LOANS (Additional Information) (Detail) - USD ($) $ in Thousands		9 Months Ended	12 Months Ended
Jan. 01, 2018	Sep. 30, 2019	Dec. 31, 2018
Loans [Abstract]
Unearned income and deferred fees		$ 1,400	$ 900
Loans receivable with a gross amortized cost basis	$ 1,697,760
Credit fair value adjustment on purchased credit impaired loans	14,518
Credit Impaired Loans Acquired In Transfer Nonaccretable Difference	10,500
Fair value of purchase credit impaired loans	27,509	9,600	15,300
Proceeds from credit impaired loans		5,800	12,400
Accretable adjustments		199	849
Non-accretable adjustments		1,600	1,300
Addition of accretable yield due to acquisitions	4,000	0	3,988
Loans [Line Items]
Outstanding balance of purchased credit impaired loans receivable		13,285	25,947
WashingtonFirst Bankshares Inc [Member]
Loans [Line Items]
Outstanding balance of purchased credit impaired loans receivable	$ 41,900	$ 12,900	$ 26,000

Gross amortized cost basis loans acquried as part of the business combination.

No definition available.

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- Definition

The amount of the credit impaired loan's contractually required payments receivable in excess of the amount of its cash flows expected to be collected. This relates to loans with deteriorating of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

+ References

No definition available.

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- Definition

Discount adjustment based on the credit quality of acquired purchased credit impaired loans.

+ References

No definition available.

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- References

No definition available.

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- Definition

Proceeds from settlement of a purchased credit impaired loan.

+ References

No definition available.

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- Definition

Fair value at acquisition of acquired loans accounted for as debt securities with evidence of deterioration of credit quality.

+ References

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-Name Accounting Standards Codification
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- Definition

Amount of additions to the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

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- Definition

Amount of reduction, resulting from a sale or transfer of a loan, in the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

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- Definition

Amount of decrease from reclassification to nonaccretable difference of the excess of a loan's cash flows expected to be collected over the investor's initial investment in acquired loans not accounted for as debt securities with evidence of deterioration of credit quality.

+ References

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- Definition

The undiscounted sum of all amounts, including amounts deemed principal, interest, fees, penalties, and other under the loan, owed to the investor at the reporting date, whether or not currently due and whether or not any such amounts have been written or charged off by the investor. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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- Definition

Amount of deferred interest and fee income, unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of acquired loans. Excludes amounts for loans and leases covered under loss sharing agreements.

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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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