Other Comprehensive Income (Loss) - Summary of Available for Sale Securities Activity (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 191,542	$ 181,321
Other comprehensive income (loss)	3,050	(2,933)
Ending balance	197,787	181,372
Accumulated Net Investment Gain (Loss) Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(5,051)	(2,901)
Unrealized gains (losses) arising during the period	4,446	(4,052)
Reclassification of realized gains during the period	0	(136)
Related deferred taxes	(934)	879
Other comprehensive income (loss)	3,512	(3,309)
Ending balance	$ (1,539)	$ (6,210)

Accumulated Other Comprehensive Income (Loss) [Roll Forward]

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

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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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