Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Unrealized gains (loss) on securities, tax expense	$ 874,000	$ 1,100,000	$ 276,000
Share-based compensation, excess tax benefit, amount			1,800,000
Purchase accounting adjustments	8,475,000	16,142,000
Retained earnings not provided for provision for income tax	10,800,000
Unrecognized deferred tax liability	2,600,000
Unrecognized tax benefits	0	0	0
Income tax benefit from revaluation of state deferred tax assets	(2,200,000)
Tax Cuts and Jobs Act of 2017, change in tax rate, income tax expense (benefit)		(1,900,000)	$ 3,600,000
Colonial American Bank
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	4,900,000	5,300,000
Operating loss carryforwards, subject to expiration	330,000
Cape Bancorp, Inc.
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	0	3,000,000.0
Operating loss carryforwards, subject to expiration	4,500,000
Tax credit	1,000,000.0	1,000,000
Sun Bancorp, Inc.
Operating Loss Carryforwards [Line Items]
Purchase accounting adjustments	3,100,000
Operating loss carryforwards	175,900,000	198,900,000
Operating loss carryforwards, subject to expiration	23,300,000	9,300,000
Tax credit	2,300,000	2,300,000
New Jersey
Operating Loss Carryforwards [Line Items]
Tax credit	1,800,000	$ 1,800,000
Other Comprehensive Income
Operating Loss Carryforwards [Line Items]
Tax Cuts and Jobs Act of 2017, change in tax rate, income tax expense (benefit)	1,800,000
Accumulated Other Comprehensive (Loss) Gain
Operating Loss Carryforwards [Line Items]
Tax Cuts and Jobs Act of 2017, change in tax rate, income tax expense (benefit)	$ 1,100,000