 2018. On December 6, 2018, the court issued an order and judgment granting final approval of the settlement. The settlement of $7.9 million was fully funded by insurance proceeds and included the dismissal of all claims against the Company and the named individuals in the lawsuit without any liability or wrongdoing attributed to them. The Company no longer has any remaining liability related to this matter Madsen Medical, Inc. Litigation On February 19, 2016, an unfavorable jury verdict was delivered against the Company in its litigation in the U.S. District Court for the Southern District of California against Madsen Medical, Inc. (“MMI”), a former sales agent. Specifically, the jury awarded MMI $7.5 million in lost profits for tortious interference, $14.0 million for unjust enrichment, $20.0 million in punitive damages, and approximately $0.3 million in damages for breach of contract. he trial court entered judgment in favor of MMI in the amount of $27.8 million, which amount excluded the $14.0 million disgorgement awarded by the jury. As of December 31, 2017, the Company believed that the outcome of the case did not constitute a probable nor an estimable loss associated with the litigation, but rather a reasonably possible loss. The Company, based on its own assessment as well as that of outside counsel, believed that it was probable upon appeal the judgment would be vacated. Accordingly, the Company did not record a loss contingency at December 31, 2017, but assessed a reasonable range of potential loss, which would be from zero to the current amount entered as a judgment, as well as attorney’s fees and interest. Following the April 12, 2018 oral argument, the Company believed that the prior judgments against it, in part or as a whole, may be upheld. Accordingly, at March 31, 2018, the Company believed that the outcome of the case constituted a probable loss. While the actual amount of the probable loss was not known, the Company assessed a range of potential loss in accordance with Accounting Standards Codification 450, Contingencies, which would be from zero to $ 29.0 million, and recorded an additional estimated loss contingency in the amount of $ 29.0 million as a current litigation liability in the Unaudited Consolidated Balance Sheet as of March 31, 2018, resulting in an aggregate litigation liability of $ 29.0 million accrued for this matter. In May 2018, the Company entered into an agreement to settle all outstanding matters with MMI for $ 27.8 million, and the Company paid the settlement amount. The Company no longer has any remaining liability related to this matter.

Regulatory Matters

Regulatory Matters	9 Months Ended
Regulatory Matters	Sep. 30, 2019
Regulatory Matter [Abstract]
Regulatory Matters	12. Regulatory Matters On August 31, 2015, the Company received a civil investigative demand (“CID”) issued by the Department of Justice (“DOJ”) pursuant to the federal False Claims Act. The CID requires the delivery of a wide range of documents and information related to an investigation by the DOJ concerning allegations that the Company assisted a physician group customer in submitting improper claims for reimbursement and made improper payments to the physician group in violation of the Anti-Kickback Statute. The Company is cooperating with the DOJ in regards to this matter. No assurance can be given as to the timing or outcome of this investigation. As of September 30, 2019, the probable outcome of this matter 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 matter.

