Stock-based Compensation - Schdule of Stock Options Outstanding (Details)	12 Months Ended
	Dec. 31, 2018 $ / shares shares
Options Outstanding, Weighted-Average Exercise Price, Minimum	$ 2.30
Options Outstanding, Weighted-Average Exercise Price, Maximum	$ 3.15
Options Outstanding, Number of Shares | shares	1,066,800
Exercise Price Range One [Member]
Options Outstanding, Weighted-Average Exercise Price, Minimum	$ 1.34
Options Outstanding, Weighted-Average Exercise Price, Maximum	$ 1.95
Options Outstanding, Number of Shares | shares	554,000
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	2 years 9 months 3 days
Options Outstanding, Weighted-Average Exercise Price,	$ 1.40
Exercise Price Range Two [Member]
Options Outstanding, Weighted-Average Exercise Price, Minimum	2.01
Options Outstanding, Weighted-Average Exercise Price, Maximum	$ 2.85
Options Outstanding, Number of Shares | shares	2,404,000
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	7 years 10 months 10 days
Options Outstanding, Weighted-Average Exercise Price,	$ 2.30
Exercise Price Range Three [Member]
Options Outstanding, Weighted-Average Exercise Price, Minimum	3.06
Options Outstanding, Weighted-Average Exercise Price, Maximum	$ 7.25
Options Outstanding, Number of Shares | shares	1,574,000
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	6 years 7 months 10 days
Options Outstanding, Weighted-Average Exercise Price,	$ 4.24
Exercise Price Range Four [Member]
Options Outstanding, Weighted-Average Exercise Price, Minimum	1.34
Options Outstanding, Weighted-Average Exercise Price, Maximum	$ 7.25
Options Outstanding, Number of Shares | shares	4,532,000
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	6 years 9 months 18 days
Options Outstanding, Weighted-Average Exercise Price,	$ 2.87