Fair Value Disclosures - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2018 USD ($) loan property	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingent Consideration from New Acquisition	$ 0	$ 0
Adjustment of Contingent Consideration	51,000	(247,000)
Valuation adjustments for loans held for sale	0	0
Carrying value of impaired loans held for investment	26,581,000
Valuation allowance of impaired loans held for investment	1,415,000	131,000
Servicing Rights Carrying Amount Before Valuation Allowance	6,800,000	6,600,000
Goodwill impairment	$ 0	0	$ 0
Number of properties written-down | property	5
OREO write-downs	$ 693,000
Other Real Estate, Number of Properties Transferred	4
Transfer of loans to other real estate owned	$ 477,000	729,000	$ 2,347,000
Number of properties sold | property	4
Proceeds from Sale of Real Estate	$ 490,000
Net gains on sales of other real estate owned	67,000
Other real estate owned	1,187,000	1,843,000
Servicing Rights Valuation Allowance		0
Sterner Insurance Associates Inc [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingent Consideration from New Acquisition		0
Adjustment of Contingent Consideration		(301,000)
Girard Partners [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingent Consideration from New Acquisition	0	0
Adjustment of Contingent Consideration	51,000	54,000
Held for Investment [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value of impaired loans held for investment	26,600,000	28,482,000
Valuation allowance of impaired loans held for investment	1,415,000	131,000
Lease Financings [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value of impaired loans held for investment	0	1,300,000
Valuation allowance of impaired loans held for investment	$ 0	$ 0
Derivative Financial Instruments, Liabilities [Member] | Interest Rate Swap [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Number of Loans with Unrealized Gain | loan	2
Unrealized Gain On Loans	$ 21,000
Commercial Loan [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Number of loans | loan	2