Description of Business and B_2

Description of Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2019
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’s principal product offering includes a minimally disruptive surgical platform called Maximum Access Surgery, or MAS. The MAS platform combines three categories of solutions that collectively minimize soft tissue disruption during spine fusion surgery, provide maximum visualization and are designed to enable safe and reproducible outcomes for the surgeon and the patient. The platform includes the Company’s proprietary software-driven nerve detection and avoidance systems and Intraoperative Monitoring (“IOM”) services and support; MaXcess, an integrated split-blade retractor system; and a wide variety of specialized implants and biologics. To assist with surgical procedures, the Company offers a technology platform called Integrated Global Alignment (“iGA”); in which products and computer assisted technology under the MAS platform help achieve more precise spinal alignment. The individual components of the MAS platform, and many of the Company’s products, can also be used in open or traditional spine surgery. The Company continues to focus 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 procedurally integrated solutions use innovative, technological advancements and the MAS platform to provide surgical efficiency, operative reliability, and procedural versatility. The Company offers a range of implants for spinal surgery, which include its porous titanium and polyetheretherketone (“PEEK”) implants under its Advanced Materials Science portfolio, fixation devices such as customizable rods, plates and screws, bone allograft in patented saline packaging, allogeneic and synthetic biologics, and disposables used in IOM. The Company makes available MAS instrument sets, MaXcess and neuromonitoring systems to hospitals to facilitate surgeon access to the spine to perform restorative and fusion procedures using the Company’s implants and fixation devices. The Company sells MAS instrument sets, MaXcess and neuromonitoring systems to hospitals, however, such sales are immaterial to the Company’s results of operations. The Company also designs and sells expandable growing rod implant systems that can be non-invasively lengthened following implantation with precise, incremental adjustments via an external remote controller using magnetic technology called MAGnetic External Control, or MAGEC, which allows for the minimally invasive treatment of early-onset and adolescent scoliosis. This technology is also the basis for the Company’s Precice limb lengthening system, which allows for the correction of long bone limb length discrepancy, as well as enhanced bone healing in patients that have experienced traumatic injury. In July 2019, the Company commercially launched Pulse, a combined hardware and software technology platform designed to achieve surgical efficiencies via real-time feedback to aid in clinical decision-making and to optimize the procedural workflow in the operating room. Pulse integrates multiple enabling technologies within a single, expandable platform and is engineered to improve workflow, reduce variability, and increase the reproducibility of surgical outcomes. The Pulse platform’s modular architecture incorporates applications for neuromonitoring, iGA surgical planning, patient-specific rod bending, smart imaging with LessRay radiation reduction, 2D and 3D imaging navigation, and integration with robotics and other smart tools. Certain applications of the Pulse platform remain under development. The Company intends to continue development on a wide variety of projects intended to broaden its MAS and other product platforms and advance the applications of its unique technology into procedurally integrated surgical solutions that improve clinical and economic outcomes. Additionally, the Company intends to continue the pursuit of business and technology acquisition targets and strategic relationships.
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The accompanying Unaudited Consolidated Financial Statements include the accounts of the Company and its majority-owned or controlled subsidiaries, collectively referred to as either NuVasive or the Company. The Company translates the financial statements of its foreign subsidiaries using end-of-period exchange rates for assets and liabilities and average exchange rates during each reporting period for results of operations. When there is a portion of equity in an acquired subsidiary not attributable, directly or indirectly, to the respective parent entity, the Company records the fair value of the non-controlling interest at the acquisition date and classifies the amounts attributable to non-controlling interest separately in equity in the Company's Consolidated Financial Statements. Any subsequent changes in a parent's ownership interest while the parent retains its controlling financial interest in its subsidiary are accounted for as equity transactions. All significant intercompany balances and transactions have been eliminated in consolidation. The accompanying Unaudited Consolidated Financial Statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Pursuant to these rules and regulations, the Company has condensed or omitted certain information and footnote disclosures it normally includes in its annual Consolidated Financial Statements prepared in accordance with generally accepted accounting principles in the United States (“GAAP”). Operating results for the three and nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for any other interim period or for the full year. These Unaudited Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and notes thereto for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the SEC. In the opinion of management, the Unaudited Consolidated Financial Statements and notes thereto include all adjustments that are of a normal and recurring nature that are necessary for the fair presentation of the Company’s financial position and of the results of operations and cash flows for the periods presented.
Use of Estimates	Use of Estimates To prepare financial statements in conformity with GAAP, management must make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates.
Recently Accounting Pronouncements Not Yet Adopted And Recently Adopted Accounting Standards	Recent Accounting Pronouncements Not Yet Adopted In June 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2016-13, Financial Instruments – Credit Losses This update is effective for annual periods beginning after December 15, 2019, and interim periods within those periods, and early adoption is permitted and In January 2017, the FASB issued Accounting Standards Update No. 2017-04, Intangibles – Goodwill and Other The Company will adopt ASU 2017-04 on January 1, 2020 and does not expect a material impact to its Consolidated Financial Statements. In August 2018, the FASB issued Accounting Standards Update No. 2018-13, Fair Value Measurement: Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement adds and modifies certain disclosure requirements for fair value measurements entities will no longer be required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, or valuation processes for Level 3 fair value measurements. However, public companies will be required to disclose the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements The Company will adopt ASU 2018-13 on January 1, 2020 and does not expect a material impact to its Consolidated Financial Statements. In September 2018, the FASB issued Accounting Standards Update No. 2018-15, Intangible – Goodwill and Other – Internal-Use Software requires a customer in a cloud computing arrangement to determine which implementation costs to capitalize as assets or expense as incurred capitalized implementation costs related to a hosting arrangement that is a service contract will be amortized over the term of the hosting arrangement, beginning when the module or component of the hosting arrangement is ready for its intended use The Company will adopt ASU 2018-15 on January 1, 2020 and does not expect a material impact to its Consolidated Financial Statements. Recently Adopted Accounting Standards In February 2016, the FASB issued Accounting Standards Update No. 2016-02 – Leases The Company adopted ASC 842 as of January 1, 2019, electing the optional transition method that allows for a cumulative-effect adjustment in the period of adoption and did not restate prior periods. The Company elected the package of practical expedients permitted under the transition guidance. As a result of the adoption, the Company recorded right-of-use assets and liabilities of $62.8 million and $75.1 million, respectively, and their corresponding deferred tax assets and liabilities on its Unaudited Consolidated Balance Sheet as of January 1, 2019. The adoption had no cumulative impact to retained earnings. See Note 10 to the Unaudited Consolidated Financial Statements for further discussion on leases. In July 2017, the FASB issued Accounting Standards Update No. 2017-11, Earnings Per Share, Distinguishing Liabilities from Equity, Derivatives and Hedging . The Company adopted In August 2017, the FASB issued Accounting Standards Update No. 2017-12, Derivatives and Hedging The Company adopted
Revenue Recognition	Revenue Recognition In accordance with Accounting Standards Codification 606 Revenue from Contracts with Customers Revenue from IOM services is recognized in the period the service is performed for the amount of consideration expected to be received.
Inventory	Inventory Net inventory as of September 30, 2019 Finished goods primarily consists of specialized implants and disposables and are stated at the lower of cost or market determined by utilizing a standard cost method, which includes capitalized variances, which approximates the weighted average cost. Work in progress and raw materials represent the underlying material, and labor for work in progress, that ultimately yield finished goods upon completion and are subject to lower of cost or market. The Company reviews the components of its inventory on a periodic basis for excess and obsolescence and adjusts inventory to its net realizable value as necessary.
Comprehensive Income	Comprehensive Income Comprehensive income is defined as the change in equity during a period from transactions and other events and circumstances from non-owner sources. Comprehensive income includes net of tax, unrealized gains or losses on the Company’s marketable securities and foreign currency translation adjustments. The cumulative translation adjustments included in accumulated other comprehensive loss were $11.3 million and $8.6 million at September 30, 2019 and December 31, 2018, respectively.
Product Shipment Costs	Product Shipment Costs Product shipment costs, included in sales, marketing and administrative expense in the accompanying Unaudited Consolidated Statements of Operations, were $7.3 million and $20.6 million for the three and nine months ended September 30, 2019, respectively, and $6.5 million and $18.9 million for the three and nine months ended September 30, 2018, respectively. The majority of the Company’s shipping costs are related to the distribution of surgical instrument sets, which are not typically sold as part of the Company’s core sales offering. Amounts billed to customers for shipping and handling of products are reflected in revenues and are not material for any period presented .
Business Transition Costs	Business Transition Costs The Company incurs certain costs related to acquisition, integration and business transition activities, which include severance, relocation, consulting, leasehold exit costs, third-party merger and acquisition costs, contingent consideration fair value adjustments and other costs directly associated with such activities. The Company incurred $(0.3) million and $5.1 million of such costs during the three and nine months ended September 30, 2019, respectively. For the three months ended September 30, 2019, such costs consisted primarily of $(0.5) million of fair value adjustments on contingent consideration liabilities associated with the Company’s 2017 and 2016 acquisitions. The Company incurred $1.4 million and $7.7 million of such costs during the three and nine months ended September 30, 2018, respectively, which consisted primarily of acquisition, integration and business transition activities, as well as $0.7 million and $1.5 million, respectively, of fair value adjustments on contingent consideration liabilities associated with the Company’s 2017 and 2016 acquisitions.

