Summary of Significant Accounting Policies - Additional Information (Detail)			12 Months Ended
		Jan. 01, 2019 USD ($)	Dec. 31, 2019 USD ($) Office community shares	Dec. 31, 2018 USD ($) shares
Summary Of Significant Accounting Policies [Line Items]
Number of banking offices (in offices) | Office			39
Number of retirement communities with banking and trust services (in communities) | community			14
Federal Reserve Bank stock			$ 14,600,000	$ 14,600,000
FHLB Stock			13,500,000	13,600,000
Other-than-temporary impairment of equity securities			$ 0	$ 0
Number of days loan or lease past due for nonaccrual of interest status			90 days
Maximum stock issuable under Univest dividend reinvestment plan | shares			1,968,750
Stock issued under Univest dividend reinvestment plan | shares			61,955	57,838
Shares available for future purchase under Univest dividend reinvestment plan | shares			197,490
Maximum stock issuable under employees stock purchase plan | shares			3,698,974
Operating lease liabilities			$ 37,617,000
Operating lease right-of-use asset			34,418,000
Investment securities available-for-sale			$ 246,924,000	$ 328,507,000
Nineteen Ninety Six Employee Stock Purchase Plan [Member]
Summary Of Significant Accounting Policies [Line Items]
Maximum stock issuable under employees stock purchase plan | shares			984,375
Minimum employees contributions to the purchase plan			2.00%
Maximum employees contributions to the purchase plan			10.00%
Employee stock purchase plan, percentage of purchase price of stock based on closing price on last trading day of each quarter end			90.00%
Maximum discount from fair value to recognize compensation expense for employee stock purchase plan			5.00%
Stock issued under employee stock purchase plans | shares			28,714	26,628
Shares available for future purchase under employee stock purchase plans | shares			599,831
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Period over which optioned shares become exercisable			3 years
Minimum [Member] | Customer Related [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangibles and other identified intangibles with finite useful lives			5 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Period over which optioned shares become exercisable			10 years
Maximum [Member] | Core Deposits and Other Intangible Assets [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangibles and other identified intangibles with finite useful lives			15 years
Maximum [Member] | Customer Related [Member]
Summary Of Significant Accounting Policies [Line Items]
Intangibles and other identified intangibles with finite useful lives			12 years
Building [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life			40 years
Owned Building on Leased Land or Land Improvements [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, description			new buildings constructed on leased land or land improvements, the estimated useful life is the initial term including anticipated renewable terms, typically not exceeding twenty-five years
Furniture, Fixtures and Equipment [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life			3 years
Furniture, Fixtures and Equipment [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated useful life			10 years
Restricted Stock [Member]
Summary Of Significant Accounting Policies [Line Items]
Period over which optioned shares become exercisable			3 years
Callable [Member]
Summary Of Significant Accounting Policies [Line Items]
Investment securities available-for-sale				$ 11,300,000
Accounting Standards Update 2016-02 [Member]
Summary Of Significant Accounting Policies [Line Items]
Operating lease liabilities		$ 39,600,000
Operating lease right-of-use asset		36,600,000
Deferred rent liability		1,000,000.0
Cumulative effect of new accounting principle in period of adoption				(1,525,000)
Accounting Standards Update 2017-08 [Member]
Summary Of Significant Accounting Policies [Line Items]
Cumulative effect of new accounting principle in period of adoption				(39,000)
Accounting Standards Update 2017-08 [Member] | Debt Securities [Member]
Summary Of Significant Accounting Policies [Line Items]
Reduction of unamortized premium balance		49,000
Reduction of retained earnings, net of tax, for incremental amortization		39,000
Retained Earnings [Member] | Accounting Standards Update 2016-02 [Member]
Summary Of Significant Accounting Policies [Line Items]
Cumulative effect of new accounting principle in period of adoption		1,500,000		(1,525,000)	[1]
Retained Earnings [Member] | Accounting Standards Update 2017-08 [Member]
Summary Of Significant Accounting Policies [Line Items]
Cumulative effect of new accounting principle in period of adoption	[1]			$ (39,000)
Cash Flow Hedging [Member]
Summary Of Significant Accounting Policies [Line Items]
Gain on fair value hedge ineffectiveness		$ 83,000

[1] (1) See Note 1, "Summary of Significant Accounting Policies - Accounting Pronouncements Adopted in 2019" for additional information.