Stockholders' Equity - Summary of RSU Activity (Details) - USD ($)		6 Months Ended
Jan. 09, 2014	Jun. 30, 2021
2013 Equity Incentive Plan
Restricted Stock Units information
Period for unrecognized compensation expense related to unvested options yet has not been recognized		2 years 1 month 6 days
2013 Equity Incentive Plan \| Upon first anniversary of start date
Restricted Stock Units information
Percent of shares subject to option grant that will vest	25.00%
RSU
Restricted Stock Units information
Vesting period		4 years
RSU \| 2013 Equity Incentive Plan
NUMBER OF SHARES
Unvested at beginning of period		192,533
Granted		444,613
Forfeited		(46,492)
Unvested at end of period		590,654
WEIGHTED-AVERAGE GRANT DATE FAIR VALUE
Unvested at beginning of period		$ 4.53
Granted		3.72
Forfeited		3.83
Unvested at end of period		$ 3.98
RSU \| 2013 Equity Incentive Plan \| Non-executive employees
Restricted Stock Units information
Unrecognized compensation expense related to unvested service RSUs		$ 1,456,954
Period for unrecognized compensation expense related to unvested options yet has not been recognized		1 year 10 months 24 days

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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Percentage of vesting of award under share-based payment arrangement.

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