Loans and Allowance for Loan Losses - Summary of Performance Status of Loan (Parenthetical) (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Financing Receivable, Recorded Investment [Line Items]
Loan premiums	$ 4,358	$ 5,758
Non - Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
TDR loans	429	$ 36,009
Medallion [Member] \| Non - Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan premiums	$ 3,145

Amount of financing receivable modified as troubled debt restructuring.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554

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Data Type:	xbrli:monetaryItemType
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