Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Changes in Fair Value of Financial Instruments (Detail)

v3.8.0.1
Fair Value Measurements - Changes in Fair Value of Financial Instruments (Detail)
$ in Thousands
3 Months Ended
Mar. 31, 2018
USD ($)
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