Other Comprehensive Income (Loss) - Reclassification of Available-for-Sale Securities to Held-to-Maturity Securities (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Reclassification of Available-for-Sale Securities to Held-to-maturity Roll Forward [Roll Forward]
Beginning balance	$ 191,542	$ 181,321
Other comprehensive income (loss)	3,050	(2,933)
Ending balance	197,787	181,372
Accumulated Net Gain (Loss) on Securities Transferred from Available-for-Sale to Held-to-Maturity
Reclassification of Available-for-Sale Securities to Held-to-maturity Roll Forward [Roll Forward]
Beginning balance	(197)	(174)
Amortization of net unrealized gains (losses)	4	(10)
Related deferred taxes	(1)	2
Other comprehensive income (loss)	3	(8)
Ending balance	$ (194)	$ (182)

Reclassification of Available-for-Sale Securities to Held-to-maturity Roll Forward [Roll Forward]

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount of tax expense (benefit) allocated to other comprehensive income (loss).

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Amount before tax of reclassification adjustments of other comprehensive income (loss).

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Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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