Shared-Based Compensation - Additional Information (Detail) shares in Thousands, $ in Millions	9 Months Ended
Sep. 30, 2021 USD ($) shares
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock units issued (in shares)	459
Total grant-date fair value of restricted stock, vested \| $	$ 2.8
TSR Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock units issued (in shares)	142
Award performance period	3 years
Percentage of shares issuable based on threshold performance	50.00%
Percentage of shares issuable based on target performance	100.00%
Percentage of shares issuable based on maximum performance	150.00%
ROIC Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock units issued (in shares)	172
Percentage of shares issuable based on target performance	100.00%
Employees \| Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards granted vesting period	3 years
Non-executive Directors \| Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock awards granted vesting period	1 year

Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Period

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- Definition

Share based compensation arrangement by share based payment award percentage of shares issuable based on threshold performance.

+ References

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- Definition

Share based compensation arrangement by share-based payment award percentage of shares issuable based on maximum performance.

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- Definition

Share based compensation arrangement by share-based payment award, percentage of shares Issuable based on target performance.

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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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
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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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- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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-Publisher FASB
-Name Accounting Standards Codification
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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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