Stockholders' Equity - Outstanding Options Granted to Consultants for Sales and Pre-marketing Services (Details)	6 Months Ended
	Jun. 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	18,945
February 2013 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares) | shares	1,500
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 12.470
Exercisable through	February 2023
August 2013 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares) | shares	4,000
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	2,700
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	3,700
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
May 2015 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares) | shares	1,057
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 19.510
Exercisable through	May 2025
February 2016 | Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options for shares of common stock (in shares) | shares	1,950
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 16.870
Exercisable through	February 2026