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Securities - Summary of Amortized Cost and Fair Values of Securities Held-to-maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost	$ 117,163	$ 138,846
Held-to-maturity Securities, Gross Unrealized Gains	450	190
Held-to-maturity Securities, Gross Unrealized Losses	(336)	(954)
Securities held-to-maturity, fair value	117,277	138,082
Obligations of States, Municipalities, and Political Subdivisions
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost	24,030	24,878
Held-to-maturity Securities, Gross Unrealized Gains	197	105
Held-to-maturity Securities, Gross Unrealized Losses	(82)	(229)
Securities held-to-maturity, fair value	24,145	24,754
Agency, Residential Mortgage-Backed Securities
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost	53,731	67,692
Held-to-maturity Securities, Gross Unrealized Gains	79	35
Held-to-maturity Securities, Gross Unrealized Losses	(203)	(283)
Securities held-to-maturity, fair value	53,607	67,444
Non-Agency, Residential Mortgage-Backed Securities
Schedule Of Held To Maturity Securities [Line Items]
Held-to-maturity Securities, Amortized Cost	39,402	46,276
Held-to-maturity Securities, Gross Unrealized Gains	174	50
Held-to-maturity Securities, Gross Unrealized Losses	(51)	(442)
Securities held-to-maturity, fair value	$ 39,525	$ 45,884

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- Definition

Amount after other than temporary impairment (OTTI) accretion, of investments in debt securities classified as held-to-maturity.

+ References

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