Loans and the Allowance for Credit Losses - Summary of Changes in Accretable Yield for All Loans Acquired from Prior Acquisitions with Deteriorated Credit Quality (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Acquired During Period [Abstract]
Balance at beginning of period	$ 6,203	$ 1,724
Acquisitions	1,602	885
Reduction due to change in projected cash flows	(1,821)	(776)
Reclass from non-accretable	3,213	7,052
Accretion	(6,125)	(2,682)
Balance at end of period	$ 3,072	$ 6,203

Amount 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.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 15
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=118938799&loc=d3e13503-111538

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=118939070&loc=d3e15032-111544

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- Definition

Amount of accretion recognized for 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.

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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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Amount of increase of reclassification from nonaccretable difference 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.

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- Definition

Certain loans acquired in transfer not accounted for as debt securities, accretable yield, reductions.

+ References

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