Fortress Biotech (FBIO) 10-Q 10 May 18 2018 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2018	May 09, 2018
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Entity Registrant Name	Fortress Biotech, Inc.
Entity Central Index Key	1,429,260
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Trading Symbol	FBIO
Entity Common Stock, Shares Outstanding		52,902,146

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 124,020	$ 113,915
Accounts receivable	8,314	7,758
Short-term investments (certificates of deposit)	37,002	36,002
Cash deposits with clearing organizations	1,041	1,041
Receivables from broker-dealers and clearing organizations	8,464	7,395
Forgivable loans receivable	1,534	1,616
Securities owned, at fair value	4,278	1,985
Inventory	222	171
Other receivables - related party	944	618
Prepaid expenses and other current assets	14,338	12,680
Total current assets	200,157	183,181
Property and equipment, net	12,278	9,513
Restricted cash	17,387	17,387
Long-term investments, at fair value	1,272	1,390
Intangible assets	14,400	15,223
Goodwill	18,645	18,645
Other assets	936	611
Total assets	265,075	245,950
Current liabilities
Accounts payable and accrued expenses	44,725	36,127
Accounts payable and accrued expenses - related party	124	222
Accrued commissions and payroll payable	10,713	10,065
Deferred clearing and marketing credits	733	786
Securities sold, not yet purchased, at fair value	0	151
Warrants issued - National	6,671	5,597
Interest payable	332	315
Interest payable - related party	657	669
Notes payable, short-term (net of debt discount of $0 and $973 at March 31, 2018 and December 31, 2017, respectively)	0	8,528
Subsidiary convertible note, short-term, at fair value	12,651	4,700
Deferred revenue	690	0
Derivative warrant liability	78	87
Other current liabilities	1,952	181
Total current liabilities	79,326	67,428
Notes payable, long-term (net of debt discount of $1,047 and $62 at March 31, 2018 and December 31, 2017, respectively)	73,444	43,222
Subsidiary convertible note, long-term, at fair value	0	10,059
Other long-term liabilities	4,759	4,739
Total liabilities	157,529	125,448
Stockholders' equity
Preferred stock, $.001 par value, 15,000,000 authorized, 5,000,000 designated Series A shares 1,000,000 shares issued and outstanding as of March 31, 2018 and December 31, 2017; liquidation value of $25.00 per share	1	1
Common stock, $.001 par value, 100,000,000 shares authorized, 52,686,537 and 50,991,285 shares issued and outstanding as of March 31, 2018 and December 31, 2017, respectively	52	51
Common stock issuable, 104,958 and 158,015 shares as of March 31, 2018 and December 31, 2017, respectively	489	500
Additional paid-in-capital	374,254	364,148
Accumulated deficit	(333,145)	(312,127)
Total stockholders' equity attributed to the Company	41,651	52,573
Non-controlling interests	65,895	67,929
Total stockholders' equity	107,546	120,502
Total liabilities and stockholders' equity	$ 265,075	$ 245,950

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument, Unamortized Discount, Current	$ 0	$ 973
Debt Instrument, Unamortized Discount, Noncurrent	$ 1,047	$ 62
Preferred Stock, par value	$ 0.001	$ 0.001
Preferred Stock, shares authorized	15,000,000	15,000,000
Preferred Stock Shares Designated	5,000,000	5,000,000
Preferred Stock, shares issued	1,000,000	1,000,000
Preferred Stock, shares outstanding	1,000,000	1,000,000
Common Stock, par value	$ 0.001	$ 0.001
Common Stock, shares authorized	100,000,000	100,000,000
Common Stock, shares issued	52,686,537	50,991,285
Common Stock, shares outstanding	52,686,537	50,991,285
Common Stock, Shares Subscribed but Unissued	104,958	158,015

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue
Investment advisory	$ 1,314,000
Other	9,915,000
Net revenue	55,425,000	$ 44,682,000
Operating expenses
Cost of goods sold - product revenue	1,472,000	469,000
Research and development	12,000
Research and development - licenses acquired	97,000	1,294,000
General and administrative	10,784,000	7,985,000
Underwriting costs	145,000	0
Loss from operations	90,911,000	62,259,000
Loss from operations	(35,486,000)	(17,577,000)
Other income (expenses)
Interest income	284,000	136,000
Interest expense and financing fee	(2,083,000)	(698,000)
Change in fair value of derivative liabilities	(1,065,000)	4,342,000
Change in fair value of subsidiary convertible note	250,000	(97,000)
Change in fair value of investments	(118,000)	(668,000)
Total other income (expenses)	(2,732,000)	3,015,000
Net loss	(38,218,000)	(14,562,000)
Less: net loss attributable to non-controlling interests	(17,200,000)	(2,580,000)
Net loss attributable to common stockholders	$ (21,018,000)	$ (11,982,000)
Basic and diluted net loss per common share	$ (0.49)	$ (0.3)
Weighted average common shares outstanding-basic and diluted	42,518,403	40,357,711
Parent Company [Member]
Revenue
Product revenue, net	$ 5,509,000	$ 2,085,000
Revenue - from a related party	394,000	693,000
Net revenue	5,903,000	2,778,000
Operating expenses
Cost of goods sold - product revenue	1,472,000	469,000
Research and development	24,958,000	7,110,000
Research and development - licenses acquired	97,000	1,294,000
General and administrative	13,548,000	10,252,000
Loss from operations	40,075,000	19,125,000
National Holdings Corporation [Member]
Revenue
Commissions	25,618,000	24,506,000
Net dealer inventory gains	2,190,000	2,511,000
Investment banking	12,704,000	7,061,000
Investment advisory	5,333,000	3,385,000
Interest and dividends	631,000	716,000
Transfer fees and clearing services	2,297,000	2,498,000
Tax preparation and accounting	523,000	856,000
Other	226,000	371,000
Net revenue	49,522,000	41,904,000
Operating expenses
Commissions, compensation and fees	43,561,000	37,258,000
Clearing fees	743,000	738,000
Communications	760,000	722,000
Occupancy	955,000	1,008,000
Licenses and registration	637,000	405,000
Professional fees	1,393,000	1,263,000
Interest	2,000	4,000
Depreciation and amortization	859,000	506,000
Other administrative expenses	1,781,000	1,230,000
Loss from operations	$ 50,836,000	$ 43,134,000

Condensed Consolidated Stateme5

Condensed Consolidated Statement of Changes in Stockholders' Equity - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Total	Series A Preferred Stock [Member]	Common Stock [Member]	Common Shares Issuable [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Non-Controlling Interests [Member]
Balance at Dec. 31, 2017	$ 120,502	$ 1	$ 51	$ 500	$ 364,148	$ (312,127)	$ 67,929
Balance (in shares) at Dec. 31, 2017		1,000,000	50,991,285
Stock-based compensation expense	5,053	$ 0	$ 0	0	5,053	0	0
Issuance of restricted stock	0	0	$ 1	0	(1)	0	0
Issuance of restricted stock (in shares)			1,472,440
Issuance of subsidiaries' common shares for license expenses	22	0	$ 0	0	22	0	0
Subsidiaries' offering, net	20,844	0	0	0	20,844	0	0
Exercise of subsidiary's warrants for cash	96	0	0	0	96	0	0
Issuance of common stock for at-the-market offering	318	0	$ 0	0	318	0	0
Issuance of common stock for at-the-market offering (in shares)			64,797
At-the-market offering cost	(6)	0	$ 0	0	(6)	0	0
Common shares issuable for 2017 Subordinated Note Financing interest expense	489	0	0	489	0	0	0
Common shares issued for 2017 Subordinated Note Financing interest expense	0	$ 0	$ 0	(500)	500	0	0
Common shares issued for 2017 Subordinated Note Financing interest expense (in shares)		0	158,015
Preferred A dividends declared and paid	(586)	$ 0	$ 0	0	(586)	0	0
Offering cost and financing fee paid to NHLD	(439)	0	0	0	(439)	0	0
Acquisition of business - NHLD	(529)	0	0	0	(529)	0	0
Non-controlling interest in subsidiaries	0	0	0	0	(15,166)	0	15,166
Net loss attributable to non-controlling interest	17,200	0	0	0	0	0	(17,200)
Net loss attributable to common stockholders	(21,018)	0	0	0	0	(21,018)	0
Balance at Mar. 31, 2018	$ 107,546	$ 1	$ 52	$ 489	$ 374,254	$ (333,145)	$ 65,895
Balance (in shares) at Mar. 31, 2018		1,000,000	52,686,537

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash Flows from Operating Activities:
Net Loss	$ (38,218)	$ (14,562)
Reconciliation of net loss to net cash used in operating activities:
Depreciation expense	365	274
Amortization of intangible asset	690	408
Amortization of debt discount	341	246
Amortization of product revenue license fee	133	133
Amortization of forgivable loans to registered representatives	160	201
Amortization of deferred clearing credit	(53)	(52)
Stock-based compensation expense	5,053	2,929
Issuance of subsidiaries' common shares for research and development expenses	0	30
Recovery of doubtful accounts	20	(115)
Common shares issuable for 2017 Subordinated Note Financing interest expense	489	0
Change in fair value of investments	118	668
Change in fair value of derivative liabilities	1,065	(4,342)
Change in fair value of subsidiary convertible note	(250)	97
Research and development-licenses acquired, expense	97	1,265
Change in fair value of subsidiaries' assets and liabilities	4	11
Increase (decrease) in cash and cash equivalents resulting from changes in operating assets and liabilities:
Accounts receivable	(556)	462
Receivables from broker-dealers and clearing organizations	(1,069)	499
Forgivable loans receivable	(78)	(17)
Securities owned, at fair value	(2,293)	1,151
Inventory	(51)	(1)
Other receivables - related party	(326)	756
Prepaid expenses and other current assets	(1,939)	635
Accounts payable and accrued expenses	8,258	(1,882)
Accounts payable and accrued expenses - related party	(98)	0
Securities sold, but not yet purchased, at fair value	(151)	(297)
Interest payable	17	2
Interest payable - related party	(12)	30
Deferred revenue	690	0
Other long-term liabilities	19	(4)
Net cash used in operating activities	(27,575)	(11,475)
Cash Flows from Investing Activities:
Purchase of research and development licenses	(75)	(665)
Purchase of property and equipment	(801)	(261)
Purchase of short-term investment (certificates of deposit)	(25,000)	0
Redemption of short-term investment (certificates of deposit)	24,000	0
Security deposits refund	0	3
Acquisition of business - National	(124)	(19)
Collection on notes receivable	25	0
Net cash used in investing activities	(1,975)	(942)
Cash Flows from Financing Activities:
Inter-company costs related to the issuance of Series A preferred stock	1,298	0
Payment of Preferred A dividends	(586)	0
Proceeds from at-the-market offering	229	0
Payment of cost related to at-the-market offering	(6)	0
Proceeds from subsidiaries' offering	23,011	55,904
Payment of costs related to subsidiaries' offering	(2,167)	(2,998)
Proceeds from exercise of subsidiary's warrants	96	0
Proceeds from 2017 Subordinated Note Financing	0	3,254
Payment of debt issuance costs associated with 2017 Subordinated Note Financing	(255)	0
Proceeds from Opus Credit Facility	0	2,000
Proceeds from 2018 Venture Notes	21,707	0
Payment of debt issue costs associated with 2018 Venture Notes	(1,814)	0
Payment of subsidiaries' Convertible Note	(1,858)	0
Net cash provided by financing activities	39,655	58,160
Net increase in cash and cash equivalents, cash deposits with clearing organizations and restricted cash	10,105	45,743
Cash and cash equivalents, cash deposits with clearing organizations and restricted cash at beginning of period	113,915	105,184
Cash and cash equivalents, cash deposits with clearing organizations and restricted cash at end of period	124,020	150,927
Supplemental disclosure of cash flow information:
Cash paid for interest	2	4
Supplemental disclosure of non-cash financing and investing activities:
Issuance of restricted stock	1	1
Issuance of warrants in conjunction with 2017 Subordinated Note Financing	0	206
Receivable from ATM issuances	89	0
Debt discount related to Opus Credit Facility	0	158
Common shares issuable for license acquired	0	1,682
Common shares issued for 2017 Subordinated Note Financing interest expense	500	0
Property, plant and equipment included in account payable and accrued liabilities	2,321	0
Business acquired:
Business acquired	124	19
National [Member]
Supplemental disclosure of cash flow information:
Cash paid for interest	394	58
Cash paid for income taxes	13	81
Supplemental disclosure of non-cash financing and investing activities:
Fixed assets (acquired but not paid)	9	23
Related Party [Member]
Supplemental disclosure of cash flow information:
Cash paid for interest	$ 853	$ 0

Organization and Description of

Organization and Description of Business	3 Months Ended
	Mar. 31, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Description of Business	1. Organization and Description of Business Fortress Biotech, Inc. (“Fortress” or the “Company”) is a biopharmaceutical company dedicated to acquiring, developing and commercializing novel pharmaceutical and biotechnology products. Fortress develops and commercializes products both within Fortress and through certain of its subsidiary companies, also referred to as the “Fortress Companies.” Additionally, the Company maintains a controlling interest in National Holdings Corporation, a diversified independent brokerage company (together with its subsidiaries, referred to as “NHLD” or “National”). In addition to its internal development programs, the Company leverages its biopharmaceutical business expertise and drug development capabilities and provides funding and management services to help the Fortress Companies achieve their goals. The Company and the Fortress Companies may seek licenses, acquisitions, partnerships, joint ventures and/or public and private financings to accelerate and provide additional funding to support their research and development programs. As of March 31, 2018, in addition to National, the Company has several consolidated Fortress Companies, some of which contain product licenses, including: Aevitas Therapeutics, Inc. (“Aevitas”), Avenue Therapeutics, Inc. (“Avenue”), Caelum Biosciences, Inc. (“Caelum”), Cellvation, Inc. (“Cellvation”), Checkpoint Therapeutics, Inc. (“Checkpoint”), Cyprium Therapeutics “Escala”), GeneXion Oncology, Inc. (“GeneXion”), Fortress Biotech China, Inc. (“Fortress China Liquidity and Capital Resources Since inception, the Company’s operations have been financed primarily through the sale of equity and debt securities and the proceeds from the exercise of warrants and stock options. The Company has incurred losses from operations and negative cash flows from operating activities since inception and expects to continue to incur substantial losses for the next several years as it continues to fully develop and prepare regulatory filings and obtain regulatory approvals for its existing and new product candidates. The Company’s current cash and cash equivalents are sufficient to fund operations for at least the next 12 months

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the unaudited interim condensed consolidated financial statements reflect all adjustments, which include only normal recurring adjustments necessary for the fair statement of the balances and results for the periods presented. Certain information and footnote disclosures normally included in the Company’s annual financial statements prepared in accordance with GAAP have been condensed or omitted. These condensed consolidated financial statement results are not necessarily indicative of results to be expected for the full fiscal year or any future period. The unaudited condensed consolidated financial statements and related disclosures have been prepared with the presumption that users of the unaudited condensed consolidated financial statements have read or have access to the audited consolidated financial statements for the preceding fiscal year for each of the Company, Avenue, Checkpoint, Mustang and National. Accordingly, these unaudited condensed consolidated financial statements should be read in conjunction with the Company’s Form 10-K, which was filed with the United States Securities and Exchange Commission (“SEC”) on March 16, 2018, from which the Company derived the balance sheet data at December 31, 2017, as well as National’s Form 10-K and 10-K/A filed with the SEC on December 22, 2017 and January 17, 2018, respectively and their Form 10-Q, filed with the SEC on February 14, 2018, Checkpoint’s Form 10-K filed with the SEC on March 16, 2018, Mustang’s Form 10-K, filed with the SEC on March 29, 2018, and Avenue’s Form 10-K, filed with the SEC on March 1, 2018. The Company’s unaudited condensed consolidated financial statements include the accounts of the Company and its subsidiaries: Avenue, Aevitas, Caelum, CB Securities, Cellvation, Coronado SO, Checkpoint, Cyprium, Escala, GeneXion, Helocyte, Innmune Limited, JMC, Mustang, NHLD, Tamid, Coronado SO, Escala, Fortress China The National assets acquired and liabilities assumed and revenues and expenses are reported on a one quarter lag. Therefore, the National assets acquired and liabilities assumed included in these condensed consolidated financial statements as of March 31, 2018 are actually the assets and liabilities as of December 31, 2017 and the revenues and expenses included in these condensed consolidated financial statements for the quarter ending March 31, 2018 are actually the revenues and expenses for the quarter ending December 31, 2017. The preparation of the Company’s unaudited condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited condensed consolidated financial statements and the reported amounts of expenses during the reporting period The Company’s unaudited condensed consolidated financial statements include certain amounts that are based on management’s best estimates and judgments. The Company’s significant estimates include, but are not limited to, useful lives assigned to long-lived and intangible assets, fair value measurements, stock-based compensation, common stock issued to acquire licenses, investments, accrued expenses, derivative warrant liabilities, revenue with customers, provisions for income taxes and contingencies. Due to the uncertainty inherent in such estimates, actual results may differ from these estimates. There have been no material changes to the Company’s significant accounting policies previously disclosed in the Company’s Form 10-K filed with the SEC on March 16, 2018, with the exception of revenue recognition. In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients 0.1 The new revenue guidance does not apply to revenue associated with financial instruments, including National’s warrants and securities that are accounted for under other U.S. GAAP, and as a result, did not have an impact on the elements of our Consolidated Statements of Operations most closely associated with financial instruments. The new revenue standard primarily impacts the following of our revenue recognition and presentation accounting policies: ⋅ Investment Banking Revenues. ⋅ Investment Banking Advisory Expenses. ⋅ Investment Banking Underwriting and Advisory Expenses. The new revenue standard requires enhanced disclosures, which are included in footnote 21 to our condensed consolidated financial statements beginning with the three months ended March 31, 2018. Contract Assets Contract assets represent the Company’s right to consideration in exchange for goods or services that the Company has transferred to a customer, excluding unconditional rights to consideration that are presented as receivables. Contract Liabilities Contract liabilities represent the Company’s obligation to deliver products or provide data to customers in the future for which cash has already been received. In May 2017, the FASB issued ASU 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments, In January 2016, the FASB issued ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Liabilities Recent Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In July 2017, the FASB issued ASU 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480) and Derivatives and Hedging (Topic 815): I. Accounting for Certain Financial Instruments with Down Round Features; II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception

National Holdings Corporation A

National Holdings Corporation Acquisition - Intangible Assets	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
National Holdings Corporation Acquisition - Intangible Assets	3. National Holdings Corporation Acquisition - Intangible Assets Intangible assets consist of trademark and customer lists acquired in the offer under the purchase method of accounting and are recorded at fair value net of accumulated amortization since the purchase date. Useful life Trademark 10 years Customer lists 6 years Intangible assets at December 31, 2017 $ 14,340 Amortization expense (690) Intangible assets at March 31, 2018 $ 13,650 Trademark Customer Total Nine Months Ended December 31, 2018 $ 226 $ 1,884 $ 2,110 Year Ended December 31, 2019 300 2,500 2,800 Year Ended December 31, 2020 301 2,506 2,807 Year Ended December 31, 2021 300 2,500 2,800 Year Ended December 31, 2022 300 1,726 2,026 Thereafter 1,107 – 1,107 Total $ 2,534 $ 11,116 $ 13,650 The Company reviews its finite-lived intangible assets for impairment when events or changes in circumstances indicate that the carrying amount of a finite-lived intangible asset may not be recoverable. Recoverability of a finite-lived intangible asset is measured by a comparison of its carrying amount to the undiscounted future cash flows expected to be generated by the asset. If the asset is considered to be impaired, the impairment recognized is measured by the amount by which the carrying amount of the asset exceeds the fair value of the asset. There were no indicators of impairment during the three months ended March 31, 2018.

