v3.20.4
Fair Value Measurement - Narrative (Details) - Credit Agreement
Dec. 31, 2018
$ / shares
shares
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]  
Number of securities called by warrants or rights (in shares) | shares 8,053,390
Warrant exercise price (in usd per share) | $ / shares $ 1.25