Financial Instruments and Fair Value Measurements - Schedule of Fair Value of Warrants Determined Using the Black-Scholes Option Pricing Model (Details)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Expected term (in years)	5 years 3 months 10 days	6 years 2 months 15 days
Expected Volatility
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assumption measurement input	43.9	42.8
Risk-free Interest Rate
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assumption measurement input	2.49	2.62
Expected Dividend Yield
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assumption measurement input	0	0