Stock Options and Restricted Stock Awards - Exercise Price (Details) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2020 USD ($) $ / shares shares
Exercise Price
Options Outstanding, Number Outstanding	2,006,150
Options Outstanding, Remaining Contractual Life	6 years 7 months 6 days
Options Outstanding, Exercise Price | $ / shares	$ 7.22
Options Exercisable, Number Outstanding	993,550
Total unrecognized compensation cost | $	$ 2,553
Weighted-average period over which total unrecognized compensation cost is expected to be recognized (in years)	4 years 9 months 18 days
2.13
Exercise Price
Options Outstanding, Number Outstanding	66,750
Options Outstanding, Remaining Contractual Life	2 years 9 months 18 days
Options Outstanding, Exercise Price | $ / shares	$ 2.13
Options Exercisable, Number Outstanding	66,750
3.00
Exercise Price
Options Outstanding, Number Outstanding	447,500
Options Outstanding, Remaining Contractual Life	3 years 6 months
Options Outstanding, Exercise Price | $ / shares	$ 3.00
Options Exercisable, Number Outstanding	447,500
3.58
Exercise Price
Options Outstanding, Number Outstanding	45,000
Options Outstanding, Remaining Contractual Life	4 years 6 months
Options Outstanding, Exercise Price | $ / shares	$ 3.58
Options Exercisable, Number Outstanding	45,000
7.47
Exercise Price
Options Outstanding, Number Outstanding	1,023,900
Options Outstanding, Remaining Contractual Life	7 years 3 months 18 days
Options Outstanding, Exercise Price | $ / shares	$ 7.47
Options Exercisable, Number Outstanding	402,300
13.22
Exercise Price
Options Outstanding, Number Outstanding	25,000
Options Outstanding, Remaining Contractual Life	7 years 10 months 24 days
Options Outstanding, Exercise Price | $ / shares	$ 13.22
Options Exercisable, Number Outstanding	10,000
12.86
Exercise Price
Options Outstanding, Number Outstanding	45,000
Options Outstanding, Remaining Contractual Life	8 years 2 months 12 days
Options Outstanding, Exercise Price | $ / shares	$ 12.86
Options Exercisable, Number Outstanding	9,000
12.94
Exercise Price
Options Outstanding, Number Outstanding	30,000
Options Outstanding, Remaining Contractual Life	8 years 3 months 18 days
Options Outstanding, Exercise Price | $ / shares	$ 12.94
Options Exercisable, Number Outstanding	6,000
11.59
Exercise Price
Options Outstanding, Number Outstanding	25,000
Options Outstanding, Remaining Contractual Life	8 years 3 months 18 days
Options Outstanding, Exercise Price | $ / shares	$ 11.59
Options Exercisable, Number Outstanding	5,000
11.15
Exercise Price
Options Outstanding, Number Outstanding	10,000
Options Outstanding, Remaining Contractual Life	8 years 8 months 12 days
Options Outstanding, Exercise Price | $ / shares	$ 11.15
Options Exercisable, Number Outstanding	2,000
11.13
Exercise Price
Options Outstanding, Number Outstanding	50,000
Options Outstanding, Remaining Contractual Life	9 years 2 months 12 days
Options Outstanding, Exercise Price | $ / shares	$ 11.13
12.92
Exercise Price
Options Outstanding, Number Outstanding	178,000
Options Outstanding, Remaining Contractual Life	9 years 4 months 24 days
Options Outstanding, Exercise Price | $ / shares	$ 12.92
12.67
Exercise Price
Options Outstanding, Number Outstanding	25,000
Options Outstanding, Remaining Contractual Life	9 years 8 months 12 days
Options Outstanding, Exercise Price | $ / shares	$ 12.67
8.76
Exercise Price
Options Outstanding, Number Outstanding	25,000
Options Outstanding, Remaining Contractual Life	9 years 9 months 18 days
Options Outstanding, Exercise Price | $ / shares	$ 8.76
10.08
Exercise Price
Options Outstanding, Number Outstanding	10,000
Options Outstanding, Remaining Contractual Life	9 years 10 months 24 days
Options Outstanding, Exercise Price | $ / shares	$ 10.08