Share-Based Compensation - Narrative (Details) - USD ($)	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of average closing price to be paid by employees	85.00%
Maximum common stock purchases through advance payroll deductions in a calendar year	$ 25,000
Share-based compensation	$ 1,220,000	$ 981,000
Forfeiture rate	0.40%
Unrecognized compensation expense related to stock options	$ 0
Aggregate intrinsic value of stock options exercised	36,000	97,000
Cash receipts of stock options exercised	$ 7,000	$ 40,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option term	10 years
Stock options vesting percentage	100.00%
Stock Options \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested period	1 year
Stock Options \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested period	2 years
RSAs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vested period	3 years
Unrecognized compensation expense related to RSAs	$ 6,444,000
Unrecognized compensation expense expected recognition period	1 year 4 months 24 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock options	$ 0
Grant date fair value of ESPP options	$ 41,000

The maximum amount allowed for advance payroll deductions in a calendar year for employee stock purchase plan.

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Share Based Compensation Arrangement by Share Based Payment Award Contractual Term Range

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- Definition

Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Annual Forfeiture Rate

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- Definition

Share Based Compensation Arrangement By Share Based Payment Award Grant Date Fair Value Of Awards

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- Definition

Share Based Compensation Arrangement by Share based Payment Award, Vesting Percentage

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- Definition

Share Based Compensation Arrangements By Share Based Payment Award Percentage Of Market Price At Eligible Employees Granted Options To Purchase Shares

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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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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- Definition

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

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- Definition

Amount of cost to be recognized for option under share-based payment arrangement.

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- Definition

Amount of cash inflow from exercise of option under share-based payment arrangement.

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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