Loans and Leases - Age Analysis of Past Due Loans and Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	$ 19,783	$ 17,406
Current	5,255,366	4,330,588
Accruing loans and leases	5,275,149	4,347,994
Nonaccrual loans and leases	31,692	38,578
Loans and leases held for investment	5,306,841	4,386,836
Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired		264
Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	16,173	13,293
Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	2,218	3,970
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	1,392	143
Commercial, Financial and Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	1,433	2,772
Current	888,405	940,815
Accruing loans and leases	889,838	943,587
Nonaccrual loans and leases	2,827	3,442
Loans and leases held for investment	892,665	947,029
Commercial, Financial and Agricultural [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired		0
Commercial, Financial and Agricultural [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	1,104	2,602
Commercial, Financial and Agricultural [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	279	150
Commercial, Financial and Agricultural [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	50	20
Paycheck Protection Program Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	0
Current	483,773
Accruing loans and leases	483,773
Nonaccrual loans and leases	0
Loans and leases held for investment	483,773	0
Paycheck Protection Program Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	0
Paycheck Protection Program Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	0
Paycheck Protection Program Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	0
Real Estate-Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	5,034	3,739
Current	2,431,099	2,008,568
Accruing loans and leases	2,436,133	2,012,307
Nonaccrual loans and leases	22,739	27,928
Loans and leases held for investment	2,458,872	2,040,441
Real Estate-Commercial [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired		206
Real Estate-Commercial [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	3,230	3,473
Real Estate-Commercial [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	859	266
Real Estate-Commercial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	945	0
Real Estate-Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	361	0
Current	242,994	232,338
Accruing loans and leases	243,355	232,338
Nonaccrual loans and leases	0	257
Loans and leases held for investment	243,355	232,595
Real Estate-Construction [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired		0
Real Estate-Construction [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	361	0
Real Estate-Construction [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	0	0
Real Estate-Construction [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	0	0
Real Estate-Residential Secured for Business Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	4,329	4,520
Current	374,331	366,473
Accruing loans and leases	378,660	370,993
Nonaccrual loans and leases	2,786	2,980
Loans and leases held for investment	381,446	373,973
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		0
Real Estate-Residential Secured for Business Purpose [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	3,726	2,078
Real Estate-Residential Secured for Business Purpose [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	603	2,442
Real Estate-Residential Secured for Business Purpose [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	0	0
Real Estate-Residential Secured for Personal Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	6,137	3,415
Current	479,377	433,548
Accruing loans and leases	485,514	436,963
Nonaccrual loans and leases	2,086	2,038
Loans and leases held for investment	487,600	439,059
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		58
Real Estate-Residential Secured for Personal Purpose [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	6,057	2,969
Real Estate-Residential Secured for Personal Purpose [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	80	446
Real Estate-Residential Secured for Personal Purpose [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	0	0
Real Estate-Home Equity Secured for Personal Purpose [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	639	902
Current	164,923	172,106
Accruing loans and leases	165,562	173,008
Nonaccrual loans and leases	1,047	1,427
Loans and leases held for investment	166,609	174,435
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
Real Estate-Home Equity Secured for Personal Purpose [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	607	605
Real Estate-Home Equity Secured for Personal Purpose [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	32	297
Real Estate-Home Equity Secured for Personal Purpose [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	0	0
Loans to Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	449	304
Current	27,033	29,579
Accruing loans and leases	27,482	29,883
Nonaccrual loans and leases	0	0
Loans and leases held for investment	27,482	29,883
Loans to Individuals [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired		0
Loans to Individuals [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	190	157
Loans to Individuals [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	74	73
Loans to Individuals [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	185	74
Lease Financings [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	1,401	1,754
Current	163,431	147,161
Accruing loans and leases	164,832	148,915
Nonaccrual loans and leases	207	506
Loans and leases held for investment	165,039	149,421
Lease Financings [Member] | Valley Green Bank and Fox Chase Bank [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Acquired credit impaired		0
Lease Financings [Member] | Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	898	1,409
Lease Financings [Member] | Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	291	296
Lease Financings [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past due	$ 212	$ 49