Broker-Dealers and Clearing Org

Broker-Dealers and Clearing Organizations, Other Receivables and Prepaid Expenses and Other Current Liabilities	3 Months Ended
	Mar. 31, 2018
Brokers and Dealers [Abstract]
Broker-Dealers and Clearing Organizations, Other Receivables and Prepaid Expenses and Other Current Liabilities	4. Broker-Dealers and Clearing Organizations, Other Receivables and Prepaid Expenses and Other Current Liabilities At December 31, 2017 and September 30, 2017, National’s receivables of 3.2 and $ 7.4 and September 30, 2017 4.9 and $ 5.2 0.6 $ 0.5

Forgivable Loans Receivable

Forgivable Loans Receivable	3 Months Ended
	Mar. 31, 2018
Forgivable Loans Receivable [Abstract]
Forgivable Loans Receivable	5. Forgivable Loans Receivable From time to time, National's operating subsidiaries may make loans, evidenced by promissory notes, primarily to newly recruited independent financial advisors as an incentive for their affiliation. The notes receivable balance is comprised of unsecured non-interest-bearing and interest-bearing loans (weighted average interest rate of 4 0.2 0.2 National provides an allowance for doubtful accounts on the notes based on historical collection experience and continually evaluates the receivables for collectability and possible write-offs where a loss is deemed probable. As of December 31, 2017, no allowance for doubtful accounts was required. There were no unamortized forgivable loans outstanding at December 31, 2017 attributable to registered representatives who ended their affiliation with National’s subsidiaries prior to the fulfillment of their obligation.

Property and Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment	6. Property and Equipment Estimated Useful March 31, December 31, Lives (in years) 2018 2017 Computer equipment 3 $ 594 $ 543 Furniture and fixtures 5 1,015 1,009 Machinery and equipment 5 143 143 Leasehold improvements 5 - 15 5,383 5,351 Construction in process (1) N/A 4,237 1,241 Total property and equipment 11,372 8,287 Less: accumulated depreciation (1,367) (1,171) Property and equipment, net $ 10,005 $ 7,116 (1) Relates to the Mustang cell processing facility Fortress's depreciation expense for the three months ended March 31, 2018 and 2017, was approximately $ 0.2 0.2 Estimated Useful December 31, September 30, Lives (in years) 2017 2017 Equipment 5 $ 1,339 $ 1,306 Furniture and fixtures 5 291 284 Leasehold improvements Lesser of useful life or term 1,011 1,006 Capital Leases (primarily composed of computer equipment) 5 276 276 Fixed assets – gross 2,917 2,872 Accumulated depreciation and amortization (644) (475) Fixed assets – net $ 2,273 $ 2,397

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	7. Fair Value Measurements Certain of the Company’s financial instruments are not measured at fair value on a recurring bass but are recorded at amounts that approximate their fair value due to their liquid or short-term nature, such as accounts payable, accrued expenses and other current liabilities. Origo Acquisition Corporation A shareholder meeting of “Origo Acquisition Corporation” (“Origo”) was held on March 12, 2018, at which the Origo shareholders approved the extension of the date by which to consummate a business combination to June 12, 2018. As of March 31, 2018, the Company valued its investment in Origo, a publicly traded company, utilizing the following assumptions: probability of a successful business combination of 38.4 10.96 0.44 0.36 0.1 1.3 0.3 Securities Owned National December 31, Risk-free interest rate 1.53% – 2.2 % Expected dividend yield – % Expected term in years .43 – 4.35 Remaining volatility 369.19% – 59.69 % Strike price $0.01 – $10.00 ($in thousands) Fair Value of Beginning balance at September 30, 2017 $ 548 Change in fair value of derivative liabilities 138 Ending balance at December 31, 2017 $ 686 Warrant Liabilities Helocyte The fair value of Helocyte’s warrant liability, which was issued in connection with Helocyte’s convertible note (see Note 11), was measured using a Monte Carlo simulation valuation methodology. A summary of the weighted average (in aggregate) significant unobservable inputs (Level 3 inputs) used in measuring Helocyte’s warrant liabilities that are categorized within Level 3 of the fair value hierarchy as of March 31, 2018 is as follows: March 31, Risk-free interest rate 2.411% - 2.447 % Expected dividend yield - % Expected term in years 3.25 – 3.67 Expected volatility 70.0 % Strike price $ 0.46 ($in thousands) Fair Value of Beginning balance at January 1, 2018 $ 87 Change in fair value of derivative liabilities (9) Ending balance at March 31, 2018 $ 78 Notes at Fair Value Helocyte Helocyte’s convertible note is measured at fair value using the Monte Carlo simulation valuation methodology. A summary of the weighted average (in aggregate) significant unobservable inputs (Level 3 inputs) used in measuring Helocyte’s convertible debt that is categorized within Level 3 of the fair value hierarchy as of March 31, 2018 is as follows: March 31, 2018 Risk-free interest rate 1.96%- 2.21 % Expected dividend yield - % Expected term in years 0.58 – 1.67 Expected volatility 53.1 % ($in thousands) Helocyte Beginning balance at January 1, 2018 $ 4,700 Payment of convertible notes (1,858) Change in fair value of convertible notes (331) Ending balance at March 31, 2018 $ 2,511 Caelum Caelum’s convertible debt is measured at fair value using the Monte Carlo simulation valuation methodology. A summary of the weighted average (in aggregate) significant unobservable inputs (Level 3 inputs) used in measuring Caelum’s convertible debt that is categorized within Level 3 of the fair value hierarchy as of March 31, 2018 is as follows: March 31, 2018 Risk-free interest rate 1.71%- 2.17 % Expected dividend yield - % Expected term in years 0.21 – 1.46 Expected volatility 53.1 % ($in thousands) Caelum Beginning balance at January 1, 2018 $ 10,059 Change in fair value of convertible notes 81 Ending balance at March 31, 2018 $ 10,140 Fair Value Measurement as of March 31, 2018 ($in thousands) Level 1 Level 2 Level 3 Total Assets Long-term investments, at fair value $ – $ – $ 1,272 $ 1,272 Total $ – $ – $ 1,272 $ 1,272 Liabilities Warrant liabilities $ – $ – $ 78 $ 78 Caelum Convertible Note, at fair value – – 10,140 10,140 Helocyte Convertible Note, at fair value – – 2,511 2,511 Total $ – $ – $ 12,729 $ 12,729 Fair Value Measurement as of December 31, 2017 ($in thousands) Level 1 Level 2 Level 3 Total Assets Long-term investments, at fair value $ – $ – $ 1,390 $ 1,390 Total $ – $ – $ 1,390 $ 1,390 Liabilities Warrant liabilities $ – $ – $ 87 $ 87 Caelum Convertible Note, at fair value – – 10,059 10,059 Helocyte Convertible Note, at fair value – – 4,700 4,700 Total $ – $ – $ 14,846 $ 14,846 Fair Value Measurement as of December 31, 2017 Level 1 Level 2 Level 3 Total Assets National Securities owned, at fair value Corporate stocks $ 65 $ - $ - $ 65 Municipal bonds 3,452 - - 3,452 Restricted stock - 75 - 75 Warrants - - 686 686 Total $ 3,517 $ 75 $ 686 $ 4,278 Liabilities National Securities sold, but not yet purchased at fair value Contingent consideration - - 717 717 Warrants issued - National - - 6,671 6,671 Total $ - $ - $ 7,388 $ 7,388 Fair Value Measurement as of September 30, 2017 Level 1 Level 2 Level 3 Total Assets National Securities owned, at fair value Corporate stocks $ 116 $ - $ - $ 116 Municipal bonds 1,239 - - 1,239 Restricted stock - 82 - 82 Warrants - - 548 548 Total $ 1,355 $ 82 $ 548 $ 1,985 Liabilities National Securities sold, but not yet purchased at fair value Municipal bonds 151 - - 151 Contingent consideration - - 311 311 Warrants issued - National - - 5,597 5,597 Total $ 151 $ - $ 5,908 $ 6,059 Warrants issued - National The fair value of the 5.4 44 December 31, Dividend yield – % Expected volatility 46.13 % Risk-free interest rate 2.20 % Life (in years) 3.69 ($ in thousands) National’s Beginning balance at September 30, 2017 $ 5,597 Change in fair value of derivative liability 1,074 Ending balance at December 31, 2017 $ 6,671 National listed the warrants on the Nasdaq Capital Market under the symbol “NHLDW” in February 2017. ($ in thousands) Investment in Helocyte Caelum Warrants Warrant Total Balance at December 31, 2017 $ 1,390 $ 4,700 $ 10,059 $ 5,597 $ 87 $ 21,833 Payment of convertible note - (1,858) - - - (1,858) Change in fair value of investments (118) - - - - (118) Change in fair value of convertible notes - (331) 81 - - (250) Change in fair value of derivative liabilities - - - 1,074 (9) 1,065 Balance at March 31, 2018 $ 1,272 $ 2,511 $ 10,140 $ 6,671 $ 78 $ 20,672 For the three months ended March 31, 2018, no transfers occurred between Level 1, Level 2 and Level 3 instruments.

Licenses Acquired

Licenses Acquired	3 Months Ended
	Mar. 31, 2018
Licenses Acquired [Abstract]
Licenses Acquired	8. Licenses Acquired In accordance with ASC 730-10-25-1, Research and Development For the Three Months Ended March 31, ($ in thousands) 2018 2017 Fortress Companies: Checkpoint $ – $ 400 Helocyte 21 – Mustang 75 575 Cellvation 1 – Caelum – 219 Cyprium – 100 Total $ 97 $ 1,294 Checkpoint ($ in thousands) For the three months ended March 31 2018 2017 Jubliant Biosys License CK-103 $ – $ 400 Total licenses acquired expense $ – $ 400 In addition, for the three months ended March 31, 2018 and 2017, approximately $ 44,000 28,000 Mustang ($ in thousands) For the three months ended March 31 2018 2017 City of Hope (COH) IL-13 License $ – $ 250 COH IV/ICV Agreement – 125 University of California License for PSCA – 200 Manufacturing License 75 – Total licenses acquired expense $ 75 $ 575 City of Hope Manufacturing Methods License In January 2018, Mustang entered into a Non-Exclusive License Agreement (the “Manufacturing License”) with COH to acquire intellectual property rights in patent applications, know-how and regulatory filings pertaining to methods of manufacturing T-cells in connection with CAR-T development and 75,000 15,000 Option on Collaboration Agreement with TGTX On February 2, 2018 Mustang entered into an Option Agreement the (“TGTX Mustang Option”) with TG Therapeutics, Inc. (“TGTX”), a related party, whereby TGTX was granted the option to enter into a global collaboration on the joint development and commercialization of product candidates pertaining to Mustang’s CD20 license agreement with the Fred Hutchinson Cancer Research Center. In consideration of the TGTX Mustang Option, TGTX paid an option fee of $ 50,000 Caelum For the three months ended March 31, 2018 and 2017, respectively, Caelum recorded expense of nil and $ 0.2 Cyprium For the three months ended March 31, 2018 and 2017, respectively, Cyprium recorded expense of nil and $ 0.1 Eunice Kennedy Shriver

Sponsored Research and Clinical

Sponsored Research and Clinical Trial Agreements	3 Months Ended
	Mar. 31, 2018
Research and Development [Abstract]
Research, Development, and Computer Software Disclosure	9. Sponsored Research and Clinical Trial Agreements Aevitas On January 25, 2018, Aevitas entered into a Sponsored Research Agreement with the University of Massachusetts (“UMass SRA”) for certain continued research and development activities related to the development of adeno-associated virus (“AAV”) gene therapies in complement-mediated diseases. The total amount to be funded by Aevitas under the UMass SRA is $ 0.8 0.8 0.1 Caelum On March 12, 2018, Caelum entered into a Sponsored Research Agreement with Columbia University to conduct preclinical research in connection with CAEL 101. The total cost of the study approximates $ 0.1 11,000 Cellvation For the three months ended March 31, 2018 and 2017, respectively, Cellvation recorded expense of $ 82,500 Checkpoint In connection with its license agreement with NeuPharma, Inc. (“NeuPharma”), Checkpoint entered into a Sponsored Research Agreement with NeuPharma for certain research and development activities and subsequently , including all amounts previously paid by the Company. 31,000 0.2 In addition, for the three months ended March 31, 2018 and 2017, approximately $31,000 and $0.2 million, respectively, was recognized in revenue in connection with the Sponsored Research Agreement in the Condensed Consolidated Statements of Operations. Helocyte ($ in thousands) For the three months ended March 31 2018 2017 COH Triplex clinical research and support $ – $ 500 COH PepVax clinical research and support – 235 Total licenses acquired expense $ – $ 735 During the first quarter of 2018, Helocyte elected to discontinue the further development of its HLA-restricted, single-antigen PepVax program and as such will cease to incur costs associated with this program. Mustang ($ in thousands) For the three months ended March 31 2018 2017 COH CAR T $ 500 $ 500 COH - CD123 150 20 COH - IL13Ra2 360 9 City of Hope - Manufacturing 114 – Fred Hutch - CD20 266 Total $ 1,390 $ 529 COH Sponsored Research Arrangement Related to Manufacturing Methods On January 3, 2018, in connection with the Manufacturing License, Mustang entered into a Sponsored Research Agreement (the “Manufacturing SRA”) with COH in connection with the optimization and development of CAR T cell manufacturing processes and procedures. Pursuant to the terms of Manufacturing SRA, Mustang paid $ 0.9 0.1 0.9 Fred Hutch Sponsored Research Agreement Related to the Manufacturing Process On March 17, 2018, due to Fred Hutch’s operation of a process development research organization whose primary focus is on the development and optimization of processes and systems associated with the manufacture of cellular therapies, Mustang entered into a Sponsored Research Agreement (the “Fred Hutch Manufacturing SRA”) with Fred Hutch in order to conduct a research program titled “Optimization of the anti-CD20 CART (Protocol 9738) manufacturing process.” Pursuant to the terms of the Fred Hutch Manufacturing SRA, Mustang will fund $0.6 million for the research program thereunder, which has an initial term of one year. For the three months ended March 31, 2018 Mustang recorded approximately $12,000, in research and development expenses in the Company’s Condensed Consolidated Statements of Operations. Tamid On November 30, 2017, in connection with its three separate license agreements with UNC, Tamid entered into a Sponsored Research Agreement with UNC (“UNC SRA”) for certain continued research and development activities related to Nanodysferlin for treatment of Dysferlinopathy, and AAV-HLA-G for ocular diseases. Total amount to be funded by Tamid under the UNC SRA is $ 2.3 three 0.8 0.2

Intangibles, net

Intangibles, net	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangibles, net	10. Intangibles, net Journey Pursuant to the terms of Journey’s license agreements for its branded products, Journey made upfront payments totaling $ 1.6 0.1 0.1

Debt and Interest

Debt and Interest	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt and Interest	11. Debt and Interest Debt 2018 Venture Notes During the period ended March 31, 2018, the Company closed a private placement of promissory notes for an aggregate of $ 21.7 36 8 NSC acted as the sole placement agent for the 2018 Venture Notes. The Company paid NSC a fee of $ 1.7 The 2018 Venture Notes allows the Company to transfer a portion of the proceeds from the 2018 Venture Notes to a Fortress subsidiary upon the completion by such subsidiary of an initial public offering in which it raises sufficient equity capital so that it has cash equal to five times the amount of the portion of the proceeds of the 2018 Venture Notes so transferred. At the time of transfer the Company’s obligation under the NSC Note will be reduced by the amount transferred. For the period ended March 31, 2018, the Company transferred $ 1.4 1.0 0.4 In connection with this transfer NSC will receive warrants to purchase each such subsidiary’s stock equal to 25 10 The value of the warrants, if any, is eliminated in consolidation. Opus Credit Facility Agreement Maturity Date Extension On March 12, 2018, the Company and Opus Point Healthcare Innovation Healthcare Fund (“OPHIF”) amended and restated the Opus Credit Facility (the “A&R Opus Credit Facility”). The A&R Opus Credit Facility extends the maturity date of the notes issued under the Opus Credit Facility from September 14, 2018 September 14, 2019 12 ($ in thousands) March 31, December 31, Interest rate Maturity IDB Note $ 14,929 $ 14,929 2.25 % August - 2020 2017 Subordinated Note Financing 3,254 3,254 8.00 % March - 2020 2017 Subordinated Note Financing 13,893 13,893 8.00 % May - 2020 2017 Subordinated Note Financing 1,820 1,820 8.00 % June - 2020 2017 Subordinated Note Financing 3,018 3,018 8.00 % August - 2020 2017 Subordinated Note Financing 6,371 6,371 8.00 % September - 2020 2018 Venture Notes 6,517 – 8.00 % February – 2021 2018 Venture Notes 15,190 – 8.00 % March - 2021 Opus Credit Facility 9,500 9,500 12.00 % September – 2019 Helocyte Convertible Note, at fair value – 1,000 5.00% - 8.00 % December 2017 Helocyte Convertible Note, at fair value 860 2,194 5.00% - 8.00 % March - 2018 Helocyte Convertible Note, at fair value 945 1,062 5.00% - 8.00 % April - 2018 Helocyte Convertible Note, at fair value 372 444 5.00% - 8.00 % May - 2018 Helocyte Convertible Note, at fair value 310 – 5.00% - 8-00 % September 2018 Helocyte Convertible Note, at fair value 23 – 5.00% - 8.00 % November 2018 Caelum Convertible Note, at fair value 1,026 1,017 8.00 % January - 2019 Caelum Convertible Note, at fair value 6,956 6,900 8.00 % February - 2019 Caelum Convertible Note, at fair value 2,158 2,142 8.00 % March - 2019 Total notes payable 87,142 67,544 Less: Discount on notes payable 1,047 1,035 Total notes payable $ 86,095 $ 66,509 Interest Expense Three Months Ended March 31, ($in thousands) 2018 2017 IDB Note Interest $ 84 $ 82 Total IDB Note 84 82 NSC Debt Interest - 71 Amortization of fees - 38 Total NSC Debt - 109 2017 Subordinated Note Financing Interest 1,048 - Amortization of fees 21 - Total 2017 Subordinated Note Financing 1,069 - Opus Credit Facility Interest 281 232 Amortization of fees 319 208 Total Opus Note 600 440 2018 Venture Notes Interest 56 - Amortization of fees 1 - Total 2018 Venture Notes 57 - LOC Fees Interest 7 8 Total LOC 7 8 Helocyte Convertible Note Interest 68 54 Financing fee - 1 Total Helocyte Convertible Note 68 55 Avenue Convertible Note Financing fee - 3 Total Avenue Convertible Note - 3 Caelum Convertible Note Interest 196 - Total Caelum Convertible Note 196 - Other Interest 2 1 Total Other 2 1 Total Interest Expense and Financing Fee $ 2,083 $ 698

