Goodwill and Other Intangible Assets - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) reportingUnit	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Jan. 06, 2022 USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 271,829,000		$ 271,829,000		$ 271,829,000
Number of reporting units | reportingUnit			1
Goodwill, impairment loss	0	$ 0	$ 0	$ 0
Amortization of intangible assets	512,000	593,000	1,028,000	1,189,000
1st Constitution Bancorp
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill						$ 115,600,000
Core Deposits
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets	8,100,000		8,100,000		$ 9,100,000
Amortization of intangible assets	$ 512,000	$ 593,000	$ 1,000,000	$ 1,200,000
Core Deposits | 1st Constitution Bancorp
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets						$ 9,000,000