Net Income Per Share (Tables)

Net Income Per Share (Tables)	9 Months Ended
Net Income Per Share (Tables)	Sep. 30, 2019
Earnings Per Share [Abstract]
Computation of Basic and Diluted Consolidated Net Income Per Share	The following table sets forth the computation of basic and diluted consolidated net income per share: Three Months Ended September 30, Nine Months Ended September 30, ( in thousands, except per share data 2019 2018 2019 2018 Numerator: Net income $ 11,010 $ 15,923 $ 35,358 $ 322 Denominator for basic and diluted net income per share: Weighted average common shares outstanding for basic 52,057 51,439 51,901 51,341 Dilutive potential common stock outstanding: Stock options and employee stock purchase plan 17 41 15 37 Restricted stock units 516 1,059 596 701 Senior Convertible Notes 466 650 155 217 Weighted average common shares outstanding for diluted 53,056 53,189 52,667 52,296 Basic net income per share $ 0.21 $ 0.31 $ 0.68 $ 0.01 Diluted net income per share $ 0.21 $ 0.30 $ 0.67 $ 0.01
Anti-dilutive Common Stock Equivalents Not Included in Calculation of Net Income Per Diluted Share	The following weighted-average outstanding common stock equivalents were not included in the calculation of net income per diluted share because their effects were anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, ( in thousands 2019 2018 2019 2018 Stock options, employee stock purchase plan, and restricted stock units 10 11 111 198 Warrants 10,865 10,865 10,865 10,865 Senior Convertible Notes — — 7,244 7,244 Total 10,875 10,876 18,220 18,307

Financial Instruments and Fai_2

Financial Instruments and Fair Value Measurements (Tables)	9 Months Ended
Financial Instruments and Fair Value Measurements (Tables)	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis	Cash equivalents are determined under the fair value categories as follows: Quoted Price in Significant Other Significant Active Market Observable Inputs Unobservable ( in thousands Total (Level 1) (Level 2) Inputs (Level 3) September 30, 2019: Cash equivalents: Money market funds $ 100,983 $ 100,983 $ — $ — Total cash equivalents $ 100,983 $ 100,983 $ — $ — December 31, 2018: Cash equivalents: Money market funds $ 56,000 $ 56,000 $ — $ — Total cash equivalents $ 56,000 $ 56,000 $ — $ —
Schedule of Fair Value of Liabilities Measured on Recurring Basis Using Unobservable Inputs	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): Nine Months Ended September 30, ( in thousands 2019 2018 Fair value measurement at beginning of period $ 50,410 $ 67,941 Contingent consideration liability recorded upon acquisition — 6,663 Change in fair value measurement 1,435 1,539 Changes resulting from foreign currency fluctuations (60 ) 17 Contingent consideration paid or settled (1,435 ) (19,000 ) Fair value measurement at end of period $ 50,350 $ 57,160

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
Goodwill and Intangible Assets (Tables)	Sep. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and intangible assets	Goodwill and intangible assets consisted of the following: Weighted- Average Amortization ( in thousands, except years Period Gross Accumulated Intangible September 30, 2019: (in years) Amount Amortization Assets, net Intangible assets subject to amortization: Developed technology 8 $ 271,748 $ (155,527 ) $ 116,221 Manufacturing know-how and trade secrets 13 30,774 (19,710 ) 11,064 Trade name and trademarks 9 25,500 (16,198 ) 9,302 Customer relationships 9 150,512 (72,607 ) 77,905 Total intangible assets subject to amortization 9 $ 478,534 $ (264,042 ) $ 214,492 Intangible assets not subject to amortization: Goodwill $ 560,744 Total goodwill and intangible assets, net $ 775,236 Weighted- Average Amortization Period Gross Accumulated Intangible December 31, 2018: (in years) Amount Amortization Assets, net Intangible assets subject to amortization: Developed technology 8 $ 271,748 $ (131,730 ) $ 140,018 Manufacturing know-how and trade secrets 13 30,814 (17,926 ) 12,888 Trade name and trademarks 9 25,500 (13,901 ) 11,599 Customer relationships 9 147,021 (59,478 ) 87,543 Total intangible assets subject to amortization 9 $ 475,083 $ (223,035 ) $ 252,048 Intangible assets not subject to amortization: Goodwill $ 561,366 Total goodwill and intangible assets, net $ 813,414
Schedule of changes in the carrying value of goodwill	The following table summarizes the changes in the carrying value of the Company’s goodwill: ( in thousands December 31, 2018 Gross goodwill $ 569,666 Accumulated impairment loss (8,300 ) 561,366 Changes to gross goodwill Changes resulting from foreign currency fluctuations (622) (622) September 30, 2019 Gross goodwill 569,044 Accumulated impairment loss (8,300 ) $ 560,744
Future amortization expense related to intangible assets	Total future amortization expense related to intangible assets subject to amortization at September 30, 2019 is set forth in the table below: ( in thousands Remaining 2019 $ 13,515 2020 52,085 2021 50,198 2022 41,441 2023 17,684 Thereafter through 2031 39,569 Total future amortization expense $ 214,492

