Loans and Allowance for Loan Losses - Summary of the Modifications Which Occurred During the Periods and the Change in the Recorded Investment Subsequent to the Modifications Occurring (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2021 loan	Dec. 31, 2021 contract	Dec. 31, 2021 USD ($)	Dec. 31, 2020 loan	Dec. 31, 2020 contract	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts	249	5		301	40		40
Pre- Modification Outstanding Recorded Investment			$ 798			$ 4,235	$ 30,085
Post-Modification Modification Outstanding Recorded Investment			798			4,239	$ 30,761
Commercial and industrial | Commercial Portfolio Segment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts	7	0		8	1		16
Pre- Modification Outstanding Recorded Investment			0			140	$ 18,912
Post-Modification Modification Outstanding Recorded Investment			0			140	$ 19,212
Commercial real estate | Commercial Portfolio Segment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts	1	0		2	1		2
Pre- Modification Outstanding Recorded Investment			0			506	$ 3,277
Post-Modification Modification Outstanding Recorded Investment			0			506	$ 3,277
Business banking | Commercial Portfolio Segment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts	8	0		12	6		2
Pre- Modification Outstanding Recorded Investment			0			1,642	$ 3,184
Post-Modification Modification Outstanding Recorded Investment			0			1,642	$ 3,184
Residential real estate | Residential Portfolio Segment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts	148	2		173	6		11
Pre- Modification Outstanding Recorded Investment			498			920	$ 2,659
Post-Modification Modification Outstanding Recorded Investment			498			920	$ 2,696
Consumer home equity | Consumer Portfolio Segment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts	83	3		103	22		9
Pre- Modification Outstanding Recorded Investment			300			969	$ 2,053
Post-Modification Modification Outstanding Recorded Investment			300			973	$ 2,392
Other consumer | Consumer Portfolio Segment
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts	2	0		3	4		0
Pre- Modification Outstanding Recorded Investment			0			58	$ 0
Post-Modification Modification Outstanding Recorded Investment			$ 0			$ 58	$ 0