Stock-Based Compensation - Narrative (Details) - USD ($)	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
The 2009 ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized		3,000,000
Maximum employee subscription rate (in percent)	10.00%
Maximum amount of stock per employee	$ 25,000
Purchase price of common stock (in percent)	85.00%
Discount from market price, offering date (in percent)	15.00%
Shares available for purchase	1,412,727
2013 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized	3,800,000
Shares available for purchase	1,018,222
Shares outstanding	0
2013 Stock Incentive Plan \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Unvested RSUs	$ 13,700,000
Weighted average vesting period	2 years 9 months 18 days
2013 Stock Incentive Plan \| Restricted Stock Units (RSUs) \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
2013 Stock Incentive Plan \| Time Vesting RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of restricted stock to employees (in shares)	43,915
2013 Stock Incentive Plan \| Performance and Time Vesting RSU's
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of restricted stock to employees (in shares)	104,500
2013 Stock Incentive Plan \| Performance RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of restricted stock to employees (in shares)	98,120
Weighted average attainment level for performance and time vesting RSUs (in percent)	93.90%

The maximum amount of stock per employee under share based compensation arrangement.

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- Definition

Share-based Compensation Arrangement By Share-based Payment Award, Number Of Shares Outstanding

+ References

No definition available.

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- Definition

Represents the weighted average attainment level associated with performance and time-vesting RSUs.

+ References

No definition available.

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- Definition

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.

+ References

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- Definition

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

+ References

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- Definition

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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- Definition

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

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- Definition

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.

+ References

No definition available.

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- Definition

The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

+ References

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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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- Definition

Purchase price of common stock expressed as a percentage of its fair value.

+ References

No definition available.

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- Definition

Total number of shares issued during the period, including shares forfeited, as a result of Restricted Stock Awards.

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