Indebtedness (Tables)

Indebtedness (Tables)	9 Months Ended
Indebtedness (Tables)	Sep. 30, 2019
Debt Disclosure [Abstract]
Carrying Value of Senior Convertible Notes	The carrying values of the Company’s Senior Convertible Notes due 2021 are as follows: ( in thousands September 30, 2019 December 31, 2018 2.25% Senior Convertible Notes due 2021: Principal amount $ 650,000 $ 650,000 Unamortized debt discount (26,992 ) (40,117 ) Unamortized debt issuance costs (5,016 ) (7,357 ) Total Senior Convertible Notes $ 617,992 $ 602,526

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
Stock-Based Compensation (Tables)	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Compensation Costs Included in Statement of Income for all Stock-based Compensation Arrangements	The compensation cost that has been included in the Unaudited Consolidated Statements of Operations for all stock-based compensation arrangements was as follows: Three Months Ended September 30, Nine Months Ended September 30, ( in thousands 2019 2018 2019 2018 Sales, marketing and administrative expense $ 6,627 $ 10,095 $ 17,317 $ 19,539 Research and development expense 1,064 863 2,716 2,201 Cost of revenue 138 110 414 322 Stock-based compensation expense before taxes 7,829 11,068 20,447 22,062 Related income tax benefits (1,957 ) (2,767 ) (5,112 ) (5,516 ) Stock-based compensation expense, net of taxes $ 5,872 $ 8,301 $ 15,335 $ 16,546
Weighted Average Assumptions Used to Estimate Fair Value of Stock Purchase Rights under ESPP	The weighted average assumptions used to estimate the fair value of stock purchase rights under the employee stock purchase plan (“ESPP”) are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 ESPP Volatility 37 % 28 % 37 % 32 % Expected term (years) 0.5 0.5 0.5 0.5 Risk free interest rate 2.4 % 2.1 % 2.5 % 1.6 % Expected dividend yield — % — % — % — %

Business Segment, Product and G

Business Segment, Product and Geographic Information (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Schedule of Revenue by Product Lines	Revenue by product line was as follows: Three Months Ended September 30, Nine Months Ended September 30, ( in thousands 2019 2018 2019 2018 Spinal hardware $ 214,190 $ 193,626 $ 623,962 $ 581,587 Surgical support 76,645 77,675 233,754 231,800 Total revenue $ 290,835 $ 271,301 $ 857,716 $ 813,387
Schedule of Revenue and Net Property and Equipment by Geographical Area	Revenue and property and equipment, net, by geographic area were as follows: Revenue Property and Equipment, Net Three Months Ended September 30, Nine Months Ended September 30, September 30, December 31, ( in thousands 2019 2018 2019 2018 2019 2018 United States $ 233,676 $ 221,318 $ 692,617 $ 661,570 $ 217,545 $ 200,404 International (excludes Puerto Rico) 57,159 49,983 165,099 151,817 45,590 38,437 Total $ 290,835 $ 271,301 $ 857,716 $ 813,387 $ 263,135 $ 238,841

Commitments (Tables)

Commitments (Tables)	9 Months Ended
Commitments (Tables)	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Right-of-use Assets and Lease Liabilities	The table below summarizes the Company’s right-of-use assets and lease liabilities as of September 30, 2019 (in thousands) September 30, 2019 Assets Operating $ 67,128 Financing 1,074 Total leased assets $ 68,202 Liabilities Current: Operating $ 5,792 Financing 508 Long-term: Operating 72,713 Financing 684 Total lease liabilities $ 79,697 Supplemental non-cash information: Weighted-average remaining lease term (years) - operating leases 12.6 Weighted-average remaining lease term (years) - finance leases 2.2 Weighted-average discount rate - operating leases 7.3 % Weighted-average discount rate - finance leases 5.2 %
Lease Costs, Cash Payments and Operating Lease Liabilities Arising From Obtaining Right-of-use Assets under Operating and Financing Lease Obligations	The table below summarizes the Company’s lease costs, cash payments, and operating lease liabilities arising from obtaining right-of-use assets under its operating and financing lease obligations during the three and nine months ended September 30, 2019: Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except years and rates) 2019 2019 Lease expense: Operating lease expense $ 3,043 $ 8,829 Finance lease expense: Depreciation of right-of-use assets 99 296 Interest expense on lease liabilities 12 38 Total lease expense $ 3,154 $ 9,163 Consolidated Statements of Cash Flows information: Operating cash flows used for operating leases $ 3,132 $ 9,304 Operating cash flows used for financing leases 12 38 Financing cash flows used for financing leases 96 281 Total cash paid for amounts included in the measurement of lease liabilities $ 3,240 $ 9,623 Supplemental non-cash information: Operating lease liabilities arising from obtaining right-of-use assets $ 6,757 $ 84,362
Future Minimum Annual Lease Payments under Operating and Financing Leases	The Company’s future minimum annual lease payments under operating and financing leases at September 30, 2019 are as follows: Financing Operating (in thousands) Leases Leases Remaining 2019 $ 140 $ 2,851 2020 561 10,750 2021 462 10,231 2022 114 9,767 2023 — 9,511 Thereafter — 82,511 Total minimum lease payments $ 1,277 $ 125,621 Less: amount representing interest (85 ) (47,116 ) Present value of obligations under leases 1,192 78,505 Less: current portion (508 ) (5,792 ) Long-term lease obligations $ 684 $ 72,713

