Business Combinations - Additional Information (Detail)			9 Months Ended
	May 02, 2016 USD ($)	Mar. 11, 2016 USD ($)	Sep. 30, 2016 Property
Cape Bancorp, Inc. [Member]
Business Acquisition [Line Items]
Purchase accounting adjustments, assets	$ 1,517,610,000
Purchase accounting adjustments, loans	1,157,753,000
Purchase accounting adjustments, deposits	1,248,367,000
Total consideration paid	196,403,000
Cash consideration	$ 30,500,000
Number of properties in lease agreement | Property			8
Retail Branch [Member]
Business Acquisition [Line Items]
Deposit premium		$ 340,000
Percentage of core deposits		2.50%
Percentage of deposit premium, contingent on the core deposit		1.00%
Purchase accounting adjustments, assets		$ 16,817,000
Purchase accounting adjustments, loans		9,000
Purchase accounting adjustments, deposits		$ 16,957,000