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Fair Value Measurements (Carrying Amount, Estimated Fair Value, and Placement in Fair Value Hierarchy of Financial Instruments) (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Securities available for sale		$ 515,971	$ 417,917
Securities held to maturity, fair value		301,878	363,259
Carrying Amount [Member] | Level 1 Inputs [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents		282,070	112,947
Accrued interest receivable		16,230	11,308
Non-maturity deposits		3,523,698	2,375,486
Short-term borrowings		5,300	275,500
Accrued interest payable		5,737	10,942
Carrying Amount [Member] | Level 2 Inputs [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Securities available for sale		515,971	417,917
Securities held to maturity, fair value		290,946	359,000
Loans held for sale		7,076	4,224
Loans		3,501,231	3,186,875
FHLB and FRB stock		8,619	20,637
Time deposits		841,230	1,180,189
Long-term borrowings		39,258	39,273
Carrying Amount [Member] | Level 2 Inputs [Member] | Cash Flow Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, liabilities		647
Carrying Amount [Member] | Level 2 Inputs [Member] | Interest Rate Product [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, assets		23,079	6,419
Derivative instruments, liabilities		23,498	6,720
Carrying Amount [Member] | Level 2 Inputs [Member] | Credit Contract [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, assets		29	13
Derivative instruments, liabilities		47	18
Carrying Amount [Member] | Level 2 Inputs [Member] | Mortgage Banking [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, assets		891	119
Derivative instruments, liabilities		13	7
Carrying Amount [Member] | Level 3 Inputs [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Loans	[1]	17,913	3,630
Estimated Fair Value [Member] | Level 1 Inputs [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Cash and cash equivalents		282,070	112,947
Accrued interest receivable		16,230	11,308
Non-maturity deposits		3,523,698	2,375,486
Short-term borrowings		5,300	275,500
Accrued interest payable		5,737	10,942
Estimated Fair Value [Member] | Level 2 Inputs [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Securities available for sale		515,971	417,917
Securities held to maturity, fair value		301,878	363,259
Loans held for sale		7,076	4,224
Loans		3,536,646	3,201,814
FHLB and FRB stock		8,619	20,637
Time deposits		843,191	1,179,991
Long-term borrowings		45,224	41,083
Estimated Fair Value [Member] | Level 2 Inputs [Member] | Cash Flow Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, liabilities		647
Estimated Fair Value [Member] | Level 2 Inputs [Member] | Interest Rate Product [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, assets		23,079	6,419
Derivative instruments, liabilities		23,498	6,720
Estimated Fair Value [Member] | Level 2 Inputs [Member] | Credit Contract [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, assets		29	13
Derivative instruments, liabilities		47	18
Estimated Fair Value [Member] | Level 2 Inputs [Member] | Mortgage Banking [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative instruments, assets		891	119
Derivative instruments, liabilities		13	7
Estimated Fair Value [Member] | Level 3 Inputs [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Loans	[1]	$ 17,913	$ 3,630
[1] Comprised of collateral dependent loans.

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Non-Maturity Deposits Fair Value Disclosure

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Fair value portion of liabilities incurred for goods and services received that are used in an entity's business and related party payables.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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Amount of Federal Home Loan Bank (FHLB) and Federal Reserve Bank stock.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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