Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - National Financial Instruments Measured at Fair Value on Recurring Basis (Detail)

v3.8.0.1
Fair Value Measurements - National Financial Instruments Measured at Fair Value on Recurring Basis (Detail) - USD ($)
$ in Thousands
Sep. 30, 2017
Jun. 30, 2017
Dec. 31, 2016
Assets      
Long-term investments, at fair value $ 923   $ 1,414
Total 923   1,414
Liabilities      
Liabilities 14,974   5,168
National Holdings Corporation [Member]      
Assets      
Total   $ 1,595  
Liabilities      
Liabilities   9,469  
Contingently Issuable Warrant [Member]      
Liabilities      
Liabilities     302
Warrant [Member]      
Liabilities      
Liabilities 313   179
Helocyte Convertible Note One [Member]      
Liabilities      
Liabilities 4,733   4,487
Avenue Convertible Note [Member]      
Liabilities      
Liabilities     200
Corporate stock Assets [Member] | National Holdings Corporation [Member]      
Assets      
Total   70  
Municipal bonds Assets [Member] | National Holdings Corporation [Member]      
Assets      
Total   1,333  
Restricted stock Assets [Member] | National Holdings Corporation [Member]      
Assets      
Total   192  
Warrants Issuable [Member] | National Holdings Corporation [Member]      
Liabilities      
Liabilities   8,832  
Contingent Consideration [Member] | National Holdings Corporation [Member]      
Liabilities      
Liabilities   637  
Caelum Convertible Notes [Member]      
Liabilities      
Liabilities 9,928    
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   886  
Liabilities      
Liabilities   0  
Fair Value, Inputs, Level 1 [Member] | Contingently Issuable Warrant [Member]      
Liabilities      
Liabilities     0
Fair Value, Inputs, Level 1 [Member] | Warrant [Member]      
Liabilities      
Liabilities 0   0
Fair Value, Inputs, Level 1 [Member] | Helocyte Convertible Note One [Member]      
Liabilities      
Liabilities 0   0
Fair Value, Inputs, Level 1 [Member] | Avenue Convertible Note [Member]      
Liabilities      
Liabilities     0
Fair Value, Inputs, Level 1 [Member] | Corporate stock Assets [Member] | National Holdings Corporation [Member]      
Assets      
Total   70  
Fair Value, Inputs, Level 1 [Member] | Municipal bonds Assets [Member] | National Holdings Corporation [Member]      
Assets      
Total   816  
Fair Value, Inputs, Level 1 [Member] | Restricted stock Assets [Member] | National Holdings Corporation [Member]      
Assets      
Total   0  
Fair Value, Inputs, Level 1 [Member] | Warrants Issuable [Member] | National Holdings Corporation [Member]      
Liabilities      
Liabilities   0  
Fair Value, Inputs, Level 1 [Member] | Contingent Consideration [Member] | National Holdings Corporation [Member]      
Liabilities      
Liabilities   0  
Fair Value, Inputs, Level 1 [Member] | Caelum Convertible Notes [Member]      
Liabilities      
Liabilities 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   709  
Liabilities      
Liabilities   0  
Fair Value, Inputs, Level 2 [Member] | Contingently Issuable Warrant [Member]      
Liabilities      
Liabilities     0
Fair Value, Inputs, Level 2 [Member] | Warrant [Member]      
Liabilities      
Liabilities 0   0
Fair Value, Inputs, Level 2 [Member] | Helocyte Convertible Note One [Member]      
Liabilities      
Liabilities 0   0
Fair Value, Inputs, Level 2 [Member] | Avenue Convertible Note [Member]      
Liabilities      
Liabilities     0
Fair Value, Inputs, Level 2 [Member] | Corporate stock Assets [Member] | National Holdings Corporation [Member]      
Assets      
Total   0  
Fair Value, Inputs, Level 2 [Member] | Municipal bonds Assets [Member] | National Holdings Corporation [Member]      
Assets      
Total   517  
Fair Value, Inputs, Level 2 [Member] | Restricted stock Assets [Member] | National Holdings Corporation [Member]      
Assets      
Total   192  
Fair Value, Inputs, Level 2 [Member] | Contingent Consideration [Member] | National Holdings Corporation [Member]      
Liabilities      
Liabilities   0  
Fair Value, Inputs, Level 2 [Member] | Caelum Convertible Notes [Member]      
Liabilities      
Liabilities 0    
Fair Value, Inputs, Level 3 [Member]      
Assets      
Long-term investments, at fair value 923   1,414
Total 923   1,414
Liabilities      
Liabilities 14,974   5,168
Fair Value, Inputs, Level 3 [Member] | National Holdings Corporation [Member]      
Assets      
Total   0  
Liabilities      
Liabilities   9,469  
Fair Value, Inputs, Level 3 [Member] | Contingently Issuable Warrant [Member]      
Liabilities      
Liabilities     302
Fair Value, Inputs, Level 3 [Member] | Warrant [Member]      
Liabilities      
Liabilities 313   179
Fair Value, Inputs, Level 3 [Member] | Helocyte Convertible Note One [Member]      
Liabilities      
Liabilities 4,733   4,487
Fair Value, Inputs, Level 3 [Member] | Avenue Convertible Note [Member]      
Liabilities      
Liabilities     $ 200
Fair Value, Inputs, Level 3 [Member] | Corporate stock Assets [Member] | National Holdings Corporation [Member]      
Assets      
Total   0  
Fair Value, Inputs, Level 3 [Member] | Municipal bonds Assets [Member] | National Holdings Corporation [Member]      
Assets      
Total   0  
Fair Value, Inputs, Level 3 [Member] | Restricted stock Assets [Member] | National Holdings Corporation [Member]      
Assets      
Total   0  
Fair Value, Inputs, Level 3 [Member] | Warrants Issuable [Member] | National Holdings Corporation [Member]      
Liabilities      
Liabilities   8,832  
Fair Value, Inputs, Level 3 [Member] | Contingent Consideration [Member] | National Holdings Corporation [Member]      
Liabilities      
Liabilities   $ 637  
Fair Value, Inputs, Level 3 [Member] | Caelum Convertible Notes [Member]      
Liabilities      
Liabilities $ 9,928