Accrued Expenses and Other Long

Accrued Expenses and Other Long-Term Liabilities	3 Months Ended
	Mar. 31, 2018
Payables and Accruals [Abstract]
Accrued Expenses and Other Long-Term Liabilities	12. Accrued Expenses and Other Long-Term Liabilities March 31, December 31, Accrued expenses: Professional fees $ 1,497 $ 1,625 Salaries, bonuses and related benefits 6,002 5,279 Accrued expenses - related party 107 95 Research and development 7,061 4,046 Dr. Falk Pharma milestone (See Note 16) 3,059 3,059 Accrued royalties payable 1,091 1,411 Accrued coupon expense 735 – Deferred coupon funding 1,516 1,087 Other 646 1,030 Total accrued expenses $ 21,714 $ 17,632 Other long-term liabilities: Deferred rent 4,759 4,739 Total other long-term liabilities $ 4,759 $ 4,739 December 31, September 30, 2017 2017 Legal $ 653 $ 877 Audit 171 176 Telecommunications 208 205 Data Services 454 464 Regulatory 663 540 Settlements 1,789 2,403 Deferred rent 684 497 Other 3,437 3,242 Total $ 8,059 $ 8,404

Non-Controlling Interests

Non-Controlling Interests	3 Months Ended
	Mar. 31, 2018
Noncontrolling Interest [Abstract]
Non-Controlling Interests	13. Non-Controlling Interests As of March 31, 2018 NCI equity share Net gain/(loss) attributable to Non-controlling Non-controlling Aevitas $ (356) $ (47) $ (403) 37.0 % Avenue 2 12,719 (6,691) 6,028 64.4 % Caelum (2,133) (707) (2,840) 33.9 % Cellvation (387) (51) (438) 21.6 % Checkpoint 1 24,662 (5,175) 19,487 67.4 % Coronado SO (290) – (290) 13.0 % Cyprium (169) (31) (200) 10.8 % Helocyte (3,124) (33) (3,157) 19.8 % JMC (461) 56 (405) 6.3 % Mustang 2 36,961 (3,733) 33,228 59.7 % National Holdings 15,805 (734) 15,071 43.4 % Tamid (132) (54) (186) 24.0 % Total $ 83,095 $ (17,200) $ 65,895 As of December 31, 2017 NCI equity share Net gain/(loss) attributable to Non-controlling Non-controlling Aevitas $ (126) $ (168) $ (294) 35.4 % Avenue 2 17,454 (4,646) 12,808 66.1 % Caelum (815) (1,262) (2,077) 34.7 % Cellvation (259) (96) (355) 21.5 % Checkpoint 1 21,635 (12,314) 9,321 62.0 % Coronado SO (236) (54) (290) 13.0 % Cyprium (143) (15) (158) 11.1 % Helocyte (1,907) (1,193) (3,100) 20.0 % JMC (469) 7 (462) 6.3 % Mustang 2 48,740 (11,911) 36,829 61.6 % National Holdings 17,021 (1,216) 15,805 43.4 % Tamid (6) (92) (98) 24.0 % Total $ 100,889 $ (32,960) $ 67,929 (1) Checkpoint is consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Checkpoint’s Class A Common Shares which provide super-majority voting rights. (2) Avenue and Mustang are consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Preferred Class A Shares which provide super-majority voting rights.

Net Loss per Common Share

Net Loss per Common Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Net Loss Per Common Share	14. Net Loss per Common Share Basic net loss per share is calculated by dividing net loss by the weighted-average number of shares of common stock outstanding for the period, without consideration for common stock equivalents. Diluted net loss per share is computed by dividing net loss by the weighted-average number of common stock and common stock equivalents outstanding for the period. The Company’s common stock equivalents, including unvested restricted stock, options, and warrants have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share. Therefore, the weighted average common stock outstanding used to calculate both basic and diluted net loss per share is the same. Three Months Ended March 31, 2018 2017 Warrants to purchase Common Stock 894,189 383,453 Opus warrants to purchase Common Stock 1,880,000 1,860,000 Options to purchase Common Stock 1,085,501 1,105,502 Convertible Preferred Stock 1,000,000 – Unvested Restricted Stock 11,050,943 9,912,161 Unvested Restricted Stock Units 1,778,154 1,249,232 Total 17,688,788 14,510,348

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2018
Stockholders' Equity Note [Abstract]
Stockholders’ Equity	15. Stockholders’ Equity Stock-based Compensation For the Three Months Ended March 31, ($ in thousands) 2018 2017 Employee awards $ 828 $ 367 Executive awards of Fortress Companies’ stock 632 1,463 Fortress Companies: Avenue 349 5 Checkpoint 1,137 979 Mustang 1,995 - Other 112 115 Total stock-based compensation $ 5,053 $ 2,929 For the three months ended March 31, 2018 and 2017, approximately $ 2.3 0.8 2.7 2.1 Stock Options Number of shares Weighted average Total weighted Weighted average Options vested and expected to vest at December 31, 2017 1,110,501 $ 3.78 $ 1,351,080 3.95 Exercised - - - - Options vested and expected to vest at March 31, 2018 1,110,501 $ 3.78 $ 1,701,361 3.71 Options vested and exercisable 1,085,501 $ 3.75 $ 1,701,361 3.68 As of March 31, 2018, Fortress had no unrecognized stock-based compensation expense related to options. Restricted Stock and Restricted Stock Units Number of shares Weighted average Unvested balance at December 31, 2017 11,874,034 $ 2.63 Restricted stock granted 1,392,856 3.99 Restricted stock vested (213,334) 2.76 Restricted stock units granted 230,000 4.98 Restricted stock units forfeited (42,417) 3.52 Restricted stock units vested (64,750) 3.49 Unvested balance at March 31, 2018 13,176,389 $ 2.81 As of March 31, 2018, and 2017, the Company had unrecognized stock-based compensation expense related to restricted stock and restricted stock unit awards of approximately $ 8.4 3.4 3.1 2.8 Warrants Number of shares Weighted average Total weighted Weighted average Outstanding as of December 31, 2017 2,774,189 $ 3.30 $ 2,204,530 4.47 Granted - - - - Forfeited - - - - Outstanding as of March 31, 2018 2,774,189 $ 3.30 $ 3,586,975 4.22 Exercisable as of March 31, 2018 869,189 $ 3.96 $ 634,225 3.81 Employee Stock Purchase Plan Eligible employees can purchase the Company’s Common Stock at the end of a predetermined offering period at 85 As of March 31, 2018, 245,652 154,348 38,000 35,000 Capital Raises Fortress At the Market Offering Pursuant to the terms of the Company’s Amended and Restated At Market Issuance Sales Agreement, or Sales Agreement, with MLV & Co. LLC, or MLV, and FBR Capital Markets & Co., or FBR (the “ATM”), for the period ended March 31, 2018, the Company issued 64,797 4.92 0.3 5,700 Fortress Companies Checkpoint Therapeutics, Inc. Checkpoint Public Offering of Common Stock On March 12, 2018, Checkpoint closed on underwritten public offering, whereby it sold 5,290,000 4.35 23.0 20.8 2.2

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	16. Commitments and Contingencies Indemnification In accordance with its certificate of incorporation, bylaws and indemnification agreements, the Company has indemnification obligations to its officers and directors for certain events or occurrences, subject to certain limits, while they are serving at the Company’s request in such capacity. There have been no claims to date, and the Company has director and officer insurance to address such claims. Pursuant to agreements with clinical trial sites, the Company provides indemnification to such sites in certain conditions. Legal Proceedings - Fortress In the ordinary course of business, the Company and its subsidiaries may be subject to both insured and uninsured litigation. Suits and claims may be brought against the Company by customers, suppliers, partners and/or third parties (including tort claims for personal injury arising from clinical trials of the Company’s product candidates and property damage) alleging deficiencies in performance, breach of contract, etc., and seeking resulting alleged damages. Dr. Falk Pharma, GmbH v. Fortress Biotech, Inc. (Frankfurt am Main Regional Court, Ref. No. 3-06 O 28/16). Dr. Falk Pharma, GmbH (“ Dr. Falk Pharma ”) and Fortress are among the parties to that certain Collaboration Agreement dated March 20, 2012, whereby they agreed to collaborate to develop a product for treatment of Crohn’s disease. A dispute has arisen between Dr. Falk Pharma and Fortress with respect to their relative rights and obligations under the Collaboration Agreement. Specifically, Dr. Falk Pharma contends that it fulfilled its contractual obligations to Fortress and is entitled to the final milestone payment due under the Collaboration Agreement - EUR 2.5 million. Fortress contends that no such payment is due because a condition of the EUR 2.5 million payment was the delivery of a Clinical Study Report that addressed the primary and secondary objectives of a Phase II trial, and Fortress contends that Dr. Falk Pharma failed to deliver such a Clinical Study Report. Dr. Falk Pharma disputes that it failed to deliver such a report and further disputes that the delivery of such a report is a condition of Fortress’s obligation to make the EUR 2.5 million payment. After the parties’ attempts to negotiate a settlement of the dispute were unsuccessful, Dr. Falk Pharma filed a lawsuit against Fortress in the above-referenced Court in Frankfurt, Germany to recover the EUR 2.5 million plus interest and attorneys’ fees, and Fortress was served with the English translation of the lawsuit on August 11, 2016. Fortress retained local counsel and, on December 14, 2016, filed an answer to the complaint, denying that it had any liability to Dr. Falk Pharma. 2.5 Litigation and Regulatory Matters - National National is a defendant or respondent in various pending and threatened arbitrations, administrative proceedings and lawsuits seeking compensatory damages. Several cases have no stated alleged damages. Claim amounts are infrequently indicative of the actual amounts National will be liable for, if any. Further, National has a history of collecting amounts awarded in these types of matters from its brokers that are still affiliated, as well as from those that are no longer affiliated. Many of these claimants also seek, in addition to compensatory damages, punitive or treble damages, and all seek interest, costs and fees. These matters arise in the normal course of business. National intends to vigorously defend itself in these actions, and the ultimate outcome of these matters cannot be determined at this time. Liabilities for potential losses from complaints, legal actions, government investigations and proceedings are established where the National believes that it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. In making these decisions, management bases its judgments on its knowledge of the situations, consultations with legal counsel and its historical experience in resolving similar matters. In many lawsuits, arbitrations and regulatory proceedings, it is not possible to determine whether a liability has been incurred or to estimate the amount of that liability until the matter is close to resolution. However, accruals are reviewed regularly and are adjusted to reflect the National’s estimates of the impact of developments, rulings, advice of counsel and any other information pertinent to a particular matter. Because of the inherent difficulty in predicting the ultimate outcome of legal and regulatory actions, management cannot predict with certainty the eventual loss or range of loss related to such matters. At December 31, 2017 and September 30, 2017, the National accrued approximately $ 1.8 2.4 0.2 6,000 0.4 0.5

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2018
Related Party Transactions [Abstract]
Related Party Note	17. Related Party Transactions Other Related Parties The Company’s Chairman, President and Chief Executive Officer, individually and through certain trusts over which he has voting and dispositive control, beneficially owned approximately 13.7 16.0 Shared Services Agreement with TGTX TGTX and the Company entered into an arrangement to share the cost of certain research and development employees. The Company’s Executive Vice Chairman, Strategic Development, is Executive Chairman and Interim Chief Executive Officer of TGTX. Under the terms of the Agreement, TGTX will reimburse the Company for the salary and benefit costs associated with these employees based upon actual hours worked on TGTX related projects. For the three months ended March 31, 2018 and 2017, the Company invoiced TGTX $0. 3 0.2 related to this arrangement Desk Space Agreements with TGTX and OPPM In connection with the Company’s Desk Space Agreements with TGTX and Opus Point Partners Management, LLC (“OPPM”), as of March 31, 2018, the Company had paid $ 0.6 42,000 3 approximately $ 32,000 14,000 3,000 137,000 61,000 Opus Credit Facility On March 12, 2018, the Company and OPHIF amended and restated the Opus Credit Facility (the “A&R Opus Credit Facility”). The A&R Opus Credit Facility extends the maturity date of the notes issued under the Opus Credit Facility from September 14, 2018 by one year to September 14, 2019. The A&R Opus Credit Facility also permits the Company to make portions of interest and principal repayments in the form of shares of the Company’s common stock and/or in common stock of the Company’s publicly-traded subsidiaries, subject to certain conditions. Fortress retains the ability to prepay the Notes at any time without penalty. The notes payable under the A&R Opus Credit Facility continue to bear interest at 12 0.3 0.2 Checkpoint Public Offering of Common Stock NSC, a subsidiary of National 56.6 1.8 The fees Mustang Option on Collaboration Agreement with TGTX On February 2, 2018 Mustang entered into an Option Agreement the (“TGTX Mustang Option”) with TG Therapeutics, Inc. (“TGTX”), a related party, whereby TGTX was granted the option to enter into a global collaboration on the joint development and commercialization of product candidates pertaining to Mustang’s CD20 license agreement with the Fred Hutchinson Cancer Research Center. In consideration of the TGTX Mustang Option, TGTX paid an option fee of $ 50,000 2018 Venture Notes For the period ended March 31, 2018, the Company raised approximately $ 21.7 1.7 Founders Agreements Fortress Company Effective Date (1) PIK Dividend as Class of Stock Helocyte March 20, 2015 2.5 % Common Stock Avenue February 17, 2015 2.5 % Common Stock Mustang March 13, 2015 2.5 % Common Stock Checkpoint March 17, 2015 0.0 % (2) Common Stock Cellvation October 31, 2016 2.5 % Common Stock Caelum January 1, 2017 2.5 % Common Stock Cyprium March 13, 2017 2.5 % Common Stock Aevitas July 28, 2017 2.5 % Common Stock Tamid November 30, 2017 (3) 2.5 % Common Stock (1) - Represents the effective date of each subsidiary’s Founders Agreement. Each PIK dividend and equity fee is payable on the annual anniversary of the effective date of the original Founders Agreement. (2) - Instead of a PIK dividend, Checkpoint pays the Company an annual equity fee in shares of Checkpoint’s common stock equal to 2.5 (3) - Represents the Trigger Date. Management Services Agreements The Company has entered in Management Services Agreements (the “MSAs”) with certain of its subsidiaries as described in the Company’s Form 10-K for the year ended December 31, 2017, filed with the SEC on March 16, 2018. Fortress Company Effective Date Annual MSA Fee Helocyte March 20, 2015 $ 500 Avenue (1) February 17, 2015 500 Mustang March 13, 2015 500 Checkpoint March 17, 2015 500 Cellvation October 31, 2016 500 Caelum January 1, 2017 500 Cyprium March 13, 2017 500 Aevitas July 28, 2017 500 Tamid November 30, 2017 500 Fortress (4,500) Consolidated (Income)/Expense $ - Chord Advisors, LLC In May 2015, the Company entered into a full-service consulting agreement with Chord Advisors, LLC (“Chord”) to provide advisory accounting services. Under the terms of the agreement, the Company pays Chord $ 10,000 5,000 11,000 13,000 National As of March 31, 2018, the Company owns approximately 56.6 Additionally, the Company’s Chairman, President and Chief Executive Officer and the Company’s Executive Vice Chairman, Strategic Development are both Co-Portfolio Managers and Partners of OPPM which owns approximately 4.6

Net Capital Requirements of Bro

Net Capital Requirements of Broker-Dealer Subsidiaries	3 Months Ended
	Mar. 31, 2018
Brokers and Dealers [Abstract]
Net Capital Requirements of Broker-Dealer Subsidiaries	18. Net Capital Requirements of Broker-Dealer Subsidiaries NSC is subject to the SEC's Uniform Net Capital Rule (Rule 15c3-1) (the "Rule"), which, among other things, requires the maintenance of minimum net capital. At December 31, 2017, National Securities had net capital of $ 10.0 9.7 250,000 Advances, dividend payments and other equity withdrawals from the Company's broker-dealer subsidiaries are restricted by the regulations of the SEC, and other regulatory agencies. These regulatory restrictions may limit the amounts that a subsidiary may dividend or advance to the Company.