Description of Business and B_3

Description of Business and Basis of Presentation (Details Textual) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Schedule Of Description Of Business And Basis Of Presentation [Line Items]
Right-of-use assets	$ 67,128,000		$ 67,128,000
Right-of-use liabilities	78,505,000		78,505,000
Inventory, finished goods	292,800,000		292,800,000		$ 259,400,000
Inventory, work in progress	8,600,000		8,600,000		5,000,000
Inventory, raw materials	7,500,000		7,500,000		8,800,000
Translation Adjustment Functional to Reporting Currency, Net of Tax	11,300,000		11,300,000		$ 8,600,000
Product shipment costs	77,028,000	$ 74,160,000	229,101,000	$ 225,030,000
Business transition costs (recoveries)	(333,000)	1,443,000	5,146,000	7,694,000
2017 and 2016 Acquisitions [Member]
Schedule Of Description Of Business And Basis Of Presentation [Line Items]
Business transition costs (recoveries)	(500,000)	700,000	1,400,000	1,500,000
Product Shipment [Member]
Schedule Of Description Of Business And Basis Of Presentation [Line Items]
Product shipment costs	7,300,000	$ 6,500,000	20,600,000	$ 18,900,000
ASU 2016-02 [Member]
Schedule Of Description Of Business And Basis Of Presentation [Line Items]
Right-of-use assets	62,800,000		62,800,000
Right-of-use liabilities	$ 75,100,000		75,100,000
Cumulative impact of new accounting principle towards retained earnings			$ 0

Net Income Per Share - Computat

Net Income Per Share - Computation of Basic and Diluted Consolidated Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net income	$ 11,010	$ 14,962	$ 9,386	$ 15,923	$ 11,531	$ (27,132)	$ 35,358	$ 322
Weighted average shares outstanding:
Weighted average common shares outstanding for basic	52,057			51,439			51,901	51,341
Dilutive potential common stock outstanding:
Weighted average common shares outstanding for diluted	53,056			53,189			52,667	52,296
Basic net income per share	$ 0.21			$ 0.31			$ 0.68	$ 0.01
Diluted net income per share	$ 0.21			$ 0.30			$ 0.67	$ 0.01
Stock Options and Employee Stock Purchase Plan [Member]
Dilutive potential common stock outstanding:
Stock options and employee stock purchase plan	17			41			15	37
Restricted Stock Units [Member]
Dilutive potential common stock outstanding:
Stock options and employee stock purchase plan	516			1,059			596	701
Senior Convertible Notes [Member]
Dilutive potential common stock outstanding:
Stock options and employee stock purchase plan	466			650			155	217

Net Income Per Share - Anti-dil

Net Income Per Share - Anti-dilutive Common Stock Equivalents Not Included in Calculation of Net Income Per Diluted Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share	10,875	10,876	18,220	18,307
Stock Options, Employee Stock Purchase Plan, and Restricted Stock Units [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share	10	11	111	198
Warrants [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share	10,865	10,865	10,865	10,865
Senior Convertible Notes [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from computation of earnings per share			7,244	7,244

Financial Instruments and Fai_3

Financial Instruments and Fair Value Measurements (Details Textual)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019USD ($)investment	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)investment	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)investment
Business Acquisition [Line Items]
Net currency exchange gains (losses) from derivatives instruments	$ (800,000)	$ (900,000)	$ (1,000,000)	$ (3,400,000)
Unrealized loss position investment \| investment	0		0		0
Impairment charges recorded for earnings			$ 0		$ 0
Contingent consideration liabilities	$ 7,774,000		7,774,000		7,560,000
Purchased in-process research and development asset		8,900,000		8,913,000
Impairment charge on strategic investment			9,000,000
LessRay Software Technology Inc [Member]
Business Acquisition [Line Items]
Payments of outstanding milestone obligation				19,000,000
Payments of outstanding milestone related to achievement of commercial milestone				9,000,000
Payments of outstanding milestone related to achievement of regulatory approval milestone				10,000,000
Payments for initial purchase price allocation				18,700,000
Increased fair value adjustments				(300,000)
Contingent Consideration Liabilities [Member]
Business Acquisition [Line Items]
Contingent consideration liabilities	50,400,000		50,400,000		50,400,000
Quoted Price in Active Market (Level 1) [Member] \| Convertible Notes due 2021 [Member]
Business Acquisition [Line Items]
Debt instrument, fair value disclosure	767,400,000		767,400,000		684,800,000
Foreign Exchange Forward [Member]
Business Acquisition [Line Items]
Notional principal amount	34,500,000		34,500,000		26,800,000
Foreign Exchange Forward [Member] \| Other Current Assets or Other Current Liabilities [Member]
Business Acquisition [Line Items]
Fair value of derivative instrument asset (liability)					$ (300,000)
Foreign Exchange Forward [Member] \| Other (Expense) Income [Member]
Business Acquisition [Line Items]
Net (losses) gains recognized on derivative instruments	$ 700,000	$ 200,000	$ 700,000	$ 500,000

Financial Instruments and Fai_4

Financial Instruments and Fair Value Measurements - Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis (Details) - Fair Value Measurements on Recurring Basis [Member] - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Cash Equivalents and Marketable Securities
Total cash equivalents	$ 100,983	$ 56,000
Money Market Funds [Member]
Cash Equivalents and Marketable Securities
Total cash equivalents	100,983	56,000
Quoted Price in Active Market (Level 1) [Member]
Cash Equivalents and Marketable Securities
Total cash equivalents	100,983	56,000
Quoted Price in Active Market (Level 1) [Member] \| Money Market Funds [Member]
Cash Equivalents and Marketable Securities
Total cash equivalents	$ 100,983	$ 56,000

Financial Instruments and Fai_5

Financial Instruments and Fair Value Measurements - Schedule of Fair Value of Liabilities Measured on Recurring Basis Using Unobservable Inputs (Details) - Contingent Consideration Liabilities [Member] - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value measurement at beginning of period	$ 50,410	$ 67,941
Contingent consideration liability recorded upon acquisition		6,663
Change in fair value measurement	1,435	1,539
Changes resulting from foreign currency fluctuations	(60)	17
Contingent consideration paid or settled	(1,435)	(19,000)
Fair value measurement at end of period	$ 50,350	$ 57,160

