Annual report pursuant to Section 13 and 15(d)

Prepaid Expenses And Other Current Assets & Patents And Intangible Assets - Narrative (Details)

v3.19.1
Prepaid Expenses And Other Current Assets & Patents And Intangible Assets - Narrative (Details)
12 Months Ended
May 15, 2018
patent
Dec. 31, 2018
USD ($)
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Finite-Lived Intangible Assets [Line Items]        
Amortization expense   $ 1,800,000 $ 800,000 $ 0
Future amortization costs   $ 5,500,000    
Amortization period   4 years 6 months    
Patents        
Finite-Lived Intangible Assets [Line Items]        
Patents, useful life   4 years    
Patent Assignment Agreement        
Finite-Lived Intangible Assets [Line Items]        
Patents, useful life   5 years    
Number of assets transferred | patent 56