Off Balance Sheet Risk and Conc

Off Balance Sheet Risk and Concentrations of Credit Risk	3 Months Ended
	Mar. 31, 2018
Risks and Uncertainties [Abstract]
Off Balance Sheet Risk and Concentrations of Credit Risk	19. Off Balance Sheet Risk and Concentrations of Credit Risk National is engaged in trading and providing a broad range of securities brokerage and investment services to a diverse group of retail and institutional clientele, as well as corporate finance and investment banking services to corporations and businesses. Counterparties to National’s business activities include broker-dealers and clearing organizations, banks and other financial institutions. National uses clearing brokers to process transactions and maintain customer accounts for National on a fee basis. National permits the clearing firms to extend credit to its clientele secured by cash and securities in the client’s account. National’s exposure to credit risk associated with the non-performance by its customers and counterparties in fulfilling their contractual obligations can be directly impacted by volatile or illiquid trading markets, which may impair the ability of customers and counterparties to satisfy their obligations to National. National has agreed to indemnify the clearing brokers for losses they incur while extending credit to National’s clients. It is National’s policy to review, as necessary, the credit standing of its customers and counterparties. Amounts due from customers that are considered uncollectible by the clearing broker are charged back to National by the clearing broker when such amounts become determinable. Upon notification of a charge back, such amounts, in total or in part, are then either (i) collected from the customers, (ii) charged to the broker initiating the transaction and/or (iii) charged to operations, based on the particular facts and circumstances. National maintains cash in bank deposits, which, at times, may exceed federally insured limits. National has not experienced and does not expect to experience losses on such accounts. A short sale involves the sale of a security that is not owned in the expectation of purchasing the same security (or a security exchangeable) at a later date at a lower price. A short sale involves the risk of a theoretically unlimited increase in the market price of the security that would result in a theoretically unlimited loss.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Segment Information	20. Segment Information The Company operates in three reportable segments, Dermatology Product Sales, Pharmaceutical and Biotechnology Product Development and National. The accounting policies of the Company’s segments are the same as those described in Note 2. Cost of goods sold is directly related to product sales only. Revenues derived from co-promote revenue had no cost of goods sold. Dermatology Pharmaceutical ($ in thousands) Products Product Three Months Ended March 31, 2018 Sales Development National Consolidated Net Revenue $ 5,509 $ 394 $ 49,522 $ 55,425 Direct cost of goods (1,472) - - (1,472) Sales and marketing costs (2,764) - - (2,764) Research and development - (25,055) - (25,055) General and administrative (397) (10,387) - (10,784) National Expenses - - (50,836) (50,836) Segment income (loss) from operations $ 876 $ (35,048) $ (1,314) $ (35,486) Segment assets $ 11,163 $ 189,560 $ 64,352 $ 265,075 Dermatology Pharmaceutical ($ in thousands) Products Product Three Months Ended March 31, 2017 Sales Development National Consolidated Net Revenue $ 2,085 $ 693 $ 41,904 $ 44,682 Direct cost of goods (469) - - (469) Sales and marketing costs (2,267) - - (2,267) Research and development - (8,404) - (8,404) General and administrative (319) (7,666) - (7,985) National Expenses - - (43,134) (43,134) Segment loss from operations $ (970) $ (15,377) $ (1,230) $ (17,577) Segment assets $ 4,039 $ 159,175 $ 48,697 $ 211,911

Revenues from Contracts and Sig

Revenues from Contracts and Significant Customers	3 Months Ended
	Mar. 31, 2018
Revenues [Abstract]
Revenues from Contracts and Significant Customers	21. Revenues from Contracts and Significant Customers Fortress On January 1, 2018, the Company adopted Topic 606 applying the modified retrospective method to all contracts that were not completed as of January 1, 2018. Results for reporting periods beginning after January 1, 2018 were presented under Topic 606, while prior period amounts were not adjusted and reported under the accounting standards in effect for the prior periods. Impact to Journey Medical Product Sales Topic 606 does not generally change the practice under which the Company recognizes product revenue from sales of Targadox®, Luxamend® and Ceracade®. The Company’s performance obligation to deliver products is satisfied at the point in time that the goods are delivered to the customer, which is when the customer obtains title to and has the risks and rewards of ownership of the products. The Company’s contracts include variable consideration in the form of refunds for rights of return, price protection, and consideration payable to the customer. As such, for the three months ended March 31, 2018 and 2017, the Company recorded a return reserve of $ 0.7 0.1 Because the Company’s agreements for product and product-related services revenue have an expected duration of one year or less, the Company has elected the practical expedient in ASC 606-10-50-14(a) to not disclose information about its remaining performance obligations. Impact to Collaboration and License Agreement Revenues In March 2015, the Company entered into an exclusive license agreement with Dana-Farber to develop a portfolio of fully human immuno-oncology targeted antibodies. Under the terms of the agreement, Checkpoint paid Dana-Farber an up-front licensing fee of $ 1.0 500,000 32,500 0.065 5 10 136,830 0.6 21.5 60.0 In connection with the license agreement with Dana-Farber, the Company entered into a collaboration agreement with TGTX, a related party, to develop and commercialize the anti-PD-L1 and anti-GITR antibody research programs in the field of hematological malignancies, while the Company retains the right to develop and commercialize these antibodies in the field of solid tumors. Michael Weiss, Chairman of the Board of Directors of Checkpoint and Fortress’ Executive Vice Chairman, Strategic Development, is also the Executive Chairman, President and Chief Executive Officer and a stockholder of TGTX. Under the terms of the collaboration agreement, TGTX paid the Company $ 0.5 21.5 7.0 14.5 60.0 The collaboration with TGTX contains a single material performance obligation under Topic 606, which is the granting of a license that is functional intellectual property. The Company’s performance obligation is satisfied at the point in time when the customer has the ability to use and benefit from the right to use the intellectual property. The collaboration agreement includes fixed fees that include the upfront fee of $ 0.5 Disaggregation of Total Revenues Three months ended Targadox® $ 5,498 Other branded revenue 11 Total product revenues $ 5,509 TGTX 394 Total Revenue $ 5,903 Contract Balances and Performance Obligations The Company recognized collaboration and license agreement revenues of $0.4 million during the three months ended March 31, 2018 that were included in the deferred revenue balance as of January 1, 2018. Significant Customers For the three months ended March 31, 2018, three of the Company’s Dermatology Products customers each accounted for more than 10.0% of its total gross product revenue in the amount of $ 4.4 3.9 2.0 0.8 0.5 At March 31, 2018, two of the Company’s Dermatology Products customers each accounted for more than 10.0% of its total accounts receivable balance in the amount of $ 3.0 2.1 At March 31, 2017, two of the Company’s Dermatology Products customers each accounted for more than 10.0% of its total accounts receivable balance in the amount of $ 0.8 0.5 Net Revenue from Pharmaceutical and Biotechnology Product Development represents collaboration revenue from TGTX in connection with Checkpoint, which is classified as related party revenue. National Revenue Recognition with Customers National recognizes revenue from contracts with customers when, or as, National satisfies its performance obligations by transferring the promised goods or services to the customers. A good or service is transferred to a customer when, or as, the customer obtains control of that good or service. A performance obligation may be satisfied over time or at a point in time. Revenue from a performance obligation satisfied over time is recognized by measuring progress in satisfying the performance obligation in a manner that depicts the transfer of the goods or services to the customer. Revenue from a performance obligation satisfied at a point in time is recognized at the point in time that National determines the customer obtains control over the promised good or service. The amount of revenue recognized reflects the consideration National expects to be entitled to in exchange for those promised goods or services (i.e., the “transaction price”). In determining the transaction price, National considers multiple factors, including the effects of variable consideration. Variable consideration is included in the transaction price only to the extent it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainties with respect to the amount are resolved. In determining when to include variable consideration in the transaction price, we consider the range of possible outcomes, the predictive value of past experiences, the time period of when uncertainties expect to be resolved and the amount of consideration that is susceptible to factors outside of influence, such as market volatility or the judgment and actions of third parties. The following provides detailed information on the recognition of National’s revenues from contracts with customers: Commissions and Other Fees. Investment Banking. National’s revenues from advisory services primarily consist of fees generated in connection with mergers and acquisition and advisory transactions. Advisory fees from mergers and acquisitions engagements are recognized at a point in time when the related transaction is completed, as the performance obligation is to successfully executes a specific transaction. Fees received prior to the completion of the transaction are deferred within other liabilities on the Condensed Consolidated Balance Sheets. A significant portion of the fees National receives for advisory services are considered variable as they are contingent upon a future event and are excluded from the transaction price until the uncertainty associated with the variable consideration is subsequently resolved, which is expected to occur upon achievement of the specified milestone. Payment for advisory services is generally due promptly upon completion of a specified milestone or, for retainer fees, periodically over the course of the engagement. National recognizes a receivable between the date of completion of the milestone and payment by the customer. Expenses associated with investment banking advisory engagements are deferred only to the extent they are explicitly reimbursable by the client and the related revenue is recognized at a point in time. All other investment banking advisory related costs are expensed as incurred. All investment banking advisory expenses are recognized within their respective expense category on the Condensed Consolidated Statements of Operations and any expenses reimbursed by the clients are recognized as Investment banking revenues. Asset Management Fees. Disaggregation of Revenue The following presents National’s revenues from contracts with customers disaggregated by major business activity for the three months ended December 31, 2017 ($ in thousands): ($ in thousands) For the Three Revenues from customer contracts: Commissions $ 25,618 Investment banking: Underwriting 2,700 Private Placement 9,815 Advisory 1,314 Other 160 Sub-total National Revenue from contracts with customers 39,607 Other National revenue 9,915 Total National Revenue $ 49,522 Information on Remaining Performance Obligations and Revenue Recognized from Past Performance National does not disclose information about remaining performance obligations pertaining to contracts that have an original expected duration of one year or less. The transaction price allocated to remaining unsatisfied or partially unsatisfied performance obligations with an original expected duration exceeding one year was not material at December 31, 2017. Investment banking advisory fees that are contingent upon completion of a specific milestone are also excluded as the fees are considered variable and not included in the transaction price at December 31, 2017. During the three months ended December 31, 2017, National deferred $0.7 million of revenue related to performance obligations that have not been settled, mainly due to resolving uncertainties in variable consideration that was constrained in prior periods. This amount reduced investment banking revenue and was recorded as deferred revenue on the Company’s condensed consolidated balance sheet as of March 31, 2018. Contract Balances The timing of National’s revenue recognition may differ from the timing of payment by customers. National records a receivable when revenue is recognized prior to payment and we have an unconditional right to payment. Alternatively, when payment precedes the provision of the related services, National records deferred revenue until the performance obligations are satisfied. Contract Costs Incremental contract costs are expensed when incurred when the amortization period of the asset that would have been recognized is one year or less; otherwise, incremental contract costs are recognized as an asset and amortized over time as services are provided to a customer.

Summary of Significant Accoun28

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements. In the opinion of management, the unaudited interim condensed consolidated financial statements reflect all adjustments, which include only normal recurring adjustments necessary for the fair statement of the balances and results for the periods presented. Certain information and footnote disclosures normally included in the Company’s annual financial statements prepared in accordance with GAAP have been condensed or omitted. These condensed consolidated financial statement results are not necessarily indicative of results to be expected for the full fiscal year or any future period. The unaudited condensed consolidated financial statements and related disclosures have been prepared with the presumption that users of the unaudited condensed consolidated financial statements have read or have access to the audited consolidated financial statements for the preceding fiscal year for each of the Company, Avenue, Checkpoint, Mustang and National. Accordingly, these unaudited condensed consolidated financial statements should be read in conjunction with the Company’s Form 10-K, which was filed with the United States Securities and Exchange Commission (“SEC”) on March 16, 2018, from which the Company derived the balance sheet data at December 31, 2017, as well as National’s Form 10-K and 10-K/A filed with the SEC on December 22, 2017 and January 17, 2018, respectively and their Form 10-Q, filed with the SEC on February 14, 2018, Checkpoint’s Form 10-K filed with the SEC on March 16, 2018, Mustang’s Form 10-K, filed with the SEC on March 29, 2018, and Avenue’s Form 10-K, filed with the SEC on March 1, 2018. The Company’s unaudited condensed consolidated financial statements include the accounts of the Company and its subsidiaries: Avenue, Aevitas, Caelum, CB Securities, Cellvation, Coronado SO, Checkpoint, Cyprium, Escala, GeneXion, Helocyte, Innmune Limited, JMC, Mustang, NHLD, Tamid, Coronado SO, Escala, Fortress China The National assets acquired and liabilities assumed and revenues and expenses are reported on a one quarter lag. Therefore, the National assets acquired and liabilities assumed included in these condensed consolidated financial statements as of March 31, 2018 are actually the assets and liabilities as of December 31, 2017 and the revenues and expenses included in these condensed consolidated financial statements for the quarter ending March 31, 2018 are actually the revenues and expenses for the quarter ending December 31, 2017. The preparation of the Company’s unaudited condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited condensed consolidated financial statements and the reported amounts of expenses during the reporting period
Use of Estimates	Use of Estimates The Company’s unaudited condensed consolidated financial statements include certain amounts that are based on management’s best estimates and judgments. The Company’s significant estimates include, but are not limited to, useful lives assigned to long-lived and intangible assets, fair value measurements, stock-based compensation, common stock issued to acquire licenses, investments, accrued expenses, derivative warrant liabilities, revenue with customers, provisions for income taxes and contingencies. Due to the uncertainty inherent in such estimates, actual results may differ from these estimates.
Significant Accounting Policies	Significant Accounting Policies There have been no material changes to the Company’s significant accounting policies previously disclosed in the Company’s Form 10-K filed with the SEC on March 16, 2018, with the exception of revenue recognition.
Recently Issued Accounting Standards	In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients 0.1 The new revenue guidance does not apply to revenue associated with financial instruments, including National’s warrants and securities that are accounted for under other U.S. GAAP, and as a result, did not have an impact on the elements of our Consolidated Statements of Operations most closely associated with financial instruments. The new revenue standard primarily impacts the following of our revenue recognition and presentation accounting policies: ⋅ Investment Banking Revenues. ⋅ Investment Banking Advisory Expenses. ⋅ Investment Banking Underwriting and Advisory Expenses. The new revenue standard requires enhanced disclosures, which are included in footnote 21 to our condensed consolidated financial statements beginning with the three months ended March 31, 2018. Contract Assets Contract assets represent the Company’s right to consideration in exchange for goods or services that the Company has transferred to a customer, excluding unconditional rights to consideration that are presented as receivables. Contract Liabilities Contract liabilities represent the Company’s obligation to deliver products or provide data to customers in the future for which cash has already been received. In May 2017, the FASB issued ASU 2017-09, Compensation-Stock Compensation (Topic 718): Scope of Modification Accounting In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows - Classification of Certain Cash Receipts and Cash Payments, In January 2016, the FASB issued ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Liabilities Recent Accounting Pronouncements In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In July 2017, the FASB issued ASU 2017-11, Earnings Per Share (Topic 260), Distinguishing Liabilities from Equity (Topic 480) and Derivatives and Hedging (Topic 815): I. Accounting for Certain Financial Instruments with Down Round Features; II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception

National Holdings Corporation29

National Holdings Corporation Acquisition - Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2018
Business Combinations [Abstract]
Schedule of Acquired Finite-Lived Intangible Assets by Major Class	Amortization is calculated using the straight-line and accelerated methods over the following estimated useful lives: Useful life Trademark 10 years Customer lists 6 years
Schedule of Finite-Lived Intangible Assets	The carrying amount related to acquired intangible assets as of March 31, 2018 are as follows ($ in thousands): Intangible assets at December 31, 2017 $ 14,340 Amortization expense (690) Intangible assets at March 31, 2018 $ 13,650
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The future amortization of these intangible assets is as follows ($ in thousands): Trademark Customer Total Nine Months Ended December 31, 2018 $ 226 $ 1,884 $ 2,110 Year Ended December 31, 2019 300 2,500 2,800 Year Ended December 31, 2020 301 2,506 2,807 Year Ended December 31, 2021 300 2,500 2,800 Year Ended December 31, 2022 300 1,726 2,026 Thereafter 1,107 – 1,107 Total $ 2,534 $ 11,116 $ 13,650

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2018
Property, Plant and Equipment [Line Items]
Components of Property and Equipment	Fortress's property and equipment, exclusive of National's property and equipment, consisted of the following ($ in thousands): Estimated Useful March 31, December 31, Lives (in years) 2018 2017 Computer equipment 3 $ 594 $ 543 Furniture and fixtures 5 1,015 1,009 Machinery and equipment 5 143 143 Leasehold improvements 5 - 15 5,383 5,351 Construction in process (1) N/A 4,237 1,241 Total property and equipment 11,372 8,287 Less: accumulated depreciation (1,367) (1,171) Property and equipment, net $ 10,005 $ 7,116 (1) Relates to the Mustang cell processing facility
National Holdings Corporation [Member]
Property, Plant and Equipment [Line Items]
Components of Property and Equipment	National's property and equipment as of December 31, 2017 and September 30, 2017, consisted of the following ($in thousands): Estimated Useful December 31, September 30, Lives (in years) 2017 2017 Equipment 5 $ 1,339 $ 1,306 Furniture and fixtures 5 291 284 Leasehold improvements Lesser of useful life or term 1,011 1,006 Capital Leases (primarily composed of computer equipment) 5 276 276 Fixed assets – gross 2,917 2,872 Accumulated depreciation and amortization (644) (475) Fixed assets – net $ 2,273 $ 2,397

