Balance Sheet Account Detail - Assets and Liabilities Measure at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	$ 940	$ 4,012
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingently issuable common stock	500	2,200
Derivative liabilities	940	4,012
Total financial liabilities	1,440	6,212
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingently issuable common stock	0	0
Derivative liabilities	0	0
Total financial liabilities	0	0
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingently issuable common stock	0	0
Derivative liabilities	0	0
Total financial liabilities	0	0
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingently issuable common stock	500	2,200
Derivative liabilities	940	4,012
Total financial liabilities	$ 1,440	$ 6,212