Income Taxes (Details 3) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summarizes the changes in the valuation allowance
Balance at beginning of year	$ 26,968	$ 27,022	$ 3,939
Additions	104	31	25,043
Deductions	(11,650)	(85)	(1,960)
Balance at end of year	$ 15,422	$ 26,968	$ 27,022

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant