Stockholders' Equity - Employee Stock Purchase Plan (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($) shares	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) hours shares	Jun. 30, 2020 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds received from sale of employee stock purchase plan | $			$ 5,222	$ 1,944
Stock purchase plan issuances (shares)			3,376	9,665
2014 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance (shares)	500,000		500,000
Share-based compensation arrangement by share-based payment award, award vesting period (in days)			90 days
Minimum hour requirement for employees participation in the ESSP (hours) | hours			20
Employee stock ownership plan (ESOP), successive offering period			6 months
Annual compensation limit percentage, employee stock purchase plan (percentage)			10.00%
Annual compensation limit, employee stock purchase plan (dollars) | $			$ 21,250
Shares issuance limit per offering period, employee stock purchase plan			2,000
Fair market value of shares available for issuance (percentage)			85.00%
APIC, share-based payment arrangement, ESPP, increase for cost recognition | $	$ 1,268	$ 395	$ 2,532	$ 773
Remaining common stock, capital shares reserved for future issuance	392,237		392,237