Business Combinations - Summary of Purchase Price Calculation (Parenthetical) (Detail)	Apr. 01, 2019 shares
National Commerce Corporation [Member]
Business Acquisition [Line Items]
Fractional shares	763

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.

No definition available.

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration