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Stockholders Equity Secondary Offering (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Secondary Offering [Abstract]
Shares, Issued	3,800,000
Shares Issued, Price Per Share	$ 34
Sale of Stock, Number of Shares Issued in Transaction	570,000
Proceeds from Issuance of Common Stock, Gross	$ 148,600
Proceeds from Issuance of Common Stock	$ 141,954	$ 0	$ 0

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- Definition

Proceeds from Issuance of Common Stock, Gross

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- Definition

Secondary Offering [Abstract]

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- Definition

The cash inflow from the additional capital contribution to the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585

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- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

+ References

No definition available.

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- Definition

Number of shares of stock issued as of the balance sheet date, including shares that had been issued and were previously outstanding but which are now held in the treasury.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644

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- Definition

Per share or per unit amount of equity securities issued.

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No definition available.

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