| Stockholders' Equity (Details Textual) - USD ($)
 |  |  |  |  |  | 1 Months Ended | 9 Months Ended |  |  | 
| Aug. 03, 2017 | Jun. 08, 2017 | Apr. 07, 2017 | Mar. 13, 2017 | Mar. 13, 2016 | Jun. 30, 2017 | Mar. 31, 2017 | Feb. 28, 2017 | Jan. 31, 2017 | Sep. 30, 2016 | Jul. 27, 2016 | Mar. 17, 2015 | Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016 | Apr. 30, 2015 | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Common Stock, Shares, Issued |  |  |  |  |  |  |  |  |  |  |  |  | 25,232,139 |  | 15,165,244 |  | 
| Common Stock, Shares Authorized |  |  |  |  |  |  |  |  |  |  |  |  | 50,000,000 |  | 50,000,000 |  | 
| Common Stock, Par or Stated Value Per Share |  |  |  |  |  |  |  |  |  |  |  |  | $ 0.0001 |  | $ 0.0001 |  | 
| Common Stock, Voting Rights |  |  |  |  |  |  |  |  |  |  |  |  | (1.1) |  |  |  | 
| Warrants Issued |  |  |  |  |  |  | 16,000 |  | 2,134,193 |  |  |  |  |  |  |  | 
| Payments of Stock Issuance Costs |  |  |  |  |  |  |  |  |  |  |  |  | $ 5,674,000 | $ 0 |  |  | 
| Preferred Stock, Shares Authorized |  |  |  |  |  |  |  |  |  |  |  |  | 2,000,000 |  | 2,000,000 |  | 
| Preferred Stock, Par or Stated Value Per Share |  |  |  |  |  |  |  |  |  |  |  |  | $ 0.0001 |  | $ 0.0001 |  | 
| Stock Issued During Period, Value, Issued for Services |  |  |  |  |  |  |  | $ 1,700,000 |  |  |  |  | $ 1,234,000 |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights |  |  |  |  |  |  |  |  |  |  |  |  | The remaining 50% (“The Performance Options”) vest and become exercisable upon the occurrence of the following milestones being achieved: (i) 25% of the Performance Options vest upon the dosing of the first patient in the first Phase 2 clinical trial of any Company product candidate, (ii) 25% of the Performance Options vest upon the dosing of the first patient in the first Phase 2 clinical trial of a second Company product candidate, (iii) 25% of the Performance Options vest upon the Company’s achievement of a fully-diluted market capitalization of $500,000,000 and (iv) 25% of the Performance Options vest upon the Company’s achievement of a fully-diluted market capitalization of $1,000,000,000. |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value |  |  |  |  |  |  |  |  |  |  |  |  | $ 5,730,000 |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate |  |  |  |  |  |  |  |  |  |  |  |  | 0.00% |  |  |  | 
| Class Of Warrant Or Right, Percentage Of Warrant Issued |  |  |  |  |  |  |  |  |  |  |  |  | 25.00% |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Exercise Price |  |  |  |  |  |  |  |  |  |  |  |  | $ 5.73 |  |  |  | 
| Director [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Allocated Share-based Compensation Expense |  |  |  |  |  |  |  |  |  |  |  |  | $ 4,900 |  |  |  | 
| Restricted Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Allocated Share-based Compensation Expense |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,000,000 |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross |  |  |  |  |  |  |  |  |  |  |  |  | 180,000 |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term |  |  |  |  |  |  |  |  |  |  |  |  | 3 years 6 months 11 days |  |  |  | 
| Restricted Stock [Member] | Director [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross |  | 180,000 |  |  |  |  |  |  |  |  |  |  | 10,000 |  |  |  | 
| Restricted Stock Units (RSUs) [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Allocated Share-based Compensation Expense |  |  |  |  |  |  |  |  |  |  |  |  | $ 600,000 |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross |  |  |  |  |  | 110,000 |  |  |  |  |  |  | 110,000 |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term |  |  |  |  |  |  |  |  |  |  |  |  | 2 years 3 months |  |  |  | 
| Employee Stock Option [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Allocated Share-based Compensation Expense |  |  |  |  |  |  |  |  |  |  |  |  | $ 2,300,000 |  |  |  | 
| Shares Issued, Price Per Share |  |  | $ 5.73 |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Stock Issued During Period, Shares, Issued for Services |  |  | 200,000 |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term |  |  |  |  |  |  |  |  |  |  |  |  | 1 year 7 months 10 days |  |  |  | 
| General and Administrative Expense [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Allocated Share-based Compensation Expense |  |  |  |  |  |  |  |  |  |  |  |  | $ 1,200,000 | $ 300,000 |  |  | 
| Common Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Common Stock, Shares, Issued |  |  |  |  |  |  |  |  |  |  | 7,000,000 |  |  |  |  |  | 
| Unregistered Common Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Stock Issued During Period, Shares, New Issues |  |  |  |  |  |  | 64,000 |  | 8,536,774 |  |  |  |  |  |  |  | 
| Series A Preferred Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Preferred Stock, Shares Issued |  |  |  |  |  |  |  |  |  |  |  |  | 250,000 |  | 250,000 |  | 
| Common Stock, Shares Authorized |  |  |  |  |  |  |  |  |  |  | 250,000 |  |  |  |  |  | 
| Stock Issued During Period, Shares, New Issues |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  | 
| Shares, Outstanding |  |  |  |  |  |  |  |  |  |  |  |  | 250,000 |  | 250,000 |  | 
