Weighted Average Shares Outstanding and Net Loss Per Share - Summary of Reconciliation of Weighted Average Shares Outstanding Used in Calculating Basic and Diluted Net Loss Per Share (Parenthetical) (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Antidilutive shares excluded from calculating diluted net loss per share	375,000	960,000	398,000	732,000