Lantheus (LNTH) 10-K 20 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Feb. 15, 2019	Jun. 30, 2018
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Trading Symbol	LNTH
Entity Registrant Name	LANTHEUS HOLDINGS, INC.
Entity Central Index Key	1,521,036
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Shell Company	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		38,547,954
Entity Public Float			$ 550.4

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 113,401,000	$ 76,290,000
Accounts receivable, net	43,753,000	40,259,000
Inventory	33,019,000	26,080,000
Other current assets	5,242,000	5,221,000
Total current assets	195,415,000	147,850,000
Property, plant and equipment, net	107,888,000	92,999,000
Intangibles, net	9,133,000	11,798,000
Goodwill	15,714,000	15,714,000
Deferred tax assets, net	81,449,000	87,010,000
Other long-term assets	30,232,000	28,487,000
Total assets	439,831,000	383,858,000
Current liabilities
Current portion of long-term debt	2,750,000	2,750,000
Revolving line of credit	0	0
Accounts payable	17,955,000	17,464,000
Accrued expenses and other liabilities	32,050,000	26,536,000
Total current liabilities	52,755,000	46,750,000
Asset retirement obligations	11,572,000	10,412,000
Long-term debt, net	263,709,000	265,393,000
Other long-term liabilities	40,793,000	38,012,000
Total liabilities	368,829,000	360,567,000
Commitments and contingencies (see Note 15)
Stockholders’ equity
Preferred stock ($0.01 par value, 25,000 shares authorized; no shares issued and outstanding)	0	0
Common stock ($0.01 par value, 250,000 shares authorized; 38,466 and 37,765 shares issued and outstanding, respectively)	385,000	378,000
Additional paid-in capital	239,865,000	232,960,000
Accumulated deficit	(168,140,000)	(209,013,000)
Accumulated other comprehensive loss	(1,108,000)	(1,034,000)
Total stockholders’ equity	71,002,000	23,291,000
Total liabilities and stockholders’ equity	$ 439,831,000	$ 383,858,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	25,000,000	25,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock, shares issued (in shares)	38,466,000	37,765,000
Common stock, shares outstanding (in shares)	38,466,000	37,765,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Revenues	$ 343,374	$ 331,378	$ 301,853
Cost of goods sold	168,489	169,243	164,073
Gross profit	174,885	162,135	137,780
Operating expenses
Sales and marketing	43,159	42,315	36,542
General and administrative	50,167	49,842	38,832
Research and development	17,071	18,125	12,203
Total operating expenses	110,397	110,282	87,577
Gain on sales of assets	0	0	6,385
Operating income	64,488	51,853	56,588
Interest expense	17,405	18,410	26,618
Debt retirement costs	0	0	1,896
Loss on extinguishment of debt	0	2,442	0
Other income	(2,465)	(8,638)	(220)
Income before income taxes	49,548	39,639	28,294
Income tax expense (benefit)	9,030	(83,746)	1,532
Net income	$ 40,518	$ 123,385	$ 26,762
Net income per common share:
Basic (in dollars per share)	$ 1.06	$ 3.31	$ 0.84
Diluted (in dollars per share)	$ 1.03	$ 3.17	$ 0.82
Weighted-average common shares outstanding:
Basic (in shares)	38,233	37,276	32,044
Diluted (in shares)	39,501	38,892	32,656

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 40,518	$ 123,385	$ 26,762
Other comprehensive (loss) income:
Reclassification adjustment for gains on sales of assets included in net income	0	0	435
Foreign currency translation	(74)	(87)	603
Total other comprehensive (loss) income	(74)	(87)	1,038
Comprehensive income	$ 40,444	$ 123,298	$ 27,800

Consolidated Statements of Chan

Consolidated Statements of Changes in Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	IPO	Common Stock	Common StockIPO	Additional Paid-In Capital	Additional Paid-In CapitalIPO	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2015			30,365,000
Beginning balance at Dec. 31, 2015	$ (185,289)		$ 303		$ 175,553		$ (359,160)	$ (1,985)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)			41,000	6,200,000
Issuance of common stock	231	$ 48,820	$ 1	$ 62	230	$ 48,758
Net income	26,762						26,762
Other comprehensive income (loss)	$ 1,038							1,038
Stock option exercises (in shares)	40,976
Vesting of restricted stock awards (in shares)			214,000
Vesting of restricted stock awards	$ 0		$ 2		(2)
Shares withheld to cover taxes (in shares)			(64,000)
Vesting of restricted stock awards	(602)		$ (1)		(601)
Shares withheld to cover taxes	2,524				2,524
Ending balance (in shares) at Dec. 31, 2016			36,756,000
Ending balance at Dec. 31, 2016	(106,516)		$ 367		226,462		(332,398)	(947)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	123,385						123,385
Other comprehensive income (loss)	$ (87)							(87)
Stock option exercises (in shares)	465,232		478,000
Stock option exercises and employee stock plan purchases	$ 3,434		$ 5		3,429
Vesting of restricted stock awards (in shares)			744,000
Vesting of restricted stock awards	0		$ 8		(8)
Shares withheld to cover taxes (in shares)			(214,000)
Vesting of restricted stock awards	(2,853)		$ (2)		(2,851)
Shares withheld to cover taxes	5,928				5,928
Ending balance (in shares) at Dec. 31, 2017			37,765,000
Ending balance at Dec. 31, 2017	23,291		$ 378		232,960		(209,013)	(1,034)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	40,518						40,518
Forfeiture of dividend equivalent right	355						355
Other comprehensive income (loss)	(74)							(74)
Stock option exercises and employee stock plan purchases (in shares)			223,000
Stock option exercises and employee stock plan purchases	$ 1,580		$ 2		1,578
Stock option exercises (in shares)	192,550
Vesting of restricted stock awards (in shares)			672,000
Vesting of restricted stock awards	$ 0		$ 7		(7)
Shares withheld to cover taxes (in shares)			(194,000)
Vesting of restricted stock awards	(3,386)		$ (2)		(3,384)
Shares withheld to cover taxes	8,718				8,718
Ending balance (in shares) at Dec. 31, 2018			38,466,000
Ending balance at Dec. 31, 2018	$ 71,002		$ 385		$ 239,865		$ (168,140)	$ (1,108)

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Stockholders' Deficit (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)
Issuance costs	$ 2,080

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating activities
Net income	$ 40,518	$ 123,385	$ 26,762
Adjustments to reconcile net income to net cash flows from operating activities:
Depreciation, amortization and accretion	13,929	19,231	18,263
Amortization of debt related costs	1,279	1,361	1,603
Provision for bad debt	321	136	53
Provision for excess and obsolete inventory	2,875	1,215	1,342
Stock-based compensation	8,718	5,928	2,524
Gain on sales of assets	0	0	(6,385)
Loss on impairment of land	0	912	0
Loss on extinguishment of debt and debt retirement costs	0	2,442	1,896
Deferred taxes	5,762	(86,946)	(155)
Long-term income tax receivable	(2,855)	(8,413)	(200)
Long-term income tax payable and other long-term liabilities	3,219	2,793	565
Other	1,399	1,049	1,284
Increases (decreases) in cash from operating assets and liabilities:
Accounts receivable	(3,985)	(3,407)	(1,059)
Inventory	(8,690)	(9,620)	(3,626)
Other current assets	(661)	(388)	(155)
Accounts payable	(2,886)	604	5,700
Accrued expenses and other liabilities	2,250	4,495	1,230
Net cash provided by operating activities	61,193	54,777	49,642
Investing activities
Capital expenditures	(20,132)	(17,543)	(7,398)
Proceeds from sale of assets	1,000	1,234	10,605
Other	0	0	74
Net cash (used in) provided by investing activities	(19,132)	(16,309)	3,281
Financing activities
Proceeds from issuance of common stock	428	187	50,900
Payments for public offering costs	0	(74)	(2,006)
Proceeds from issuance of long-term debt	0	274,313	0
Payments on long-term debt	(2,862)	(286,694)	(78,729)
Deferred financing costs	0	(1,576)	(11)
Proceeds from stock option exercises	1,152	3,247	231
Payments for minimum statutory tax withholding related to net share settlement of equity awards	(3,386)	(2,853)	(602)
Net cash used in financing activities	(4,668)	(13,450)	(30,217)
Effect of foreign exchange rates on cash and cash equivalents	(282)	94	(124)
Net increase in cash and cash equivalents	37,111	25,112	22,582
Cash and cash equivalents, beginning of year	76,290	51,178	28,596
Cash and cash equivalents, end of year	113,401	76,290	51,178
Supplemental disclosure of cash flow information
Interest	15,869	16,653	24,441
Income taxes, net of refunds of $35, $17 and $82, respectively	90	106	265
Schedule of non-cash investing and financing activities
Additions of property, plant and equipment included in liabilities	7,395	2,738	4,990
Receivable in connection with sale of Australian subsidiary	$ 0	$ 0	$ 1,479

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Cash Flows [Abstract]
Income taxes, refunds	$ 35	$ 17	$ 82

