Stock-Based Compensation - Employee Stock Purchase Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jun. 07, 2017
Class of Stock
Proceeds from employee stock purchases	$ 25	$ 26
2017 Employee Stock Purchase Plan
Class of Stock
Common stock shares authorized for issuance under stock purchase plan			412,500
Proceeds from employee stock purchases	$ 100	$ 100
Common shares available for grant			302,493
Employee Stock Purchase Plans
Class of Stock
Common stock share issued	18,848	11,096