Share-Based Compensation Plans - Additional Information (Details) shares in Thousands, $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($) item shares
2017 Plan
Share-based Compensation Plans
Shares available for grant	1,418
Maximum \| 2017 Plan
Share-based Compensation Plans
Shares available for grant	3,000
Restricted Stock
Share-based Compensation Plans
Shares granted	180
Shares withheld for taxes	56
Common stock in lieu of taxes \| $	$ 5,994
Restricted Stock \| 2008 Plan
Share-based Compensation Plans
Shares granted	180
Vesting period	5 years
Number of anniversaries of the vesting date following the date of grant \| item	4
Restricted Stock \| Share-based Compensation Award, Tranche One \| 2008 Plan
Share-based Compensation Plans
Vesting right percentage	20.00%
Restricted Stock \| Share-based Compensation Award, Tranche Two \| 2008 Plan
Share-based Compensation Plans
Vesting right percentage	20.00%
Restricted Stock \| Share-based Compensation Award, Tranche Three \| 2008 Plan
Share-based Compensation Plans
Vesting right percentage	20.00%
Restricted Stock \| Share-based Compensation Award Tranche Four \| 2008 Plan
Share-based Compensation Plans
Vesting right percentage	20.00%
Restricted Stock \| Share-based Compensation Award Tranche Five \| 2008 Plan
Share-based Compensation Plans
Vesting right percentage	20.00%
Stock Options
Share-based Compensation Plans
Options granted	0

Number of anniversaries of grant date upon which restricted stock units vest.

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- Definition

Amount of decrease to equity for grantee's tax withholding obligation for award 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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

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).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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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.

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(1)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

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

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- Definition

Number of shares used to settle grantee's tax withholding obligation for award under share-based payment arrangement.

+ References

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