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business Lantheus Holdings, Inc., a Delaware corporation, is the parent company of Lantheus Medical Imaging, Inc. (“LMI”), also a Delaware corporation. The Company is a global leader in the development, manufacture and commercialization of innovative diagnostic medical imaging agents and other products that assist clinicians in the diagnosis and treatment of cardiovascular and other diseases. The Company’s commercial products are used by cardiologists, nuclear physicians, radiologists, internal medicine physicians, technologists and sonographers working in a variety of clinical settings. The Company sells its products to radiopharmacies, integrated delivery networks, hospitals, clinics and group practices. The Company sells its products globally and have operations in the U.S., Puerto Rico and Canada and third-party distribution relationships in Europe, Canada, Australia, Asia-Pacific and Latin America. The Company’s product portfolio includes an ultrasound contrast agent and nuclear imaging products. The Company’s principal products include the following: • DEFINITY is a microbubble contrast agent used in ultrasound exams of the heart, also known as echocardiography exams. DEFINITY contains perflutren-containing lipid microspheres and is indicated in the U.S. for use in patients with suboptimal echocardiograms to assist in imaging the left ventricular chamber and left endocardial border of the heart in ultrasound procedures • TechneLite is a Technetium generator that provides the essential nuclear material used by radiopharmacies to radiolabel Cardiolite, Neurolite and other Technetium-based radiopharmaceuticals used in nuclear medicine procedures. TechneLite uses Moly as its active ingredient. Sales of the Company’s microbubble contrast agent, DEFINITY, are made in the U.S. and Canada through a DEFINITY direct sales team. In the U.S., the Company’s nuclear imaging products, including TechneLite, Xenon, Neurolite and Cardiolite, are primarily distributed through commercial radiopharmacies, the majority of which are controlled by or associated with Cardinal, UPPI, GE Healthcare and Triad. A small portion of the Company’s nuclear imaging product sales in the U.S. are made through the Company’s direct sales force to hospitals and clinics that maintain their own in-house radiopharmaceutical preparation capabilities. The Company owns one radiopharmacy in Puerto Rico where they sell their own products as well as products of third parties to end-users. The Company also maintains its own direct sales force in Canada for certain customers so that they can control the importation, marketing, distribution and sale of its imaging agents in Canada in this sales channel. In Europe, Australia, Asia-Pacific and Latin America, the Company relies on third-party distributors to market, sell and distribute its nuclear imaging and contrast agent products, either on a country-by-country basis or on a multi-country regional basis.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. GAAP. The consolidated financial statements include the accounts of the Company and its direct and indirect wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Reclassifications Certain immaterial reclassifications in the prior period consolidated statement of cash flows have been reclassified to conform to the current year period financial statement presentation. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the consolidated financial statements, and the reported amounts of revenues and expenses during the reporting period. The more significant estimates reflected in the Company’s consolidated financial statements include, but are not limited to, certain judgments regarding revenue recognition, goodwill, tangible and intangible asset valuation, inventory valuation, asset retirement obligations, income tax liabilities and related indemnification receivable, deferred tax assets and liabilities and accrued expenses. Actual results could materially differ from those estimates or assumptions. Revenue Recognition The Company recognizes revenue when it transfers control of promised goods or services to its customers in an amount that reflects the consideration to which the Company expects to be entitled to in exchange for those goods and services. See Note 3, “Revenue from Contracts with Customers” for further discussion on revenues. Accounts Receivable, net Accounts receivable consist of amounts billed and currently due from customers. The Company maintains an allowance for doubtful accounts for estimated losses. In determining the allowance, consideration includes the probability of recoverability based on past experience and general economic factors. Certain accounts receivable may be fully reserved when the Company becomes aware of any specific collection issues. Also included in accounts receivable are miscellaneous receivables of $0.3 million and $0.8 million as of December 31, 2018 and 2017 , respectively. Income Taxes The Company accounts for income taxes using an asset and liability approach. Income tax expense (benefit) represents income taxes paid or payable for the current year plus the change in deferred taxes during the year. Deferred taxes result from differences between the financial and tax bases of the Company’s assets and liabilities. Deferred tax assets and liabilities are measured using the currently enacted tax rates that apply to taxable income in effect for the years in which those tax attributes are expected to be recovered or paid, and are adjusted for changes in tax rates and tax laws when such changes are enacted. The Company recognizes deferred tax assets to the extent that the Company believes that these assets are more-likely-than-not to be realized. Valuation allowances are recorded to reduce deferred tax assets when it is more-likely-than-not that the future tax benefit will not be realized. The assessment of whether or not a valuation allowance is required involves weighing both positive and negative evidence, including both historical and prospective information, with greater weight given to evidence that is objectively verifiable. A history of recent losses is negative evidence that is difficult to overcome with positive evidence. In evaluating prospective information there are four sources of taxable income: reversals of taxable temporary differences, items that can be carried back to prior tax years (such as net operating losses), pre-tax income, and prudent and feasible tax planning strategies. Adjustments to the deferred tax valuation allowances are made in the period when those assessments are made. The Company accounts for uncertain tax positions using a 2-step recognition threshold and measurement analysis method to determine the financial statement impact of uncertain tax positions taken or expected to be taken in a tax return. Differences between tax positions taken in a tax return and amounts recognized in the financial statements are recorded as adjustments to other long-term assets and liabilities, or adjustments to deferred taxes, or both. The Company records the related interest and penalties to income tax expense (benefit). Net Income per Common Share Basic earnings per common share is computed by dividing net income by the weighted-average number of shares of common stock outstanding during the period. Diluted earnings per common share is computed by dividing net income by the weighted-average number of shares of common stock outstanding during the period, plus the potential dilutive effect of other securities if those securities were converted or exercised. During periods in which the Company incurs net losses, both basic and diluted loss per common share is calculated by dividing the net loss by the weighted-average shares of common stock outstanding and potentially dilutive securities are excluded from the calculation because their effect would be antidilutive. Cash and Cash Equivalents Cash and cash equivalents include savings deposits, certificates of deposit and money market funds that have original maturities of three months or less when purchased. Concentration of Risks and Limited Suppliers Financial instruments which potentially subject the Company to concentrations of credit risk consist principally of trade accounts receivable. The Company periodically reviews its accounts receivable for collectability and provides for an allowance for doubtful accounts to the extent that amounts are not expected to be collected. The Company sells primarily to large national distributors, which in turn, resell the Company’s products. As of December 31, 2018 and 2017, one customer accounted for approximately 11% and 15% , respectively, of accounts receivable, net. No customer accounted for greater than 10% of revenues for the year ended December 31, 2018 . Three customers accounted for approximately 12% , 10% and 10% of revenues for the year ended December 31, 2017 . Two customers accounted for approximately 11% and 10% of revenues for the year ended December 31, 2016 . The Company relies on certain materials used in its development and manufacturing processes, some of which are procured from only one or a few sources. The failure of one of these suppliers to deliver on schedule could delay or interrupt the manufacturing or commercialization process and would adversely affect the Company’s operating results. In addition, a disruption in the commercial supply of, or a significant increase in the cost of one of the Company’s materials from these sources could have a material adverse effect on the Company’s business, financial position and results of operations. The Company has Moly supply agreements with IRE of Belgium, running through December 31, 2019, and renewable by us on a year-to-year basis thereafter, and NTP of South Africa, for itself and on behalf of its subcontractor ANSTO of Australia, running through December 31, 2020. The Company also has a Xenon supply agreement with IRE which runs through June 30, 2019, also subject to extensions. The Company currently relies on IRE as the sole supplier of bulk-unprocessed Xenon which the Company processes and finishes for its customers. The Company currently relies on JHS as its sole source manufacturer of DEFINITY, Neurolite, Cardiolite and evacuation vials for TechneLite. The following table sets forth revenues for each of the Company’s products representing 10% or more of revenues: Year Ended December 31, 2018 2017 2016 DEFINITY 53.3% 47.5% 43.6% TechneLite 28.8% 31.6% 32.9% Inventory Inventory includes material, direct labor and related manufacturing overhead and is stated at the lower of cost or market on a first-in, first-out basis. The Company assesses the recoverability of inventory to determine whether adjustments for excess and obsolete inventory are required. Inventory that is in excess of future requirements is written down to its estimated net realizable value based on product shelf life, forecasted demand and other factors. Inventory costs associated with product that has not yet received regulatory approval are capitalized if the Company believes there is probable future commercial use of the product and future economic benefits of the asset. If future commercial use of the product is not probable, then inventory costs associated with such product are expensed as incurred. At December 31, 2018 and 2017 , the Company had no capitalized inventories associated with product that did not have regulatory approval. Property, Plant and Equipment, net Property, plant & equipment are stated at cost. Replacements of major units of property are capitalized, and replaced properties are retired. Replacements of minor components of property and repair and maintenance costs are charged to expense as incurred. Certain costs to obtain or develop computer software are capitalized and amortized over the estimated useful life of the software. Depreciation and amortization is computed on a straight-line basis over the estimated useful lives of the related assets. The estimated useful lives of the major classes of depreciable assets are as follows: Class Range of Estimated Useful Lives Buildings 10 - 50 years Land improvements 15 - 40 years Machinery and equipment 3 - 15 years Furniture and fixtures 15 years Leasehold improvements Lesser of lease term or 15 years Computer software 3 - 5 years Upon retirement or other disposal of property, plant & equipment, the cost and related amount of accumulated depreciation are removed from the asset and accumulated depreciation accounts, respectively. The difference, if any, between the net asset value and the proceeds is included in operating income. Included within machinery, equipment and fixtures are spare parts. Spare parts include replacement parts relating to plant & equipment and are either recognized as an expense when consumed or reclassified and capitalized as part of the related asset and depreciated over the remaining useful life of the related asset. Goodwill Goodwill is not amortized but is instead tested for impairment at least annually and whenever events or circumstances indicate that it is more likely-than-not that they may be impaired. The Company has elected to perform the annual test for goodwill impairment as of October 31 of each year. All goodwill has been allocated to the U.S. reporting unit. In performing the Company’s annual assessment, the Company is permitted to first perform a qualitative test and if necessary, perform a quantitative test. If the Company is required to perform the quantitative impairment test of goodwill, the Company compares the fair value of a reporting unit to its carrying value. If the reporting unit’s carrying value exceeds its fair value, the Company would record an impairment loss to the extent that the carrying value of goodwill exceeds its implied fair value. The Company estimates the fair value of its reporting unit using discounted cash flow or other valuation models, such as comparative transactions and market multiples. The Company did not recognize any goodwill impairment charges during the years ended December 31, 2018, 2017 or 2016. Intangible and Long-Lived Assets The Company tests intangible and long-lived assets for recoverability whenever events or changes in circumstances suggest that the carrying value of an asset or group of assets may not be recoverable. The Company measures the recoverability of assets to be held and used by comparing the carrying amount of the asset to future undiscounted net cash flows expected to be generated by the asset. If those assets are considered to be impaired, the impairment equals the amount by which the carrying amount of the assets exceeds the fair value of the assets. Any impairments are recorded as permanent reductions in the carrying amount of the assets. Long-lived assets, other than goodwill and other intangible assets that are held for sale are recorded at the lower of the carrying value or the fair market value less the estimated cost to sell. Intangible assets, consisting of patents, trademarks and customer relationships related to the Company’s products are amortized in a method equivalent to the estimated utilization of the economic benefit of the asset. Contingencies In the normal course of business, the Company is subject to loss contingencies, such as legal proceedings and claims arising out of its business, that cover a wide range of matters, including, among others, product and environmental liability. The Company records accruals for those loss contingencies when it is probable that a liability will be incurred and the amount of loss can be reasonably estimated. The Company does not recognize gain contingencies until realized. Fair Values of Financial Instruments The estimated fair values of the Company’s financial instruments, including its cash and cash equivalents, accounts receivable, accounts payable and accrued expenses approximate the carrying values of these instruments due to their short term nature. The estimated fair value of the Company’s long term debt approximates its carrying values as the applicable interest rates are subject to change with market interest rates. Advertising and Promotion Costs Advertising and promotion costs are expensed as incurred. During the years ended December 31, 2018 , 2017 and 2016 , the Company incurred $4.0 million , $4.4 million and $3.6 million , respectively in advertising and promotion costs, which are included in sales and marketing in the consolidated statements of operations. Research and Development Research and development costs are expensed as incurred and relate primarily to the development of new products to add to the Company’s portfolio and costs related to its medical affairs and medical information functions. Nonrefundable advance payments for goods or services that will be used or rendered for future research and development activities are deferred and recognized as an expense as the goods are delivered or the related services are performed. Foreign Currency The consolidated statements of operations of the Company’s foreign subsidiaries are translated into U.S. Dollars using weighted-average exchange rates. The net assets of the Company’s foreign subsidiaries are translated into U.S. Dollars using the end of period exchange rates. The impact from translating the net assets of these subsidiaries at changing rates are recorded in the foreign currency translation adjustment account, which is included in accumulated other comprehensive loss in the consolidated balance sheets. Remeasurement of the Company’s foreign currency denominated transactions are included in net income. Transaction gains and losses are reported as a component of o ther income , in the consolidated statements of operations. Stock-Based Compensation The Company’s stock-based compensation cost is measured at the grant date of the stock-based award based on the fair value of the award and is recognized as expense over the requisite service period, which generally represents the vesting period, and includes an estimate of the awards that will be forfeited. The Company estimates the fair value of each stock-based award on its measurement date using either the current market price of the stock, the Black-Scholes option valuation model or the Monte Carlo Simulation valuation model, whichever is most appropriate. The Black-Scholes and Monte Carlo Simulation valuation models incorporate assumptions such as stock price volatility, the expected life of options or awards, a risk-free interest rate and dividend yield. Expense for performance restricted stock awards is recognized based upon the fair value of the awards on the date of grant and the number of shares expected to vest based on the terms of the u nderlying award agreement and the requisite service period(s). Other Income Other income consisted of the following: Years Ended December 31, (in thousands) 2018 2017 2016 Foreign currency losses (gains) $ 557 $ (253 ) $ 853 Tax indemnification income (2,855 ) (8,367 ) (1,055 ) Other income (167 ) (18 ) (18 ) Total other income $ (2,465 ) $ (8,638 ) $ (220 ) Comprehensive Income (Loss) Comprehensive income (loss) consists of net income and other gains and losses affecting stockholders’ equity that, under U.S. GAAP, are excluded from net income. For the Company, other comprehensive income (loss) consists of foreign currency translation gains and losses. The accumulated other comprehensive loss balance consists entirely of foreign currency translation gains and losses. Asset Retirement Obligations The Company’s compliance with federal, state, local and foreign environmental laws and regulations may require it to remove or mitigate the effects of the disposal or release of chemical substances in jurisdictions where it does business or maintains properties. The Company establishes accruals when those costs are legally obligated and probable and can be reasonably estimated. Accrual amounts are estimated based on currently available information, regulatory requirements, remediation strategies, historical experience, the relative shares of the total remediation costs and a relevant discount rate, when the time periods of estimated costs can be reasonably predicted. Changes in these assumptions could impact the Company’s future reported results. The Company has identified conditional asset retirement obligations related to the future removal and disposal of asbestos contained in certain of the buildings located on the Company’s North Billerica, Massachusetts campus. The asbestos is appropriately contained, and the Company believes it is compliant with all applicable environmental regulations. If these properties undergo major renovations or are demolished, certain environmental regulations are in place, which specify the manner in which asbestos must be handled and disposed. The Company is required to record the fair value of these conditional liabilities if they can be reasonably estimated. As of December 31, 2018 and 2017 , sufficient information was not available to estimate a liability for such conditional asset retirement obligations as the obligations to remove the asbestos from these properties have indeterminable settlement dates. As such, no liability for conditional asset retirement obligations has been recorded in the accompanying consolidated balance sheets as of December 31, 2018 and 2017 . Self-Insurance Reserves The Company’s consolidated balance sheets at December 31, 2018 and 2017 include $0.6 million and $0.5 million of accrued liabilities associated with employee medical costs that are retained by the Company. The Company estimates the required liability of those claims on an undiscounted basis based upon various assumptions which include, but are not limited to, the Company’s historical loss experience and projected loss development factors. The required liability is also subject to adjustment in the future based upon changes in claims experience, including changes in the number of incidents (frequency) and change in the ultimate cost per incident (severity). The Company also maintains a separate cash account to fund these medical claims and must maintain a minimum balance as determined by the plan administrator. The balance of this restricted cash account was approximately $0.1 million at both December 31, 2018 and 2017 , and is included in other current assets. Recent Accounting Pronouncements Standard Description Effective Date for Company Effect on the Consolidated Financial Statements Recently Issued Accounting Standards Not Yet Adopted ASU 2016-02, Leases (Topic 842) This ASU supersedes existing guidance on accounting for leases in Leases (Topic 840) and generally requires all leases to be recognized on the balance sheet. The provisions of ASU 2016-02 are effective for annual reporting periods beginning after December 15, 2018; early adoption is permitted. In July 2018, an amendment was made that allows companies the option of using the effective date of the new standard as the initial application date (at the beginning of the period in which it is adopted, rather than at the beginning of the earliest comparative period). January 1, 2019 The Company has completed its assessment on the impact of the standard, including optional practical expedients and transition methods that the Company will elect upon adoption. The implementation plan included identifying the Company’s lease population, assessing significant leases under the new guidance and identifying changes to processes and controls. The Company concluded that upon adoption of this standard there will not be a significant impact to its Balance Sheet. The Company will utilize the prospective approach of adopting this standard. The Company has identified and implemented appropriate changes to its business processes and controls to support recognition and disclosure under this standard. Standard Description Effective Date for Company Effect on the Consolidated Financial Statements Accounting Standards Adopted During the Year Ended December 31, 2018 ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting This ASU clarifies when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new guidance, modification accounting is required only if the fair value, vesting conditions or classification of the award (as equity or liability) changes as a result of the change in terms or conditions. January 1, 2018 The adoption of this standard did not have a material impact on the Company’s consolidated financial statements. ASU 2014-09, Revenue from Contracts with Customers (Topic 606) and related amendments This ASU and related amendments affect any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets, unless those contracts are within the scope of other standards. The guidance in this ASU supersedes the revenue recognition requirements in Topic 605, Revenue Recognition and most industry-specific guidance. The core principle of the guidance is that an entity should recognize revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. January 1, 2018 See Note 3, "Revenue from Contracts with Customers" for the required disclosures related to the impact of adopting this standard. The adoption of this standard did not have a material impact on the Company’s consolidated balance sheets and statements of operations.

