Share-Based Compensation - Summary of Company's Restricted Stock Activity (Detail)	9 Months Ended
Sep. 30, 2019 $ / shares shares
Restricted Stock
Number of Shares
Balance at beginning of period (in shares) \| shares	11,701
Granted (in shares) \| shares	13,052
Vested (in shares) \| shares	(11,643)
Forfeited (in shares) \| shares	0
Balance at end of period (in shares) \| shares	13,110
Weighted Average Price
Balance at beginning of period (in usd per share) \| $ / shares	$ 20.18
Granted (in usd per share) \| $ / shares	15.96
Vested (in usd per share) \| $ / shares	20.24
Forfeited (in usd per share) \| $ / shares	0
Balance of end of period (in usd per share) \| $ / shares	$ 15.93
RSUs
Number of Shares
Balance at beginning of period (in shares) \| shares	299,347
Granted (in shares) \| shares	141,059
Vested (in shares) \| shares	(107,396)
Forfeited (in shares) \| shares	(7,565)
Balance at end of period (in shares) \| shares	325,445
Weighted Average Price
Balance at beginning of period (in usd per share) \| $ / shares	$ 16.60
Granted (in usd per share) \| $ / shares	16.62
Vested (in usd per share) \| $ / shares	12.20
Forfeited (in usd per share) \| $ / shares	17.86
Balance of end of period (in usd per share) \| $ / shares	$ 18.03

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=109197908&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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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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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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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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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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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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