Investment Securities - Held-To-Maturity Investment (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Held-to-maturity Securities
Amortized Cost	$ 566,046	$ 624,099
Unrealized Gains	10,576	2,548
Unrealized Losses	1,120	7,975
Held-to-maturity, fair value	575,502	618,672
State and political subdivisions
Held-to-maturity Securities
Amortized Cost	565,546	623,599
Unrealized Gains	10,576	2,548
Unrealized Losses	1,080	7,915
Held-to-maturity, fair value	575,042	618,232
Trust preferred securities
Held-to-maturity Securities
Amortized Cost	500	500
Unrealized Gains	0	0
Unrealized Losses	40	60
Held-to-maturity, fair value	$ 460	$ 440

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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).

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

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