Revenue from Contracts with Cus

Revenue from Contracts with Customers	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customers	Revenue from Contracts with Customers Adoption of ASC Topic 606, “Revenue from Contracts with Customers” The Company adopted ASC 606 on January 1, 2018 using the modified retrospective method for all contracts not completed as of the date of adoption. The reported results for 2018 reflect the application of ASC 606 guidance while the reported results for 2017 were prepared under the guidance of ASC 605. For the Company’s accounting policy for revenue recognition under ASC 605, refer to Item 8 of the Annual Report on Form 10-K for the year ended December 31, 2017. The adoption of ASC 606 did not have a material impact on the Company’s consolidated balance sheet, results of operations, equity or cash flows as of the adoption date or for the periods presented. Revenue Recognition In accordance with ASC 606, revenue is recognized when a customer obtains control of promised goods or services. The amount of revenue recognized reflects the consideration to which the Company expects to be entitled to receive in exchange for these goods or services. To achieve this core principle, the Company applies the following five steps: (1) identify the contracts with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the Company satisfies a performance obligation. Disaggregation of Revenue The following table summarizes revenue by revenue source and reportable segment as follows: Year Ended December 31, 2018 Major Products/Service Lines (in thousands) U.S. International Total Product revenue, net (1) $ 288,580 $ 52,556 $ 341,136 License and royalty revenues — 2,238 2,238 Total revenues $ 288,580 $ 54,794 $ 343,374 _ _____________________________ (1) The Company’s principal products include DEFINITY and TechneLite and are categorized within product revenue, net. The Company applies the same revenue recognition policies and judgments for all of its principal products. Product Revenue, Net The Company sells its products principally to hospitals and clinics, radiopharmacies and distributors. The Company considers customer purchase orders, which in some cases are governed by master sales or group purchasing organization agreements, to be the contracts with a customer. For each contract, the Company considers the promise to transfer products, each of which is distinct, to be the identified performance obligations. In determining the transaction price, the Company evaluates whether the price is subject to refund or adjustment to determine the net consideration to which the Company expects to be entitled. The Company typically invoices customers upon satisfaction of identified performance obligations. As the Company’s standard payment terms are 30 to 60 days from invoicing, the Company has elected to use the significant financing component practical expedient under ASC 606-10-32-18. The Company allocates the transaction price to each distinct product based on their relative standalone selling price. The product price as specified on the purchase order is considered the standalone selling price as it is an observable input which depicts the price as if sold to a similar customer in similar circumstances. Revenue is recognized when control of the product is transferred to the customer (i.e., when the Company’s performance obligation is satisfied), which typically occurs upon delivery to the customer. Further, in determining whether control has transferred, the Company considers if there is a present right to payment and legal title, along with risks and rewards of ownership having transferred to the customer. Frequently, the Company receives orders for products to be delivered over multiple dates that may extend across several reporting periods. The Company invoices for each delivery upon shipment and recognizes revenues for each distinct product delivered, assuming transfer of control has occurred. The Company generally does not separately charge customers for shipping and handling costs, but any shipping and handling costs charged to customers are included in product revenue, net. Taxes collected from customers relating to product sales and remitted to governmental authorities are excluded from revenues. Variable Consideration Revenues from product sales are recorded at the net sales price (transaction price), which includes estimates of variable consideration for which reserves are established for discounts, returns, rebates and allowances that are offered within contracts between the Company and its customers. These reserves are based on the amounts earned or to be claimed on the related sales and are classified as a current liability. Where appropriate, these estimates take into consideration a range of possible outcomes which are probability-weighted for relevant factors such as the Company’s historical experience, current contractual and statutory requirements, specific known market events and trends, industry data and forecasted customer buying and payment patterns. Overall, these reserves reflect the Company’s best estimates of the amount of consideration to which it is entitled based on the terms of the contract. The amount of variable consideration which is included in the transaction price may be constrained, and is included in the net sales price only to the extent that it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur in a future period. Actual amounts of consideration ultimately received may differ from the Company’s estimates. If actual results in the future vary from the Company’s estimates, the Company adjusts these estimates, which would affect product revenue and earnings in the period such variances become known. Rebates and Allowances : The Company provides certain customers with rebates and allowances that are explicitly stated in the Company’s contracts and are recorded as a reduction of revenue in the period the related product revenue is recognized. The Company establishes a liability for such amounts, which is included in accrued expenses in the accompanying consolidated balance sheets. These rebates and allowances result from performance-based offers that are primarily based on attaining contractually specified sales volumes and administrative fees the Company is required to pay to group purchasing organizations. The Company estimates the amount of rebates and allowances that are explicitly stated in the Company’s contracts based on a combination of actual purchases and an estimate of the customer’s buying patterns. Product Returns : The Company generally offers customers a limited right of return due to non-conforming product. The Company estimates the amount of its product sales that may be returned by its customers and records this estimate as a reduction of revenue in the period the related product revenue is recognized. The Company currently estimates product return liabilities using its historical product return information and considers other factors that it believes could significantly impact its expected returns, including product recalls. Reserves for product returns are not significant to the Company due to the nature of its products including radiopharmaceutical products with limited half-lives. The following table summarizes activity for reserves relating to rebate and allowances (including group purchasing organization administrative fees and returns) for the year ended December 31, 2018 : (in thousands) Rebates and Balance, January 1, 2018 2,860 Provision related to current period revenues 13,202 Adjustments relating to prior period revenues (361 ) Payments or credits made during the period (11,047 ) Balance, December 31, 2018 $ 4,654 License and Royalty Revenues The Company has entered into licensing agreements, which are within the scope of ASC 606, under which it licenses certain rights to third parties. The terms of these arrangements typically include payment to the Company of one or more of the following: non-refundable, up-front license fees; development, regulatory and commercial milestone payments; and royalties on net sales of licensed products. The Company also has distribution licenses which are treated as combined performance obligations with the delivery of its products and are classified as product revenue, net. In determining the appropriate amount of revenue to be recognized as it fulfills its obligations under each of its agreements, the Company performs the five-step approach stated earlier. The Company uses judgment in determining the number of performance obligations in a license agreement by assessing whether the license is distinct or should be combined with another performance obligation, as well as the nature of the license. As part of the accounting for these arrangements, the Company must develop assumptions that require judgment to determine the stand-alone selling price for each performance obligation identified in the contract. The Company uses key assumptions to determine the stand-alone selling price, which may include market conditions, reimbursement rates for personnel costs, development timelines and probabilities of regulatory success. Licenses of intellectual property : If the license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from non-refundable, up-front fees allocated to the license when the license is transferred to the customer and the customer is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time and, if over time, the appropriate method of measuring progress for purposes of recognizing revenue from non-refundable, up-front fees. The Company evaluates the measure of progress each reporting period and, if necessary, adjusts the measure of performance and related revenue recognition. Milestone Payments : At the inception of each arrangement that includes development milestone payments, the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the control of the Company or the licensee, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. The transaction price is then allocated to each performance obligation on a relative stand-alone selling price basis, for which the Company recognizes revenue as or when the performance obligations under the contract are satisfied. At the end of each subsequent reporting period, the Company re-evaluates the probability of achievement of such development milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect license and royalty revenues and earnings in the period of adjustment. At December 31, 2018, the Company is constraining variable consideration related to milestone payments requiring regulatory approvals. Royalty Revenues : For arrangements that include sales-based royalties, including milestone payments based on the level of sales, and the license is deemed to be the predominant item to which the royalties relate, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied). Contract Costs The Company recognizes an asset for incremental costs of obtaining a contract with a customer if it expects to recover those costs. The Company’s sales incentive compensation plans qualify for capitalization since these plans are directly related to sales achieved during a period of time. However, the Company has elected the practical expedient under ASC 340-40-25-4 to expense the costs as they are incurred, within selling and marketing expenses, since the amortization period is less than one year. The Company recognized certain revenues as follows: (in thousands) Year Ended December 31, 2018 Amounts included in the contract liability at the beginning of the period $ 33 Performance obligations satisfied (or partially satisfied) in previous periods $ — The Company’s performance obligations are typically part of contracts that have an original expected duration of one year or less. As such, under the optional exemption provided by ASC 606-10-50-14, the Company is not disclosing the aggregate amount of the transaction price allocated to performance obligations that are unsatisfied (or partially satisfied) as of the end of the reporting period.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. In order to increase consistency and comparability of fair value measurements, financial instruments are categorized based on a hierarchy that prioritizes observable and unobservable inputs used to measure fair value into three broad levels, which are described below: • Level 1 — Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. • Level 2 — Inputs include quoted prices for similar assets and liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability (i.e., interest rates, yield curves, etc.) and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market corroborated inputs). • Level 3 — Unobservable inputs that reflect a Company’s estimates about the assumptions that market participants would use in pricing the asset or liability. The Company develops these inputs based on the best information available, including its own data. The Company’s financial assets measured at fair value on a recurring basis consist of money market funds. The Company invests excess cash from its operating cash accounts in overnight investments and reflects these amounts in cash and cash equivalents in the consolidated balance sheets at fair value using quoted prices in active markets for identical assets. The tables below present information about the Company’s assets and liabilities measured at fair value on a recurring basis: December 31, 2018 (in thousands) Total Fair Level 1 Level 2 Level 3 Money market $ 61,391 $ 61,391 $ — $ — Total $ 61,391 $ 61,391 $ — $ — December 31, 2017 (in thousands) Total Fair Value Level 1 Level 2 Level 3 Money market $ 8,700 $ 8,700 $ — $ — Total $ 8,700 $ 8,700 $ — $ — Nonrecurring Fair Value Measurements As of December 31, 2017, the Company wrote down the value of land held for sale in the U.S. segment to its fair value, less estimated costs to sell, using level 3 inputs. See Note 8, “Property, Plant and Equipment, Net” for further discussion regarding land held for sale.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The components of income before income taxes is summarized as follows: Year Ended December 31, (in thousands) 2018 2017 2016 U.S. $ 46,945 $ 39,559 $ 23,736 International 2,603 80 4,558 Income before income taxes $ 49,548 $ 39,639 $ 28,294 The income tax expense (benefit) is summarized as follows: Year Ended December 31, (in thousands) 2018 2017 2016 Current Federal $ (21 ) $ (58 ) $ (91 ) State 3,424 3,242 1,689 International (135 ) 16 (49 ) 3,268 3,200 1,549 Deferred Federal 7,821 (71,742 ) — State 1,411 (15,220 ) — International (3,470 ) 16 (17 ) 5,762 (86,946 ) (17 ) Income tax expense (benefit) $ 9,030 $ (83,746 ) $ 1,532 The reconciliation of income taxes at the U.S. federal statutory rate to the actual income taxes is as follows: Year Ended December 31, (in thousands) 2018 2017 2016 U.S. statutory rate $ 10,405 $ 13,873 $ 9,903 Permanent items 505 (1,916 ) (570 ) Write-off of foreign tax and research credits — — 7,125 Foreign tax credits — — (319 ) Uncertain tax positions 3,227 3,128 1,529 Other tax credits (742 ) (175 ) 90 State and local taxes 2,125 1,252 433 Impact of rate change on deferred taxes — 45,129 (383 ) True-up of prior year tax — 7 (2,751 ) Foreign tax rate differential 30 97 (242 ) Valuation allowance (4,073 ) (141,094 ) (13,292 ) Benefit of windfall related to stock compensation (1,760 ) (2,723 ) — Increase in indemnification deferred tax asset (731 ) (1,055 ) — Other 44 (269 ) 9 Income tax expense (benefit) $ 9,030 $ (83,746 ) $ 1,532 The components of deferred income tax assets (liabilities) are as follows: December 31, (in thousands) 2018 2017 Deferred Tax Assets Federal benefit of state tax liabilities $ 7,809 $ 7,510 Reserves, accruals and other 11,005 9,251 Inventory obsolescence 428 239 Capitalized research and development 7,491 9,941 Amortization of intangibles other than goodwill 2,809 3,903 Net operating loss carryforwards 55,938 63,202 Depreciation — 972 Deferred tax assets 85,480 95,018 Deferred Tax Liabilities Reserves, accruals and other (1,078 ) (1,346 ) Customer relationships (986 ) (1,294 ) Depreciation (727 ) — Deferred tax liability (2,791 ) (2,640 ) Less: valuation allowance (1,240 ) (5,368 ) $ 81,449 $ 87,010 Recorded in the accompanying consolidated balance sheets as: Noncurrent deferred tax assets $ 81,449 $ 87,010 On December 22, 2017, the United States enacted the Tax Cuts and Jobs Act of 2017 (the “Act”). The Act is significant and has wide-ranging effects. The Company has completed its study of the ramifications of the Act, and has confirmed the primary material impact of the Act to be the remeasurement of the Company’s deferred tax assets, which was recorded in fiscal 2017 as a result of the reduction in U.S. corporate tax rates from 35% to 21%. As of December 31, 2017, the Company determined it had no accumulated unrepatriated foreign earnings, and therefore recorded no liability for the repatriation transition tax. The Company has also completed its evaluation of and accounting for all other relevant changes resulting from the Act, and has determined that through December 31, 2018, these changes do not materially impact the Company's effective tax rate. The Company regularly assesses its ability to realize its deferred tax assets. Assessing the realizability of deferred tax assets requires significant management judgment. In determining whether its deferred tax assets are more-likely-than-not realizable, the Company evaluated all available positive and negative evidence, and weighed the objective evidence and expected impact. During the fourth quarter of fiscal year 2018, the Company's Canada subsidiary entered an accumulated three year period of profitability, removing a strong item of negative evidence previously supporting the recording of a full valuation allowance. Management has determined that the weight of the relevant positive evidence now outweighs the negative evidence, and has released the valuation allowance against its Canada subsidiary's net deferred tax assets, resulting in an income tax benefit of $4.0 million in fiscal 2018. The Company continues to record a valuation allowance of $1.2 million against the net deferred tax assets of its U.K. subsidiary. During the fourth quarter of 2017, the Company determined based on its consideration of the weight of positive and negative evidence that there was sufficient positive evidence that its U.S. federal and state deferred tax assets were more-likely-than-not realizable. The Company’s conclusion was primarily driven by the achievement of a sustained level of U.S. profitability, the expectation of sustained future profitability, and mitigating factors related to external supplier and customer risk sufficient to outweigh the available negative evidence. Accordingly, the Company released the valuation allowance previously recorded against its U.S. net deferred tax assets, resulting in a fiscal 2017 income tax benefit of $141.1 million . The Company will continue to assess the level of the valuation allowance required. If the weight of negative evidence exists in future periods to again support the recording of a partial or full valuation allowance against the Company’s deferred tax assets, there would likely be a material negative impact on the Company’s results of operations in that future period. A summary of the changes in the Company’s valuation allowance is summarized below: (in thousands) Amount Balance, January 1, 2017 $ 140,915 Charged to income tax expense (benefit) 2,305 Adoption of ASU 2016-09 2,929 Foreign currency 313 Release valuation allowance (141,094 ) Balance, December 31, 2017 5,368 Charged to income tax expense (benefit) (103 ) Foreign currency (56 ) Release valuation allowance (3,969 ) Balance, December 31, 2018 $ 1,240 The Company’s U.S. federal income tax returns are subject to examination for three years. The state and foreign income tax returns are subject to examination for periods varying from three to four years depending on the specific jurisdictions’ statutes of limitation. At December 31, 2018 , the Company has U.S. federal net operating loss carryovers of $207.2 million , which will expire between 2032 and 2037 , and U.S. federal research credits of $0.4 million which will begin to expire in 2037. The Company has Massachusetts state research credit carryforwards of $2.8 million , which will expire between 2024 and 2033. The Company has Massachusetts investment tax credit carryforwards of $1.4 million , of which $0.6 million have no expiration date, and the remainder of which will begin to expire in 2019 and fully expire in 2021. A reconciliation of the Company’s changes in uncertain tax positions for 2018 and 2017 is as follows: (in thousands) Amount Balance of uncertain tax positions as of January 1, 2017 $ 10,441 Additions related to current year tax positions — Reductions related to prior year tax positions (506 ) Settlements — Lapse of statute of limitations (69 ) Balance of uncertain tax positions as of December 31, 2017 9,866 Additions related to current year tax positions — Reductions related to prior year tax positions (4 ) Settlements — Lapse of statute of limitations (74 ) Balance of uncertain tax positions as of December 31, 2018 $ 9,788 As of December 31, 2018 and 2017 , total liabilities for uncertain tax positions including interest and penalties were $40.2 million and $37.0 million , respectively, consisting of uncertain tax positions of $9.8 million and $9.9 million , interest accruals of $28.2 million and $24.9 million , and penalty accruals of $2.2 million and $2.2 million , respectively. As of December 31, 2018 , all of the liabilities were included in other long-term liabilities, and as of December 31, 2017, $36.3 million were included in other long-term liabilities, while $0.7 million reduced the Company’s deferred tax assets. Included in the 2018 , 2017 and 2016 tax provisions are $3.2 million , $3.1 million and $1.5 million , respectively, relating to interest and penalties, net of benefits for reversals of uncertain tax positions, interest and penalties, recognized upon settlements or lapses of relevant statutes of limitation. In connection with the Company’s acquisition of the medical imaging business from BMS in 2008, the Company entered into a tax indemnification agreement with BMS. A long-term receivable is recorded to account for the expected value to the Company of future indemnification payments, net of actual tax benefits received. The tax indemnification receivable is recognized within other long-term assets. The total long-term asset related to the indemnification was $29.5 million and $26.3 million at December 31, 2018 and 2017 , respectively. The changes in the tax indemnification asset are recognized within other income in the consolidated statement of operations. In accordance with the Company’s accounting policy, the change in the tax liability, penalties and interest associated with these obligations (net of any offsetting federal or state benefit) is recognized within income tax expense. Accordingly, as these reserves change, adjustments are included in income tax expense while the offsetting adjustment is included in other income. Assuming that the receivable from BMS continues to be considered recoverable by the Company, there will be minimal effect on net income and no net cash outflows related to these liabilities. During the year ended December 31, 2018 and 2017, BMS made no payments on behalf of the Company with respect to indemnified contingent tax liabilities. In 2016 , BMS made payments on behalf of the Company totaling $0.7 million to several states in connection with prior year state income tax filings. The amount due from BMS as of December 31, 2018, increased by $3.3 million , due to the accrual of interest on the existing contingent liabilities. The amount due from BMS, included within other long-term assets, increased by $8.4 million in 2017, primarily due to the decrease in U.S. corporate tax rates effective January 1, 2018. In 2016 , the amount due from BMS decreased by $1.3 million for the year ended December 31, 2016 , which represented the release of asset balances associated with pre-acquisition year-related tax payments made by BMS. Included in other income for the years ended December 31, 2018 , 2017 and 2016 , is tax indemnification income of $2.9 million , $8.4 million and $1.1 million , respectively. For the year ended December 31, 2017 , $6.5 million of the tax indemnification income is related to the impact of the U.S. federal tax rate reduction, and the remainder arises from increases in the indemnified liabilities.

Sales of Certain International

Sales of Certain International Segment Assets	12 Months Ended
	Dec. 31, 2018
Discontinued Operations and Disposal Groups [Abstract]
Sales of Certain International Segment Assets	Sales of Certain International Segment Assets Sale of Certain Canadian Assets During the fourth quarter of 2015, the Company committed to a plan to sell certain assets and liabilities associated with the Company’s Canadian operations in the International Segment. This event qualified for held for sale accounting and the Company determined that the fair value of the net assets being sold significantly exceeded the carrying value as of December 31, 2015. The transaction was finalized in the first quarter of 2016. Effective January 7, 2016, the Canadian subsidiary of the Company entered into an asset purchase agreement (“Canadian Asset Purchase Agreement”) pursuant to which it would sell substantially all of the assets of its Canadian radiopharmacy businesses and Gludef manufacturing and distribution business to one of its existing Canadian radiopharmacy customers. The purchase price for the asset sale was $9.0 million in cash and also included a working capital adjustment of $0.5 million , which was settled in the third quarter of 2016. The Canadian Asset Purchase Agreement contained customary representations, warranties and covenants by each of the parties. Subject to certain limitations, the buyer will be indemnified for damages resulting from breaches or inaccuracies of the Company’s representations, warranties and covenants in the Canadian Asset Purchase Agreement. As part of the transaction, the Company and the buyer also entered into a customary transition services agreement and a long-term supply contract under which the Company will supply the buyer with certain of the Company’s products on commercial terms and under which the buyer has agreed to certain product minimum purchase commitments. The Company does not believe the sale of certain net assets in the international segment constituted a strategic shift that would have a major effect on its operations or financial results. As a result, this transaction is not classified as discontinued operations in the Company’s consolidated financial statements. This sale of assets resulted in a pre-tax book gain of $5.9 million , which is recorded within gain on sales of assets in the accompanying consolidated statements of operations for the year ended December 31, 2016. Sale of Australian Radiopharmacy Servicing Subsidiary Effective August 11, 2016 , the Company entered into a share purchase agreement (“Australian Share Purchase Agreement”) with one of its existing radiopharmacy customers under which it sold all of the stock of its Australian radiopharmacy servicing subsidiary. The aggregate share sale price was AUD $2.0 million (approximately $1.5 million ) in cash and also included a working capital adjustment of approximately AUD $2.0 million (approximately $1.5 million ) for total proceeds of AUD $4.0 million (approximately $ 3.0 million ) from the sale. As a result of this sale, the Company disposed of net assets of $2.2 million , primarily comprised of working capital accounts of $2.0 million . This share sale resulted in an adjusted pre-tax book gain of $0.5 million , which is recorded within gain on sales of assets in the accompanying consolidated statements of operations for the year ended December 31, 2016. As a result of the sale of the Australian subsidiary, the Company reclassified $0.4 million from other comprehensive income to gain on sale of assets in the accompanying consolidated statements of operations for the year ended December 31, 2016. The Australian Share Purchase Agreement contains customary representations, warranties and covenants by each of the parties. Subject to certain limitations, the buyer will be indemnified for damages resulting from breaches or inaccuracies of the Company’s representations, warranties and covenants in the Australian Share Purchase Agreement. As part of the transaction, the Company and the buyer also entered into a long-term supply and distribution contract under which the Company will supply the buyer and its subsidiaries with the Company’s products on commercial terms and under which the buyer has agreed to certain product minimum purchase commitments. The Company does not believe this sale of certain net assets in the international segment constituted a strategic shift that would have a major effect on its operations or financial results. As a result, this transaction is not classified as discontinued operations in the Company’s accompanying consolidated financial statements.

Inventory

Inventory	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory consisted of the following: December 31, (in thousands) 2018 2017 Raw materials $ 11,100 $ 10,447 Work in process 4,261 5,509 Finished goods 17,658 10,124 Total inventory $ 33,019 $ 26,080 As of December 31, 2017 , the Company had $1.1 million of inventory classified within other long-term assets, which represent raw materials not expected to be used by the Company during the next twelve months. As of December 31, 2018 , the Company had no inventory classified within other long-term assets.

Property, Plant & Equipment, Ne

Property, Plant & Equipment, Net	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property, Plant & Equipment, Net	Property, Plant and Equipment, Net Property, plant and equipment, net, consisted of the following: December 31, (in thousands) 2018 2017 Land $ 13,450 $ 13,450 Buildings 64,444 76,059 Machinery, equipment and fixtures 69,298 71,870 Computer software 19,266 20,271 Construction in progress 24,169 7,622 190,627 189,272 Less: accumulated depreciation and amortization (82,739 ) (96,273 ) Total property, plant and equipment, net $ 107,888 $ 92,999 Depreciation and amortization expense related to property, plant & equipment, net, was $10.1 million , $14.8 million and $12.1 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. Long-Lived Assets Held for Sale During the fourth quarter of 2017, the Company committed to a plan to sell a portion of its land in the U.S. segment. This event qualified for held for sale accounting and the land was written down to its fair value, less estimated costs to sell, which is classified in other current assets at December 31, 2017. This resulted in a loss of $0.9 million , which is included within general and administrative expenses in the accompanying consolidated statement of operations. The fair value was estimated utilizing Level 3 inputs and using a market approach, based on available data for transactions in the region, discussions with real estate brokers and the asking price of comparable properties in its principal market. During the first quarter of 2018, the Company completed the sale of the land for proceeds of $1.0 million .

