Fair value of restricted stock granted based on the Corporation's outstanding common stock on the date of the grant.

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The percentage of outstanding shares of restricted stock forfeited due to the U.S. Treasury not able to recover the full amount of its original investment under TARP.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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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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Number of shares for which recognition of compensation cost was accelerated.

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Percentage of vesting of share-based compensation awards.

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Total number of shares issued during the period, including shares forfeited, as a result of Restricted Stock Awards.

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STOCK-BASED COMPENSATION - Restricted Stock - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	May 10, 2017
Omnibus Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense			$ 1.7	$ 3.3
Omnibus Plan [Member] \| Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted shares restricted stocks			407,886
Stock-based compensation expense			$ 3.4	$ 4.0	$ 3.9
Unrecognized compensation cost related to non-vested shares			$ 2.2
Period for cost recognition not yet recognized			1 year 3 months 18 days
Forefeited			16,000
Omnibus Plan [Member] \| Restricted Stock [Member] \| Director [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted shares restricted stocks			65,447	148,424
Vesting period			1 year	1 year
Omnibus Plan [Member] \| Restricted Stock [Member] \| Management [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted shares restricted stocks			342,439	951,332
Vesting period				2 years
Retirement Eligible Shares			20,447
Omnibus Plan [Member] \| Restricted Stock [Member] \| Restricted stock vesting after two years [Member] \| Management [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock vesting percentage			50.00%
Omnibus Plan [Member] \| Restricted Stock [Member] \| Restricted stock vesting after three years [Member] \| Management [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock vesting percentage			50.00%
Troubled Asset Relief Program [Member] \| Restricted Stock [Member] \| Senior Officers [Member] \| Government [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted shares restricted stocks		838,332
Troubled Asset Relief Program [Member] \| Restricted Stock [Member] \| Senior Officers [Member] \| Department Of Treasury [Member] \| Government [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Restricted stock vesting percentage	50.00%
Secondary Offering Of Common Stock						10,291,553
Forefeited	2,370,571
Percentage Of Outstanding Shares Of Restricted Stock Forfeited	50.00%
Fair Value Of Restricted Stock Granted	$ 2.71