Fair Value of Financial Instruments (Fair Values of Financial Assets and Liabilities on Balance Sheets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Jun. 30, 2018
Fair Value
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	$ 28,132	$ 29,728
Cash and Cash Equivalents, Fair Value Disclosure	72,194	84,802
Unrealized Gain (Loss) on Investments	6,500
Held-to-maturity Securities, Fair Value	41,213	38,426
Financial assets:
Bank premises and equipment, net	52,510	58,292
Bank owned life insurance	62,176	67,943
Financial liabilities:
Federal Reserve Bank Stock	10,179	10,959
Loans Receivable and Loans Held-for-sale, Fair Value Disclosure	2,274,194	2,686,506
Servicing Asset	2,305	2,622
Deposits, Fair Value Disclosure	2,730,071	2,943,138
Short-term Debt, Fair Value	209,628	360,705
Long-term Debt, Fair Value	142,108	109,104
Carrying Amount
Financial liabilities:
Other Investments	38,371	41,713
Loans Receivable and Loans Held-for-sale, Fair Value Disclosure	2,338,344	2,667,225
Deposits, Fair Value Disclosure	2,730,330	2,949,259
Short-term Debt, Fair Value	209,491	360,727
Long-term Debt, Fair Value	144,019	113,085
Level 2
Fair Value
Held-to-maturity Securities, Fair Value	41,213	38,426
Financial liabilities:
Other Investments	38,371	41,713
Commercial mortgage-backed securities | Level 2
Fair Value
Held-to-maturity Securities, Fair Value	4,569	3,547
Commercial mortgage-backed securities | Level 1
Fair Value
Held-to-maturity Securities, Fair Value	0	0
Residential mortgage-backed securities | Level 2
Fair Value
Held-to-maturity Securities, Fair Value	32,227	29,853
Residential mortgage-backed securities | Level 1
Fair Value
Held-to-maturity Securities, Fair Value	0	0
States and political subdivisions | Level 2
Fair Value
Held-to-maturity Securities, Fair Value	4,417	5,026
States and political subdivisions | Level 1
Fair Value
Held-to-maturity Securities, Fair Value	0	0
Commercial mortgage-backed securities
Fair Value
Held-to-maturity Securities, Fair Value	4,569	3,547
Residential mortgage-backed securities
Fair Value
Held-to-maturity Securities, Fair Value	32,227	29,853
States and political subdivisions
Fair Value
Held-to-maturity Securities, Fair Value	4,417	5,026
Recurring Basis [Member] | Level 2
Fair Value
Investment in Federal Home Loan Bank Stock, Fair Value Disclosure	28,132	29,728
Financial liabilities:
Federal Reserve Bank Stock	10,179	10,959
Recurring Basis [Member] | Non-qualified deferred comp
Financial liabilities:
Other Investments		966
Recurring Basis [Member] | FHLMC stock
Financial liabilities:
Other Investments		$ 60
Recurring Basis [Member] | FHLMC stock | Level 2
Financial liabilities:
Other Investments	$ 60