Asset Retirement Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2018
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations The Company considers its legal obligation to remediate its facilities upon a decommissioning of its radioactive-related operations as an asset retirement obligation. The Company has production facilities which manufacture and process radioactive materials at its North Billerica, Massachusetts and San Juan, Puerto Rico sites. The Company is required to provide the U.S. Nuclear Regulatory Commission and Massachusetts Department of Public Health financial assurance demonstrating the Company’s ability to fund the decommissioning of its North Billerica, Massachusetts production facility upon closure, although the Company does not intend to close the facility. The Company has provided this financial assurance in the form of a $28.2 million surety bond. The fair value of a liability for asset retirement obligations is recognized in the period in which the liability is incurred. As of December 31, 2018 , the liability is measured at the present value of the obligation expected to be incurred, of approximately $26.9 million , and is adjusted in subsequent periods as accretion expense is recorded. The corresponding asset retirement costs are capitalized as part of the carrying values of the related long-lived assets and depreciated over the assets’ useful lives. The following table provides a summary of the changes in the Company’s asset retirement obligations: (in thousands) Amount Balance, January 1, 2018 $ 10,412 Accretion expense 1,160 Balance, December 31, 2018 $ 11,572

Intangibles, Net

Intangibles, Net	12 Months Ended
	Dec. 31, 2018
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Intangibles, Net	Intangibles, Net Intangibles, net, consisted of the following: December 31, 2018 (in thousands) Amortization Cost Accumulated Amortization Net Trademarks Straight-Line $ 13,540 $ (9,856 ) $ 3,684 Customer relationships Accelerated 98,912 (93,463 ) 5,449 Patents Straight-Line 6,570 (6,570 ) — Total $ 119,022 $ (109,889 ) $ 9,133 December 31, 2017 (in thousands) Amortization Cost Accumulated Amortization Net Trademarks Straight-Line $ 13,540 $ (9,304 ) $ 4,236 Customer relationships Accelerated 99,133 (92,072 ) 7,061 Patents Straight-Line 42,780 (42,279 ) 501 Total $ 155,453 $ (143,655 ) $ 11,798 The Company recorded amortization expense for its intangible assets of $2.6 million , $3.3 million and $5.1 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The below table summarizes the estimated aggregate amortization expense expected to be recognized on the above intangible assets: (in thousands) Amount 2019 $ 1,803 2020 1,568 2021 1,309 2022 1,173 2023 579 2024 and thereafter 2,701 Total $ 9,133

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued Expenses and Other Liabilities	Accrued Expenses and Other Liabilities Accrued expenses are comprised of the following: December 31, (in thousands) 2018 2017 Compensation and benefits $ 15,962 $ 14,469 Freight, distribution and operations 7,721 3,604 Accrued rebates, discounts and chargebacks 4,654 2,860 Accrued professional fees 1,673 2,852 Other 2,040 2,751 Total accrued expenses and other liabilities $ 32,050 $ 26,536

Financing Arrangements

Financing Arrangements	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Financing Arrangements	Financing Arrangements On March 30, 2017, the Company refinanced its previous $365 million seven -year term loan agreement (the facility thereunder, the “2015 Term Facility”) with a new five -year $275 million term loan facility (the “2017 Term Facility” and the loans thereunder, the “Term Loans”). In addition, the Company replaced its previous $50 million five -year asset based loan facility (the “ABL Facility”) with a new $75 million five -year revolving credit facility (the “2017 Revolving Facility” and, together with the 2017 Term Facility, the “2017 Facility”). The terms of the 2017 Facility are set forth in that certain Amended and Restated Credit Agreement, dated as of March 30, 2017 (the “Credit Agreement”), by and among Holdings, the Company, the lenders from time to time party thereto and JPMorgan Chase Bank, N.A., as administrative agent and collateral agent. The 2017 Term Facility was issued net of a $0.7 million discount. The Company has the right to request an increase to the 2017 Term Facility or request the establishment of one or more new incremental term loan facilities, in an aggregate principal amount of up to $75 million , plus additional amounts, in certain circumstances. The net proceeds of the 2017 Term Facility, together with approximately $15.3 million of cash on hand, were used to refinance in full the aggregate remaining principal amount of the loans outstanding under the 2015 Term Facility and pay related interest, transaction fees and expenses. No amounts were outstanding under the ABL Facility at that time. The Company accounted for the refinancing as both a debt extinguishment and debt modification by evaluating the refinancing on a creditor by creditor basis. The Company recorded a loss on extinguishment of debt of $2.2 million related to the write-off of unamortized debt issuance costs and incurred general and administrative expenses of $1.7 million related to third-party costs associated with the modified debt. In addition, the Company incurred and capitalized $1.6 million of new debt issuance costs related to the refinancing. On November 29, 2017, the Company entered into Amendment No. 1 (the “Repricing Amendment”) to the 2017 Facility to, among other things, (i) reduce the applicable interest rate margins with respect to the LIBOR and Base Rate Term Loans (as defined in the Credit Agreement) and (ii) reduce the applicable interest rate margins with respect to the LIBOR and Base Rate Revolving Loans (as defined in the Credit Agreement) . The Company accounted for the Repricing Amendment as both a debt extinguishment and debt modification by evaluating the refinancing on a creditor by creditor basis. 2017 Term Facility The Term Loans under the 2017 Term Facility bear interest, with pricing based from time to time at the Company’s election at (i) LIBOR plus a spread of 3.75% or (ii) the Base Rate (as defined in the Credit Agreement) plus a spread of 2.75% . Interest is payable (i) with respect to LIBOR Term Loans, at the end of each Interest Period (as defined in the Credit Agreement) and (ii) with respect to Base Rate Term Loans, at the end of each quarter. At December 31, 2018 , the Company’s interest rate under the 2017 Term Facility was 6.3% . The Company is permitted to voluntarily prepay the Term Loans, in whole or in part. The 2017 Term Facility requires the Company to make mandatory prepayments of the outstanding Term Loans in certain circumstances. The 2017 Term Facility amortizes at 1.00% per year until its June 30, 2022 maturity date. The Company’s maturities of principal obligations under the 2017 Term Facility are as follows as of December 31, 2018 : (in thousands) Amount 2019 2,750 2020 2,750 2021 2,750 2022 261,937 Total principal outstanding 270,187 Unamortized debt discount (1,584 ) Unamortized debt issuance costs (2,144 ) Total 266,459 Less: current portion (2,750 ) Total long-term debt $ 263,709 2017 Revolving Facility Under the terms of the 2017 Revolving Facility, the lenders thereunder agreed to extend credit to the Company from time to time until March 30, 2022 (the “Revolving Termination Date”) consisting of revolving loans (the “Revolving Loans” and, together with the Term Loans, the “Loans”) in an aggregate principal amount not to exceed $75 million (the “Revolving Commitment”) at any time outstanding. The 2017 Revolving Facility includes a $20 million sub-facility for the issuance of letters of credit (the “Letters of Credit”). The Letters of Credit and the borrowings under the 2017 Revolving Facility are expected to be used for working capital and other general corporate purposes. The Revolving Loans under the 2017 Revolving Facility bear interest, with pricing based from time to time at the Company’s election at (i) LIBOR plus a spread of 3.00% or (ii) the Base Rate (as defined in the Credit Agreement) plus a spread of 2.00% . The 2017 Revolving Facility also includes an unused line fee, which is set at 0.38% while the Company’s secured leverage ratio (as defined in the Credit Agreement) is greater than 3.00 to 1.00 and 0.25% when the Company’s secured leverage ratio is less than or equal to 3.00 to 1.00. The Company is permitted to voluntarily prepay the Revolving Loans, in whole or in part, or reduce or terminate the Revolving Commitment, in each case, without premium or penalty. On any business day on which the total amount of outstanding Revolving Loans and Letters of Credit exceeds the total Revolving Commitment, the Company must prepay the Revolving Loans in an amount equal to such excess. As of December 31, 2018 , there were no outstanding borrowings under the 2017 Revolving Facility. 2017 Facility Covenants The 2017 Facility contains a number of affirmative, negative, reporting and financial covenants, in each case subject to certain exceptions and materiality thresholds. The 2017 Facility requires the Company to be in quarterly compliance, measured on a trailing four quarter basis, with a financial covenant. The maximum consolidated leverage ratio permitted by the financial covenant is displayed in the table below: 2017 Facility Financial Covenant Period Consolidated Q1 2019 4.75 to 1.00 Thereafter 4.50 to 1.00 The 2017 Facility contains usual and customary restrictions on the ability of the Company and its subsidiaries to: (i) incur additional indebtedness (ii) create liens; (iii) consolidate, merge, sell or otherwise dispose of all or substantially all of its assets; (iv) sell certain assets; (v) pay dividends on, repurchase or make distributions in respect of capital stock or make other restricted payments; (vi) make certain investments; (vii) repay subordinated indebtedness prior to stated maturity; and (viii) enter into certain transactions with its affiliates. Upon an event of default, the administrative agent under the Credit Agreement will have the right to declare the Loans and other obligations outstanding immediately due and payable and all commitments immediately terminated or reduced. The 2017 Facility is guaranteed by Holdings and Lantheus MI Real Estate, LLC, and obligations under the 2017 Facility are generally secured by first priority liens over substantially all of the assets of each of LMI, Holdings and Lantheus MI Real Estate, LLC (subject to customary exclusions set forth in the transaction documents) owned as of March 30, 2017 or thereafter acquired.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation Equity Incentive Plans As of December 31, 2018 , the Company’s approved equity incentive plans included the 2015 Equity Incentive Plan (“2015 Plan”), the 2013 Equity Incentive Plan (“2013 Plan”), and the 2008 Equity Incentive Plan (“2008 Plan”). These plans are administered by the Board of Directors and permit the granting of stock options, stock appreciation rights, restricted stock, restricted stock units and dividend equivalent rights (“DERs”) to employees, officers, directors and consultants of the Company. The Company has certain stock option and restricted stock awards outstanding under each of its equity incentive plans but, upon adoption of the 2015 Plan, no longer grants new equity awards under its 2008 and 2013 Plans. The Company adopted its 2015 Plan in June 2015 and subsequently amended the plan in April 2017 to increase the common stock reserved for issuance under the plan to an aggregate 5,755,277 shares. Stock-based compensation expense recognized in the consolidated statements of operations is summarized below: Year Ended December 31, (in thousands) 2018 2017 2016 Cost of goods sold $ 1,140 $ 1,692 $ 359 Sales and marketing 1,244 640 339 General and administrative 4,990 2,964 1,438 Research and development 1,344 632 388 Total stock-based compensation expense $ 8,718 $ 5,928 $ 2,524 Stock Options Stock option awards under the 2015 Plan are granted with an exercise price equal to the fair value of the Company’s common stock at the date of grant. All option awards have a ten -year contractual term. A summary of option activity for 2018 is presented below: Total Stock Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Balance at January 1, 2018 565,425 $ 13.65 Options granted — $ — Options exercised (192,550 ) $ 5.98 Options cancelled and expired (15,800 ) $ 20.44 Outstanding at December 31, 2018 357,075 $ 17.50 4.4 535,427 Vested and expected to vest at December 31, 2018 357,075 $ 17.50 4.4 535,427 Exercisable at December 31, 2018 353,049 $ 17.56 4.4 522,423 During the years ended December 31, 2018 , 2017 and 2016 , 192,550 , 465,232 and 40,976 options were exercised having aggregate intrinsic values of $2.4 million , $5.1 million and $0.2 million , respectively. Restricted Stock A summary of restricted stock awards and restricted stock units activity for 2018 is presented below: Shares Weighted- Average Grant Date Fair Value Per Share Nonvested balance at January 1, 2018 1,765,262 $ 5.72 Granted 647,850 $ 15.46 Vested (672,345 ) $ 6.37 Forfeited (232,228 ) $ 11.87 Nonvested balance at December 31, 2018 1,508,539 $ 9.51 As of December 31, 2018 , there was $9.5 million of unrecognized compensation expense related to outstanding restricted stock, which is expected to be recognized over a weighted-average period of 2.2 years. Performance Restricted Stock Awards Performance awards vest based on the requisite service period subject to the achievement of specific financial performance targets. The Company monitors the probability of achieving the performance targets on a quarterly basis and may adjust periodic stock compensation expense accordingly. The performance targets include the achievement of internal performance targets only. A summary of performance restricted stock award activity for 2018 is presented below: Shares Weighted- Nonvested balance at January 1, 2018 291,172 $ 16.70 Granted — $ — Vested — $ — Forfeited (49,292 ) $ 16.62 Nonvested balance at December 31, 2018 241,880 $ 16.71 As of December 31, 2018 , there was $2.9 million of unrecognized compensation expense related to outstanding performance restricted stock which is expected to be recognized over a weighted-average period of 1.2 years. Total Stockholder Return Restricted Stock Awards (“TSR Awards”) During the year ended December 31, 2018, the Company granted total stockholder return (“TSR”) Awards that include a three -year market condition where the performance measurement period is three years. Vesting of the TSR Awards is based on the Company’s level of attainment of specified TSR targets relative to the percentage appreciation of a specified index of companies for the respective three -year period and is also subject to the continued employment of the grantees. The number of shares that are earned over the performance period ranges from 0% to 200% of the initial award. The fair value of these awards are based on a Monte Carlo Simulation valuation model with the following assumptions: Year Ended December 31, 2018 Expected volatility 84.3 % Risk-free interest rate 2.4 % Expected life (in years) 2.8 Expected dividend yield — A summary of TSR Award activity for 2018 is presented below: Shares Weighted- Nonvested balance at January 1, 2018 — $ — Granted 206,896 $ 22.76 Vested — $ — Forfeited (26,983 ) $ 22.76 Nonvested balance at December 31, 2018 179,913 $ 22.76 As of December 31, 2018, there was $3.1 million of unrecognized compensation expense related to outstanding performance restricted stock which is expected to be recognized over a weighted-average period of 2.2 years. Modifications During the years ended December 31, 2018 and 2017, the Company recognized approximately $0.3 million and $1.3 million , respectively, of stock-based compensation expense associated with the modification of awards. The modification of these awards affected the vesting terms of the awards. Employee Stock Purchase Plan In April 2017, the Company’s stockholders approved the 2017 Employee Stock Purchase Plan (“2017 ESPP”), which authorized the issuance of up to 250,000 shares of common stock thereunder. Under the terms of the 2017 ESPP, eligible U.S. employees can elect to acquire shares of the Company’s common stock through periodic payroll deductions during a series of six month offering periods, which will generally begin in March and September of each year. Purchases under the 2017 ESPP are effected on the last business day of each offering period at a 15% discount to the closing price on that day. The 2017 ESPP was implemented, subject to stockholder approval, on March 10, 2017, and the first purchases thereunder were made on September 13, 2017.

Net Income (Loss) Per Common Sh

Net Income (Loss) Per Common Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Net Income (Loss) Per Common Share	Net Income Per Common Share A summary of net income per common share is presented below: Year Ended (in thousands, except per share amounts) 2018 2017 2016 Net income $ 40,518 $ 123,385 $ 26,762 Basic weighted-average common shares outstanding 38,233 37,276 32,044 Effect of dilutive stock options 61 288 612 Effect of dilutive restricted stock 1,207 1,328 — Diluted weighted-average common shares outstanding 39,501 38,892 32,656 Basic income per common share $ 1.06 $ 3.31 $ 0.84 Diluted income per common share $ 1.03 $ 3.17 $ 0.82 Antidilutive securities excluded from diluted net income per common share 424 604 1,563

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Leases and Purchase Commitments The Company leases certain buildings, hardware and office space under operating leases and equipment under capital leases. In addition, the Company has entered into purchasing arrangements in which minimum quantities of goods or services have been committed to be purchased on an annual basis. As of December 31, 2018 , future payments required under noncancelable lease agreements and purchase commitments are as follows: (in thousands) Amount 2019 $ 2,264 2020 259 2021 238 2022 238 2023 238 2024 and thereafter 178 Total $ 3,415 Rent expense was $0.3 million , $0.3 million and $0.4 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. The Company has entered into agreements which contain certain percentage volume purchase requirements. The Company has excluded these future purchase commitments from the table above since there are no minimum purchase commitments or payments under these agreements. Legal Proceedings From time to time, the Company is a party to various legal proceedings arising in the ordinary course of business. In addition, the Company has in the past been, and may in the future be, subject to investigations by governmental and regulatory authorities, which expose it to greater risks associated with litigation, regulatory or other proceedings, as a result of which the Company could be required to pay significant fines or penalties. The costs and outcome of litigation, regulatory or other proceedings cannot be predicted with certainty, and some lawsuits, claims, actions or proceedings may be disposed of unfavorably to the Company. In addition, intellectual property disputes often have a risk of injunctive relief which, if imposed against the Company, could materially and adversely affect its financial condition or results of operations. The Company is currently in arbitration with Pharmalucence in connection with a Manufacturing and Supply Agreement dated November 12, 2013, under which Pharmalucence agreed to manufacture and supply DEFINITY for the Company. The commercial arrangement contemplated by that agreement was repeatedly delayed and ultimately never successfully realized. After extended settlement discussions between Sun Pharma, the ultimate parent of Pharmalucence, and the Company, which did not lead to a mutually acceptable outcome, on November 10, 2017, the Company filed an arbitration demand (and later an amended arbitration demand) with the American Arbitration Association against Pharmalucence, alleging breach of contract, breach of the covenant of good faith and fair dealing, tortious misrepresentation and violation of the Massachusetts Consumer Protection Law, also known as Chapter 93A. The Company is seeking monetary damages but cannot predict the outcome of this dispute resolution proceeding and whether the Company will be able to obtain any financial recovery as a result of this proceeding. As of December 31, 2018, except as disclosed above the Company had no material ongoing litigation in which the Company was a party. In addition, the Company had no material ongoing regulatory or other proceedings and no knowledge of any investigations by government or regulatory authorities in which the Company is a target, in either case that the Company believes could have a material and adverse effect on its current business.

