Stockholders' Equity - Outstanding Options Granted to Consultants for Sales and Pre-marketing Services (Details)	3 Months Ended
	Mar. 31, 2021 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 0
Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares) | shares	31,785
August 2013 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares) | shares	7,500
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 7.047
Exercisable through	August 2023
March 2014 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares) | shares	4,950
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 13.287
Exercisable through	March 2024
May 2014 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares) | shares	6,000
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 7.337
Exercisable through	May 2024
November 2014 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares) | shares	10,335
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 7.220
Exercisable through	November 2024
February 2016 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares) | shares	3,000
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 5.623
Exercisable through	February 2026