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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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Cash paid for expenses incurred during underwriting activities (the process to review insurance applications, evaluate risks, accept or reject applications, and determine the premiums to be charged) for insurance companies.

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The cash outflow for cost incurred directly with the issuance of an equity security.

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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

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The cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, and other types of equity.

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Price of a single share of a number of saleable stocks of a company.

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No definition available.

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Number of new stock issued during the period.

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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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No definition available.

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The Company and Basis of Presentation (IPO and Capital Requirements) (Details) - USD ($) $ / shares in Units, $ in Thousands				3 Months Ended	6 Months Ended	12 Months Ended
	Feb. 12, 2018	Sep. 08, 2016	Aug. 04, 2016	Mar. 31, 2018	Jun. 30, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jun. 30, 2019	Aug. 03, 2016
Sale of Stock
Issuance of stock (in shares)	3,592,858			3,592,858
Other offering expenses					$ 2,093	$ 2,091	$ 1,287	$ 3,963
Common stock, shares authorized						100,000,000	100,000,000		100,000,000	100,000,000
Preferred stock, shares authorized						10,000,000	10,000,000		10,000,000	10,000,000
Common stock, par value (in dollar per share)						$ 0.001	$ 0.001		$ 0.001
Preferred stock, par value (in dollar per share)						$ 0.001	$ 0.001		$ 0.001	$ 0.001
IPO
Sale of Stock
Issuance of stock (in shares)			3,000,000
Share price (in dollars per share)			$ 10.00
Net proceeds			$ 26,100
Underwriting discounts and commissions		$ 2,100
Other offering expenses		$ 2,100
Overallotment
Sale of Stock
Issuance of stock (in shares)	450,000	27,755		450,000
Share price (in dollars per share)		$ 10.00