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Intangible assets subject to amortization:
Weighted Average Amortization Period	9 years	9 years
Gross Amount	$ 478,534	$ 475,083
Accumulated Amortization	(264,042)	(223,035)
Intangible Assets, net	214,492	252,048
Intangible assets not subject to amortization:
Goodwill	560,744	561,366
Total goodwill and intangible assets, net	$ 775,236	$ 813,414
Developed Technology [Member]
Intangible assets subject to amortization:
Weighted Average Amortization Period	8 years	8 years
Gross Amount	$ 271,748	$ 271,748
Accumulated Amortization	(155,527)	(131,730)
Intangible Assets, net	$ 116,221	$ 140,018
Manufacturing know-how and trade secrets [Member]
Intangible assets subject to amortization:
Weighted Average Amortization Period	13 years	13 years
Gross Amount	$ 30,774	$ 30,814
Accumulated Amortization	(19,710)	(17,926)
Intangible Assets, net	$ 11,064	$ 12,888
Trade name and trademarks [Member]
Intangible assets subject to amortization:
Weighted Average Amortization Period	9 years	9 years
Gross Amount	$ 25,500	$ 25,500
Accumulated Amortization	(16,198)	(13,901)
Intangible Assets, net	$ 9,302	$ 11,599
Customer relationships [Member]
Intangible assets subject to amortization:
Weighted Average Amortization Period	9 years	9 years
Gross Amount	$ 150,512	$ 147,021
Accumulated Amortization	(72,607)	(59,478)
Intangible Assets, net	$ 77,905	$ 87,543

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Schedule of Changes in the Carrying Value of Goodwill (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Gross goodwill	$ 569,044	$ 569,666
Accumulated impairment loss	(8,300)	(8,300)
Goodwill	560,744	$ 561,366
Changes to gross goodwill
Changes resulting from foreign currency fluctuations	(622)
Goodwill period increase (decrease)	$ (622)

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets (Details Textual) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expense related to intangible assets	$ 13.5	$ 13.3	$ 41.2	$ 40.2

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets - Future Amortization Expense Related to Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Future amortization expense related to intangible assets
Remaining 2019	$ 13,515
2020	52,085
2021	50,198
2022	41,441
2023	17,684
Thereafter through 2031	39,569
Intangible Assets, net	$ 214,492	$ 252,048

Carrying Value of Senior Conver

Carrying Value of Senior Convertible Notes (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018	Mar. 31, 2016
Debt Instrument [Line Items]
Total Senior Convertible Notes	$ 617,992,000	$ 602,526,000
2.25% Senior Convertible Notes [Member] \| Convertible Notes due 2021 [Member]
Debt Instrument [Line Items]
Principal amount	650,000,000	650,000,000	$ 650,000,000
Unamortized debt discount	(26,992,000)	(40,117,000)
Unamortized debt issuance costs	$ (5,016,000)	$ (7,357,000)

Carrying Value of Senior Conv_2

Carrying Value of Senior Convertible Notes (Parenthetical) (Details)	Sep. 30, 2019	Dec. 31, 2018	Mar. 31, 2016
2.25% Senior Convertible Notes [Member] \| Convertible Notes due 2021 [Member]
Debt Instrument [Line Items]
Interest rate on convertible notes	2.25%	2.25%	2.25%

Indebtedness (Details Textual)

