Loans Receivable and Allowance for Loan Losses - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2019 USD ($) SecurityLoan borrower Contract	Dec. 31, 2018 USD ($) SecurityLoan borrower Contract	Dec. 31, 2017 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortization of interest income	$ 845,000	$ 894,000	$ 1,000,000.0
Principal amount of nonaccrual loans	$ 40,200,000	$ 25,700,000
Number of loans 90 days past due and still accruing | Contract	0	0
Increase in interest income	$ 1,700,000	$ 1,400,000	1,900,000
Amount of cash basis interest income recognized on impaired loans	2,123,000	$ 1,965,000	1,800,000
Impaired loan defined floor limit (greater than)	$ 1,000,000.0
Impaired loans number | SecurityLoan	158	152
Impaired loans	$ 70,641,000	$ 50,684,000
Number of borrowers | borrower	128	124
Charge-offs	$ 15,032,000	$ 30,018,000	$ 8,941,000
Allowances for loan losses	$ 5,067,000	$ 1,165,000
Weighted average modified interest rate	3.83%	5.41%
Yield percentage rate	3.82%	5.46%
Number of Loans | SecurityLoan	1	3
Loans declined	$ 153,000
Average balances of impaired loans	74,100,000	$ 53,900,000
Loan commitments	1,260,000,000	1,260,000,000
Undisbursed home equity and personal credit lines	212,400,000	233,900,000
Team Capital
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Certain loans acquired in transfer not accounted for as debt securities	$ 746,000	$ 899,000
Impaired Loans Troubled Debt Restructurings
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans number | SecurityLoan	147	148
Impaired loans	$ 48,300,000	$ 46,800,000
Number of troubled debt restructurings | SecurityLoan	133	129
Loans and leases receivable, impaired, nonperforming, accrual of interest	$ 42,700,000	$ 35,600,000
Charge-offs	11,600,000	8,300,000
Allowances for loan losses	177,130	119,000
No Allowance For Loan Losses Required
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired financing receivable with no related allowance	$ 16,000,000.0	$ 31,100,000
Commercial
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans number | SecurityLoan	158	152
Impaired loans	$ 70,600,000	$ 50,700,000
Commercial | Non Accrual
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans number | SecurityLoan	25	23
Impaired loans	$ 27,900,000	$ 15,100,000