Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Unrealized gains (loss) on securities, tax expense	$ 1,100,000	$ 276,000	$ 330,000
Share-based compensation, excess tax benefit, amount		1,800,000
Income tax benefit (expense) attributable to stock plans prior to ASU adoption			(62,000)
Purchase accounting adjustments	59,110,000	3,436,000
Retained earnings not provided for provision for income tax	10,800,000
Unrecognized deferred tax liability	2,300,000
Unrecognized tax benefits	0	0	$ 0
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	5,300,000	5,900,000
Operating loss carryforwards, subject to expiration	330,000
Cape Bancorp, Inc.
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	6,100,000	10,500,000
Operating loss carryforwards, subject to expiration	4,500,000
Tax credit	1,000,000	1,000,000
Sun Bancorp, Inc.
Operating Loss Carryforwards [Line Items]
Purchase accounting adjustments	57,600,000
Operating loss carryforwards	218,900,000
Operating loss carryforwards, subject to expiration	9,300,000
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)	$ 1,200,000