Borrowings (Additional Information) (Details) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Short-term Debt [Line Items]
Line of credit, maximum borrowing capacity		$ 10,000,000.0
Line of credit, amount outstanding		$ 0
Line of credit, expiration date		Dec. 20, 2018
Loans Pledged as Collateral		$ 144,400,000
Available-for-sale Securities Pledged as Collateral		31,000
Securities Sold under Agreements to Repurchase	[1]	244,646,000	$ 230,612,000
Amortization of Debt Issuance Costs		54,000
Federal Home Loan Bank Advances [Member]
Short-term Debt [Line Items]
Line of credit, maximum borrowing capacity		9,900,000	9,900,000
Line of credit, amount outstanding		0	$ 0
PNC [Member]
Short-term Debt [Line Items]
Line of credit, maximum borrowing capacity		50,000,000
Federal Reserve Bank Advances [Member]
Short-term Debt [Line Items]
Line of credit, maximum borrowing capacity		$ 99,800,000
Short Term Borrowing Maturing January 2017 [Member] | Short-term Debt | Minimum [Member]
Short-term Debt [Line Items]
Federal Home Loan Bank Advances Maturities Summary Fixed Interest Rate Within One Year From Balance Sheet Date		1.45%
Short Term Borrowing Maturing January 2017 [Member] | Short-term Debt | Maximum [Member]
Short-term Debt [Line Items]
Federal Home Loan Bank Advances Maturities Summary Fixed Interest Rate Within One Year From Balance Sheet Date		1.63%

[1] (1) Presented within short-term borrowings on the consolidated statements of condition.