Stockholders' Equity - Incentive Plan (Details) - USD ($)		12 Months Ended
	Jun. 12, 2014	Dec. 31, 2020	May 08, 2018
Class of Stock [Line Items]
Number of shares authorized (in shares)			6,000,000.0
Available future grants and awards (in shares)		1,400,000
Award vesting period		4 years
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period		8 years
Share-based Compensation Arrangement by Share-based Payment Award, Anniversary Period		18 months
Restricted Stock Awards
Class of Stock [Line Items]
Award vesting period		4 years
Restricted Stock Units
Class of Stock [Line Items]
Award vesting period		3 years
Share-based Compensation Arrangement by Share-based Payment Award, Award Cliff Period		1 year
Employee Stock | Stock Purchase Plan
Class of Stock [Line Items]
Maximum stock purchase per employee	$ 1,000,000
Stock purchase plan restricted sale of stock period	2 years
Percent of common stock granted in proportion to common stock purchased	20.00%
Vesting percentage of restricted stock granted in relation to shares purchased under the Stock Purchase Plan	50.00%
Vesting period of restricted stock granted in relation to shares purchased under the Stock Purchase Plan	2 years
Term for stock option purchase in relation to Stock Purchase Plan	5 years
Vesting period of stock options purchased in relation to shares purchased under the Stock Purchase Plan	2 years
Vesting percentage of purchase of stock options in relation to shares purchased under the Stock Purchase Plan	50.00%
Employee Stock | Stock Purchase Plan | Non-Employee Chairman
Class of Stock [Line Items]
Vesting percentage of purchase of stock options in relation to shares purchased under the Stock Purchase Plan	50.00%
Employee Stock | Stock Purchase Plan | Non-Employee Board Member
Class of Stock [Line Items]
Vesting percentage of purchase of stock options in relation to shares purchased under the Stock Purchase Plan	35.00%
Employee Stock | Stock Purchase Plan | Executive Officer | Minimum
Class of Stock [Line Items]
Vesting percentage of purchase of stock options in relation to shares purchased under the Stock Purchase Plan	50.00%
Employee Stock | Stock Purchase Plan | Executive Officer | Maximum
Class of Stock [Line Items]
Vesting percentage of purchase of stock options in relation to shares purchased under the Stock Purchase Plan	70.00%