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2018
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following tables classify the fair value hierarchy of Fortress's financial instruments, exclusive of National's financial instruments, measured at fair value as of March 31, 2018 and December 31, 2017: Fair Value Measurement as of March 31, 2018 ($in thousands) Level 1 Level 2 Level 3 Total Assets Long-term investments, at fair value $ – $ – $ 1,272 $ 1,272 Total $ – $ – $ 1,272 $ 1,272 Liabilities Warrant liabilities $ – $ – $ 78 $ 78 Caelum Convertible Note, at fair value – – 10,140 10,140 Helocyte Convertible Note, at fair value – – 2,511 2,511 Total $ – $ – $ 12,729 $ 12,729 Fair Value Measurement as of December 31, 2017 ($in thousands) Level 1 Level 2 Level 3 Total Assets Long-term investments, at fair value $ – $ – $ 1,390 $ 1,390 Total $ – $ – $ 1,390 $ 1,390 Liabilities Warrant liabilities $ – $ – $ 87 $ 87 Caelum Convertible Note, at fair value – – 10,059 10,059 Helocyte Convertible Note, at fair value – – 4,700 4,700 Total $ – $ – $ 14,846 $ 14,846
Schedule of changes in fair value of financial instruments	The table below provides a roll-forward of the changes in fair value of Level 3 financial instruments for the three months ended March 31, 2018: ($ in thousands) Investment in Helocyte Caelum Warrants Warrant Total Balance at December 31, 2017 $ 1,390 $ 4,700 $ 10,059 $ 5,597 $ 87 $ 21,833 Payment of convertible note - (1,858) - - - (1,858) Change in fair value of investments (118) - - - - (118) Change in fair value of convertible notes - (331) 81 - - (250) Change in fair value of derivative liabilities - - - 1,074 (9) 1,065 Balance at March 31, 2018 $ 1,272 $ 2,511 $ 10,140 $ 6,671 $ 78 $ 20,672
Warrants Issuable [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques	December 31, Dividend yield – % Expected volatility 46.13 % Risk-free interest rate 2.20 % Life (in years) 3.69
Fair Value for Derivative Contingently Issuable Warrant Liabilities	($ in thousands) National’s Beginning balance at September 30, 2017 $ 5,597 Change in fair value of derivative liability 1,074 Ending balance at December 31, 2017 $ 6,671
Helocyte [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques	A summary of the weighted average (in aggregate) significant unobservable inputs (Level 3 inputs) used in measuring Helocyte’s warrant liabilities that are categorized within Level 3 of the fair value hierarchy as of March 31, 2018 is as follows: March 31, Risk-free interest rate 2.411% - 2.447 % Expected dividend yield - % Expected term in years 3.25 – 3.67 Expected volatility 70.0 % Strike price $ 0.46
Fair Value for Derivative Contingently Issuable Warrant Liabilities	($in thousands) Fair Value of Beginning balance at January 1, 2018 $ 87 Change in fair value of derivative liabilities (9) Ending balance at March 31, 2018 $ 78
Helocyte [Member] | Convertible Debt [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques	March 31, 2018 Risk-free interest rate 1.96%- 2.21 % Expected dividend yield - % Expected term in years 0.58 – 1.67 Expected volatility 53.1 %
Fair Value for Derivative Contingently Issuable Warrant Liabilities	($in thousands) Helocyte Beginning balance at January 1, 2018 $ 4,700 Payment of convertible notes (1,858) Change in fair value of convertible notes (331) Ending balance at March 31, 2018 $ 2,511
National Warrant Liabilities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques	December 31, Risk-free interest rate 1.53% – 2.2 % Expected dividend yield – % Expected term in years .43 – 4.35 Remaining volatility 369.19% – 59.69 % Strike price $0.01 – $10.00
Fair Value for Derivative Contingently Issuable Warrant Liabilities	($in thousands) Fair Value of Beginning balance at September 30, 2017 $ 548 Change in fair value of derivative liabilities 138 Ending balance at December 31, 2017 $ 686
Caelum [Member] | Convertible Debt [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques	March 31, 2018 Risk-free interest rate 1.71%- 2.17 % Expected dividend yield - % Expected term in years 0.21 – 1.46 Expected volatility 53.1 %
Fair Value for Derivative Contingently Issuable Warrant Liabilities	($in thousands) Caelum Beginning balance at January 1, 2018 $ 10,059 Change in fair value of convertible notes 81 Ending balance at March 31, 2018 $ 10,140
National Holdings Corporation [Member]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table shows the fair values hierarchy of National's financial instruments measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets as of December 31, 2017 and September 30, 2017: Fair Value Measurement as of December 31, 2017 Level 1 Level 2 Level 3 Total Assets National Securities owned, at fair value Corporate stocks $ 65 $ - $ - $ 65 Municipal bonds 3,452 - - 3,452 Restricted stock - 75 - 75 Warrants - - 686 686 Total $ 3,517 $ 75 $ 686 $ 4,278 Liabilities National Securities sold, but not yet purchased at fair value Contingent consideration - - 717 717 Warrants issued - National - - 6,671 6,671 Total $ - $ - $ 7,388 $ 7,388 Fair Value Measurement as of September 30, 2017 Level 1 Level 2 Level 3 Total Assets National Securities owned, at fair value Corporate stocks $ 116 $ - $ - $ 116 Municipal bonds 1,239 - - 1,239 Restricted stock - 82 - 82 Warrants - - 548 548 Total $ 1,355 $ 82 $ 548 $ 1,985 Liabilities National Securities sold, but not yet purchased at fair value Municipal bonds 151 - - 151 Contingent consideration - - 311 311 Warrants issued - National - - 5,597 5,597 Total $ 151 $ - $ 5,908 $ 6,059

Licenses Acquired (Tables)

Licenses Acquired (Tables)	3 Months Ended
	Mar. 31, 2018
Research and Development Arrangement, Contract to Perform for Others	As such, for the three months ended March 31, 2018 and 2017, the purchase price of licenses acquired was classified as research and development-licenses acquired in the Condensed Consolidated Statements of Operations, as reflected in the table below: For the Three Months Ended March 31, ($ in thousands) 2018 2017 Fortress Companies: Checkpoint $ – $ 400 Helocyte 21 – Mustang 75 575 Cellvation 1 – Caelum – 219 Cyprium – 100 Total $ 97 $ 1,294
Checkpoint Therapeutics, Inc [Member]
Schedule of Licenses Acquired Expenses [Table Text Block]	The table below provides a summary of Checkpoint’s expense related to its licenses, for the three months ended March 31, 2018 and 2017 by license as recorded in the Condensed Consolidated Statements of Operations: ($ in thousands) For the three months ended March 31 2018 2017 Jubliant Biosys License CK-103 $ – $ 400 Total licenses acquired expense $ – $ 400
Mustang Therapeutics, Inc [Member]
Schedule of Licenses Acquired Expenses [Table Text Block]	The table below provides a summary of Mustang’s expense related to its licenses, for the three months ended March 31, 2018 and 2017 by license as recorded in the Condensed Consolidated Statements of Operations: ($ in thousands) For the three months ended March 31 2018 2017 City of Hope (COH) IL-13 License $ – $ 250 COH IV/ICV Agreement – 125 University of California License for PSCA – 200 Manufacturing License 75 – Total licenses acquired expense $ 75 $ 575

Sponsored Research and Clinic33

Sponsored Research and Clinical Trial Agreements (Tables)	3 Months Ended
	Mar. 31, 2018
Research and Development [Abstract]
Schedule of Expense Related to Clinical Research Arrangements	The table below provides a summary of Helocyte’s expense related to its clinical research arrangements, for the three months ended March 31, 2018 and 2017, by agreement as recorded in the Condensed Consolidated Statements of Operations: ($ in thousands) For the three months ended March 31 2018 2017 COH Triplex clinical research and support $ – $ 500 COH PepVax clinical research and support – 235 Total licenses acquired expense $ – $ 735
Schedule of Expense Related to Sponsered Research Arrangements	The table below provides a summary of Mustang’s expense related to its sponsored research agreements, for the three months ended March 31, 2018 and 2017, by license as recorded in the Condensed Consolidated Statements of Operations: ($ in thousands) For the three months ended March 31 2018 2017 COH CAR T $ 500 $ 500 COH - CD123 150 20 COH - IL13Ra2 360 9 City of Hope - Manufacturing 114 – Fred Hutch - CD20 266 Total $ 1,390 $ 529

Debt and Interest (Tables)

Debt and Interest (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Schedule Of Interest Expenses	Total debt consists of the following as of March 31, 2018 and December 31, 2017: ($ in thousands) March 31, December 31, Interest rate Maturity IDB Note $ 14,929 $ 14,929 2.25 % August - 2020 2017 Subordinated Note Financing 3,254 3,254 8.00 % March - 2020 2017 Subordinated Note Financing 13,893 13,893 8.00 % May - 2020 2017 Subordinated Note Financing 1,820 1,820 8.00 % June - 2020 2017 Subordinated Note Financing 3,018 3,018 8.00 % August - 2020 2017 Subordinated Note Financing 6,371 6,371 8.00 % September - 2020 2018 Venture Notes 6,517 – 8.00 % February – 2021 2018 Venture Notes 15,190 – 8.00 % March - 2021 Opus Credit Facility 9,500 9,500 12.00 % September – 2019 Helocyte Convertible Note, at fair value – 1,000 5.00% - 8.00 % December 2017 Helocyte Convertible Note, at fair value 860 2,194 5.00% - 8.00 % March - 2018 Helocyte Convertible Note, at fair value 945 1,062 5.00% - 8.00 % April - 2018 Helocyte Convertible Note, at fair value 372 444 5.00% - 8.00 % May - 2018 Helocyte Convertible Note, at fair value 310 – 5.00% - 8-00 % September 2018 Helocyte Convertible Note, at fair value 23 – 5.00% - 8.00 % November 2018 Caelum Convertible Note, at fair value 1,026 1,017 8.00 % January - 2019 Caelum Convertible Note, at fair value 6,956 6,900 8.00 % February - 2019 Caelum Convertible Note, at fair value 2,158 2,142 8.00 % March - 2019 Total notes payable 87,142 67,544 Less: Discount on notes payable 1,047 1,035 Total notes payable $ 86,095 $ 66,509
Schedule Of Interest Expenses For Debt Arrangements	The following table shows the details of interest expense for all debt arrangements during the periods presented. Interest expense includes contractual interest and amortization of the debt discount and amortization of fees represents fees associated with loan transaction costs, amortized over the life of the loan: Three Months Ended March 31, ($in thousands) 2018 2017 IDB Note Interest $ 84 $ 82 Total IDB Note 84 82 NSC Debt Interest - 71 Amortization of fees - 38 Total NSC Debt - 109 2017 Subordinated Note Financing Interest 1,048 - Amortization of fees 21 - Total 2017 Subordinated Note Financing 1,069 - Opus Credit Facility Interest 281 232 Amortization of fees 319 208 Total Opus Note 600 440 2018 Venture Notes Interest 56 - Amortization of fees 1 - Total 2018 Venture Notes 57 - LOC Fees Interest 7 8 Total LOC 7 8 Helocyte Convertible Note Interest 68 54 Financing fee - 1 Total Helocyte Convertible Note 68 55 Avenue Convertible Note Financing fee - 3 Total Avenue Convertible Note - 3 Caelum Convertible Note Interest 196 - Total Caelum Convertible Note 196 - Other Interest 2 1 Total Other 2 1 Total Interest Expense and Financing Fee $ 2,083 $ 698

Accrued Expenses and Other Lo35

Accrued Expenses and Other Long-Term Liabilities (Tables)	3 Months Ended
	Mar. 31, 2018
Components of Accrued Expenses and Other Long-Term Liabilities	Accrued expenses and other long-term liabilities, excluding National, consisted of the following: March 31, December 31, Accrued expenses: Professional fees $ 1,497 $ 1,625 Salaries, bonuses and related benefits 6,002 5,279 Accrued expenses - related party 107 95 Research and development 7,061 4,046 Dr. Falk Pharma milestone (See Note 16) 3,059 3,059 Accrued royalties payable 1,091 1,411 Accrued coupon expense 735 – Deferred coupon funding 1,516 1,087 Other 646 1,030 Total accrued expenses $ 21,714 $ 17,632 Other long-term liabilities: Deferred rent 4,759 4,739 Total other long-term liabilities $ 4,759 $ 4,739
National Holdings Corporation [Member]
Components of Accrued Expenses and Other Long-Term Liabilities	National's accounts payable and other accrued expenses as of December 31, 2017 and September 30, 2017, consisted of the following: December 31, September 30, 2017 2017 Legal $ 653 $ 877 Audit 171 176 Telecommunications 208 205 Data Services 454 464 Regulatory 663 540 Settlements 1,789 2,403 Deferred rent 684 497 Other 3,437 3,242 Total $ 8,059 $ 8,404

Non-Controlling Interests (Tabl

Non-Controlling Interests (Tables)	3 Months Ended
	Mar. 31, 2018
Noncontrolling Interest [Abstract]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net	As of March 31, 2018 NCI equity share Net gain/(loss) attributable to Non-controlling Non-controlling Aevitas $ (356) $ (47) $ (403) 37.0 % Avenue 2 12,719 (6,691) 6,028 64.4 % Caelum (2,133) (707) (2,840) 33.9 % Cellvation (387) (51) (438) 21.6 % Checkpoint 1 24,662 (5,175) 19,487 67.4 % Coronado SO (290) – (290) 13.0 % Cyprium (169) (31) (200) 10.8 % Helocyte (3,124) (33) (3,157) 19.8 % JMC (461) 56 (405) 6.3 % Mustang 2 36,961 (3,733) 33,228 59.7 % National Holdings 15,805 (734) 15,071 43.4 % Tamid (132) (54) (186) 24.0 % Total $ 83,095 $ (17,200) $ 65,895 As of December 31, 2017 NCI equity share Net gain/(loss) attributable to Non-controlling Non-controlling Aevitas $ (126) $ (168) $ (294) 35.4 % Avenue 2 17,454 (4,646) 12,808 66.1 % Caelum (815) (1,262) (2,077) 34.7 % Cellvation (259) (96) (355) 21.5 % Checkpoint 1 21,635 (12,314) 9,321 62.0 % Coronado SO (236) (54) (290) 13.0 % Cyprium (143) (15) (158) 11.1 % Helocyte (1,907) (1,193) (3,100) 20.0 % JMC (469) 7 (462) 6.3 % Mustang 2 48,740 (11,911) 36,829 61.6 % National Holdings 17,021 (1,216) 15,805 43.4 % Tamid (6) (92) (98) 24.0 % Total $ 100,889 $ (32,960) $ 67,929 (1) Checkpoint is consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Checkpoint’s Class A Common Shares which provide super-majority voting rights. (2) Avenue and Mustang are consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Preferred Class A Shares which provide super-majority voting rights.

Net Loss per Common Share (Tabl

Net Loss per Common Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Computations of Diluted Weighted Average Shares Outstanding	Three Months Ended March 31, 2018 2017 Warrants to purchase Common Stock 894,189 383,453 Opus warrants to purchase Common Stock 1,880,000 1,860,000 Options to purchase Common Stock 1,085,501 1,105,502 Convertible Preferred Stock 1,000,000 – Unvested Restricted Stock 11,050,943 9,912,161 Unvested Restricted Stock Units 1,778,154 1,249,232 Total 17,688,788 14,510,348

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Schedule of Share-based Compensation, Activity	The following table summarizes the stock-based compensation expense from stock option, employee stock purchase programs and restricted Common Stock awards and warrants for the three months ended March 31, 2018 and 2017: For the Three Months Ended March 31, ($ in thousands) 2018 2017 Employee awards $ 828 $ 367 Executive awards of Fortress Companies’ stock 632 1,463 Fortress Companies: Avenue 349 5 Checkpoint 1,137 979 Mustang 1,995 - Other 112 115 Total stock-based compensation $ 5,053 $ 2,929
Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding And Exercisable	The following table summarizes Fortress stock option activities excluding activity related to Fortress Companies: Number of shares Weighted average Total weighted Weighted average Options vested and expected to vest at December 31, 2017 1,110,501 $ 3.78 $ 1,351,080 3.95 Exercised - - - - Options vested and expected to vest at March 31, 2018 1,110,501 $ 3.78 $ 1,701,361 3.71 Options vested and exercisable 1,085,501 $ 3.75 $ 1,701,361 3.68
Nonvested Restricted Stock Shares Activity	The following table summarizes Fortress restricted stock awards and restricted stock units activities, excluding activities related to Fortress Companies: Number of shares Weighted average Unvested balance at December 31, 2017 11,874,034 $ 2.63 Restricted stock granted 1,392,856 3.99 Restricted stock vested (213,334) 2.76 Restricted stock units granted 230,000 4.98 Restricted stock units forfeited (42,417) 3.52 Restricted stock units vested (64,750) 3.49 Unvested balance at March 31, 2018 13,176,389 $ 2.81
Schedule of Warrant Activities	The following table summarizes Fortress warrant activities, excluding activities related to Fortress Companies: Number of shares Weighted average Total weighted Weighted average Outstanding as of December 31, 2017 2,774,189 $ 3.30 $ 2,204,530 4.47 Granted - - - - Forfeited - - - - Outstanding as of March 31, 2018 2,774,189 $ 3.30 $ 3,586,975 4.22 Exercisable as of March 31, 2018 869,189 $ 3.96 $ 634,225 3.81

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2018
Related Party Transactions [Abstract]
Schedule of Effective Date and Equity Fee Payable	The Company has entered into Founders Agreements and, in some cases, Exchange Agreements with certain of its subsidiaries as described in the Company’s Form 10-K for the year ended December 31, 2017, filed with the SEC on March 16, 2018. The following table summarizes, by subsidiary, the effective date of the Founders Agreements and PIK dividend or equity fee payable to the Company in accordance with the terms of the Founders Agreements, Exchange Agreements and the subsidiaries’ certificates of incorporation. Fortress Company Effective Date (1) PIK Dividend as Class of Stock Helocyte March 20, 2015 2.5 % Common Stock Avenue February 17, 2015 2.5 % Common Stock Mustang March 13, 2015 2.5 % Common Stock Checkpoint March 17, 2015 0.0 % (2) Common Stock Cellvation October 31, 2016 2.5 % Common Stock Caelum January 1, 2017 2.5 % Common Stock Cyprium March 13, 2017 2.5 % Common Stock Aevitas July 28, 2017 2.5 % Common Stock Tamid November 30, 2017 (3) 2.5 % Common Stock (1) - Represents the effective date of each subsidiary’s Founders Agreement. Each PIK dividend and equity fee is payable on the annual anniversary of the effective date of the original Founders Agreement. (2) - Instead of a PIK dividend, Checkpoint pays the Company an annual equity fee in shares of Checkpoint’s common stock equal to 2.5 (3) - Represents the Trigger Date.
Schedule of The Effective Date and Annual Management Services agreement Fee Income Expense	Fortress Company Effective Date Annual MSA Fee Helocyte March 20, 2015 $ 500 Avenue (1) February 17, 2015 500 Mustang March 13, 2015 500 Checkpoint March 17, 2015 500 Cellvation October 31, 2016 500 Caelum January 1, 2017 500 Cyprium March 13, 2017 500 Aevitas July 28, 2017 500 Tamid November 30, 2017 500 Fortress (4,500) Consolidated (Income)/Expense $ -

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The following tables summarize, for the periods indicated, operating results by reportable segment: Cost of goods sold is directly related to product sales only. Revenues derived from co-promote revenue had no cost of goods sold. Dermatology Pharmaceutical ($ in thousands) Products Product Three Months Ended March 31, 2018 Sales Development National Consolidated Net Revenue $ 5,509 $ 394 $ 49,522 $ 55,425 Direct cost of goods (1,472) - - (1,472) Sales and marketing costs (2,764) - - (2,764) Research and development - (25,055) - (25,055) General and administrative (397) (10,387) - (10,784) National Expenses - - (50,836) (50,836) Segment income (loss) from operations $ 876 $ (35,048) $ (1,314) $ (35,486) Segment assets $ 11,163 $ 189,560 $ 64,352 $ 265,075 Dermatology Pharmaceutical ($ in thousands) Products Product Three Months Ended March 31, 2017 Sales Development National Consolidated Net Revenue $ 2,085 $ 693 $ 41,904 $ 44,682 Direct cost of goods (469) - - (469) Sales and marketing costs (2,267) - - (2,267) Research and development - (8,404) - (8,404) General and administrative (319) (7,666) - (7,985) National Expenses - - (43,134) (43,134) Segment loss from operations $ (970) $ (15,377) $ (1,230) $ (17,577) Segment assets $ 4,039 $ 159,175 $ 48,697 $ 211,911

Revenues from Contracts and S41

Revenues from Contracts and Significant Customers (Tables)	3 Months Ended
	Mar. 31, 2018
Disaggregation of Revenue	The Company has three marketed products, Targadox®, Luxamend® and Ceracade. Substantially all of the Company’s product revenues are recorded in the U.S. Substantially all of the Company’s collaboration revenues are from its collaboration with TGTX. Revenues by product and collaborator are summarized as follows (in thousands): Three months ended Targadox® $ 5,498 Other branded revenue 11 Total product revenues $ 5,509 TGTX 394 Total Revenue $ 5,903
Revenue From Contracts With Customers [Member]
Disaggregation of Revenue	The following presents National’s revenues from contracts with customers disaggregated by major business activity for the three months ended December 31, 2017 ($ in thousands): ($ in thousands) For the Three Revenues from customer contracts: Commissions $ 25,618 Investment banking: Underwriting 2,700 Private Placement 9,815 Advisory 1,314 Other 160 Sub-total National Revenue from contracts with customers 39,607 Other National revenue 9,915 Total National Revenue $ 49,522

Summary of Significant Accoun42

Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions	Jan. 02, 2018USD ($)
Accounting Policies [Line Items]
National investment banking expenses	$ 0.1

National Holdings Corporation43

National Holdings Corporation Acquisition - Intangible Assets - Amortization is calculated using the straight-line method over the estimated useful lives (Detail)	3 Months Ended
	Mar. 31, 2018
Trademark [Member]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years
Customer Lists [Member]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	6 years

National Holdings Corporation44

National Holdings Corporation Acquisition - Intangible Assets - gross carrying amounts related to acquired intangible assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Intangible assets at December 31, 2017	$ 14,340
Amortization expense	(690)	$ (408)
Intangible assets at March 31, 2018	$ 13,650

National Holdings Corporation45

National Holdings Corporation Acquisition - Intangible Assets - future amortization of these intangible assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Total	$ 14,400	$ 15,223
National Holdings Corporation [Member]
Nine Months Ended December 31, 2018	2,110
Year Ended December 31, 2019	2,800
Year Ended December 31, 2020	2,807
Year Ended December 31, 2021	2,800
Year Ended December 31, 2022	2,026
Thereafter	1,107
Total	13,650
Customer Lists [Member]
Nine Months Ended December 31, 2018	1,884
Year Ended December 31, 2019	2,500
Year Ended December 31, 2020	2,506
Year Ended December 31, 2021	2,500
Year Ended December 31, 2022	1,726
Thereafter	0
Total	11,116
Trademarks [Member]
Nine Months Ended December 31, 2018	226
Year Ended December 31, 2019	300
Year Ended December 31, 2020	301
Year Ended December 31, 2021	300
Year Ended December 31, 2022	300
Thereafter	1,107
Total	$ 2,534

Broker-Dealers and Clearing O46

Broker-Dealers and Clearing Organizations, Other Receivables and Prepaid Expenses and Other Current Liabilities - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017
Brokers And Dealers [Line Items]
Receivables from Brokers-Dealers and Clearing Organizations	$ 8,464	$ 7,395
Broker -Dealers And clearing Organisation [Member]
Brokers And Dealers [Line Items]
Receivables from Brokers-Dealers and Clearing Organizations		3,200	$ 7,400
Allowance for Doubtful Accounts Receivable		600	500
Broker -Dealers And clearing Organisation [Member] | Other Receivable [Member]
Brokers And Dealers [Line Items]
Accounts Receivable, Net		$ 4,900	$ 5,200

Forgivable Loans Receivable - A

Forgivable Loans Receivable - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2006
Notes, Loans and Financing Receivable, Net, Current	$ 1,534	$ 1,616	$ 200
Forgivable Loan Receivable [Member]
Debt Instrument, Interest Rate, Stated Percentage	4.00%

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation	$ 365	$ 274

Property and Equipment - Compon

Property and Equipment - Components of Property and Equipment (Detail) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017
Property, Plant and Equipment [Line Items]
Total property and equipment			$ 2,917	$ 2,872
Less: accumulated depreciation			(644)	(475)
Property and equipment, net		$ 12,278	9,513	2,397
Fortress Biotech Inc [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment		11,372	8,287
Less: accumulated depreciation		(1,367)	(1,171)
Property and equipment, net		10,005	7,116
Computer equipment [Member] | Fortress Biotech Inc [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment		$ 594	543
Useful Life (Years)		3 years
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment			291	284
Useful Life (Years)		5 years
Furniture and fixtures [Member] | Fortress Biotech Inc [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment		$ 1,015	1,009
Useful Life (Years)		5 years
Machinery and equipment [Member] | Fortress Biotech Inc [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment		$ 143	143
Useful Life (Years)		5 years
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment			1,011	$ 1,006
Leasehold improvements [Member] | Fortress Biotech Inc [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment		$ 5,383	5,351
Leasehold improvements [Member] | Fortress Biotech Inc [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful Life (Years)		15 years
Leasehold improvements [Member] | Fortress Biotech Inc [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful Life (Years)		5 years
Construction in process [Member] | Fortress Biotech Inc [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	[1]	$ 4,237	$ 1,241
[1]	Relates to the Mustang cell processing facility

Property and Equipment - Schedu

Property and Equipment - Schedule Of Interest Expenses For Debt Arrangements (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017
Property, Plant and Equipment [Line Items]
Total property and equipment		$ 2,917	$ 2,872
Less: accumulated depreciation		(644)	(475)
Property and equipment, net	$ 12,278	9,513	2,397
Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment		1,339	1,306
Property Plant And Equipment Useful Life	5 years
Furniture And Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment		291	284
Property Plant And Equipment Useful Life	5 years
Leaseholds And Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment		1,011	1,006
Property, Plant and Equipment, Estimated Useful Lives	Lesser of useful life or term
Capital leases (primarily composed of computer equipment) [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment		$ 276	$ 276
Property Plant And Equipment Useful Life	5 years

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in and Advances to Affiliates, at Fair Value, Period Increase (Decrease), Total	$ 100
Investment Owned, at Fair Value	4,278	$ 1,985
Origo Acquisition Corporation [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment Owned, at Fair Value	$ 1,300
Fair Value Assumptions Probability Of Business Combination	38.40%
Working Capital Note Convertible To Equity	$ 300
National Holdings Corporation [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage of Outstanding Stock To Be Issued Upon Exercise of Warrants	44.00%
Warrants Not Settleable in Cash, Fair Value Disclosure	$ 5,400
Binomial Lattice Model [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Assumptions, Exercise Price	$ 0.44
Binomial Lattice Model [Member] | Warrant [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Acquisition, Share Price	0.36
Private Units [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Share Price	$ 10.96

Fair Value Measurements - Warra

Fair Value Measurements - Warrant Liabilities And Convertible Notes At Fair Value (Detail) - $ / shares	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Warrants Issuable [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Risk-free interest rate		2.20%
Expected dividend yield		0.00%
Expected term in years		3 years 8 months 8 days
Expected volatility		46.13%
Helocyte [Member] | Convertible Debt [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Expected dividend yield	0.00%
Expected volatility	53.10%
Helocyte [Member] | Minimum [Member] | Convertible Debt [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Risk-free interest rate	1.96%
Expected term in years	6 months 29 days
Helocyte [Member] | Maximum [Member] | Convertible Debt [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Risk-free interest rate	2.21%
Expected term in years	1 year 8 months 1 day
Helocyte [Member] | Warrant [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Risk-free interest rate	2.411%
Expected term in years	3 years 3 months
Helocyte [Member] | Warrant [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Risk-free interest rate	2.447%
Expected term in years	3 years 8 months 1 day
National Warrant Liabilities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Expected dividend yield	0.00%
National Warrant Liabilities [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Risk-free interest rate	1.53%
Expected term in years	5 months 5 days
Strike price	$ 0.01
Remaining volatility	59.69%
National Warrant Liabilities [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Risk-free interest rate	2.20%
Expected term in years	4 years 4 months 6 days
Strike price	$ 10
Remaining volatility	369.19%
Caelum Convertible Notes [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Expected dividend yield	0.00%
Expected volatility	53.10%
Caelum Convertible Notes [Member] | Minimum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Risk-free interest rate	1.71%
Expected term in years	2 months 16 days
Caelum Convertible Notes [Member] | Maximum [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Risk-free interest rate	2.17%
Expected term in years	1 year 5 months 16 days

Fair Value Measurements - Deriv

Fair Value Measurements - Derivative Contingently Issuable Warrant liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Payment of convertible notes	$ (1,858)
National [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value at the beginning of period:	6,671	$ 5,597
Change in fair value		1,074
Fair value at end of period:		6,671
Helocyte [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value at the beginning of period:	87
Change in fair value	(9)
Fair value at end of period:	78	87
Helocyte [Member] | Convertible Debt [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value at the beginning of period:	4,700
Payment of convertible notes	(1,858)
Change in fair value	(331)
Fair value at end of period:	2,511	4,700
National Warrant Liabilities [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value at the beginning of period:	686	548
Change in fair value		138
Fair value at end of period:		686
Caelum Convertible Notes [Member]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Fair value at the beginning of period:	10,059
Change in fair value	81
Fair value at end of period:	$ 10,140	$ 10,059

Fair Value Measurements - Natio

Fair Value Measurements - National Financial Instruments Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017
Assets
Long-term investments, at fair value	$ 1,272	$ 1,390
Total	1,272	1,390
Liabilities
Liabilities	12,729	14,846
National Holdings Corporation [Member]
Assets
Total		4,278	$ 1,985
Liabilities
Liabilities		7,388	6,059
Warrant [Member]
Liabilities
Liabilities	78	87
Warrant [Member] | National Holdings Corporation [Member]
Assets
Total		686	548
Helocyte Convertible Note One [Member]
Liabilities
Liabilities	2,511	4,700
Corporate stock Assets [Member] | National Holdings Corporation [Member]
Assets
Total		65	116
Municipal bonds Assets [Member] | National Holdings Corporation [Member]
Assets
Total		3,452	1,239
Restricted stock Assets [Member] | National Holdings Corporation [Member]
Assets
Total		75	82
Municipal bonds Liabilities [Member] | National Holdings Corporation [Member]
Liabilities
Liabilities			151
Contingent Consideration [Member] | National Holdings Corporation [Member]
Liabilities
Liabilities		717	311
Warrants Issuable [Member] | National Holdings Corporation [Member]
Liabilities
Liabilities		6,671	5,597
Caelum Convertible Notes [Member]
Liabilities
Liabilities	10,140	10,059
Fair Value, Inputs, Level 1 [Member]
Assets
Long-term investments, at fair value	0	0
Total	0	0
Liabilities
Liabilities	0	0
Fair Value, Inputs, Level 1 [Member] | National Holdings Corporation [Member]
Assets
Total		3,517	1,355
Liabilities
Liabilities		0	151
Fair Value, Inputs, Level 1 [Member] | Warrant [Member]
Liabilities
Liabilities	0	0
Fair Value, Inputs, Level 1 [Member] | Warrant [Member] | National Holdings Corporation [Member]
Assets
Total		0	0
Fair Value, Inputs, Level 1 [Member] | Helocyte Convertible Note One [Member]
Liabilities
Liabilities	0	0
Fair Value, Inputs, Level 1 [Member] | Corporate stock Assets [Member] | National Holdings Corporation [Member]
Assets
Total		65	116
Fair Value, Inputs, Level 1 [Member] | Municipal bonds Assets [Member] | National Holdings Corporation [Member]
Assets
Total		3,452	1,239
Fair Value, Inputs, Level 1 [Member] | Restricted stock Assets [Member] | National Holdings Corporation [Member]
Assets
Total		0	0
Fair Value, Inputs, Level 1 [Member] | Municipal bonds Liabilities [Member] | National Holdings Corporation [Member]
Liabilities
Liabilities			151
Fair Value, Inputs, Level 1 [Member] | Contingent Consideration [Member] | National Holdings Corporation [Member]
Liabilities
Liabilities		0	0
Fair Value, Inputs, Level 1 [Member] | Warrants Issuable [Member] | National Holdings Corporation [Member]
Liabilities
Liabilities		0	0
Fair Value, Inputs, Level 1 [Member] | Caelum Convertible Notes [Member]
Liabilities
Liabilities	0	0
Fair Value, Inputs, Level 2 [Member]
Assets
Long-term investments, at fair value	0	0
Total	0	0
Liabilities
Liabilities	0	0
Fair Value, Inputs, Level 2 [Member] | National Holdings Corporation [Member]
Assets
Total		75	82
Liabilities
Liabilities		0	0
Fair Value, Inputs, Level 2 [Member] | Warrant [Member]
Liabilities
Liabilities	0	0
Fair Value, Inputs, Level 2 [Member] | Warrant [Member] | National Holdings Corporation [Member]
Assets
Total		0	0
Fair Value, Inputs, Level 2 [Member] | Helocyte Convertible Note One [Member]
Liabilities
Liabilities	0	0
Fair Value, Inputs, Level 2 [Member] | Corporate stock Assets [Member] | National Holdings Corporation [Member]
Assets
Total		0	0
Fair Value, Inputs, Level 2 [Member] | Municipal bonds Assets [Member] | National Holdings Corporation [Member]
Assets
Total		0	0
Fair Value, Inputs, Level 2 [Member] | Restricted stock Assets [Member] | National Holdings Corporation [Member]
Assets
Total		75	82
Fair Value, Inputs, Level 2 [Member] | Municipal bonds Liabilities [Member] | National Holdings Corporation [Member]
Liabilities
Liabilities			0
Fair Value, Inputs, Level 2 [Member] | Contingent Consideration [Member] | National Holdings Corporation [Member]
Liabilities
Liabilities		0	0
Fair Value, Inputs, Level 2 [Member] | Warrants Issuable [Member] | National Holdings Corporation [Member]
Liabilities
Liabilities		0	0
Fair Value, Inputs, Level 2 [Member] | Caelum Convertible Notes [Member]
Liabilities
Liabilities	0	0
Fair Value, Inputs, Level 3 [Member]
Assets
Long-term investments, at fair value	1,272	1,390
Total	1,272	1,390
Liabilities
Liabilities	12,729	14,846
Fair Value, Inputs, Level 3 [Member] | National Holdings Corporation [Member]
Assets
Total		686	548
Liabilities
Liabilities		7,388	5,908
Fair Value, Inputs, Level 3 [Member] | Warrant [Member]
Liabilities
Liabilities	78	87
Fair Value, Inputs, Level 3 [Member] | Warrant [Member] | National Holdings Corporation [Member]
Assets
Total		686	548
Fair Value, Inputs, Level 3 [Member] | Helocyte Convertible Note One [Member]
Liabilities
Liabilities	2,511	4,700
Fair Value, Inputs, Level 3 [Member] | Corporate stock Assets [Member] | National Holdings Corporation [Member]
Assets
Total		0	0
Fair Value, Inputs, Level 3 [Member] | Municipal bonds Assets [Member] | National Holdings Corporation [Member]
Assets
Total		0	0
Fair Value, Inputs, Level 3 [Member] | Restricted stock Assets [Member] | National Holdings Corporation [Member]
Assets
Total		0	0
Fair Value, Inputs, Level 3 [Member] | Municipal bonds Liabilities [Member] | National Holdings Corporation [Member]
Liabilities
Liabilities			0
Fair Value, Inputs, Level 3 [Member] | Contingent Consideration [Member] | National Holdings Corporation [Member]
Liabilities
Liabilities		717	311
Fair Value, Inputs, Level 3 [Member] | Warrants Issuable [Member] | National Holdings Corporation [Member]
Liabilities
Liabilities		6,671	$ 5,597
Fair Value, Inputs, Level 3 [Member] | Caelum Convertible Notes [Member]
Liabilities
Liabilities	$ 10,140	$ 10,059

Fair Value Measurements - Chang

Fair Value Measurements - Changes in Fair Value of Financial Instruments (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	$ 21,833
Payment of convertible note	(1,858)
Change in fair value of investments	(118)
Change in fair value of convertible notes	(250)
Change in fair value of derivative liabilities	1,065
Balance	20,672
Helocyte Convertible Note At Fair Value [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	4,700
Payment of convertible note	(1,858)
Change in fair value of investments	0
Change in fair value of convertible notes	(331)
Change in fair value of derivative liabilities	0
Balance	2,511
Warrants Issued Issuable [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	5,597
Payment of convertible note	0
Change in fair value of investments	0
Change in fair value of convertible notes	0
Change in fair value of derivative liabilities	1,074
Balance	6,671
Caelum Convertible Notes, at fair value [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	10,059
Payment of convertible note	0
Change in fair value of investments	0
Change in fair value of convertible notes	81
Change in fair value of derivative liabilities	0
Balance	10,140
Warrant liabilities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	87
Payment of convertible note	0
Change in fair value of investments	0
Change in fair value of convertible notes	0
Change in fair value of derivative liabilities	(9)
Balance	78
Investment In Origo [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance	1,390
Payment of convertible note	0
Change in fair value of investments	(118)
Change in fair value of convertible notes	0
Change in fair value of derivative liabilities	0
Balance	$ 1,272

Licenses Acquired - Additional

Licenses Acquired - Additional Information (Detail) - USD ($)	1 Months Ended		3 Months Ended
	Jan. 31, 2018	Mar. 31, 2015	Mar. 31, 2018	Mar. 31, 2017	Feb. 02, 2018
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research And Development In Process			$ 97,000	$ 1,294,000
Payments for Fees		$ 1,000,000
City Of Hope [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payment of Upfront Fees	$ 75,000
Collaborative Agreements with TGTX [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Proceeds from Option Fee					$ 50,000
Collaborative Agreements with TGTX [Member] | NeuPharma [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Payments for Fees			44,000	28,000
Caelum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research And Development In Process			0	200,000
Cyprium [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research And Development In Process			$ 0	$ 100,000
Manufacturing Methods License [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Annual Maintenance Fee Payable	$ 15,000

Licenses Acquired - Summary Of

Licenses Acquired - Summary Of Research and Development Arrangement Contract (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and Development Total	$ 97	$ 1,294
Checkpoint Therapeutics, Inc [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and Development Total	0	400
Helocyte [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and Development Total	21	0
Mustang Therapeutics, Inc [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and Development Total	75	575
Cellvation [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and Development Total	1	0
Caelum Biosciences, Inc. [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and Development Total	0	219
Cyprium Therapeutics, Inc. [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and Development Total	$ 0	$ 100

Licenses Acquired - license as

Licenses Acquired - license as recorded in the Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Research And Development In Process	$ 97	$ 1,294
Checkpoint Therapeutics, Inc [Member]
Research And Development In Process	0	400
Checkpoint Therapeutics, Inc [Member] | Jubliant Biosys License CK-103 [Member]
Research And Development In Process	0	400
Mustang Therapeutics, Inc [Member]
Research And Development In Process	75	575
Mustang Therapeutics, Inc [Member] | City of Hope (COH) IL-13 License [Member]
Research And Development In Process	0	250
Mustang Therapeutics, Inc [Member] | COH IV/ICV Agreement [Member]
Research And Development In Process	0	125
Mustang Therapeutics, Inc [Member] | University of California License for PSCA [Member]
Research And Development In Process	0	200
Mustang Therapeutics, Inc [Member] | Manufacturing License [Member]
Research And Development In Process	$ 75	$ 0

Sponsored Research and Clinic59

Sponsored Research and Clinical Trial Agreements - Additional Information (Detail) - USD ($)	Mar. 12, 2018	Mar. 31, 2018	Mar. 31, 2017
Research And Development Expense		$ 12,000
Columbia University [Member]
Research And Development Expense		11,000	$ 0
Research and Development Arrangement, Contract to Perform for Others, Costs Incurred, Gross	$ 100,000
University of Texas [Member]
Research And Development Expense		82,500
University of North Carolina [Member]
Research And Development Expense		200,000
Checkpoint Therapeutics, Inc [Member]
Research And Development Expense		31,000	$ 200,000
Mustang Therapeutics Inc [Member]
Research And Development Expense		100,000
Payments Made to Fund for Research Program		$ 900,000
Research Program Fund		2 years
Upfront Prepayment		$ 900,000
Proceeds For Research Program		600,000
Umass Sponsored Research Agreement [Member]
Research And Development Expense		100,000
Sponsor Research Agreement, Funding Commitment		800,000
Payments For Research And Development Expenses		800,000
UNC Sponsored Research Agreement [Member]
Sponsor Research Agreement, Funding Commitment		$ 2,300,000
UNC Sponsored Research Agreement [Member] | UNC [Member]
Sponsor Research Agreement Term		3 years
UNC Sponsored Research Agreement [Member] | Tamid [Member]
Payments For Research And Development Expenses		$ 800,000

Sponsored Research and Clinic60

Sponsored Research and Clinical Trial Agreements - summary of Helocyte’s expense related to its clinical research arrangements (Detail) - Helocyte Inc [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Payments For Research And Development Expenses	$ 0	$ 735
COH Triplex Clinical Research and Support [Member]
Payments For Research And Development Expenses	0	500
COH PepVax Clinical Research And Support [Member]
Payments For Research And Development Expenses	$ 0	$ 235

Sponsored Research and Clinic61

Sponsored Research and Clinical Trial Agreements - summary of Mustang’s expense related to its sponsored research agreements (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Research And Development In Process	$ 97	$ 1,294
Mustang Therapeutics Inc [Member]
Research And Development In Process	1,390	529
COH CAR T [Member] | Mustang Therapeutics Inc [Member]
Research And Development In Process	500	500
COH - CD123 [Member] | Mustang Therapeutics Inc [Member]
Research And Development In Process	150	20
COH - IL13Ra2 [Member] | Mustang Therapeutics Inc [Member]
Research And Development In Process	360	9
City of Hope - Manufacturing [Member] | Mustang Therapeutics Inc [Member]
Research And Development In Process	114	0
Fred Hutch - CD20 [Member] | Mustang Therapeutics Inc [Member]
Research And Development In Process	$ 266

Intangibles, net - Additional I

Intangibles, net - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Indefinite-lived Intangible Assets [Line Items]
Cost of Goods Sold, Amortization	$ 133	$ 133
Journey Medical Corporation [Member]
Indefinite-lived Intangible Assets [Line Items]
Payments to Acquire Intangible Assets	1,600
Cost of Goods Sold, Amortization	$ 100	$ 100

Debt and Interest- Additional I

Debt and Interest- Additional Information (Detail) - USD ($) $ in Millions	Mar. 12, 2018	Mar. 31, 2018	Dec. 31, 2017
Opus Credit Facility [Member]
Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		12.00%
Debt instrument Expiration Period	Sep. 14, 2019		Sep. 14, 2018
Venture Notes [Member]
Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		8.00%
Debt Instrument, Face Amount		$ 21.7
Debt Instrument, Term		36 months
Debt Instrument, Maturity Date, Description		The notes mature in 36 months from issuance, provided that during the first 24 months the Company may extend the maturity date by six months.
NSC [Member] | Venture Notes [Member]
Debt [Line Items]
Warrant On Sale Price Of Note Percentage		25.00%
Payments of Financing Costs		$ 1.7
Class of Warrant or Right, Expiration Period		10 years
Aevitas Therapeutics, Inc [Member] | Venture Notes [Member]
Debt [Line Items]
Proceeds from Notes Payable		$ 1.4
Tamid Bio, Inc [Member] | Venture Notes [Member]
Debt [Line Items]
Proceeds from Notes Payable		1
Cellvation [Member] | Venture Notes [Member]
Debt [Line Items]
Proceeds from Notes Payable		$ 0.4

Debt and Interest - Long-term d

Debt and Interest - Long-term debt (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Debt [Line Items]
Total notes payable	$ 87,142	$ 67,544
Less: Discount of notes payable	1,047	1,035
Total notes payable, net	86,095	66,509
IDB Note [Member]
Debt [Line Items]
Total notes payable	$ 14,929	14,929
Interest Rate	2.25%
Maturity Date	August - 2020
2017 Subordinated Note Financing One [Member]
Debt [Line Items]
Total notes payable	$ 3,254	3,254
Interest Rate	8.00%
Maturity Date	March - 2020
2017 Subordinated Note Financing Two [Member]
Debt [Line Items]
Total notes payable	$ 13,893	13,893
Interest Rate	8.00%
Maturity Date	May - 2020
2017 Subordinated Note Financing Three [Member]
Debt [Line Items]
Total notes payable	$ 1,820	1,820
Interest Rate	8.00%
Maturity Date	June - 2020
2017 Subordinated Note Financing Four [Member]
Debt [Line Items]
Total notes payable	$ 3,018	3,018
Interest Rate	8.00%
Maturity Date	August - 2020
2017 Subordinated Note Financing Five [Member]
Debt [Line Items]
Total notes payable	$ 6,371	6,371
Interest Rate	8.00%
Maturity Date	September - 2020
2018 Venture Notes One [Member]
Debt [Line Items]
Total notes payable	$ 6,517	0
Interest Rate	8.00%
Maturity Date	February – 2021
2018 Venture Notes Two [Member]
Debt [Line Items]
Total notes payable	$ 15,190	0
Interest Rate	8.00%
Maturity Date	March - 2021
Opus Credit Facility [Member]
Debt [Line Items]
Total notes payable	$ 9,500	9,500
Interest Rate	12.00%
Maturity Date	September – 2019
Helocyte Convertible Note One [Member]
Debt [Line Items]
Total notes payable	$ 0	1,000
Maturity Date	December 2,017
Helocyte Convertible Note One [Member] | Minimum [Member]
Debt [Line Items]
Interest Rate	5.00%
Helocyte Convertible Note One [Member] | Maximum [Member]
Debt [Line Items]
Interest Rate	8.00%
Helocyte Convertible Note Two [Member]
Debt [Line Items]
Total notes payable	$ 860	2,194
Maturity Date	March - 2018
Helocyte Convertible Note Two [Member] | Minimum [Member]
Debt [Line Items]
Interest Rate	5.00%
Helocyte Convertible Note Two [Member] | Maximum [Member]
Debt [Line Items]
Interest Rate	8.00%
Helocyte Convertible Note Three [Member]
Debt [Line Items]
Total notes payable	$ 945	1,062
Maturity Date	April - 2018
Helocyte Convertible Note Three [Member] | Minimum [Member]
Debt [Line Items]
Interest Rate	5.00%
Helocyte Convertible Note Three [Member] | Maximum [Member]
Debt [Line Items]
Interest Rate	8.00%
Helocyte Convertible Note four [Member]
Debt [Line Items]
Total notes payable	$ 372	444
Maturity Date	May - 2018
Helocyte Convertible Note four [Member] | Minimum [Member]
Debt [Line Items]
Interest Rate	5.00%
Helocyte Convertible Note four [Member] | Maximum [Member]
Debt [Line Items]
Interest Rate	8.00%
Helocyte Convertible Note Five [Member]
Debt [Line Items]
Total notes payable	$ 310	0
Maturity Date	September 2,018
Helocyte Convertible Note Five [Member] | Minimum [Member]
Debt [Line Items]
Interest Rate	5.00%
Helocyte Convertible Note Five [Member] | Maximum [Member]
Debt [Line Items]
Interest Rate	8.00%
Helocyte Convertible Note Six [Member]
Debt [Line Items]
Total notes payable	$ 23	0
Maturity Date	November 2,018
Helocyte Convertible Note Six [Member] | Minimum [Member]
Debt [Line Items]
Interest Rate	5.00%
Helocyte Convertible Note Six [Member] | Maximum [Member]
Debt [Line Items]
Interest Rate	8.00%
Caelum Convertible Note one [Member]
Debt [Line Items]
Total notes payable	$ 1,026	1,017
Interest Rate	8.00%
Maturity Date	January - 2019
Caelum Convertible Note Two [Member]
Debt [Line Items]
Total notes payable	$ 6,956	6,900
Interest Rate	8.00%
Maturity Date	February - 2019
Caelum Convertible Note one Three [Member]
Debt [Line Items]
Total notes payable	$ 2,158	$ 2,142
Interest Rate	8.00%
Maturity Date	March - 2019

Debt and Interest - Schedule of

Debt and Interest - Schedule of Interest Expenses for Debt Arrangements (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Debt [Line Items]
Total Interest Expense and Financing Fee	$ 2,083	$ 698
LOC Fees [Member]
Debt [Line Items]
Interest	7	8
Interest and Debt Expense	7	8
IDB Note [Member]
Debt [Line Items]
Interest	84	82
Interest and Debt Expense	84	82
NSC Debt [Member]
Debt [Line Items]
Interest	0	71
Amortization of fees	0	38
Interest and Debt Expense	0	109
2017 Subordinated Note Financing [Member]
Debt [Line Items]
Interest	1,048	0
Amortization of fees	21	0
Interest and Debt Expense	1,069	0
Opus Credit Facility [Member]
Debt [Line Items]
Interest	281	232
Amortization of fees	319	208
Interest and Debt Expense	600	440
2018 Venture Notes [Member]
Debt [Line Items]
Interest	56	0
Amortization of fees	1	0
Interest and Debt Expense	57	0
Helocyte Convertible Note [Member]
Debt [Line Items]
Interest	68	54
Financing fee	0	1
Interest and Debt Expense	68	55
Avenue Convertible Note [Member]
Debt [Line Items]
Financing fee	0	3
Interest and Debt Expense	0	3
Caelum Convertible Notes [Member]
Debt [Line Items]
Interest	196	0
Interest and Debt Expense	196	0
Other [Member]
Debt [Line Items]
Interest	2	1
Interest and Debt Expense	$ 2	$ 1

Accrued Expenses and Other Lo66

Accrued Expenses and Other Long-Term Liabilities - Components of Accrued Expenses and Other Long-Term Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accrued expenses:
Professional fees	$ 1,497	$ 1,625
Salaries, bonuses and related benefits	6,002	5,279
Accrued expenses - related party	107	95
Research and development	7,061	4,046
Dr. Falk Pharma milestone	3,059	3,059
Accrued royalties payable	1,091	1,411
Accrued coupon expense	735	0
Deferred coupon funding	1,516	1,087
Other	646	1,030
Total accrued expenses	21,714	17,632
Other long-term liabilities:
Deferred rent	4,759	4,739
Total other long-term liabilities	$ 4,759	$ 4,739

Accrued Expenses and Other Lo67

Accrued Expenses and Other Long-Term Liabilities- Accounts Payable and Other Accrued Expenses (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017
Legal	$ 1,497	$ 1,625
Other	646	1,030
Total	$ 44,725	36,127
National Holdings Corporation [Member]
Legal		653	$ 877
Audit		171	176
Telecommunications		208	205
Data Services		454	464
Regulatory		663	540
Settlements		1,789	2,403
Deferred rent		684	497
Other		3,437	3,242
Total		$ 8,059	$ 8,404

Non-Controlling Interests - Sum

Non-Controlling Interests - Summary Of Non-controlling Interests in Consolidated Entities (Detail) - USD ($) $ in Thousands		3 Months Ended		12 Months Ended
		Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Noncontrolling Interest [Line Items]
NCI equity share		$ 83,095		$ 100,889
Net gain/(loss) attributable to non-controlling interests		(17,200)	$ (2,580)	(32,960)
Non-controlling interests in consolidated entities		65,895		67,929
Avenue [Member]
Noncontrolling Interest [Line Items]
NCI equity share	[1]	12,719		17,454
Net gain/(loss) attributable to non-controlling interests	[1]	(6,691)		(4,646)
Non-controlling interests in consolidated entities	[1]	$ 6,028		$ 12,808
Non-controlling ownership	[1]	64.40%		66.10%
Coronado SO [Member]
Noncontrolling Interest [Line Items]
NCI equity share		$ (290)		$ (236)
Net gain/(loss) attributable to non-controlling interests		0		(54)
Non-controlling interests in consolidated entities		$ (290)		$ (290)
Non-controlling ownership		13.00%		13.00%
Mustang Therapeutics, Inc [Member]
Noncontrolling Interest [Line Items]
NCI equity share	[1]	$ 36,961		$ 48,740
Net gain/(loss) attributable to non-controlling interests	[1]	(3,733)		(11,911)
Non-controlling interests in consolidated entities	[1]	$ 33,228		$ 36,829
Non-controlling ownership	[1]	59.70%		61.60%
Checkpoint Therapeutics, Inc [Member]
Noncontrolling Interest [Line Items]
NCI equity share	[2]	$ 24,662		$ 21,635
Net gain/(loss) attributable to non-controlling interests	[2]	(5,175)		(12,314)
Non-controlling interests in consolidated entities	[2]	$ 19,487		$ 9,321
Non-controlling ownership	[2]	67.40%		62.00%
JMC [Member]
Noncontrolling Interest [Line Items]
NCI equity share		$ (461)		$ (469)
Net gain/(loss) attributable to non-controlling interests		56		7
Non-controlling interests in consolidated entities		$ (405)		$ (462)
Non-controlling ownership		6.30%		6.30%
Helocyte [Member]
Noncontrolling Interest [Line Items]
NCI equity share		$ (3,124)		$ (1,907)
Net gain/(loss) attributable to non-controlling interests		(33)		(1,193)
Non-controlling interests in consolidated entities		$ (3,157)		$ (3,100)
Non-controlling ownership		19.80%		20.00%
Cellvation [Member]
Noncontrolling Interest [Line Items]
NCI equity share		$ (387)		$ (259)
Net gain/(loss) attributable to non-controlling interests		(51)		(96)
Non-controlling interests in consolidated entities		$ (438)		$ (355)
Non-controlling ownership		21.60%		21.50%
Caelum [Member]
Noncontrolling Interest [Line Items]
NCI equity share		$ (2,133)		$ (815)
Net gain/(loss) attributable to non-controlling interests		(707)		(1,262)
Non-controlling interests in consolidated entities		$ (2,840)		$ (2,077)
Non-controlling ownership		33.90%		34.70%
National Holdings [Member]
Noncontrolling Interest [Line Items]
NCI equity share		$ 15,805		$ 17,021
Net gain/(loss) attributable to non-controlling interests		(734)		(1,216)
Non-controlling interests in consolidated entities		$ 15,071		$ 15,805
Non-controlling ownership		43.40%		43.40%
Aevitas [Member]
Noncontrolling Interest [Line Items]
NCI equity share		$ (356)		$ (126)
Net gain/(loss) attributable to non-controlling interests		(47)		(168)
Non-controlling interests in consolidated entities		$ (403)		$ (294)
Non-controlling ownership		37.00%		35.40%
Cyprium [Member]
Noncontrolling Interest [Line Items]
NCI equity share		$ (169)		$ (143)
Net gain/(loss) attributable to non-controlling interests		(31)		(15)
Non-controlling interests in consolidated entities		$ (200)		$ (158)
Non-controlling ownership		10.80%		11.10%
Tamid [Member]
Noncontrolling Interest [Line Items]
NCI equity share		$ (132)		$ (6)
Net gain/(loss) attributable to non-controlling interests		(54)		(92)
Non-controlling interests in consolidated entities		$ (186)		$ (98)
Non-controlling ownership		24.00%		24.00%
[1]	Avenue and Mustang are consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Preferred Class A Shares which provide super-majority voting rights.
[2]	Checkpoint is consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Checkpoint’s Class A Common Shares which provide super-majority voting rights.

Net Loss per Common Share - Com

Net Loss per Common Share - Computations of Diluted Weighted Average Shares Outstanding (Detail) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of weighted average shares outstanding	17,688,788	14,510,348
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of weighted average shares outstanding	1,000,000	0
Warrants to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of weighted average shares outstanding	894,189	383,453
Opus warrants to purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of weighted average shares outstanding	1,880,000	1,860,000
Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of weighted average shares outstanding	1,085,501	1,105,502
Unvested Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of weighted average shares outstanding	11,050,943	9,912,161
Unvested Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total of weighted average shares outstanding	1,778,154	1,249,232

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($)	Mar. 12, 2018	Mar. 31, 2018	Mar. 31, 2017	Feb. 12, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee Stock Purchase Plan to eligible employees, compensation expense recognized		$ 38,000	$ 35,000
Share-based Compensation		5,053,000	2,929,000
Adjustments To Additional Paid In Capital At Market Offering Costs		$ (6,000)
Market Offering [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares Issued, Price Per Share		$ 4.92
Proceeds from issuance of Common stock		$ 300,000
Issuance of Common Stock for At the Market Offering in shares		64,797
Adjustments To Additional Paid In Capital At Market Offering Costs		$ 5,700
Checkpoint [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares Issued, Price Per Share				$ 4.35
Proceeds from issuance of Common stock	$ 20,800,000
Stock Issued During Period, Shares, New Issues	5,290,000
Stock Issued During Period, Value, New Issues	$ 23,000,000
Payments of Stock Issuance Costs	$ 2,200,000
Research and Development Expense [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Allocated Share-based Compensation Expense		2,300,000	800,000
General and Administrative Expense [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Allocated Share-based Compensation Expense		$ 2,700,000	$ 2,100,000
Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition		3 years 1 month 6 days
Share-based Compensation		$ 8,400,000
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			2 years 9 months 18 days
Share-based Compensation			$ 3,400,000
Employee Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Employee Stock Purchase Plan to eligible employees, Reckoning fair value percentage during offering period		85.00%
Common Stock issued in connection with the first ESPP offering		245,652
Common Stock, Capital Shares Reserved for Future Issuance		154,348

Stockholders' Equity - Employee

Stockholders' Equity - Employee Stock Purchase Programs (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 5,053	$ 2,929
Avenue [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	349	5
Checkpoint [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,137	979
Mustang [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,995	0
Other [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	112	115
Employee Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	828	367
Executive Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 632	$ 1,463

Stockholders' Equity - Stock Op

Stockholders' Equity - Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Options Outstanding	1,110,501
Number of shares, Options Exercised	0
Number of shares, Options Outstanding	1,110,501	1,110,501
Number of shares, Options Exercisable	1,085,501
Weighted Average Exercise Price, Options Exercised	$ 0
Total Weighted Average Intrinsic Value, Options Exercised	$ 0
Total Weighted Average Intrinsic Value, Options vested and exercisable	$ 1,701,361
Weighted Average Remaining Contractual Life, Options Exercisable	3 years 8 months 16 days	3 years 11 months 12 days
Weighted average exercise price, Options vested and expected to vest	$ 3.78
Weighted average exercise price, Options vested and expected to vest	3.78	$ 3.78
Weighted average exercise price, Options vested and exercisable	$ 3.75
Total Weighted average intrinsic value, Options vested and expected to vest	$ 1,351,080
Total Weighted average intrinsic value, Options vested and expected to vest	$ 1,701,361	$ 1,351,080
Weighted average remaining contractual life (years), Options vested and expected to vest	3 years 8 months 16 days	3 years 11 months 12 days
Weighted average remaining contractual life (years), Options vested and exercisable	3 years 8 months 5 days

Stockholders' Equity - Restrict

Stockholders' Equity - Restricted Stock Activity (Detail) - Restricted Stock [Member]	3 Months Ended
	Mar. 31, 2018$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Unvested balance | shares	11,874,034
Number of shares, Restricted stock granted | shares	1,392,856
Number of shares, Restricted stock vested | shares	(213,334)
Number of shares, Restricted stock units granted | shares	230,000
Number of shares, Restricted stock units forfeited | shares	(42,417)
Number of shares, Restricted stock units vested | shares	(64,750)
Number of shares, Unvested balance | shares	13,176,389
Weighted average grant price, Unvested balance | $ / shares	$ 2.63
Weighted average grant price, Restricted stock granted | $ / shares	3.99
Weighted average grant price, Restricted stock vested | $ / shares	2.76
Weighted average grant price, Restricted stock units granted | $ / shares	4.98
Weighted average grant price, Restricted stock units forfeited | $ / shares	3.52
Weighted average grant price, Restricted stock units vested | $ / shares	3.49
Weighted average grant price, Unvested balance | $ / shares	$ 2.81

Stockholders' Equity - Summariz

Stockholders' Equity - Summarizes Fortress warrant activities (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Subsidiary or Equity Method Investee [Line Items]
Weighted average remaining contractual life, Forfeited (years)	0 years
Warrant [Member]
Subsidiary or Equity Method Investee [Line Items]
Number of shares, Outstanding	2,774,189
Number of shares, Granted	0
Forfeited	0
Number of shares, Outstanding	2,774,189	2,774,189
Number of shares, Exercisable	869,189
Weighted average exercise price, Outstanding	$ 3.3
Weighted average exercise price, Granted	0
Weighted average exercise price, Forfeited	0
Weighted average exercise price, Outstanding	3.3	$ 3.3
Weighted average exercise price, Exercisable	$ 3.96
Total weighted average intrinsic value, Outstanding	$ 2,204,530
Total weighted average intrinsic value, Granted	0
Total weighted average intrinsic value, Forfeited	0
Total weighted average intrinsic value, Outstanding	3,586,975	$ 2,204,530
Total weighted average intrinsic value, Exercisable	$ 634,225
Weighted average remaining contractual life, Granted (years)	0 years
Weighted average remaining contractual life (years), Outstanding	4 years 2 months 19 days	4 years 5 months 19 days
Weighted average remaining contractual life, Exercisable (years)	3 years 9 months 22 days

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) € in Millions	Aug. 11, 2016	Jul. 27, 2017EUR (€)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2017USD ($)
Operating Leased Assets [Line Items]
Loss Contingency, Accrual, Current			$ 1,800,000		$ 2,400,000
Loss Contingency Accrual, Provision			200,000	$ 6,000
Legal Fees			$ 400,000	$ 500,000
Business Combination, Contingent Consideration Arrangements, Description	Fortress contends that no such payment is due because a condition of the EUR 2.5 million payment was the delivery of a Clinical Study Report that addressed the primary and secondary objectives of a Phase II trial, and Fortress contends that Dr. Falk Pharma failed to deliver such a Clinical Study Report. Dr. Falk Pharma disputes that it failed to deliver such a report and further disputes that the delivery of such a report is a condition of Fortress’s obligation to make the EUR 2.5 million payment. After the parties’ attempts to negotiate a settlement of the dispute were unsuccessful, Dr. Falk Pharma filed a lawsuit against Fortress in the above-referenced Court in Frankfurt, Germany to recover the EUR 2.5 million plus interest and attorneys’ fees, and Fortress was served with the English translation of the lawsuit on August 11, 2016. Fortress retained local counsel and, on December 14, 2016, filed an answer to the complaint, denying that it had any liability to Dr. Falk Pharma.
Dr. Falk Pharma [Member]
Operating Leased Assets [Line Items]
Proceeds from Legal Settlements | €		€ 2.5

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended
	May 31, 2015	Mar. 31, 2018	Mar. 31, 2017	Feb. 02, 2018
Related Party Transaction [Line Items]
Lease Sharing Agreements Contributions To Property Under Lease		$ 32,000
Description Of Fee Paid		NSC received a fee of approximately $1.8 million, or 8% on the gross proceeds raised of $23.0 million. The fees were eliminated in consolidation.
Proceeds from Other Debt		$ 21,707,000	$ 0
Noninterest Expense Transfer Agent and Custodian Fees		$ 1,700,000
National Holdings Corporation [Member]
Related Party Transaction [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired		56.60%
Opus Credit Facility [Member]
Related Party Transaction [Line Items]
Payments of Loan Costs		$ 300,000	200,000
Debt Instrument, Interest Rate, Stated Percentage		12.00%
Chief Executive Officer [Member]
Related Party Transaction [Line Items]
Interest own in percent by principal stockholder or director		13.70%
Chord Advisors, LLC [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 10,000
Board of Directors Chairman [Member] | National Holdings Corporation [Member]
Related Party Transaction [Line Items]
Equity Method Investment, Ownership Percentage		4.60%
TG Therapeutics, Inc [Member]
Related Party Transaction [Line Items]
Due from Related Parties, Current		$ 14,000
Checkpoint [Member] | Chord Advisors, LLC [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party		$ 11,000	13,000
Founders Agreement [Member] | Avenue Therapeutics, Inc. [Member]
Related Party Transaction [Line Items]
Other Fee,Percentage		2.50%
OPPM [Member]
Related Party Transaction [Line Items]
Payments for Rent		$ 42,000
Due from Related Parties, Current		$ 3,000
Executives Vice Chairman [Member]
Related Party Transaction [Line Items]
Interest own in percent by principal stockholder or director		16.00%
Collaborative Agreements with TGTX [Member]
Related Party Transaction [Line Items]
Proceeds from Option Fee				$ 50,000
Avenue [Member] | Chord Advisors, LLC [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 5,000
Desk Share Agreements [Member]
Related Party Transaction [Line Items]
Payments for Rent		$ 600,000
Desk Share Agreements [Member] | TG Therapeutics, Inc [Member]
Related Party Transaction [Line Items]
Due from Related Parties, Current		137,000
Desk Share Agreements [Member] | OPPM [Member]
Related Party Transaction [Line Items]
Due from Related Parties, Current		61,000
Shared Services Agreement [Member] | TG Therapeutics, Inc [Member]
Related Party Transaction [Line Items]
Proceeds from Related Party Agreement		300,000	$ 200,000
Due from Related Parties		$ 300,000

Related Party Transactions - Sc

Related Party Transactions - Schedule of Effective Date and Equity Fee Payable (Detail)	3 Months Ended
	Mar. 31, 2018
Helocyte Inc [Member]
Dividends, Paid-in-kind,Percentage	2.50%
Dividends Payable, Date Declared	Mar. 20, 2015	[1]
Avenue Therapeutics, Inc. [Member]
Dividends, Paid-in-kind,Percentage	2.50%
Dividends Payable, Date Declared	Feb. 17, 2015	[1]
Mustang Bio, Inc [Member]
Dividends, Paid-in-kind,Percentage	2.50%
Dividends Payable, Date Declared	Mar. 13, 2015	[1]
Checkpoint Therapeutics, Inc [Member]
Dividends, Paid-in-kind,Percentage	0.00%	[2]
Dividends Payable, Date Declared	Mar. 17, 2015	[1]
Cellvation Inc [Member]
Dividends, Paid-in-kind,Percentage	2.50%
Dividends Payable, Date Declared	Oct. 31, 2016	[1]
Caelum Biosciences, Inc. [Member]
Dividends, Paid-in-kind,Percentage	2.50%
Dividends Payable, Date Declared	Jan. 1, 2017	[1]
Cyprium Biosciences, Inc [Member]
Dividends, Paid-in-kind,Percentage	2.50%
Dividends Payable, Date Declared	Mar. 13, 2017	[1]
Aevitas Inc [Member]
Dividends, Paid-in-kind,Percentage	2.50%
Dividends Payable, Date Declared	Jul. 28, 2017	[1]
Tamid [Member]
Dividends, Paid-in-kind,Percentage	2.50%
Dividends Payable, Date Declared	Nov. 30, 2017	[3]
[1]	Represents the effective date of each subsidiary’s Founders Agreement. Each PIK dividend and equity fee is payable on the annual anniversary of the effective date of the original Founders Agreement.
[2]	Instead of a PIK dividend, Checkpoint pays the Company an annual equity fee in shares of Checkpoint’s common stock equal to 2.5% of Checkpoint’s fully diluted outstanding capitalization.
[3]	Represents the Trigger Date.

Related Party Transactions - 78

Related Party Transactions - Schedule of The Effective Date and Annual Management Services agreement Fee (Income) Expense (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Annual Management Services Agreement Fee Income Expense	$ 0
Helocyte Inc [Member]
Annual Management Services Agreement Fee Income Expense	$ 500
Annual Consulting Fee Payable Effective Date	Mar. 20, 2015
Avenue Therapeutics, Inc. [Member]
Annual Management Services Agreement Fee Income Expense	$ 500
Annual Consulting Fee Payable Effective Date	Feb. 17, 2015
Mustang Bio, Inc [Member]
Annual Management Services Agreement Fee Income Expense	$ 500
Annual Consulting Fee Payable Effective Date	Mar. 13, 2015
Checkpoint Therapeutics, Inc [Member]
Annual Management Services Agreement Fee Income Expense	$ 500
Annual Consulting Fee Payable Effective Date	Mar. 17, 2015
Cellvation Inc [Member]
Annual Management Services Agreement Fee Income Expense	$ 500
Annual Consulting Fee Payable Effective Date	Oct. 31, 2016
Caelum Biosciences, Inc. [Member]
Annual Management Services Agreement Fee Income Expense	$ 500
Annual Consulting Fee Payable Effective Date	Jan. 1, 2017
Cyprium Biosciences, Inc [Member]
Annual Management Services Agreement Fee Income Expense	$ 500
Annual Consulting Fee Payable Effective Date	Mar. 13, 2017
Fortress Biotech Inc [Member]
Annual Management Services Agreement Fee Income Expense	$ (4,500)
Aevitas Inc [Member]
Annual Management Services Agreement Fee Income Expense	$ 500
Annual Consulting Fee Payable Effective Date	Jul. 28, 2017
Tamid [Member]
Annual Management Services Agreement Fee Income Expense	$ 500
Annual Consulting Fee Payable Effective Date	Nov. 30, 2017

Net Capital Requirements of B79

Net Capital Requirements of Broker-Dealer Subsidiaries - Additional Information (Detail) - National Securities [Member]	Dec. 31, 2017USD ($)
Net Capital	$ 10,000,000
Excess Net Capital at 1000 Percent	9,700,000
Minimum Net Capital Required for Broker-Dealer Subsidiary	$ 250,000

Segment Information - Operating

Segment Information - Operating Results by Reportable Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Net Revenue	$ 55,425	$ 44,682
Direct cost of goods	(1,472)	(469)
Sales and marketing costs	(2,764)	(2,267)
Research and development	(25,055)	(8,404)
General and administrative	(10,784)	(7,985)
National Expenses	90,911	62,259
Segment income (loss) from operations	(35,486)	(17,577)
Segment assets	265,075		$ 245,950
Dermatology Products Sales [Member]
Segment Reporting Information [Line Items]
Net Revenue	5,509	2,085
Direct cost of goods	(1,472)	(469)
Sales and marketing costs	(2,764)	(2,267)
Research and development	0	0
General and administrative	(397)	(319)
National Expenses	0	0
Segment income (loss) from operations	876	(970)
Segment assets	11,163	4,039
Pharmaceutical And Biotechnology Product Development [Member]
Segment Reporting Information [Line Items]
Net Revenue	394	693
Direct cost of goods	0	0
Sales and marketing costs	0	0
Research and development	(25,055)	(8,404)
General and administrative	(10,387)	(7,666)
National Expenses	0	0
Segment income (loss) from operations	(35,048)	(15,377)
Segment assets	189,560	159,175
National [Member]
Segment Reporting Information [Line Items]
Net Revenue	49,522	41,904
Direct cost of goods	0	0
Sales and marketing costs	0	0
Research and development	0	0
General and administrative	0	0
National Expenses	(50,836)	(43,134)
Segment income (loss) from operations	(1,314)	(1,230)
Segment assets	64,352	48,697
Consolidated [Member]
Segment Reporting Information [Line Items]
National Expenses		(43,134)
Segment assets	$ 265,075	$ 211,911

Revenues from Contracts and S81

Revenues from Contracts and Significant Customers - Additional Information (Detail) - USD ($)		May 11, 2015	Sep. 30, 2015	Mar. 31, 2015	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Stock Issued During Period, Value, Issued for Services					$ 1,000	$ 1,000
Revenue Recognition Milestone Method Payments Due					500,000
Payments for Fees				$ 1,000,000
License and Services Revenue					400,000
Collaborative Arrangement, Fixed Fee					500,000
Return Reserve					700,000	100,000
Customer One [Member]
Sales Revenue, Goods, Gross					4,400,000	800,000
Accounts Receivable, Net					3,000,000	800,000
Customer Two [Member]
Sales Revenue, Goods, Gross					3,900,000	500,000
Accounts Receivable, Net					2,100,000	$ 500,000
Customer Three [Member]
Sales Revenue, Goods, Gross					$ 2,000,000
Checkpoint Therapeutics, Inc [Member]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	[1]				67.40%		62.00%
First Commercial Sale Milestone [Member] | Checkpoint Therapeutics, Inc [Member]
Revenue Recognition Milestone Method Payments Due					$ 21,500,000
Additional Sales Milestone [Member] | Checkpoint Therapeutics, Inc [Member]
Revenue Recognition Milestone Method Payments Due					60,000,000
Clinical Development Milestone [Member] | Checkpoint Therapeutics, Inc [Member]
Revenue Recognition Milestone Method Payments Due					7,000,000
Commercial Sales In Specified Territories [Member] | Checkpoint Therapeutics, Inc [Member]
Revenue Recognition Milestone Method Payments Due					$ 14,500,000
Dana Farber Cancer Institute [Member]
Proceeds from Issuance of Common Stock		$ 10,000,000
Stock Issued During Period, Shares, Issued for Services		500,000	136,830
Stock Issued During Period, Value, Issued for Services		$ 32,500	$ 600,000
Shares Issued, Price Per Share		$ 0.065
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners				5.00%
Dana Farber Cancer Institute [Member] | First Commercial Sale Milestone [Member]
Revenue Recognition Milestone Method Payments Due			21,500,000
Dana Farber Cancer Institute [Member] | Additional Sales Milestone [Member]
Revenue Recognition Milestone Method Payments Due			$ 60,000,000
[1]	Checkpoint is consolidated with Fortress’ operations because Fortress maintains voting control through its ownership of Checkpoint’s Class A Common Shares which provide super-majority voting rights.

Revenues from Contracts and S82

Revenues from Contracts and Significant Customers - Company’s product revenue (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Sales Revenue, Goods, Net	$ 5,509
Total Revenue	55,425	$ 44,682
TGTX [Member]
Sales Revenue, Goods, Net	394
Targadox [Member]
Sales Revenue, Goods, Net	5,498
Other branded revenue [Member]
Sales Revenue, Goods, Net	$ 11

Revenues from Contracts and S83

Revenues from Contracts and Significant Customers - presents National’s revenues (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Commissions	$ 25,618
Investment banking:
Underwriting	2,700
Private Placement	9,815
Advisory	1,314
Other	160
Sub-total National Revenue from contracts with customers	39,607
Other National revenue	9,915
Total National Revenue	$ 49,522