Investment Securities - Securities Held to Maturity in an Unrealized Loss Position (Details) - Mortgage-backed securities - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value
Held to maturity securities, less than 12 months, fair value	$ 1,814	$ 1,315
Held to maturity securities, 12 months or longer, fair value	7,187	7,123
Held to maturity securities, fair value	9,001	8,438
Unrealized Losses
Held to maturity securities, less than 12 months, unrealized losses	(13)	(4)
Held to maturity securities, 12 months or longer, unrealized losses	(130)	(242)
Held to maturity securities, unrealized losses	$ (143)	$ (246)

Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for 12 months or longer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 320
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- Definition

Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.

+ References

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-Publisher FASB
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Fair value of investment in debt security measured at amortized cost (held-to-maturity), in unrealized loss position.

+ References

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-Publisher FASB
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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity), in continuous loss position for less than 12 months.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), in continuous unrealized loss position for less than 12 months.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity), in continuous unrealized loss position for 12 months or longer.

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