Stockholders' Equity - Outstanding Options Granted to Consultants for Sales and Pre-marketing Services (Details)	9 Months Ended
	Sep. 30, 2020 $ / 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	13,038
August 2013 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares) | shares	3,100
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 21.140
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	2,300
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 39.860
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	2,600
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 22.010
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	4,038
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 21.660
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	1,000
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 16.870
Exercisable through	February 2026