Significant Accounting Policies - Error Identified in Weighted Average Number of Shares Used in Calculation of Earnings per Share (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Error Corrections And Prior Period Adjustments Restatement [Line Items]
Weighted average number of common shares outstanding	70,221,566	68,658,304	70,221,566	66,816,698
Net loss per share - basic	$ (0.06)	$ 0.00	$ (0.07)	$ (0.03)
As Previously Reported [Member]
Error Corrections And Prior Period Adjustments Restatement [Line Items]
Weighted average number of common shares outstanding		54,118,506		54,118,506
Net loss per share - basic		$ (0.01)		$ (0.04)