Derivatives and Hedging Activities - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2021 USD ($) Derivative	Dec. 31, 2020 USD ($) Derivative	Dec. 31, 2019 USD ($)
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net gain (loss) on change in fair value	$ 4,080,000	$ (8,750,000)	$ (2,536,000)
Collateral posted with market value on liability positions with credit risk-related contingent features	$ 43,100,000
Interest Rate Swaps [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of interest rate swaps | Derivative	135	112
Aggregate notional amount	$ 730,600,000	$ 649,900,000
Net gain (loss) on change in fair value	2,000,000.0	(2,000,000.0)	(1,100,000)
Income (loss) on derivative instrument not designated hedges	$ 4,500,000	$ 8,100,000	$ 4,500,000
Risk Participation in Agreements [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of interest rate swaps | Derivative	13	12
Aggregate notional amount	$ 128,200,000	$ 101,100,000
Risk Participation out Agreement [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Number of interest rate swaps | Derivative	1	1
Aggregate notional amount	$ 9,800,000	$ 10,000,000.0
Other Contract [Member] | Forward TBA Contracts [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Aggregate notional amount	$ 48,500,000	$ 183,500,000