Business Combinations - Summary of Purchased Performing and PCI Loans Receivable (Detail) - Bay Banks [Member] $ in Thousands	Jan. 31, 2021 USD ($)
Business Acquisition [Line Items]
Principal payments receivable	$ 1,048,289
Fair value adjustment - credit and interest	(17,856)
Fair value of acquired loans	1,030,433
Purchased Performing [Member]
Business Acquisition [Line Items]
Principal payments receivable	936,523
Fair value adjustment - credit and interest	(2,784)
Fair value of acquired loans	933,739
PCI [Member]
Business Acquisition [Line Items]
Principal payments receivable	111,766
Fair value adjustment - credit and interest	(15,072)
Fair value of acquired loans	$ 96,694