Fair Value of Financial Instruments (Fair Values of Financial Assets and Liabilities on Balance Sheets) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, at Carrying Value	$ 246,073	$ 152,100		$ 219,274			$ 115,193
Held-to-maturity investment securities, at amortized cost (fair value of $179,887 at June 30, 2021 and $68,082 at December 31, 2020) (a)	180,224	66,458
Debt Securities, Held-to-maturity, Fair Value	179,887	68,082
Loans held for sale	2,751	4,659
Cash Surrender Value, Fair Value Disclosure	72,482	71,591
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Valuation Allowance for Impairment of Recognized Servicing Assets, Deductions for Aggregate Write-Downs	16	161
Commercial Portfolio Segment
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Financing Receivable, Allowance for Credit Loss	8,686	12,763	$ 10,108	$ 10,106	$ 8,743	$ 4,960
Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and cash equivalents	246,073	152,100
Debt Securities, Held-to-maturity, Fair Value	179,887	68,082
Other investment securities	32,212	37,261
Loans and leases, net of deferred fees and costs	3,487,505	3,458,732
Loans held for sale	2,919	4,733
Cash Surrender Value, Fair Value Disclosure	72,482	71,591
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Deposits, Fair Value Disclosure	3,963,511	3,773,602
Short-term Debt, Fair Value	67,000	74,170
Long-term Debt, Fair Value	99,328	117,364
Reported Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and cash equivalents	246,073	152,100
Held-to-maturity investment securities, at amortized cost (fair value of $179,887 at June 30, 2021 and $68,082 at December 31, 2020) (a)	180,224	66,458
Federal Home Loan Bank ("FHLB") stock	16,523	21,718
Federal Reserve Bank ("FRB") stock	13,311	13,311
Other investment securities	32,212	37,261
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Deposits, Fair Value Disclosure	4,232,623	3,910,459
Short-term Debt, Fair Value	66,496	73,261
Long-term Debt, Fair Value	95,081	110,568
States and political subdivisions
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Held-to-maturity investment securities, at amortized cost (fair value of $179,887 at June 30, 2021 and $68,082 at December 31, 2020) (a)	102,425	35,199
Debt Securities, Held-to-maturity, Fair Value	101,740	35,484
States and political subdivisions | Reported Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Held-to-maturity investment securities, at amortized cost (fair value of $179,887 at June 30, 2021 and $68,082 at December 31, 2020) (a)	102,224	35,139
States and political subdivisions | Level 2
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Debt Securities, Held-to-maturity, Fair Value	101,740	35,484
Residential mortgage-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Debt Securities, Held-to-maturity, Fair Value	24,743	26,742
Residential mortgage-backed securities | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Debt Securities, Held-to-maturity, Fair Value	24,743	26,742
Residential mortgage-backed securities | Reported Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Held-to-maturity investment securities, at amortized cost (fair value of $179,887 at June 30, 2021 and $68,082 at December 31, 2020) (a)	24,067	25,890
Commercial mortgage-backed securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Debt Securities, Held-to-maturity, Fair Value	23,959	5,856
Commercial mortgage-backed securities | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Debt Securities, Held-to-maturity, Fair Value	23,959	5,856
Commercial mortgage-backed securities | Reported Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Held-to-maturity investment securities, at amortized cost (fair value of $179,887 at June 30, 2021 and $68,082 at December 31, 2020) (a)	23,830	5,429
Agency Securities
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Debt Securities, Held-to-maturity, Fair Value	29,445
Agency Securities | Reported Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Held-to-maturity investment securities, at amortized cost (fair value of $179,887 at June 30, 2021 and $68,082 at December 31, 2020) (a)	30,103	0
Agency Securities | Level 2
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Debt Securities, Held-to-maturity, Fair Value	29,445	0
Nonqualified Plan [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Other investment securities	2,013	1,867
Nonqualified Plan [Member] | Reported Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Other investment securities	2,013	1,867
Other Security Investments [Member] | Reported Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Other investment securities	$ 365	$ 365