Summary of Significant Accounting Policies - Cumulative adjustments (Details) $ in Millions	12 Months Ended
Dec. 31, 2019 USD ($)
Reduction in accrued and other liabilities
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Correction of cumulative errors	$ 3.6
Reduction in research and development expenses
Quantifying Misstatement in Current Year Financial Statements [Line Items]
Correction of cumulative errors	$ 3.6

Amount of each individual error being corrected in the correcting adjustment.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 250
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 1.N)
-URI http://asc.fasb.org/extlink&oid=112272810&loc=d3e30840-122693

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Balance Type:	debit
Period Type:	duration