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
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