401(k) Plan

401(k) Plan	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
401(k) Plan	401(k) Plan The Company maintains a qualified 401(k) plan (the “401(k) Plan”) for its U.S. employees. The 401(k) Plan covers U.S. employees who meet certain eligibility requirements. Under the terms of the 401(k) Plan, the employees may elect to make tax-deferred contributions through payroll deductions within statutory and plan limits, and the Company may elect to make non-elective discretionary contributions. The Company may also make optional contributions to the 401(k) Plan for any plan year at its discretion. Expense recognized by the Company for matching contributions made to the 401(k) Plan was $1.8 million , $1.8 million and $1.6 million for the years ended December 31, 2018 , 2017 and 2016 , respectively.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Segment Information	Segment Informatio n The Company reports two operating segments, U.S. and International, based on geographic customer base. The results of these operating segments are regularly reviewed by the Company’s chief operating decision maker, the President and Chief Executive Officer. The Company’s segments derive revenues through the manufacture, marketing, selling and distribution of medical imaging products, focused primarily on cardiovascular diagnostic imaging. All goodwill has been allocated to the U.S. operating segment. The Company does not identify or allocate assets to its segments. Selected information regarding the Company’s segments are provided as follows: Year Ended (in thousands) 2018 2017 2016 Revenues from external customers U.S. $ 288,580 $ 290,002 $ 257,420 International 54,794 41,376 44,433 Total revenues from external customers $ 343,374 $ 331,378 $ 301,853 Revenues by product DEFINITY $ 183,073 $ 157,268 $ 131,612 TechneLite 98,858 104,644 99,217 Other 61,443 69,466 71,024 Total revenues $ 343,374 $ 331,378 $ 301,853 Geographical revenues U.S. $ 288,580 $ 290,002 $ 257,420 All other 54,794 41,376 44,433 Total revenues $ 343,374 $ 331,378 $ 301,853 Operating income U.S. $ 56,327 $ 49,239 $ 46,909 International 8,161 2,614 9,679 Operating income 64,488 51,853 56,588 Interest expense 17,405 18,410 26,618 Debt retirement costs — — 1,896 Loss on extinguishment of debt — 2,442 — Other income (2,465 ) (8,638 ) (220 ) Income before income taxes $ 49,548 $ 39,639 $ 28,294 Depreciation and amortization U.S. $ 12,278 $ 17,672 $ 15,995 International 491 517 1,335 Total depreciation and amortization $ 12,769 $ 18,189 $ 17,330 December 31, (in thousands) 2018 2017 Long-lived assets U.S. $ 106,755 $ 91,537 International 1,133 1,462 Total long-lived assets $ 107,888 $ 92,999

Valuation and Qualifying Accoun

Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2018
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation and Qualifying Accounts	Valuation and Qualifying Accounts (in thousands) Balance at Beginning of Year Charged to Income Deductions from Reserves (1) Other Adjustments Balance at End of Year Allowance for doubtful accounts Year ended December 31, 2018 $ 977 $ 321 $ (179 ) $ — $ 1,119 Year ended December 31, 2017 $ 969 $ 136 $ (128 ) $ — $ 977 Year ended December 31, 2016 $ 881 $ 53 $ (30 ) $ 65 $ 969 Rebates and allowances Year ended December 31, 2018 $ 2,860 $ 13,202 $ (11,047 ) $ (361 ) $ 4,654 Year ended December 31, 2017 $ 2,297 $ 9,568 $ (8,351 ) $ (654 ) $ 2,860 Year ended December 31, 2016 $ 2,303 $ 7,255 $ (6,809 ) $ (452 ) $ 2,297 ________________________________ (1) Amounts charged to deductions from allowance for doubtful accounts represent the write-off of uncollectible balances and represent payments for rebates and allowances.

Quarterly Consolidated Financia

Quarterly Consolidated Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly Consolidated Financial Data (Unaudited)	Quarterly Consolidated Financial Data (Unaudited) Summarized quarterly consolidated financial data is presented below: Quarterly Periods During the Year Ended Q1 Q2 Q3 Q4 (in thousands, except per share data) Revenues $ 82,630 $ 85,573 $ 88,900 $ 86,271 Gross profit $ 42,309 $ 43,846 $ 44,885 $ 43,845 Net income $ 8,211 $ 9,745 $ 9,269 $ 13,293 Basic income per weighted-average share (b) $ 0.22 $ 0.25 $ 0.24 $ 0.35 Diluted income per weighted-average share (b) $ 0.21 $ 0.25 $ 0.24 $ 0.34 Quarterly Periods During the Year Ended Q1 Q2 Q3 Q4 (in thousands, except per share data) Revenues $ 81,359 $ 88,837 $ 79,941 $ 81,241 Gross profit $ 39,762 $ 45,947 $ 38,527 $ 37,899 Net income (a) $ 4,138 $ 13,595 $ 8,526 $ 97,126 Basic income per weighted-average share (b) $ 0.11 $ 0.37 $ 0.23 $ 2.58 Diluted income per weighted-average share (b) $ 0.11 $ 0.35 $ 0.22 $ 2.47 ________________________________ (a) Net income for the fourth quarter of 2017 reflects the income tax benefit due to the release of the Company’s valuation allowance of $141.1 million against its deferred tax assets offset by a provision of $45.1 million for remeasuring the Company’s deferred tax assets for the change in tax rates enacted under the Tax Cuts and Jobs Act of 2017. (b) Quarterly and annual computations are prepared independently. Accordingly, the sum of each quarter may not necessarily total the fiscal year period amounts noted elsewhere within this Annual Report on Form 10-K.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. GAAP. The consolidated financial statements include the accounts of the Company and its direct and indirect wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Reclassifications	Reclassifications Certain immaterial reclassifications in the prior period consolidated statement of cash flows have been reclassified to conform to the current year period financial statement presentation.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the consolidated financial statements, and the reported amounts of revenues and expenses during the reporting period. The more significant estimates reflected in the Company’s consolidated financial statements include, but are not limited to, certain judgments regarding revenue recognition, goodwill, tangible and intangible asset valuation, inventory valuation, asset retirement obligations, income tax liabilities and related indemnification receivable, deferred tax assets and liabilities and accrued expenses. Actual results could materially differ from those estimates or assumptions.
Revenue Recognition	Revenue Recognition The Company recognizes revenue when it transfers control of promised goods or services to its customers in an amount that reflects the consideration to which the Company expects to be entitled to in exchange for those goods and services. See Note 3, “Revenue from Contracts with Customers” for further discussion on revenues.
Accounts Receivable	Accounts Receivable, net Accounts receivable consist of amounts billed and currently due from customers. The Company maintains an allowance for doubtful accounts for estimated losses. In determining the allowance, consideration includes the probability of recoverability based on past experience and general economic factors. Certain accounts receivable may be fully reserved when the Company becomes aware of any specific collection issues.
Income Taxes	Income Taxes The Company accounts for income taxes using an asset and liability approach. Income tax expense (benefit) represents income taxes paid or payable for the current year plus the change in deferred taxes during the year. Deferred taxes result from differences between the financial and tax bases of the Company’s assets and liabilities. Deferred tax assets and liabilities are measured using the currently enacted tax rates that apply to taxable income in effect for the years in which those tax attributes are expected to be recovered or paid, and are adjusted for changes in tax rates and tax laws when such changes are enacted. The Company recognizes deferred tax assets to the extent that the Company believes that these assets are more-likely-than-not to be realized. Valuation allowances are recorded to reduce deferred tax assets when it is more-likely-than-not that the future tax benefit will not be realized. The assessment of whether or not a valuation allowance is required involves weighing both positive and negative evidence, including both historical and prospective information, with greater weight given to evidence that is objectively verifiable. A history of recent losses is negative evidence that is difficult to overcome with positive evidence. In evaluating prospective information there are four sources of taxable income: reversals of taxable temporary differences, items that can be carried back to prior tax years (such as net operating losses), pre-tax income, and prudent and feasible tax planning strategies. Adjustments to the deferred tax valuation allowances are made in the period when those assessments are made. The Company accounts for uncertain tax positions using a 2-step recognition threshold and measurement analysis method to determine the financial statement impact of uncertain tax positions taken or expected to be taken in a tax return. Differences between tax positions taken in a tax return and amounts recognized in the financial statements are recorded as adjustments to other long-term assets and liabilities, or adjustments to deferred taxes, or both. The Company records the related interest and penalties to income tax expense (benefit).
Net Income (Loss) per Common Share	Net Income per Common Share Basic earnings per common share is computed by dividing net income by the weighted-average number of shares of common stock outstanding during the period. Diluted earnings per common share is computed by dividing net income by the weighted-average number of shares of common stock outstanding during the period, plus the potential dilutive effect of other securities if those securities were converted or exercised. During periods in which the Company incurs net losses, both basic and diluted loss per common share is calculated by dividing the net loss by the weighted-average shares of common stock outstanding and potentially dilutive securities are excluded from the calculation because their effect would be antidilutive.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents include savings deposits, certificates of deposit and money market funds that have original maturities of three months or less when purchased.
Concentration of Risks and Limited Suppliers	Concentration of Risks and Limited Suppliers Financial instruments which potentially subject the Company to concentrations of credit risk consist principally of trade accounts receivable. The Company periodically reviews its accounts receivable for collectability and provides for an allowance for doubtful accounts to the extent that amounts are not expected to be collected. The Company sells primarily to large national distributors, which in turn, resell the Company’s products. As of December 31, 2018 and 2017, one customer accounted for approximately 11% and 15% , respectively, of accounts receivable, net. No customer accounted for greater than 10% of revenues for the year ended December 31, 2018 . Three customers accounted for approximately 12% , 10% and 10% of revenues for the year ended December 31, 2017 . Two customers accounted for approximately 11% and 10% of revenues for the year ended December 31, 2016 . The Company relies on certain materials used in its development and manufacturing processes, some of which are procured from only one or a few sources. The failure of one of these suppliers to deliver on schedule could delay or interrupt the manufacturing or commercialization process and would adversely affect the Company’s operating results. In addition, a disruption in the commercial supply of, or a significant increase in the cost of one of the Company’s materials from these sources could have a material adverse effect on the Company’s business, financial position and results of operations. The Company has Moly supply agreements with IRE of Belgium, running through December 31, 2019, and renewable by us on a year-to-year basis thereafter, and NTP of South Africa, for itself and on behalf of its subcontractor ANSTO of Australia, running through December 31, 2020. The Company also has a Xenon supply agreement with IRE which runs through June 30, 2019, also subject to extensions. The Company currently relies on IRE as the sole supplier of bulk-unprocessed Xenon which the Company processes and finishes for its customers. The Company currently relies on JHS as its sole source manufacturer of DEFINITY, Neurolite, Cardiolite and evacuation vials for TechneLite.
Inventory	Inventory Inventory includes material, direct labor and related manufacturing overhead and is stated at the lower of cost or market on a first-in, first-out basis. The Company assesses the recoverability of inventory to determine whether adjustments for excess and obsolete inventory are required. Inventory that is in excess of future requirements is written down to its estimated net realizable value based on product shelf life, forecasted demand and other factors. Inventory costs associated with product that has not yet received regulatory approval are capitalized if the Company believes there is probable future commercial use of the product and future economic benefits of the asset. If future commercial use of the product is not probable, then inventory costs associated with such product are expensed as incurred.
Property, Plant & Equipment	Property, Plant and Equipment, net Property, plant & equipment are stated at cost. Replacements of major units of property are capitalized, and replaced properties are retired. Replacements of minor components of property and repair and maintenance costs are charged to expense as incurred. Certain costs to obtain or develop computer software are capitalized and amortized over the estimated useful life of the software. Depreciation and amortization is computed on a straight-line basis over the estimated useful lives of the related assets. The estimated useful lives of the major classes of depreciable assets are as follows: Class Range of Estimated Useful Lives Buildings 10 - 50 years Land improvements 15 - 40 years Machinery and equipment 3 - 15 years Furniture and fixtures 15 years Leasehold improvements Lesser of lease term or 15 years Computer software 3 - 5 years Upon retirement or other disposal of property, plant & equipment, the cost and related amount of accumulated depreciation are removed from the asset and accumulated depreciation accounts, respectively. The difference, if any, between the net asset value and the proceeds is included in operating income. Included within machinery, equipment and fixtures are spare parts. Spare parts include replacement parts relating to plant & equipment and are either recognized as an expense when consumed or reclassified and capitalized as part of the related asset and depreciated over the remaining useful life of the related asset.
Goodwill, Intangibles and Long-Lived Assets	Goodwill Goodwill is not amortized but is instead tested for impairment at least annually and whenever events or circumstances indicate that it is more likely-than-not that they may be impaired. The Company has elected to perform the annual test for goodwill impairment as of October 31 of each year. All goodwill has been allocated to the U.S. reporting unit. In performing the Company’s annual assessment, the Company is permitted to first perform a qualitative test and if necessary, perform a quantitative test. If the Company is required to perform the quantitative impairment test of goodwill, the Company compares the fair value of a reporting unit to its carrying value. If the reporting unit’s carrying value exceeds its fair value, the Company would record an impairment loss to the extent that the carrying value of goodwill exceeds its implied fair value. The Company estimates the fair value of its reporting unit using discounted cash flow or other valuation models, such as comparative transactions and market multiples. The Company did not recognize any goodwill impairment charges during the years ended December 31, 2018, 2017 or 2016. Intangible and Long-Lived Assets The Company tests intangible and long-lived assets for recoverability whenever events or changes in circumstances suggest that the carrying value of an asset or group of assets may not be recoverable. The Company measures the recoverability of assets to be held and used by comparing the carrying amount of the asset to future undiscounted net cash flows expected to be generated by the asset. If those assets are considered to be impaired, the impairment equals the amount by which the carrying amount of the assets exceeds the fair value of the assets. Any impairments are recorded as permanent reductions in the carrying amount of the assets. Long-lived assets, other than goodwill and other intangible assets that are held for sale are recorded at the lower of the carrying value or the fair market value less the estimated cost to sell. Intangible assets, consisting of patents, trademarks and customer relationships related to the Company’s products are amortized in a method equivalent to the estimated utilization of the economic benefit of the asset.
Contingencies	Contingencies In the normal course of business, the Company is subject to loss contingencies, such as legal proceedings and claims arising out of its business, that cover a wide range of matters, including, among others, product and environmental liability. The Company records accruals for those loss contingencies when it is probable that a liability will be incurred and the amount of loss can be reasonably estimated. The Company does not recognize gain contingencies until realized.
Fair Values of Financial Instruments	Fair Values of Financial Instruments The estimated fair values of the Company’s financial instruments, including its cash and cash equivalents, accounts receivable, accounts payable and accrued expenses approximate the carrying values of these instruments due to their short term nature. The estimated fair value of the Company’s long term debt approximates its carrying values as the applicable interest rates are subject to change with market interest rates.
Advertising and Promotion Costs	Advertising and Promotion Costs Advertising and promotion costs are expensed as incurred.
Research and Development	Research and Development Research and development costs are expensed as incurred and relate primarily to the development of new products to add to the Company’s portfolio and costs related to its medical affairs and medical information functions. Nonrefundable advance payments for goods or services that will be used or rendered for future research and development activities are deferred and recognized as an expense as the goods are delivered or the related services are performed.
Foreign Currency	Foreign Currency The consolidated statements of operations of the Company’s foreign subsidiaries are translated into U.S. Dollars using weighted-average exchange rates. The net assets of the Company’s foreign subsidiaries are translated into U.S. Dollars using the end of period exchange rates. The impact from translating the net assets of these subsidiaries at changing rates are recorded in the foreign currency translation adjustment account, which is included in accumulated other comprehensive loss in the consolidated balance sheets. Remeasurement of the Company’s foreign currency denominated transactions are included in net income. Transaction gains and losses are reported as a component of o ther income , in the consolidated statements of operations.
Stock-Based Compensation	Stock-Based Compensation The Company’s stock-based compensation cost is measured at the grant date of the stock-based award based on the fair value of the award and is recognized as expense over the requisite service period, which generally represents the vesting period, and includes an estimate of the awards that will be forfeited. The Company estimates the fair value of each stock-based award on its measurement date using either the current market price of the stock, the Black-Scholes option valuation model or the Monte Carlo Simulation valuation model, whichever is most appropriate. The Black-Scholes and Monte Carlo Simulation valuation models incorporate assumptions such as stock price volatility, the expected life of options or awards, a risk-free interest rate and dividend yield. Expense for performance restricted stock awards is recognized based upon the fair value of the awards on the date of grant and the number of shares expected to vest based on the terms of the u nderlying award agreement and the requisite service period(s).
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) consists of net income and other gains and losses affecting stockholders’ equity that, under U.S. GAAP, are excluded from net income. For the Company, other comprehensive income (loss) consists of foreign currency translation gains and losses.
Asset Retirement Obligations	Asset Retirement Obligations The Company’s compliance with federal, state, local and foreign environmental laws and regulations may require it to remove or mitigate the effects of the disposal or release of chemical substances in jurisdictions where it does business or maintains properties. The Company establishes accruals when those costs are legally obligated and probable and can be reasonably estimated. Accrual amounts are estimated based on currently available information, regulatory requirements, remediation strategies, historical experience, the relative shares of the total remediation costs and a relevant discount rate, when the time periods of estimated costs can be reasonably predicted. Changes in these assumptions could impact the Company’s future reported results. The Company has identified conditional asset retirement obligations related to the future removal and disposal of asbestos contained in certain of the buildings located on the Company’s North Billerica, Massachusetts campus. The asbestos is appropriately contained, and the Company believes it is compliant with all applicable environmental regulations. If these properties undergo major renovations or are demolished, certain environmental regulations are in place, which specify the manner in which asbestos must be handled and disposed. The Company is required to record the fair value of these conditional liabilities if they can be reasonably estimated. As of December 31, 2018 and 2017 , sufficient information was not available to estimate a liability for such conditional asset retirement obligations as the obligations to remove the asbestos from these properties have indeterminable settlement dates. As such, no liability for conditional asset retirement obligations has been recorded in the accompanying consolidated balance sheets as of December 31, 2018 and 2017 .
Self-Insurance Reserves	Self-Insurance Reserves The Company’s consolidated balance sheets at December 31, 2018 and 2017 include $0.6 million and $0.5 million of accrued liabilities associated with employee medical costs that are retained by the Company. The Company estimates the required liability of those claims on an undiscounted basis based upon various assumptions which include, but are not limited to, the Company’s historical loss experience and projected loss development factors. The required liability is also subject to adjustment in the future based upon changes in claims experience, including changes in the number of incidents (frequency) and change in the ultimate cost per incident (severity). The Company also maintains a separate cash account to fund these medical claims and must maintain a minimum balance as determined by the plan administrator.
Recent Accounting Standards	Recent Accounting Pronouncements Standard Description Effective Date for Company Effect on the Consolidated Financial Statements Recently Issued Accounting Standards Not Yet Adopted ASU 2016-02, Leases (Topic 842) This ASU supersedes existing guidance on accounting for leases in Leases (Topic 840) and generally requires all leases to be recognized on the balance sheet. The provisions of ASU 2016-02 are effective for annual reporting periods beginning after December 15, 2018; early adoption is permitted. In July 2018, an amendment was made that allows companies the option of using the effective date of the new standard as the initial application date (at the beginning of the period in which it is adopted, rather than at the beginning of the earliest comparative period). January 1, 2019 The Company has completed its assessment on the impact of the standard, including optional practical expedients and transition methods that the Company will elect upon adoption. The implementation plan included identifying the Company’s lease population, assessing significant leases under the new guidance and identifying changes to processes and controls. The Company concluded that upon adoption of this standard there will not be a significant impact to its Balance Sheet. The Company will utilize the prospective approach of adopting this standard. The Company has identified and implemented appropriate changes to its business processes and controls to support recognition and disclosure under this standard. Standard Description Effective Date for Company Effect on the Consolidated Financial Statements Accounting Standards Adopted During the Year Ended December 31, 2018 ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting This ASU clarifies when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new guidance, modification accounting is required only if the fair value, vesting conditions or classification of the award (as equity or liability) changes as a result of the change in terms or conditions. January 1, 2018 The adoption of this standard did not have a material impact on the Company’s consolidated financial statements. ASU 2014-09, Revenue from Contracts with Customers (Topic 606) and related amendments This ASU and related amendments affect any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets, unless those contracts are within the scope of other standards. The guidance in this ASU supersedes the revenue recognition requirements in Topic 605, Revenue Recognition and most industry-specific guidance. The core principle of the guidance is that an entity should recognize revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. January 1, 2018 See Note 3, "Revenue from Contracts with Customers" for the required disclosures related to the impact of adopting this standard. The adoption of this standard did not have a material impact on the Company’s consolidated balance sheets and statements of operations.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Schedule of product concentration risk	The following table sets forth revenues for each of the Company’s products representing 10% or more of revenues: Year Ended December 31, 2018 2017 2016 DEFINITY 53.3% 47.5% 43.6% TechneLite 28.8% 31.6% 32.9%
Schedule of estimated useful lives of major classes of depreciable assets	The estimated useful lives of the major classes of depreciable assets are as follows: Class Range of Estimated Useful Lives Buildings 10 - 50 years Land improvements 15 - 40 years Machinery and equipment 3 - 15 years Furniture and fixtures 15 years Leasehold improvements Lesser of lease term or 15 years Computer software 3 - 5 years
Schedule of other income	Other income consisted of the following: Years Ended December 31, (in thousands) 2018 2017 2016 Foreign currency losses (gains) $ 557 $ (253 ) $ 853 Tax indemnification income (2,855 ) (8,367 ) (1,055 ) Other income (167 ) (18 ) (18 ) Total other income $ (2,465 ) $ (8,638 ) $ (220 )
Schedule of recent account pronouncements	Standard Description Effective Date for Company Effect on the Consolidated Financial Statements Recently Issued Accounting Standards Not Yet Adopted ASU 2016-02, Leases (Topic 842) This ASU supersedes existing guidance on accounting for leases in Leases (Topic 840) and generally requires all leases to be recognized on the balance sheet. The provisions of ASU 2016-02 are effective for annual reporting periods beginning after December 15, 2018; early adoption is permitted. In July 2018, an amendment was made that allows companies the option of using the effective date of the new standard as the initial application date (at the beginning of the period in which it is adopted, rather than at the beginning of the earliest comparative period). January 1, 2019 The Company has completed its assessment on the impact of the standard, including optional practical expedients and transition methods that the Company will elect upon adoption. The implementation plan included identifying the Company’s lease population, assessing significant leases under the new guidance and identifying changes to processes and controls. The Company concluded that upon adoption of this standard there will not be a significant impact to its Balance Sheet. The Company will utilize the prospective approach of adopting this standard. The Company has identified and implemented appropriate changes to its business processes and controls to support recognition and disclosure under this standard. Standard Description Effective Date for Company Effect on the Consolidated Financial Statements Accounting Standards Adopted During the Year Ended December 31, 2018 ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting This ASU clarifies when to account for a change to the terms or conditions of a share-based payment award as a modification. Under the new guidance, modification accounting is required only if the fair value, vesting conditions or classification of the award (as equity or liability) changes as a result of the change in terms or conditions. January 1, 2018 The adoption of this standard did not have a material impact on the Company’s consolidated financial statements. ASU 2014-09, Revenue from Contracts with Customers (Topic 606) and related amendments This ASU and related amendments affect any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of nonfinancial assets, unless those contracts are within the scope of other standards. The guidance in this ASU supersedes the revenue recognition requirements in Topic 605, Revenue Recognition and most industry-specific guidance. The core principle of the guidance is that an entity should recognize revenue upon the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. January 1, 2018 See Note 3, "Revenue from Contracts with Customers" for the required disclosures related to the impact of adopting this standard. The adoption of this standard did not have a material impact on the Company’s consolidated balance sheets and statements of operations.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Schedule of disaggregation of revenue	The following table summarizes revenue by revenue source and reportable segment as follows: Year Ended December 31, 2018 Major Products/Service Lines (in thousands) U.S. International Total Product revenue, net (1) $ 288,580 $ 52,556 $ 341,136 License and royalty revenues — 2,238 2,238 Total revenues $ 288,580 $ 54,794 $ 343,374 _ _____________________________ (1) The Company’s principal products include DEFINITY and TechneLite and are categorized within product revenue, net. The Company applies the same revenue recognition policies and judgments for all of its principal products.
Schedule of contracts with customer	The Company recognized certain revenues as follows: (in thousands) Year Ended December 31, 2018 Amounts included in the contract liability at the beginning of the period $ 33 Performance obligations satisfied (or partially satisfied) in previous periods $ — The following table summarizes activity for reserves relating to rebate and allowances (including group purchasing organization administrative fees and returns) for the year ended December 31, 2018 : (in thousands) Rebates and Balance, January 1, 2018 2,860 Provision related to current period revenues 13,202 Adjustments relating to prior period revenues (361 ) Payments or credits made during the period (11,047 ) Balance, December 31, 2018 $ 4,654

