Summary of Significant Accounting Policies - AOCIL (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			$ (552)
(Decrease) increase in other comprehensive loss	$ 1,061	$ 46	1,347	$ (92)
Reclassifications of losses realized from sale of available-for-sale securities				32
Increase (decrease) in other comprehensive income (loss)	1,061	46	1,347	(92)
Ending balance	795		795
Unrealized (loss) gain on available-for-sale securities, net of tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
(Decrease) increase in other comprehensive loss	1,061	46	1,347	(124)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(266)	(904)	(552)	(766)
Ending balance	$ 795	$ (858)	$ 795	$ (858)

Amount of adjustment to accumulated other comprehensive income or loss.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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Amount after tax and reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

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

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