Indebtedness (Details Textual)	1 Months Ended		3 Months Ended		9 Months Ended		12 Months Ended
Indebtedness (Details Textual)	Apr. 30, 2017USD ($)	Mar. 31, 2016USD ($)$ / shares	Sep. 30, 2019USD ($)$ / sharesshares	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)d$ / sharesshares	Sep. 30, 2018USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2018USD ($)
Revolving Senior Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 500,000,000
Credit facility, expiration date					2022-04
Loan outstanding			$ 0		$ 0			$ 0
Revolving Senior Credit Facility [Member] \| Federal Funds Effective Rate [Member]
Debt Instrument [Line Items]
Credit facility bear interest rate	0.50%
Revolving Senior Credit Facility [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Credit facility bear interest rate	1.00%
Multicurrency Borrowings [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 100,000,000
Standby Letters of Credit [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	50,000,000
Swing Line Loans [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 5,000,000
2021 Warrants [Member]
Debt Instrument [Line Items]
Cash proceeds from the sale of warrants		$ 44,900,000
Warrant strike price \| $ / shares		$ 80
2021 Hedge [Member]
Debt Instrument [Line Items]
Number of common stock to be purchased \| shares					10,865,270
stock price \| $ / shares			$ 59.82		$ 59.82
Derivative, maturity date					Mar. 15, 2021
Minimum [Member] \| Revolving Senior Credit Facility [Member]
Debt Instrument [Line Items]
Unused line fee	0.20%
Minimum [Member] \| Revolving Senior Credit Facility [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Credit facility bear interest rate	0.00%
Minimum [Member] \| Revolving Senior Credit Facility [Member] \| Eurocurrency [Member]
Debt Instrument [Line Items]
Credit facility bear interest rate	1.00%
Minimum [Member] \| 2021 Warrants [Member]
Debt Instrument [Line Items]
Class of warrant or rights expiry month and year					2021-06
Maximum [Member] \| Revolving Senior Credit Facility [Member]
Debt Instrument [Line Items]
Unused line fee	0.35%
Maximum [Member] \| Revolving Senior Credit Facility [Member] \| Base Rate [Member]
Debt Instrument [Line Items]
Credit facility bear interest rate	1.00%
Maximum [Member] \| Revolving Senior Credit Facility [Member] \| Eurocurrency [Member]
Debt Instrument [Line Items]
Credit facility bear interest rate	2.00%
Maximum [Member] \| 2021 Warrants [Member]
Debt Instrument [Line Items]
Class of warrant or rights expiry month and year					2021-12
Additional Paid-in Capital [Member] \| 2021 Hedge [Member]
Debt Instrument [Line Items]
Cost of hedge transaction							$ 111,200,000
Common Stock [Member] \| Maximum [Member] \| 2021 Warrants [Member]
Debt Instrument [Line Items]
Number of preferred or common stock into which the warrants is converted \| shares			10,865,270		10,865,270
2.25% Senior Convertible Notes [Member] \| Convertible Notes due 2021 [Member]
Debt Instrument [Line Items]
Principal amount		$ 650,000,000	$ 650,000,000		$ 650,000,000			$ 650,000,000
Proceeds from issuance of convertible debt, net of issuance costs		$ 634,100,000
Interest rate on convertible notes		2.25%	2.25%		2.25%			2.25%
Debt instrument, maturity date		Mar. 15, 2021
Initial conversion rate adjustment, shares		16.7158
Principal amount of debt considered for conversion rate		$ 1,000
Initial conversion price of convertible notes \| $ / shares		$ 59.82
Contractual coupon interest expense			$ 3,700,000	$ 3,700,000	$ 11,000,000	$ 11,000,000
Amortization of debt discount (premium)			4,400,000	4,200,000	13,100,000	12,500,000
Amortization of debt issuance costs			$ 800,000	$ 700,000	$ 2,300,000	$ 2,100,000
Effective interest rate			5.80%		5.80%
Debt redemption price percentage					100.00%
Principal payments due			$ 0		$ 0
2.25% Senior Convertible Notes [Member] \| Convertible Notes due 2021 [Member] \| Scenario Two [Member]
Debt Instrument [Line Items]
Consecutive trading days considered for debt conversion \| d					5
2.25% Senior Convertible Notes [Member] \| Convertible Notes due 2021 [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Percentage of conversion price					130.00%
2.25% Senior Convertible Notes [Member] \| Convertible Notes due 2021 [Member] \| Minimum [Member] \| Scenario One [Member]
Debt Instrument [Line Items]
Consecutive trading days considered for debt conversion \| d					20
2.25% Senior Convertible Notes [Member] \| Convertible Notes due 2021 [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Percentage of conversion price					98.00%
2.25% Senior Convertible Notes [Member] \| Convertible Notes due 2021 [Member] \| Maximum [Member] \| Scenario One [Member]
Debt Instrument [Line Items]
Consecutive trading days considered for debt conversion \| d					30
2.25% Senior Convertible Notes [Member] \| Convertible Notes due 2021 [Member] \| Additional Paid-in Capital [Member]
Debt Instrument [Line Items]
Amount reclassified to stockholders' equity							$ 84,800,000

Stock-Based Compensation - Comp

Stock-Based Compensation - Compensation Costs Included in Statement of Income for all Stock-based Compensation Arrangements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	$ 7,829	$ 11,068	$ 20,447	$ 22,062
Related income tax benefits	(1,957)	(2,767)	(5,112)	(5,516)
Stock-based compensation expense, net of taxes	5,872	8,301	15,335	16,546
Sales, Marketing and Administrative Expense [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	6,627	10,095	17,317	19,539
Research and Development Expense [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	1,064	863	2,716	2,201
Cost of Revenue [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense before taxes	$ 138	$ 110	$ 414	$ 322

Stock-Based Compensation (Detai

Stock-Based Compensation (Details Textual) - USD ($)	3 Months Ended	9 Months Ended	12 Months Ended
Stock-Based Compensation (Details Textual) - USD ($)	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options granted		0
Number of common stock issued to exercise stock options	0	18,000	128,000
ESPP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Maximum percentage of annual compensation	15.00%	15.00%
Maximum amount withheld to purchase shares of the company		$ 21,250
Percentage of issuance price of stock under the stock issuance program		85.00%
ESPP offering period		6 months
Performance Based Restricted Stock Units (PRSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unamortized cost related to share-based compensation	$ 46,400,000	$ 46,400,000
Weighted average contractual term		2 years 3 months 18 days
Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unamortized cost related to share-based compensation	$ 46,400,000	$ 46,400,000
Weighted average contractual term		2 years 3 months 18 days
Restricted Stock Units (RSUs) and Performance-Based Restricted Stock Units (PRSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock issued upon vesting of RSUs and PRSUs	64,000	675,000	190,000

Stock-Based Compensation - Weig

Stock-Based Compensation - Weighted Average Assumptions Used to Estimate Fair Value of Stock Purchase Rights under ESPP (Details) - ESPP [Member]	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Weighted average assumptions used to estimate fair value of stock options granted and stock purchase rights under ESPP
Volatility	37.00%	28.00%	37.00%	32.00%
Expected term (years)	6 months	6 months	6 months	6 months
Risk free interest rate	2.40%	2.10%	2.50%	1.60%

Income Taxes (Details Textual)

Income Taxes (Details Textual) $ in Millions	9 Months Ended
Income Taxes (Details Textual) $ in Millions	Sep. 30, 2019USD ($)
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent	25.00%
Increase in gross unrecognized tax benefits	$ 1
Remaining unrecognized tax positions	$ 0.6

Business Segment, Product and_2

Business Segment, Product and Geographic Information (Details Textual)	9 Months Ended
	Sep. 30, 2019segment
Segment Reporting [Abstract]
Number of operating segments	1
Number of reportable segments	1

Business Segment, Product and_3

Business Segment, Product and Geographic Information - Schedule of Revenue by Product Lines (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Entity Wide Information Revenue From External Customer [Line Items]
Total revenue	$ 290,835	$ 271,301	$ 857,716	$ 813,387
Spinal Hardware [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Total revenue	214,190	193,626	623,962	581,587
Surgical Support [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Total revenue	$ 76,645	$ 77,675	$ 233,754	$ 231,800

