Fair Value Measurement - Assets and Liabilities Measured at Fair Value on Nonrecurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Losses from Fair Value Adjustments Assets and Liabilities	$ 4,708	$ (1,554)	$ (2,514)	$ (2,071)
Individually evaluated loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	5,619		5,619		$ 5,719
Fair Value Nonrecurring Basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	5,794		5,794		6,030
Fair Value Nonrecurring Basis | Individually evaluated loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	5,619		5,619		5,719
Losses from Fair Value Adjustments Assets and Liabilities	4,749		(2,281)
Fair Value Nonrecurring Basis | Foreclosed assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	175		175		311
Losses from Fair Value Adjustments Assets and Liabilities	(41)		(233)
Fair Value Nonrecurring Basis | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0		0		0
Fair Value Nonrecurring Basis | Level 1 | Individually evaluated loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0		0		0
Losses from Fair Value Adjustments Assets and Liabilities		(1,567)		(2,182)
Fair Value Nonrecurring Basis | Level 1 | Foreclosed assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0		0		0
Losses from Fair Value Adjustments Assets and Liabilities		$ 13		$ 111
Fair Value Nonrecurring Basis | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0		0		0
Fair Value Nonrecurring Basis | Level 2 | Individually evaluated loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0		0		0
Fair Value Nonrecurring Basis | Level 2 | Foreclosed assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	0		0		0
Fair Value Nonrecurring Basis | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	5,794		5,794		6,030
Fair Value Nonrecurring Basis | Level 3 | Individually evaluated loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	5,619		5,619		5,719
Fair Value Nonrecurring Basis | Level 3 | Foreclosed assets
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 175		$ 175		$ 311