Mortgage Banking Derivatives - Summary of Notional Amount and Fair Value of Mortgage Banking Derivatives (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Included in mortgage banking derivatives liability:
Derivative liability, fair value	$ 170,087	$ 149,084
Interest Rate Lock Commitments [Member]
Included in mortgage banking derivatives asset:
Derivative asset, notional amount	43,160	66,452
Included in mortgage banking derivatives asset:
Derivative asset, fair value	1,475	2,073
Forward Sale And Commitments [Member]
Included in mortgage banking derivatives asset:
Derivative asset, notional amount	3,069
Included in mortgage banking derivatives liability:
Derivative liability, notional amount	500	47,260
Included in mortgage banking derivatives asset:
Derivative asset, fair value	114
Included in mortgage banking derivatives liability:
Derivative liability, fair value	4	$ 388
GSE - Mortgage-backed Securities and CMO's [Member]
Included in mortgage banking derivatives liability:
Derivative liability, notional amount	44,500
Included in mortgage banking derivatives liability:
Derivative liability, fair value	$ 74