Income Taxes - Summary of Valuation Allowance for Deferred Tax Assets (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred Tax Assets, Valuation Allowance [Roll Forward]
Balance at beginning of year	$ 66,435	$ 44,321	$ 44,861
Additions	21,998	22,114	0
Deductions	0	0	540
Balance at end of year	$ 88,433	$ 66,435	$ 44,321

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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant