Fair Value (Carrying Amounts and Estimated Fair Values of Company's Financial Instruments) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financial Assets:
Interest Bearing Time Deposits with Banks	$ 250	$ 0
Loans, Net	2,712,236	2,125,944
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(3,072,632)	(2,484,052)
Time Deposits	(588,483)	(387,885)
Short-term Borrowings	(249,774)	(133,499)
Long-term Debt	(126,635)	(141,717)
Reported Value Measurement
Financial Assets:
Cash and Short-term Investments	96,550	70,359
Interest Bearing Time Deposits with Banks	250	0
Loans, Net	2,707,498	2,119,152
Accrued Interest Receivable	16,634	13,258
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(2,484,149)	(2,096,167)
Time Deposits	(588,483)	(387,885)
Short-term Borrowings	(249,774)	(133,499)
Long-term Debt	(126,635)	(141,717)
Accrued Interest Payable	(1,740)	(1,058)
Estimate of Fair Value Measurement
Financial Assets:
Cash and Short-term Investments	96,550	70,359
Interest Bearing Time Deposits with Banks	250	0
Loans, Net	2,689,393	2,120,154
Accrued Interest Receivable	16,634	13,258
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(2,484,149)	(2,096,167)
Time Deposits	(586,338)	(388,640)
Short-term Borrowings	(249,774)	(133,499)
Long-term Debt	(128,828)	(140,418)
Accrued Interest Payable	(1,740)	(1,058)
Estimate of Fair Value Measurement | Level 1
Financial Assets:
Cash and Short-term Investments	64,549	58,233
Interest Bearing Time Deposits with Banks	0	0
Loans, Net	0	0
Accrued Interest Receivable	0	0
Financial Liabilities:
Demand, Savings, and Money Market Deposits	(2,484,149)	(2,096,167)
Time Deposits	0	0
Short-term Borrowings	(204,500)	(92,000)
Long-term Debt	0	0
Accrued Interest Payable	0	0
Estimate of Fair Value Measurement | Level 2
Financial Assets:
Cash and Short-term Investments	32,001	12,126
Interest Bearing Time Deposits with Banks	250	0
Loans, Net	0	0
Accrued Interest Receivable	4,143	3,574
Financial Liabilities:
Demand, Savings, and Money Market Deposits	0	0
Time Deposits	(586,338)	(388,640)
Short-term Borrowings	(45,274)	(41,499)
Long-term Debt	(117,513)	(129,366)
Accrued Interest Payable	(1,718)	(1,042)
Estimate of Fair Value Measurement | Level 3
Financial Assets:
Cash and Short-term Investments	0	0
Interest Bearing Time Deposits with Banks	0	0
Loans, Net	2,689,393	2,120,154
Accrued Interest Receivable	12,491	9,684
Financial Liabilities:
Demand, Savings, and Money Market Deposits	0	0
Time Deposits	0	0
Short-term Borrowings	0	0
Long-term Debt	(11,315)	(11,052)
Accrued Interest Payable	$ (22)	$ (16)