Shared-Based Compensation - Reconciliation of Restricted Stock Option Activity (Detail) shares in Thousands	3 Months Ended
Mar. 31, 2021 $ / shares shares
Restricted stock
Nonvested Shares (in thousands)
Nonvested restricted shares, beginning balance (in shares) \| shares	385
Nonvested restricted shares, granted (in shares) \| shares	425
Nonvested restricted shares, vested (in shares) \| shares	(284)
Nonvested restricted shares, forfeited (in shares) \| shares	(12)
Nonvested restricted shares, ending balance (in shares) \| shares	514
Weighted Average Grant-Date Fair Value (per share)
Beginning balance (in dollars per share) \| $ / shares	$ 9.42
Granted (in dollars per share) \| $ / shares	6.79
Vested (in dollars per share) \| $ / shares	9.50
Forfeited (in dollars per share) \| $ / shares	7.76
Ending balance (in dollars per share) \| $ / shares	$ 7.24
TSR Awards
Nonvested Shares (in thousands)
Nonvested restricted shares, beginning balance (in shares) \| shares	138
Nonvested restricted shares, granted (in shares) \| shares	142
Nonvested restricted shares, ending balance (in shares) \| shares	280
Weighted Average Grant-Date Fair Value (per share)
Beginning balance (in dollars per share) \| $ / shares	$ 10.58
Granted (in dollars per share) \| $ / shares	8.58
Ending balance (in dollars per share) \| $ / shares	$ 9.56
ROIC Awards
Nonvested Shares (in thousands)
Nonvested restricted shares, beginning balance (in shares) \| shares	160
Nonvested restricted shares, granted (in shares) \| shares	172
Nonvested restricted shares, ending balance (in shares) \| shares	332
Weighted Average Grant-Date Fair Value (per share)
Beginning balance (in dollars per share) \| $ / shares	$ 9.13
Granted (in dollars per share) \| $ / shares	7.20
Ending balance (in dollars per share) \| $ / shares	$ 8.13

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

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)(3)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

+ References

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-Publisher FASB
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-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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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).

+ References

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-Publisher FASB
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The weighted average fair value at grant date for nonvested equity-based awards issued 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

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

+ References

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-Publisher FASB
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- Definition

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

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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- References

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