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of assets and liabilities measured at fair value on a recurring basis	The Company’s financial assets measured at fair value on a recurring basis consist of money market funds. The Company invests excess cash from its operating cash accounts in overnight investments and reflects these amounts in cash and cash equivalents in the consolidated balance sheets at fair value using quoted prices in active markets for identical assets. The tables below present information about the Company’s assets and liabilities measured at fair value on a recurring basis: December 31, 2018 (in thousands) Total Fair Level 1 Level 2 Level 3 Money market $ 61,391 $ 61,391 $ — $ — Total $ 61,391 $ 61,391 $ — $ — December 31, 2017 (in thousands) Total Fair Value Level 1 Level 2 Level 3 Money market $ 8,700 $ 8,700 $ — $ — Total $ 8,700 $ 8,700 $ — $ —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of components of income before income taxes	The components of income before income taxes is summarized as follows: Year Ended December 31, (in thousands) 2018 2017 2016 U.S. $ 46,945 $ 39,559 $ 23,736 International 2,603 80 4,558 Income before income taxes $ 49,548 $ 39,639 $ 28,294
Schedule of income tax expense (benefit)	The income tax expense (benefit) is summarized as follows: Year Ended December 31, (in thousands) 2018 2017 2016 Current Federal $ (21 ) $ (58 ) $ (91 ) State 3,424 3,242 1,689 International (135 ) 16 (49 ) 3,268 3,200 1,549 Deferred Federal 7,821 (71,742 ) — State 1,411 (15,220 ) — International (3,470 ) 16 (17 ) 5,762 (86,946 ) (17 ) Income tax expense (benefit) $ 9,030 $ (83,746 ) $ 1,532
Schedule of reconciliation of income taxes at the U.S. federal statutory rate to the actual income taxes	The reconciliation of income taxes at the U.S. federal statutory rate to the actual income taxes is as follows: Year Ended December 31, (in thousands) 2018 2017 2016 U.S. statutory rate $ 10,405 $ 13,873 $ 9,903 Permanent items 505 (1,916 ) (570 ) Write-off of foreign tax and research credits — — 7,125 Foreign tax credits — — (319 ) Uncertain tax positions 3,227 3,128 1,529 Other tax credits (742 ) (175 ) 90 State and local taxes 2,125 1,252 433 Impact of rate change on deferred taxes — 45,129 (383 ) True-up of prior year tax — 7 (2,751 ) Foreign tax rate differential 30 97 (242 ) Valuation allowance (4,073 ) (141,094 ) (13,292 ) Benefit of windfall related to stock compensation (1,760 ) (2,723 ) — Increase in indemnification deferred tax asset (731 ) (1,055 ) — Other 44 (269 ) 9 Income tax expense (benefit) $ 9,030 $ (83,746 ) $ 1,532
Schedule of components of deferred incomes tax assets (liabilities)	The components of deferred income tax assets (liabilities) are as follows: December 31, (in thousands) 2018 2017 Deferred Tax Assets Federal benefit of state tax liabilities $ 7,809 $ 7,510 Reserves, accruals and other 11,005 9,251 Inventory obsolescence 428 239 Capitalized research and development 7,491 9,941 Amortization of intangibles other than goodwill 2,809 3,903 Net operating loss carryforwards 55,938 63,202 Depreciation — 972 Deferred tax assets 85,480 95,018 Deferred Tax Liabilities Reserves, accruals and other (1,078 ) (1,346 ) Customer relationships (986 ) (1,294 ) Depreciation (727 ) — Deferred tax liability (2,791 ) (2,640 ) Less: valuation allowance (1,240 ) (5,368 ) $ 81,449 $ 87,010 Recorded in the accompanying consolidated balance sheets as: Noncurrent deferred tax assets $ 81,449 $ 87,010
Schedule of valuation allowance	A summary of the changes in the Company’s valuation allowance is summarized below: (in thousands) Amount Balance, January 1, 2017 $ 140,915 Charged to income tax expense (benefit) 2,305 Adoption of ASU 2016-09 2,929 Foreign currency 313 Release valuation allowance (141,094 ) Balance, December 31, 2017 5,368 Charged to income tax expense (benefit) (103 ) Foreign currency (56 ) Release valuation allowance (3,969 ) Balance, December 31, 2018 $ 1,240
Schedule of reconciliation of the Company's changes in uncertain tax positions	A reconciliation of the Company’s changes in uncertain tax positions for 2018 and 2017 is as follows: (in thousands) Amount Balance of uncertain tax positions as of January 1, 2017 $ 10,441 Additions related to current year tax positions — Reductions related to prior year tax positions (506 ) Settlements — Lapse of statute of limitations (69 ) Balance of uncertain tax positions as of December 31, 2017 9,866 Additions related to current year tax positions — Reductions related to prior year tax positions (4 ) Settlements — Lapse of statute of limitations (74 ) Balance of uncertain tax positions as of December 31, 2018 $ 9,788

Inventory (Tables)

Inventory (Tables)	12 Months Ended
	Dec. 31, 2018
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consisted of the following: December 31, (in thousands) 2018 2017 Raw materials $ 11,100 $ 10,447 Work in process 4,261 5,509 Finished goods 17,658 10,124 Total inventory $ 33,019 $ 26,080

Property, Plant & Equipment, _2

Property, Plant & Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Schedule of property, plant, and equipment, net	Property, plant and equipment, net, consisted of the following: December 31, (in thousands) 2018 2017 Land $ 13,450 $ 13,450 Buildings 64,444 76,059 Machinery, equipment and fixtures 69,298 71,870 Computer software 19,266 20,271 Construction in progress 24,169 7,622 190,627 189,272 Less: accumulated depreciation and amortization (82,739 ) (96,273 ) Total property, plant and equipment, net $ 107,888 $ 92,999

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2018
Asset Retirement Obligation Disclosure [Abstract]
Summary of asset retirement obligations	The following table provides a summary of the changes in the Company’s asset retirement obligations: (in thousands) Amount Balance, January 1, 2018 $ 10,412 Accretion expense 1,160 Balance, December 31, 2018 $ 11,572

Intangibles, Net (Tables)

Intangibles, Net (Tables)	12 Months Ended
	Dec. 31, 2018
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Schedule of intangibles	Intangibles, net, consisted of the following: December 31, 2018 (in thousands) Amortization Cost Accumulated Amortization Net Trademarks Straight-Line $ 13,540 $ (9,856 ) $ 3,684 Customer relationships Accelerated 98,912 (93,463 ) 5,449 Patents Straight-Line 6,570 (6,570 ) — Total $ 119,022 $ (109,889 ) $ 9,133 December 31, 2017 (in thousands) Amortization Cost Accumulated Amortization Net Trademarks Straight-Line $ 13,540 $ (9,304 ) $ 4,236 Customer relationships Accelerated 99,133 (92,072 ) 7,061 Patents Straight-Line 42,780 (42,279 ) 501 Total $ 155,453 $ (143,655 ) $ 11,798
Schedule of expected future amortization expense	The below table summarizes the estimated aggregate amortization expense expected to be recognized on the above intangible assets: (in thousands) Amount 2019 $ 1,803 2020 1,568 2021 1,309 2022 1,173 2023 579 2024 and thereafter 2,701 Total $ 9,133

Accrued Expenses and Other Li_2

Accrued Expenses and Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Schedule of accrued expenses	Accrued expenses are comprised of the following: December 31, (in thousands) 2018 2017 Compensation and benefits $ 15,962 $ 14,469 Freight, distribution and operations 7,721 3,604 Accrued rebates, discounts and chargebacks 4,654 2,860 Accrued professional fees 1,673 2,852 Other 2,040 2,751 Total accrued expenses and other liabilities $ 32,050 $ 26,536

Financing Arrangements (Tables)

Financing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of minimum payments, maturities of principal obligations under term facility	The Company’s maturities of principal obligations under the 2017 Term Facility are as follows as of December 31, 2018 : (in thousands) Amount 2019 2,750 2020 2,750 2021 2,750 2022 261,937 Total principal outstanding 270,187 Unamortized debt discount (1,584 ) Unamortized debt issuance costs (2,144 ) Total 266,459 Less: current portion (2,750 ) Total long-term debt $ 263,709
Schedule of term facility financial covenants	The maximum consolidated leverage ratio permitted by the financial covenant is displayed in the table below: 2017 Facility Financial Covenant Period Consolidated Q1 2019 4.75 to 1.00 Thereafter 4.50 to 1.00

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of stock-based compensation expense recognized	Stock-based compensation expense recognized in the consolidated statements of operations is summarized below: Year Ended December 31, (in thousands) 2018 2017 2016 Cost of goods sold $ 1,140 $ 1,692 $ 359 Sales and marketing 1,244 640 339 General and administrative 4,990 2,964 1,438 Research and development 1,344 632 388 Total stock-based compensation expense $ 8,718 $ 5,928 $ 2,524
Schedule of option activity	A summary of option activity for 2018 is presented below: Total Stock Options Weighted- Average Exercise Price Weighted- Average Remaining Contractual Term (Years) Aggregate Intrinsic Value Balance at January 1, 2018 565,425 $ 13.65 Options granted — $ — Options exercised (192,550 ) $ 5.98 Options cancelled and expired (15,800 ) $ 20.44 Outstanding at December 31, 2018 357,075 $ 17.50 4.4 535,427 Vested and expected to vest at December 31, 2018 357,075 $ 17.50 4.4 535,427 Exercisable at December 31, 2018 353,049 $ 17.56 4.4 522,423
Summary of restricted stock awards activity	A summary of TSR Award activity for 2018 is presented below: Shares Weighted- Nonvested balance at January 1, 2018 — $ — Granted 206,896 $ 22.76 Vested — $ — Forfeited (26,983 ) $ 22.76 Nonvested balance at December 31, 2018 179,913 $ 22.76 A summary of performance restricted stock award activity for 2018 is presented below: Shares Weighted- Nonvested balance at January 1, 2018 291,172 $ 16.70 Granted — $ — Vested — $ — Forfeited (49,292 ) $ 16.62 Nonvested balance at December 31, 2018 241,880 $ 16.71 A summary of restricted stock awards and restricted stock units activity for 2018 is presented below: Shares Weighted- Average Grant Date Fair Value Per Share Nonvested balance at January 1, 2018 1,765,262 $ 5.72 Granted 647,850 $ 15.46 Vested (672,345 ) $ 6.37 Forfeited (232,228 ) $ 11.87 Nonvested balance at December 31, 2018 1,508,539 $ 9.51
Schedule of valuation model	The fair value of these awards are based on a Monte Carlo Simulation valuation model with the following assumptions: Year Ended December 31, 2018 Expected volatility 84.3 % Risk-free interest rate 2.4 % Expected life (in years) 2.8 Expected dividend yield —

