Loans and Leases - Age Analysis of Past Due Loans and Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 25,143	$ 23,165
Current	3,593,341	3,255,369
Acquired credit impaired	1,583	7,352
Loans and leases held for investment	3,620,067	3,285,886
Recorded Investment 90 Days or more Past Due and Accruing Interest	761	987
Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired	1,583	7,352
Financing Receivables, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	13,682	10,625
Financing Receivables, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	4,285	4,804
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	7,176	7,736
Commercial, Financial and Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	5,131	3,127
Current	890,658	819,550
Loans and leases held for investment	896,211	823,266
Recorded Investment 90 Days or more Past Due and Accruing Interest	0	0
Commercial, Financial and Agricultural [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired	422	589
Commercial, Financial and Agricultural [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	2,182	1,536
Commercial, Financial and Agricultural [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,440	256
Commercial, Financial and Agricultural [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,509	1,335
Real Estate-Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	2,691	5,633
Current	1,539,094	1,363,606
Loans and leases held for investment	1,542,141	1,374,949
Recorded Investment 90 Days or more Past Due and Accruing Interest	0	0
Real Estate-Commercial [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired	356	5,710
Real Estate-Commercial [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	733	1,482
Real Estate-Commercial [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	548	1,560
Real Estate-Commercial [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,410	2,591
Real Estate-Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	2,335	202
Current	173,501	174,642
Loans and leases held for investment	175,836	174,844
Recorded Investment 90 Days or more Past Due and Accruing Interest	0	0
Real Estate-Construction [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired	0	0
Real Estate-Construction [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,970	202
Real Estate-Construction [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Real Estate-Construction [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	365	0
Real Estate-Residential Secured for Business Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	3,321	3,357
Current	338,061	289,927
Loans and leases held for investment	341,967	294,068
Recorded Investment 90 Days or more Past Due and Accruing Interest	162	0
Real Estate-Residential Secured for Business Purpose [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired	585	784
Real Estate-Residential Secured for Business Purpose [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,651	1,390
Real Estate-Residential Secured for Business Purpose [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	315	428
Real Estate-Residential Secured for Business Purpose [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,355	1,539
Real Estate-Residential Secured for Personal Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	5,509	5,027
Current	315,845	285,512
Loans and leases held for investment	321,574	290,808
Recorded Investment 90 Days or more Past Due and Accruing Interest	0	481
Real Estate-Residential Secured for Personal Purpose [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired	220	269
Real Estate-Residential Secured for Personal Purpose [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	4,368	3,243
Real Estate-Residential Secured for Personal Purpose [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,118	905
Real Estate-Residential Secured for Personal Purpose [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	23	879
Real Estate-Home Equity Secured for Personal Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	2,211	1,380
Current	182,059	161,459
Loans and leases held for investment	184,270	162,839
Recorded Investment 90 Days or more Past Due and Accruing Interest	148	171
Real Estate-Home Equity Secured for Personal Purpose [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired	0	0
Real Estate-Home Equity Secured for Personal Purpose [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,414	717
Real Estate-Home Equity Secured for Personal Purpose [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	333	142
Real Estate-Home Equity Secured for Personal Purpose [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	464	521
Loans to Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	555	561
Current	27,745	29,812
Loans and leases held for investment	28,300	30,373
Recorded Investment 90 Days or more Past Due and Accruing Interest	195	142
Loans to Individuals [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired	0	0
Loans to Individuals [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	221	324
Loans to Individuals [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	139	95
Loans to Individuals [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	195	142
Lease Financings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	3,390	3,878
Current	126,378	130,861
Loans and leases held for investment	129,768	134,739
Recorded Investment 90 Days or more Past Due and Accruing Interest	256	193
Lease Financings [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired	0	0
Lease Financings [Member] | Financing Receivables, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	1,143	1,731
Lease Financings [Member] | Financing Receivables, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	392	1,418
Lease Financings [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 1,855	$ 729