Equity Incentive Plans - Additional Information (Details) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2021 USD ($) Metric $ / shares shares	Dec. 31, 2020 Metric $ / shares shares	Dec. 31, 2019 Metric $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted, Wtd. Avg. grant date fair value \| $ / shares	$ 0.79	$ 1.59	$ 3.64
Options granted (in shares)	478,000	500,000	400,000
Vesting period (in years)	3 years
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs related to awards \| $	$ 0.8
Expected weighted average period to recognize expense	2 years 1 month 6 days
Restricted Stock Award
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation costs related to awards \| $	$ 16.0
Expected weighted average period to recognize expense	2 years 1 month 6 days
Granted (in shares)	1,551,000
Performance measurement \| Metric	2	2	2
Restricted Stock Award \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights (as percent)	0.00%	0.00%	0.00%
Restricted Stock Award \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights (as percent)	200.00%	200.00%	200.00%
Restricted Stock Award \| Tranche One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights (as percent)	50.00%	50.00%	50.00%
Performance period	3 years	3 years	3 years
Restricted Stock Award \| Tranche Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights (as percent)	50.00%	50.00%	50.00%
Performance period	3 years	3 years	3 years
Restricted Stock Award \| Share-based Payment Arrangement, Tranche Three
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance period	1 year
Restricted Stock Award \| Certain Employees and Executive Officers
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted (in shares)	1,551,000	900,000	788,000
Market and Performance Shares \| Certain Employees and Executive Officers
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted (in shares)	919,000	360,000	250,000
Employee Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Discount on purchase of Common Stock for employee from the current market price	5.00%
Capital shares reserved for future issuance	750,000
Issuance of common stock (ESPP) (in shares)	42,627	49,896	30,153
2018 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional shares authorized	16,800,000

Share-Based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions, Award Performance Period

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Share-Based Compensation Arrangement By Share-Based Payment Award, Fair Value Assumptions, Number Of Annual Performance Metrics

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Aggregate number of common shares reserved for future issuance.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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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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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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Discount rate from fair value on purchase date that participants pay for shares.

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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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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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Net number of share options (or share units) granted during the period.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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

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Number of shares issued during the period as a result of an employee stock purchase plan.

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