Quarterly report pursuant to Section 13 or 15(d)

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

v3.19.2
Fair Value Measurements - Changes in Fair Value of Financial Instruments (Details)
$ in Thousands
6 Months Ended
Jun. 30, 2019
USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]  
Balance $ 11,193
Caelum [Member]  
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]  
Balance 10,905
Balance 11,193
Caelum Convertible Notes [Member] | Caelum [Member]  
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]  
Balance 9,914
Conversion of the convertible notes (9,914)
Balance $ 0