Fair Value - Summary of Assets Measured at Fair Value (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Disclosure Of Other Real Estate Owned Measured At Fair Value On A Recurring And Nonrecurring Basis Table [Line Items]
Loans held for sale	$ 144,111	$ 148,209	[1]
OREO	227	0	[1]
Fair Value, Nonrecurring [Member]
Disclosure Of Other Real Estate Owned Measured At Fair Value On A Recurring And Nonrecurring Basis Table [Line Items]
Impaired loans, net	8,233	2,187
Loans held for sale	144,111	148,209
OREO	227
Fair Value, Nonrecurring [Member] | Level 2 [Member]
Disclosure Of Other Real Estate Owned Measured At Fair Value On A Recurring And Nonrecurring Basis Table [Line Items]
Loans held for sale	144,111	148,209
Fair Value, Nonrecurring [Member] | Level 3 [Member]
Disclosure Of Other Real Estate Owned Measured At Fair Value On A Recurring And Nonrecurring Basis Table [Line Items]
Impaired loans, net	8,233	$ 2,187
OREO	$ 227

[1] Derived from audited December 31, 2020 Consolidated Financial Statements.