Net Income (Loss) Per Common _2

Net Income (Loss) Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Summary of net income (loss) per common share	A summary of net income per common share is presented below: Year Ended (in thousands, except per share amounts) 2018 2017 2016 Net income $ 40,518 $ 123,385 $ 26,762 Basic weighted-average common shares outstanding 38,233 37,276 32,044 Effect of dilutive stock options 61 288 612 Effect of dilutive restricted stock 1,207 1,328 — Diluted weighted-average common shares outstanding 39,501 38,892 32,656 Basic income per common share $ 1.06 $ 3.31 $ 0.84 Diluted income per common share $ 1.03 $ 3.17 $ 0.82 Antidilutive securities excluded from diluted net income per common share 424 604 1,563

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of future payments required	As of December 31, 2018 , future payments required under noncancelable lease agreements and purchase commitments are as follows: (in thousands) Amount 2019 $ 2,264 2020 259 2021 238 2022 238 2023 238 2024 and thereafter 178 Total $ 3,415

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Schedule of selected information for each business segment	Selected information regarding the Company’s segments are provided as follows: Year Ended (in thousands) 2018 2017 2016 Revenues from external customers U.S. $ 288,580 $ 290,002 $ 257,420 International 54,794 41,376 44,433 Total revenues from external customers $ 343,374 $ 331,378 $ 301,853 Revenues by product DEFINITY $ 183,073 $ 157,268 $ 131,612 TechneLite 98,858 104,644 99,217 Other 61,443 69,466 71,024 Total revenues $ 343,374 $ 331,378 $ 301,853 Geographical revenues U.S. $ 288,580 $ 290,002 $ 257,420 All other 54,794 41,376 44,433 Total revenues $ 343,374 $ 331,378 $ 301,853 Operating income U.S. $ 56,327 $ 49,239 $ 46,909 International 8,161 2,614 9,679 Operating income 64,488 51,853 56,588 Interest expense 17,405 18,410 26,618 Debt retirement costs — — 1,896 Loss on extinguishment of debt — 2,442 — Other income (2,465 ) (8,638 ) (220 ) Income before income taxes $ 49,548 $ 39,639 $ 28,294 Depreciation and amortization U.S. $ 12,278 $ 17,672 $ 15,995 International 491 517 1,335 Total depreciation and amortization $ 12,769 $ 18,189 $ 17,330 December 31, (in thousands) 2018 2017 Long-lived assets U.S. $ 106,755 $ 91,537 International 1,133 1,462 Total long-lived assets $ 107,888 $ 92,999

Valuation and Qualifying Acco_2

Valuation and Qualifying Accounts (Tables)	12 Months Ended
	Dec. 31, 2018
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule of valuation and qualifying accounts	(in thousands) Balance at Beginning of Year Charged to Income Deductions from Reserves (1) Other Adjustments Balance at End of Year Allowance for doubtful accounts Year ended December 31, 2018 $ 977 $ 321 $ (179 ) $ — $ 1,119 Year ended December 31, 2017 $ 969 $ 136 $ (128 ) $ — $ 977 Year ended December 31, 2016 $ 881 $ 53 $ (30 ) $ 65 $ 969 Rebates and allowances Year ended December 31, 2018 $ 2,860 $ 13,202 $ (11,047 ) $ (361 ) $ 4,654 Year ended December 31, 2017 $ 2,297 $ 9,568 $ (8,351 ) $ (654 ) $ 2,860 Year ended December 31, 2016 $ 2,303 $ 7,255 $ (6,809 ) $ (452 ) $ 2,297 ________________________________ (1) Amounts charged to deductions from allowance for doubtful accounts represent the write-off of uncollectible balances and represent payments for rebates and allowances.

Quarterly Consolidated Financ_2

Quarterly Consolidated Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Summary of quarterly financial information	Summarized quarterly consolidated financial data is presented below: Quarterly Periods During the Year Ended Q1 Q2 Q3 Q4 (in thousands, except per share data) Revenues $ 82,630 $ 85,573 $ 88,900 $ 86,271 Gross profit $ 42,309 $ 43,846 $ 44,885 $ 43,845 Net income $ 8,211 $ 9,745 $ 9,269 $ 13,293 Basic income per weighted-average share (b) $ 0.22 $ 0.25 $ 0.24 $ 0.35 Diluted income per weighted-average share (b) $ 0.21 $ 0.25 $ 0.24 $ 0.34 Quarterly Periods During the Year Ended Q1 Q2 Q3 Q4 (in thousands, except per share data) Revenues $ 81,359 $ 88,837 $ 79,941 $ 81,241 Gross profit $ 39,762 $ 45,947 $ 38,527 $ 37,899 Net income (a) $ 4,138 $ 13,595 $ 8,526 $ 97,126 Basic income per weighted-average share (b) $ 0.11 $ 0.37 $ 0.23 $ 2.58 Diluted income per weighted-average share (b) $ 0.11 $ 0.35 $ 0.22 $ 2.47 ________________________________ (a) Net income for the fourth quarter of 2017 reflects the income tax benefit due to the release of the Company’s valuation allowance of $141.1 million against its deferred tax assets offset by a provision of $45.1 million for remeasuring the Company’s deferred tax assets for the change in tax rates enacted under the Tax Cuts and Jobs Act of 2017. (b) Quarterly and annual computations are prepared independently. Accordingly, the sum of each quarter may not necessarily total the fiscal year period amounts noted elsewhere within this Annual Report on Form 10-K.

Description of Business (Detail

Description of Business (Details)	Dec. 31, 2018pharmacy
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of stores (in pharmacies)	1

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Accounts Receivable (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Miscellaneous receivables	$ 0.3	$ 0.8

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Concentration Risk (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounts Receivable | Customer Concentration Risk | Company A
Concentration Risk [Line Items]
Concentration risk percentage	11.00%	15.00%
Revenues | Customer Concentration Risk | Company A
Concentration Risk [Line Items]
Concentration risk percentage		12.00%	11.00%
Revenues | Customer Concentration Risk | Company B
Concentration Risk [Line Items]
Concentration risk percentage		10.00%	10.00%
Revenues | Customer Concentration Risk | Company C
Concentration Risk [Line Items]
Concentration risk percentage		10.00%
Revenues | Product Concentration Risk | DEFINITY
Concentration Risk [Line Items]
Concentration risk percentage	53.30%	47.50%	43.60%
Revenues | Product Concentration Risk | TechneLite
Concentration Risk [Line Items]
Concentration risk percentage	28.80%	31.60%	32.90%

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Inventory (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Inventory without regulatory approval	$ 0	$ 0

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Estimated Useful Lives (Detail)	12 Months Ended
	Dec. 31, 2018
Computer software | Minimum
Property, Plant & Equipment [Line Items]
Estimated useful lives	3 years
Computer software | Maximum
Property, Plant & Equipment [Line Items]
Estimated useful lives	5 years
Buildings
Property, Plant & Equipment [Line Items]
Estimated useful lives	10 years
Buildings | Maximum
Property, Plant & Equipment [Line Items]
Estimated useful lives	50 years
Land improvements | Minimum
Property, Plant & Equipment [Line Items]
Estimated useful lives	15 years
Land improvements | Maximum
Property, Plant & Equipment [Line Items]
Estimated useful lives	40 years
Machinery and equipment | Minimum
Property, Plant & Equipment [Line Items]
Estimated useful lives	3 years
Machinery and equipment | Maximum
Property, Plant & Equipment [Line Items]
Estimated useful lives	15 years
Furniture and fixtures | Minimum
Property, Plant & Equipment [Line Items]
Estimated useful lives	15 years
Leasehold improvements | Maximum
Property, Plant & Equipment [Line Items]
Estimated useful lives	15 years

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Goodwill (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Goodwill, impairment loss	$ 0	$ 0	$ 0

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Advertising and Promotion Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Advertising and promotion costs	$ 4	$ 4.4	$ 3.6

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Other Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Foreign currency losses (gains)	$ 557	$ (253)	$ 853
Tax indemnification income	(2,855)	(8,367)	(1,055)
Other income	(167)	(18)	(18)
Total other income	$ (2,465)	$ (8,638)	$ (220)

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Self-Insurance Reserves (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Accrued liabilities associated with employee medical costs	$ 0.6	$ 0.5
Restricted cash account	$ 0.1	$ 0.1

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 86,271	$ 88,900	$ 85,573	$ 82,630	$ 81,241	$ 79,941	$ 88,837	$ 81,359	$ 343,374
Product revenue, net
Disaggregation of Revenue [Line Items]
Revenues									341,136
License and royalty revenues
Disaggregation of Revenue [Line Items]
Revenues									2,238
U.S.
Disaggregation of Revenue [Line Items]
Revenues									288,580
U.S. | Product revenue, net
Disaggregation of Revenue [Line Items]
Revenues									288,580
U.S. | License and royalty revenues
Disaggregation of Revenue [Line Items]
Revenues									0
International
Disaggregation of Revenue [Line Items]
Revenues									54,794
International | Product revenue, net
Disaggregation of Revenue [Line Items]
Revenues									52,556
International | License and royalty revenues
Disaggregation of Revenue [Line Items]
Revenues									$ 2,238

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Rebates and Allowances (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, January 1, 2018	$ 2,860
Provision related to current period revenues	13,202
Adjustments relating to prior period revenues	(361)
Payments or credits made during the period	(11,047)
Balance, December 31, 2018	$ 4,654

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Contract Costs (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Revenue from Contract with Customer [Abstract]
Amounts included in the contract liability at the beginning of the period	$ 33
Performance obligations satisfied (or partially satisfied) in previous periods	$ 0

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 61,391	$ 8,700
Money market
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market	61,391	8,700
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	61,391	8,700
Level 1 | Money market
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market	61,391	8,700
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Level 2 | Money market
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	0	0
Level 3 | Money market
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market	$ 0	$ 0

Income Taxes - Schedule of Comp

Income Taxes - Schedule of Components of Income (Loss) Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
U.S.	$ 46,945	$ 39,559	$ 23,736
International	2,603	80	4,558
Income before income taxes	$ 49,548	$ 39,639	$ 28,294

Income Taxes - Schedule of (Ben

Income Taxes - Schedule of (Benefit) Provision for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current
Federal		$ (21)	$ (58)	$ (91)
State		3,424	3,242	1,689
International		(135)	16	(49)
Current provision (benefit) for income taxes		3,268	3,200	1,549
Deferred
Federal		7,821	(71,742)	0
State		1,411	(15,220)	0
International		(3,470)	16	(17)
Deferred provision (benefit) for income taxes		5,762	(86,946)	(17)
Income tax expense (benefit)	$ 4,000	$ 9,030	$ (83,746)	$ 1,532

Income Taxes - Differences in S

Income Taxes - Differences in Statutory Rate and Effective Rate (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
U.S. statutory rate			$ 10,405	$ 13,873	$ 9,903
Permanent items			505	(1,916)	(570)
Write-off of foreign tax and research credits			0	0	7,125
Foreign tax credits			0	0	(319)
Uncertain tax positions			3,227	3,128	1,529
Other tax credits			(742)	(175)	90
State and local taxes			2,125	1,252	433
Impact of rate change on deferred taxes		$ 45,100	0	45,129	(383)
True-up of prior year tax			0	7	(2,751)
Foreign tax rate differential			30	97	(242)
Valuation allowance			(4,073)	(141,094)	(13,292)
Benefit of windfall related to stock compensation			(1,760)	(2,723)	0
Increase in indemnification deferred tax asset			(731)	(1,055)	0
Other			44	(269)	9
Income tax expense (benefit)	$ 4,000		$ 9,030	$ (83,746)	$ 1,532

Income Taxes - Components of De

Income Taxes - Components of Deferred Income Tax Assets (Liabilities) (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Assets
Federal benefit of state tax liabilities	$ 7,809	$ 7,510
Reserves, accruals and other	11,005	9,251
Inventory obsolescence	428	239
Capitalized research and development	7,491	9,941
Amortization of intangibles other than goodwill	2,809	3,903
Net operating loss carryforwards	55,938	63,202
Depreciation	0	972
Deferred tax assets	85,480	95,018
Deferred Tax Liabilities
Reserves, accruals and other	(1,078)	(1,346)
Customer relationships	(986)	(1,294)
Depreciation	(727)	0
Deferred tax liability	(2,791)	(2,640)
Less: valuation allowance	(1,240)	(5,368)	$ (140,915)
Net deferred tax liabilities	81,449	87,010
Recorded in the accompanying consolidated balance sheets as
Reserves, accruals and other	$ 81,449	$ 87,010

Income Taxes - Valuation Allowa

Income Taxes - Valuation Allowance (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Valuation Allowance [Line Items]
Deferred tax asset, valuation allowance		$ 5,368	$ 140,915
Charged to income tax expense (benefit)		(103)	2,305
Foreign currency		(56)	313
Release valuation allowance	$ (141,100)	(3,969)	(141,094)
Deferred tax asset, valuation allowance	$ 5,368	$ 1,240	$ 5,368
ASU 2016-09
Valuation Allowance [Line Items]
Adoption of ASU 2016-09				$ 2,929

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of Uncertain Tax Positions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Beginning balance of uncertain tax positions	$ 9,866	$ 10,441
Additions related to current year tax positions	0	0
Reductions related to prior year tax positions	(4)	(506)
Settlements	0	0
Lapse of statute of limitations	(74)	(69)
Ending balance of uncertain tax positions	$ 9,788	$ 9,866

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes And Tax Related [Line Items]
Income tax expense (benefit)	$ 4,000,000		$ 9,030,000	$ (83,746,000)	$ 1,532,000
Deferred tax asset, valuation allowance	1,240,000	$ 5,368,000	1,240,000	5,368,000	140,915,000
Release valuation allowance		141,100,000	3,969,000	141,094,000
Total liabilities for tax obligation and associated interest and penalties	40,200,000	37,000,000	40,200,000	37,000,000
Income tax provisions for uncertain tax benefits	9,800,000	9,900,000	9,800,000	9,900,000
Interest accruals	28,200,000	24,900,000	28,200,000	24,900,000
Penalty accruals	2,200,000	2,200,000	2,200,000	2,200,000
Other tax long-term liabilities		36,300,000		36,300,000
Uncertain tax positions			3,227,000	3,128,000	1,529,000
Tax indemnification receivable	29,500,000	26,300,000	29,500,000	26,300,000
Tax indemnification income			2,855,000	8,367,000	1,055,000
Federal
Income Taxes And Tax Related [Line Items]
Net operating loss carryovers	207,200,000		207,200,000
Tax indemnification income				6,500,000
State Research Credit
Income Taxes And Tax Related [Line Items]
Tax credits	2,800,000		2,800,000
Massachusetts | Investment Tax Credits
Income Taxes And Tax Related [Line Items]
Tax credits	1,400,000		1,400,000
Net operating loss carryovers without expiration date	600,000		600,000
BMS
Income Taxes And Tax Related [Line Items]
Payments for state income tax settlements			0	0	700,000
Decrease in amount due from BMS included within other long-term assets			3,300,000	8,400,000	$ 1,300,000
Deferred Tax Assets
Income Taxes And Tax Related [Line Items]
Penalty accruals		$ 700,000		$ 700,000
2037 | Federal
Income Taxes And Tax Related [Line Items]
Net operating loss carryovers	$ 400,000		$ 400,000

Sales of Certain Internationa_2

Sales of Certain International Segment Assets (Detail) $ in Thousands, $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2016USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016AUD ($)	Dec. 31, 2016USD ($)
Assets Of Disposal Group Including Discontinued Operation [Line Items]
Gain on sale of assets		$ 0	$ 0		$ 6,385
Canadian Radiopharmacies and Gludef Manufacturing and Distribution Business
Assets Of Disposal Group Including Discontinued Operation [Line Items]
Purchase price for asset sale	$ 9,000
Working capital adjustment	$ 500
Gain on sale of assets					5,900
Australian Radiopharmacy Servicing Subsidiary
Assets Of Disposal Group Including Discontinued Operation [Line Items]
Gain on sale of assets					500
Share sale price				$ 2	1,500
Working capital adjustment in sale of stock units				2	1,500
Gross proceeds from sale of stock units				$ 4	3,000
Net proceeds from sale of stock units					2,200
Working Capital Assets Liabilities Sold					2,000
Reclassification from other comprehensive income to gain on sales of assets					$ 400

Inventory - Schedule of Invento

Inventory - Schedule of Inventory (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 11,100	$ 10,447
Work in process	4,261	5,509
Finished goods	17,658	10,124
Total inventory	$ 33,019	$ 26,080

Inventory - Additional Informat

Inventory - Additional Information (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Other Noncurrent Assets
Inventory [Line Items]
Raw materials	$ 0	$ 1.1

Property, Plant & and Equipment

Property, Plant & and Equipment, Net - Schedule of Property, Plant & Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant & Equipment [Line Items]
Property, plant and equipment, gross	$ 190,627	$ 189,272
Less: accumulated depreciation and amortization	(82,739)	(96,273)
Property, plant and equipment, net	107,888	92,999
Land
Property, Plant & Equipment [Line Items]
Property, plant and equipment, gross	13,450	13,450
Buildings
Property, Plant & Equipment [Line Items]
Property, plant and equipment, gross	64,444	76,059
Machinery, equipment and fixtures
Property, Plant & Equipment [Line Items]
Property, plant and equipment, gross	69,298	71,870
Construction in progress
Property, Plant & Equipment [Line Items]
Property, plant and equipment, gross	24,169	7,622
Computer software
Property, Plant & Equipment [Line Items]
Property, plant and equipment, gross	$ 19,266	$ 20,271

Property, Plant & Equipment, _3

Property, Plant & Equipment, Net - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant & Equipment [Line Items]
Depreciation and amortization		$ 12,769	$ 18,189	$ 17,330
Loss on impairment of land		0	912	0
Proceeds from sale of excess land	$ 1,000
Property, Plant and Equipment
Property, Plant & Equipment [Line Items]
Depreciation and amortization		$ 10,100	$ 14,800	$ 12,100

Asset Retirement Obligations -

Asset Retirement Obligations - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Asset Retirement Obligation Disclosure [Abstract]
Financial assurance in form of surety bond	$ 28.2
Asset retirement obligation liabilities expected, present value	$ 26.9

Asset Retirement Obligations _2

Asset Retirement Obligations - Schedule of Reconciliation of Company's Asset Retirement Obligations (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at the beginning of the period	$ 10,412
Accretion expense	1,160
Balance at the ending of the period	$ 11,572

Intangibles, Net - Schedule of

Intangibles, Net - Schedule of Intangibles, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Cost	$ 119,022	$ 155,453
Accumulated Amortization	(109,889)	(143,655)
Net	9,133	11,798
Trademarks
Finite-Lived Intangible Assets [Line Items]
Cost	13,540	13,540
Accumulated Amortization	(9,856)	(9,304)
Net	3,684	4,236
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Cost	98,912	99,133
Accumulated Amortization	(93,463)	(92,072)
Net	5,449	7,061
Patents
Finite-Lived Intangible Assets [Line Items]
Cost	6,570	42,780
Accumulated Amortization	(6,570)	(42,279)
Net	$ 0	$ 501

Intangibles, Net - Additional I

Intangibles, Net - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Amortization expense	$ 2.6	$ 3.3	$ 5.1

Intangibles, Net - Schedule o_2

Intangibles, Net - Schedule of Expected Future Amortization Expense Related to Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Intangible Assets, Net (Excluding Goodwill) [Abstract]
2,019	$ 1,803
2,020	1,568
2,021	1,309
2,022	1,173
2,023	579
2024 and thereafter	2,701
Net	$ 9,133	$ 11,798

Accrued Expenses and Other Li_3

Accrued Expenses and Other Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Compensation and benefits	$ 15,962	$ 14,469
Freight, distribution and operations	7,721	3,604
Accrued rebates, discounts and chargebacks	4,654	2,860
Accrued professional fees	1,673	2,852
Other	2,040	2,751
Total accrued expenses and other liabilities	$ 32,050	$ 26,536

Financing Arrangements - Additi

Financing Arrangements - Additional Information (Detail) - USD ($)	Mar. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Loss on extinguishment of debt and debt retirement costs	$ 2,200,000	$ 0	$ (2,442,000)	$ (1,896,000)
Third-party costs associated with modified debt	1,700,000
Debt issuance costs	1,600,000
2015 Term Facility
Debt Instrument [Line Items]
Debt instrument, face amount	$ 365,000,000
Debt instrument, term (in years)	7 years
Cash paid during the execution of refinancing	$ 15,300,000
Revolving Line of Credit
Debt Instrument [Line Items]
Debt instrument, face amount	$ 75,000,000
Debt instrument, term (in years)	5 years
2017 Term Facility
Debt Instrument [Line Items]
Debt instrument, face amount	$ 275,000,000
Debt instrument, term (in years)	5 years
Debt instrument, discount amount	$ 700,000
Increase in aggregate principal amount	75,000,000
Aggregate principal amount outstanding		$ 270,187,000
Asset Based Loan (ABL) Facility
Debt Instrument [Line Items]
Debt instrument, face amount	$ 50,000,000
Debt instrument, term (in years)	5 years

Financing Arrangements - Term F

Financing Arrangements - Term Facility (Details) - 2017 Term Facility	12 Months Ended
	Dec. 31, 2018
Debt Instrument [Line Items]
Interest rate at end of period	6.30%
Amortization (in percent)	1.00%
LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (in percent)	3.75%
Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate (in percent)	2.75%

Financing Arrangements - Schedu

Financing Arrangements - Schedule of Minimum Payments Maturities of Principal Obligations Under Term Facility (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Less: current portion	$ (2,750)	$ (2,750)
Total long-term debt	263,709	$ 265,393
2017 Term Facility
Debt Instrument [Line Items]
2,019	2,750
2,020	2,750
2,021	2,750
2,022	261,937
Total principal outstanding	270,187
Unamortized debt discount	(1,584)
Unamortized debt issuance costs	(2,144)
Total	266,459
Less: current portion	(2,750)
Total long-term debt	$ 263,709

Financing Arrangements - Revolv

Financing Arrangements - Revolving Facility (Details)	12 Months Ended
	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Mar. 30, 2017USD ($)
Debt Instrument [Line Items]
Revolving line of credit	$ 0	$ 0
Revolving Credit Facility
Debt Instrument [Line Items]
Debt instrument, face amount			$ 75,000,000
Revolving Credit Facility | Leverage Ratio Range One
Debt Instrument [Line Items]
Unused line of credit fee (in percentage)	0.38%
Debt instrument covenant leverage ratio	3
Revolving Credit Facility | Leverage Ratio Range Two
Debt Instrument [Line Items]
Unused line of credit fee (in percentage)	0.25%
Debt instrument covenant leverage ratio	3
Revolving Credit Facility | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (in percent)	3.00%
Revolving Credit Facility | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate (in percent)	2.00%
Revolving Credit Facility | Letter of Credit
Debt Instrument [Line Items]
Debt instrument, face amount	$ 20,000,000
2017 Term Facility
Debt Instrument [Line Items]
Increase in aggregate principal amount			75,000,000
Debt instrument, face amount			$ 275,000,000
2017 Term Facility | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate (in percent)	3.75%
2017 Term Facility | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate (in percent)	2.75%

Financing Arrangements - Sche_2

Financing Arrangements - Schedule of Term Facility Financial Covenants (Detail) - 2017 Facility	12 Months Ended
	Dec. 31, 2018
Q1 2019
Debt Instrument [Line Items]
Debt instrument covenant leverage ratio	4.75
Thereafter
Debt Instrument [Line Items]
Debt instrument covenant leverage ratio	4.50

Stock-Based Compensation - Equi

Stock-Based Compensation - Equity Incentive Plans (Details)	Jun. 30, 2015shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share based compensation, shares authorized (in shares)	5,755,277

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense Recognized (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 8,718	$ 5,928	$ 2,524
Cost of goods sold
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,140	1,692	359
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,244	640	339
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	4,990	2,964	1,438
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,344	$ 632	$ 388

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Options (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Contractual term	10 years
Total Stock Options
Options outstanding, beginning balance (in shares)	565,425
Options granted (in shares)	0
Options exercised (in shares)	(192,550)	(465,232)	(40,976)
Options cancelled and expired (in shares)	(15,800)
Options outstanding, ending balance (in shares)	357,075	565,425
Vested and expected to vest (in shares)	357,075
Exercisable (in shares)	353,049
Weighted- Average Exercise Price
Options outstanding, beginning balance, weighted average exercise price (in dollars per share)	$ 13.65
Options granted, weighted average exercise price (in dollars per share)	0
Options exercised, weighted average exercise price (in dollars per share)	5.98
Options cancelled and expired, weighted average exercise price (in dollars per share)	20.44
Options outstanding, ending balance, weighted average exercise price (in dollars per share)	17.50	$ 13.65
Vested and expected to vest, weighted average exercise price (in dollars per share)	17.50
Exercisable, weighted average exercise price (in dollars per share)	$ 17.56
Stock Option Activity, Additional Disclosures
Options outstanding, weighted average remaining contractual term (in years)	4 years 4 months 24 days
Vested and expected to vest, weighted average remaining contractual term (in years)	4 years 4 months 24 days
Exercisable, weighted average remaining contractual term (in years)	4 years 4 months 24 days
Options outstanding, aggregate intrinsic value	$ 535,427
Vested and expected to vest, aggregate intrinsic value	535,427
Exercisable, aggregate intrinsic value	522,423
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 2,400	$ 5,100	$ 200

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Restricted Stock Awards Activity (Detail) - Restricted Stock $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)$ / sharesshares
Shares
Non-vested restricted stock, beginning balance (in shares) | shares	1,765,262
Granted (in shares) | shares	647,850
Vested (in shares) | shares	(672,345)
Forfeited (in shares) | shares	(232,228)
Non-vested restricted stock, ending balance (in shares) | shares	1,508,539
Weighted- Average Grant Date Fair Value Per Share
Weighted average grant date fair value per share, non-vested restricted stock, beginning balance (in dollars per share) | $ / shares	$ 5.72
Weighted average grant date fair value per share, granted (in dollars per share) | $ / shares	15.46
Weighted average grant date fair value per share, vested (in dollars per share) | $ / shares	6.37
Weighted average grant date fair value per share, forfeited (in dollars per share) | $ / shares	11.87
Weighted average grant date fair value per share, non-vested restricted stock, ending balance (in dollars per share) | $ / shares	$ 9.51
Unrecognized compensation expense | $	$ 9.5
Weighted-average remaining period for recognition of unrecognized compensation costs	2 years 2 months 12 days

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Performance Restricted Stock Awards Activity (Details) - Performance Restricted Stock $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)$ / sharesshares
Shares
Non-vested restricted stock, beginning balance (in shares) | shares	291,172
Granted (in shares) | shares	0
Vested (in shares) | shares	0
Cancelled (in shares) | shares	(49,292)
Non-vested restricted stock, ending balance (in shares) | shares	241,880
Weighted- Average Grant Date Fair Value Per Share
Weighted average grant date fair value per share, non-vested restricted stock, beginning balance (in dollars per share) | $ / shares	$ 16.70
Weighted average grant date fair value per share, granted (target) (in dollars per share) | $ / shares	0
Weighted average grant date fair value per share, vested (in dollars per share) | $ / shares	0
Weighted average grant date fair value per share, forfeited (in dollars per share) | $ / shares	16.62
Weighted average grant date fair value per share, non-vested restricted stock, ending balance (in dollars per share) | $ / shares	$ 16.71
Unrecognized compensation expense | $	$ 2.9
Weighted-average remaining period for recognition of unrecognized compensation costs	1 year 2 months 12 days

Stock-Based Compensation - Tota

Stock-Based Compensation - Total Stockholder Return Restricted Awards (Details) - Total Stockholder Return Restricted Stock Awards $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance awards, measurement period	3 years
Expected volatility	84.30%
Risk-free interest rate	2.40%
Expected life (in years)	2 years 9 months 18 days
Expected dividend yield	0.00%
Unrecognized compensation expense	$ 3.1
Weighted-average remaining period for recognition of unrecognized compensation costs	2 years 2 months 12 days
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentages attainable during period	0.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentages attainable during period	200.00%

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of TSR Award Activity (Details) - Total Stockholder Return Restricted Stock Awards	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Shares
Non-vested restricted stock, beginning balance (in shares) | shares	0
Granted (in shares) | shares	206,896
Vested (in shares) | shares	0
Forfeited (in shares) | shares	(26,983)
Non-vested restricted stock, ending balance (in shares) | shares	179,913
Weighted- Average Grant Date Fair Value Per Share
Weighted average grant date fair value per share, non-vested restricted stock, beginning balance (in dollars per share) | $ / shares	$ 0
Weighted average grant date fair value per share, granted (in dollars per share) | $ / shares	22.76
Weighted average grant date fair value per share, vested (in dollars per share) | $ / shares	0
Weighted average grant date fair value per share, forfeited (in dollars per share) | $ / shares	22.76
Weighted average grant date fair value per share, non-vested restricted stock, ending balance (in dollars per share) | $ / shares	$ 22.76

Stock-Based Compensation - Modi

Stock-Based Compensation - Modifications (Details) - USD ($)	1 Months Ended	12 Months Ended
	Apr. 30, 2017	Dec. 31, 2018	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation expense	$ 250,000	$ 300,000	$ 1,300,000

Stock-based Compensation - Empl

Stock-based Compensation - Employee Stock Purchase Plan (Details) - USD ($)	1 Months Ended	12 Months Ended
	Apr. 30, 2017	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share-based Compensation Expense	$ 250,000	$ 300,000	$ 1,300,000
2017 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee stock purchase plan discount percentage	15.00%

Net Income (Loss) Per Common _3

Net Income (Loss) Per Common Share - Summary of Net Income (Loss) Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Line Items]
Net income									$ 40,518	$ 123,385	$ 26,762
Basic weighted-average common shares outstanding (in shares)									38,233	37,276	32,044
Effect of dilutive stock options (in shares)									61	288	612
Effect of dilutive performance restricted stock (in shares)									1,207	1,328	0
Diluted weighted-average common shares outstanding (in shares)									39,501	38,892	32,656
Basic income (loss) per common share outstanding (in dollars per share)	$ 0.35	$ 0.24	$ 0.25	$ 0.22	$ 2.58	$ 0.23	$ 0.37	$ 0.11	$ 1.06	$ 3.31	$ 0.84
Diluted income (loss) per common share outstanding (in dollars per share)	$ 0.34	$ 0.24	$ 0.25	$ 0.21	$ 2.47	$ 0.22	$ 0.35	$ 0.11	$ 1.03	$ 3.17	$ 0.82
Stock Options | Nonvested Restricted Stock
Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted income (loss) per common share (in shares)									424	604	1,563

Commitments - Schedule of Minim

Commitments - Schedule of Minimum Lease and Purchase Commitments Under Noncancelable Arrangements (Detail) $ in Thousands	Dec. 31, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
2,019	$ 2,264
2,020	259
2,021	238
2,022	238
2,023	238
2024 and thereafter	178
Total	$ 3,415

Commitments - Additional Inform

Commitments - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 300,000	$ 300,000	$ 400,000
Minimum purchase commitments or payments under agreements	$ 0

401(k) Plan - Additional Inform

401(k) Plan - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Expense recognized by the Company for matching contributions	$ 1.8	$ 1.8	$ 1.6

Segment Information - Additiona

Segment Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018segment
Segment Reporting [Abstract]
Number of operating segments (in segments)	2

Segment Information - Schedule

Segment Information - Schedule of Selected Information for Each Business Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 343,374	$ 331,378	$ 301,853
Operating income
Operating income	64,488	51,853	56,588
Interest expense	17,405	18,410	26,618
Debt retirement costs	0	0	1,896
Loss on extinguishment of debt	0	2,442	0
Other income	2,465	8,638	220
Income before income taxes	49,548	39,639	28,294
Depreciation and amortization	12,769	18,189	17,330
Long-lived assets	107,888	92,999
DEFINITY
Segment Reporting Information [Line Items]
Revenues	183,073	157,268	131,612
TechneLite
Segment Reporting Information [Line Items]
Revenues	98,858	104,644	99,217
Other
Segment Reporting Information [Line Items]
Revenues	61,443	69,466	71,024
U.S.
Segment Reporting Information [Line Items]
Revenues	288,580	290,002	257,420
All other
Segment Reporting Information [Line Items]
Revenues	54,794	41,376	44,433
U.S.
Segment Reporting Information [Line Items]
Revenues	288,580	290,002	257,420
Operating income
Operating income	56,327	49,239	46,909
Depreciation and amortization	12,278	17,672	15,995
Long-lived assets	106,755	91,537
International
Segment Reporting Information [Line Items]
Revenues	54,794	41,376	44,433
Operating income
Operating income	8,161	2,614	9,679
Depreciation and amortization	491	517	$ 1,335
Long-lived assets	$ 1,133	$ 1,462

Valuation and Qualifying Acco_3

Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for doubtful accounts
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	$ 977	$ 969	$ 881
Charged to Income	321	136	53
Deductions from Reserves	(179)	(128)	(30)
Other Adjustments	0	0	65
Balance at End of Year	1,119	977	969
Rebates and allowances
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Year	2,860	2,297	2,303
Charged to Income	13,202	9,568	7,255
Deductions from Reserves	(11,047)	(8,351)	(6,809)
Other Adjustments	(361)	(654)	(452)
Balance at End of Year	$ 4,654	$ 2,860	$ 2,297

Quarterly Consolidated Financ_3

Quarterly Consolidated Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 86,271	$ 88,900	$ 85,573	$ 82,630	$ 81,241	$ 79,941	$ 88,837	$ 81,359	$ 343,374
Gross profit	43,845	44,885	43,846	42,309	37,899	38,527	45,947	39,762	$ 174,885	$ 162,135	$ 137,780
Net income	$ 13,293	$ 9,269	$ 9,745	$ 8,211	$ 97,126	$ 8,526	$ 13,595	$ 4,138
Basic income per weighted-average share (in dollars per share)	$ 0.35	$ 0.24	$ 0.25	$ 0.22	$ 2.58	$ 0.23	$ 0.37	$ 0.11	$ 1.06	$ 3.31	$ 0.84
Diluted income per weighted-average share (in dollars per share)	$ 0.34	$ 0.24	$ 0.25	$ 0.21	$ 2.47	$ 0.22	$ 0.35	$ 0.11	$ 1.03	$ 3.17	$ 0.82
Release valuation allowance					$ (141,100)				$ (3,969)	$ (141,094)
Impact of rate change on deferred taxes					$ 45,100				$ 0	$ 45,129	$ (383)