Stockholders' Equity - Stock Options Activities (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares
Number
Options outstanding, Balance (in shares) | shares	454,348
Granted (in shares) | shares	0
Exercised (in shares) | shares	(121,487)
Forfeited and expired (in shares) | shares	(500)
Options outstanding, Balance (in shares) | shares	332,361	454,348
Weighted average exercise price
Options outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 20.628
Granted, weighted average exercise price (in dollars per share) | $ / shares	0
Exercised, weighted average exercise price (in dollars per share) | $ / shares	20.177
Forfeited and expired, weighted average exercise price (in dollars per share) | $ / shares	1.576
Options outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 20.822	$ 20.628
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Options outstanding, aggregate intrinsic value | $	$ 31,441	$ 25,935
Options outstanding, weighted average remaining contractual life (Year)	3 years 8 months 1 day	4 years 4 months 2 days