Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v3.20.1
Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Feb. 11, 2019
Nov. 14, 2018
Jul. 03, 2018
Dec. 31, 2019
Dec. 31, 2020
Dec. 31, 2018
Nov. 12, 2018
Income Tax Disclosure [Line Items]              
Deferred Tax Assets, Valuation Allowance       $ 168,223   $ 132,114  
Operating Loss Carryforwards, Valuation Allowance       168,200      
Business Acquisition, Percentage of Voting Interests Acquired             33.30%
Income Tax Credits and Adjustments       12,400      
State income tax credits       $ 400      
Stock Issued During Period, Shares, New Issues     164,473        
Common Stock, Shares, Issued       74,027,425   57,845,447  
Proceeds from Issuance of Common Stock $ 13,100            
Sale of Stock, Number of Shares Issued in Transaction 4,000,000            
Scenario, Forecast [Member]              
Income Tax Disclosure [Line Items]              
Deferred Tax Assets, Valuation Allowance         $ 487,000    
National Holdings Corporation [Member]              
Income Tax Disclosure [Line Items]              
Operating Loss Carryforwards, Valuation Allowance       $ 445,900      
Business Acquisition, Percentage of Voting Interests Acquired           32.10%  
Sale of Stock, Number of Shares Issued in Transaction 4,000,000 3,000,000          
Common Stock [Member]              
Income Tax Disclosure [Line Items]              
Common Stock, Shares, Issued   3,000,000          
Proceeds from Issuance of Common Stock   $ 9,800          
Common Stock [Member] | NHLD [Member]              
Income Tax Disclosure [Line Items]              
Business Acquisition, Percentage of Voting Interests Acquired   56.10%          
Common Stock [Member] | B. Riley Financial Inc. [Member]              
Income Tax Disclosure [Line Items]              
Stock Issued During Period, Shares, New Issues   7,000,000