Business Segment, Product and_4

Business Segment, Product and Geographic Information - Schedule of Revenue and Net Property and Equipment by Geographical Area (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Revenues and Net Property and Equipment by Geographical Areas [Line Items]
Revenue	$ 290,835	$ 271,301	$ 857,716	$ 813,387
Property and Equipment, Net	263,135		263,135		$ 238,841
United States
Revenues and Net Property and Equipment by Geographical Areas [Line Items]
Revenue	233,676	221,318	692,617	661,570
Property and Equipment, Net	217,545		217,545		200,404
International [Member]
Revenues and Net Property and Equipment by Geographical Areas [Line Items]
Revenue	57,159	$ 49,983	165,099	$ 151,817
Property and Equipment, Net	$ 45,590		$ 45,590		$ 38,437

Commitments (Details Textual)

Commitments (Details Textual) $ in Millions	9 Months Ended
Commitments (Details Textual) $ in Millions	Sep. 30, 2019USD ($)
Commitments And Contingencies Disclosure [Line Items]
Restricted cash for security deposit	$ 2.4
Lease, practical expedients, package	true
Executive Severance Plans [Member]
Commitments And Contingencies Disclosure [Line Items]
Other commitments, future minimum payments, remainder of fiscal year	$ 16.2
Corporate Office Facilities [Member]
Commitments And Contingencies Disclosure [Line Items]
Future lease payment obligations	$ 59.9
Minimum [Member]
Commitments And Contingencies Disclosure [Line Items]
Initial terms of lease	1 year
Maximum [Member]
Commitments And Contingencies Disclosure [Line Items]
Initial terms of lease	17 years

Commitments - Right-of-use Asse

Commitments - Right-of-use Assets and Lease Liabilities (Details) $ in Thousands	Sep. 30, 2019USD ($)
Assets
Right-of-use assets	$ 67,128
Financing	1,074
Total leased assets	68,202
Current:
Operating	5,792
Financing	508
Long-term:
Operating	72,713
Financing	684
Total lease liabilities	$ 79,697
Weighted-average remaining lease term (years) - operating leases	12 years 7 months 6 days
Weighted-average remaining lease term (years) - finance leases	2 years 2 months 12 days
Weighted-average discount rate - operating leases	7.30%
Weighted-average discount rate - finance leases	5.20%

Commitments - Lease Costs, Cash

Commitments - Lease Costs, Cash Payments and Operating Lease Liabilities Arising From Obtaining Right-of-use Assets under Operating and Financing Lease Obligations (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Lease expense:
Operating lease expense	$ 3,043	$ 8,829
Finance lease expense:
Depreciation of right-of-use assets	99	296
Interest expense on lease liabilities	12	38
Total lease expense	3,154	9,163
Operating cash flows used for operating leases	3,132	9,304
Operating cash flows used for financing leases	12	38
Financing cash flows used for financing leases	96	281
Total cash paid for amounts included in the measurement of lease liabilities	3,240	9,623
Operating lease liabilities arising from obtaining right-of-use assets	$ 6,757	$ 84,362

Commitments - Future Minimum An

Commitments - Future Minimum Annual Lease Payments under Operating and Financing Leases (Details) $ in Thousands	Sep. 30, 2019USD ($)
Financing Leases
Remaining 2019	$ 140
2020	561
2021	462
2022	114
Total minimum lease payments	1,277
Less: amount representing interest	(85)
Present value of obligations under leases	1,192
Less: current portion	(508)
Long-term lease obligations	684
Operating Leases
Remaining 2019	2,851
2020	10,750
2021	10,231
2022	9,767
2023	9,511
Thereafter	82,511
Total minimum lease payments	125,621
Less: amount representing interest	(47,116)
Present value of obligations under leases	78,505
Less: current portion	(5,792)
Long-term lease obligations	$ 72,713

Contingencies (Details)

Contingencies (Details) - USD ($)	Dec. 06, 2018	Feb. 13, 2018	Jul. 05, 2016	Mar. 18, 2016	Feb. 19, 2016	Sep. 30, 2019	Dec. 31, 2018	May 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Loss Contingencies [Line Items]
Litigation accrual						$ 2,065,000	$ 1,415,000
Securities Litigation [Member]
Loss Contingencies [Line Items]
Settlement agreement, consideration		$ 7,900,000
Settlement funded by insurance proceeds	$ 7,900,000
Madsen Medical, Inc. Litigation [Member]
Loss Contingencies [Line Items]
Jury award				$ 27,800,000
Loss contingency, settlement agreement, court						On March 18, 2016, the trial court entered judgment in favor of MMI in the amount of $27.8 million, which amount excluded the $14.0 million disgorgement awarded by the jury.
Litigation accrual								$ 27,800,000	$ 29,000,000
Madsen Medical, Inc. Litigation [Member] \| Minimum [Member]
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss									0	$ 0
Madsen Medical, Inc. Litigation [Member] \| Maximum [Member]
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss									$ 29,000,000
Madsen Medical, Inc. Litigation [Member] \| Loss Profits for Tortious Interference [Member]
Loss Contingencies [Line Items]
Jury award					$ 7,500,000
Madsen Medical, Inc. Litigation [Member] \| Unjust Enrichment [Member]
Loss Contingencies [Line Items]
Jury award					14,000,000
Madsen Medical, Inc. Litigation [Member] \| Punitive Damages [Member]
Loss Contingencies [Line Items]
Jury award					20,000,000
Madsen Medical, Inc. Litigation [Member] \| Damages for Breach of Contract [Member]
Loss Contingencies [Line Items]
Jury award					$ 300,000
Madsen Medical, Inc. Litigation [Member] \| Attorney Fees And Costs [Member]
Loss Contingencies [Line Items]
Jury award			$ 1,100,000