Organization, Basis of Presentation and Summary of Significant Accounting Policies - Schedule of Reconciliation of Liabilities Measured at Fair Value (Details) - Significant Unobservable Inputs (Level 3) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Warrant Liabilities
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Issuance of warrants	$ 48,313
Change in fair value	59,060
Ending Balance	107,373
Convertible Promissory Notes
Fair Value Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning Balance	1,950
Issuance of convertible promissory notes	90,750	$ 1,900
Exchange of convertible promissory notes (Note 4)	(2,399)
Change in fair value	4,928	50
Ending Balance	$ 95,229	$ 1,950