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Borrowed Funds (Borrowed funds obligations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Schedule of Debt [Line Items]
Borrowed funds	$ 303,113		$ 344,878
Borrowed funds, Rate	1.74%		1.65%
Securities Sold under Agreements to Repurchase [Member]
Schedule of Debt [Line Items]
Short-term Debt, Maximum Month-end Outstanding Amount	$ 38,967	$ 58,088
Borrowed funds	$ 32,913		$ 54,878
Borrowed funds, Rate	0.09%		0.12%
Federal Funds Purchased [Member]
Schedule of Debt [Line Items]
Short-term Debt, Maximum Month-end Outstanding Amount	$ 10,200	$ 5,200
Borrowed funds	$ 10,200		$ 0
Borrowed funds, Rate	1.89%		0.00%
Federal Home Loan Bank Advances [Member]
Schedule of Debt [Line Items]
Borrowed funds	$ 260,000		$ 290,000
Borrowed funds, Rate	1.94%		1.94%

X

- Definition

[Line Items] for Schedule of Debt [Table]

+ References

No definition available.

+ Details

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- Definition

Represents the aggregate of total long-term debt, including current maturities and short-term debt.

+ References

No definition available.

+ Details

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- Definition

Weighted average interest rate of debt outstanding.

+ References

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- Definition

For the form of debt having an initial term of less than one year or less than the normal operating cycle, if longer, maximum month-end borrowings during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(19))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Details

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