Stockholders' Equity - Early Exercise of Stock Options (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance (in shares)	199,895
Ending balance (in shares)	163,305
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Other long-term liabilities	$ 0.7	$ 0.9
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning balance (in shares)	200,000
Early exercise of options (in shares)	0
Vested (in shares)	(37,000)
Repurchased (in shares)	0
Ending balance (in shares)	163,000