Stock-Based Compensation - Narrative (Details) - shares	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Stock options and assumed options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options exercised (in shares)	63,748	85,466
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units granted (in shares)	100,728	190,250
Restricted stock units vested (in shares)	23,048	43,460
2015 Equity Incentive Plan \| Stock options and assumed options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	5,000	8,000

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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- Definition

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

+ References

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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

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

+ References

No definition available.

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- Definition

Number of share options (or share units) exercised during the current period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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