Income Taxes - Schedule of NOL Carryforwards (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Federal and state research and development tax credit and other credit carryforwards	$ 88,200	$ 65,900
Domestic country
Operating Loss Carryforwards [Line Items]
NOL carryforwards	52,500	99,200
State and local jurisdiction
Operating Loss Carryforwards [Line Items]
NOL carryforwards	20,500	89,500
Foreign country
Operating Loss Carryforwards [Line Items]
NOL carryforwards	$ 8,500	$ 0

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible research tax credit carryforwards.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32632-109319

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32621-109319

Name:	us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant