(Interest Income - Taxable/Non-Taxable Invest. Sec.) (Details 5) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Interest Income from Investment Securities, Taxable	$ 28,671	$ 25,767
Interest Income from Investment Securities, Non-Taxable	4,766	5,023
Total Interest Income from Investment Securities	$ 33,437	$ 30,790

Amount of operating interest income, including, but not limited to, amortization and accretion of premiums and discounts on securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(e))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Amount of operating interest income, including amortization and accretion of premiums and discounts, on securities exempt from state, federal and other income tax.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.2)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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Amount of operating interest income, including amortization and accretion of premiums and discounts, on securities subject to state, federal and other income tax.

+ References

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- References

No definition available.

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