| Stock Issued During Period, Shares, Issued for Services |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  | 
| Stock Issued During Period, Value, Issued for Services |  |  |  |  |  |  |  |  |  |  |  |  | $ 0 |  |  |  | 
| Common Class B [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Stock Repurchased and Retired During Period, Shares |  |  |  |  |  |  |  |  |  |  | 7,200,000 |  |  |  |  |  | 
| Common Class A [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Common Stock, Shares, Issued |  |  |  |  |  |  |  |  |  |  |  |  | 1,000,000 |  | 1,000,000 |  | 
| Stock Issued During Period, Shares, New Issues |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  | 
| Shares, Outstanding |  |  |  |  |  |  |  |  |  |  |  |  | 1,000,000 |  | 1,000,000 |  | 
| Stock Issued During Period, Shares, Issued for Services |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  | 
| Stock Issued During Period, Value, Issued for Services |  |  |  |  |  |  |  |  |  |  |  |  | $ 0 |  |  |  | 
| Preferred Class A [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Preferred Stock, Shares Issued |  |  |  |  |  |  |  |  |  |  |  |  | 250,000 |  |  |  | 
| Preferred Stock, Shares Authorized |  |  |  |  |  |  |  |  |  |  |  |  | 2,000,000 |  |  |  | 
| Preferred Stock, Par or Stated Value Per Share |  |  |  |  |  |  |  |  |  |  |  |  | $ 0.0001 |  |  |  | 
| Fortress Biotech, Inc [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Shares Of Common Stock, Percentage |  |  |  |  |  |  |  |  |  |  |  |  | 2.50% |  |  |  | 
| Shares Issued, Price Per Share |  |  |  | $ 5.73 |  |  |  |  |  |  |  |  |  |  |  |  | 
| Stock Issued During Period, Shares, Issued for Services |  |  |  | 767,264 |  |  |  |  |  |  |  |  |  |  |  |  | 
| Stock Issued During Period, Value, Issued for Services |  |  |  | $ 4,400,000 |  |  |  |  |  |  |  |  |  |  |  |  | 
| Fortress Biotech, Inc [Member] | Common Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Stock Issued During Period, Shares, New Issues |  |  |  |  |  |  |  |  |  |  |  |  | 215,269 | 47,870 |  |  | 
| Fortress Biotech, Inc [Member] | Common Class B [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Common Stock, Shares, Issued |  |  |  |  | 250,000 |  |  |  |  |  |  |  |  |  |  |  | 
| Diluted Outstanding Equity, Percentage |  |  |  |  | 2.50% |  |  |  |  |  |  |  |  |  |  |  | 
| National Holdings Corporation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Warrants Issued | 2,500 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| National Holdings Corporation [Member] | Unregistered Common Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Stock Issued During Period, Shares, New Issues | 10,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| City of Hope National Medical Center [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Stock Issued During Period, Shares, New Issues |  |  |  |  |  |  |  | 293,588 |  |  |  |  |  |  |  |  | 
| City of Hope National Medical Center [Member] | Original Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Payment Of Upfront Fees |  |  |  |  |  |  |  |  |  |  |  | $ 2,000,000 |  |  |  |  | 
| City of Hope National Medical Center [Member] | Common Stock [Member] | Original Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Shares, Issued |  |  |  |  |  |  |  |  |  |  |  |  | 293,588 |  |  |  | 
| City of Hope National Medical Center [Member] | Common Class A [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Shares, Issued |  |  |  |  |  |  |  |  |  |  |  |  | 1,000,000 |  |  |  | 
| City of Hope National Medical Center [Member] | Common Class A [Member] | Original Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10.00% | 
| Shares, Outstanding |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,000,000 | 
| National Securities, Inc [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Percentage Of Placement Agent Fee |  |  |  |  |  |  |  |  |  | 10.00% |  |  |  |  |  |  | 
| Percentage Of Shares Issued To Placement Agent | 10.00% |  |  |  |  |  |  |  |  | 10.00% |  |  |  |  |  |  | 
| Warrants Issued | 1,000 |  |  |  |  |  | 6,400 |  | 853,677 |  |  |  |  |  |  |  | 
| Private Placement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Warrant Purchase Price Per Unit |  |  |  |  |  |  |  |  |  | $ 65,000 |  |  |  |  |  |  | 
| Stock Issued During Period, Shares, New Issues |  |  |  |  |  |  |  |  |  | 10,000 |  |  |  |  |  |  | 
| Class of Warrant or Right, Number of Securities Called by Warrants or Rights |  |  |  |  |  |  |  |  |  | 2,500 |  |  |  | 2,500 |  |  | 
| Class of Warrant or Right, Exercise Price of Warrants or Rights |  |  |  |  |  |  |  |  |  | $ 8.50 |  |  | $ 8.50 | $ 8.50 |  |  | 
| Private Placement [Member] | National Holdings Corporation [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Percentage Of Placement Agent Fee |  |  |  |  |  |  | 10.00% |  | 10.00% |  |  |  |  |  |  |  | 
| Percentage Of Shares Issued To Placement Agent |  |  |  |  |  |  | 10.00% |  | 10.00% |  |  |  |  |  |  |  | 
| Payments of Stock Issuance Costs |  |  |  |  |  |  | $ 42,000 |  | $ 5,500,000 |  |  |  |  |  |  |  | 
| Proceeds from Issuance of Private Placement | $ 65,000 |  |  |  |  |  | $ 400,000 |  | $ 55,500,000 |  |  |  |  |  |  |  |