Cash, Cash Equivalents and Short-Term Investments - Additional Information (Details)	6 Months Ended	12 Months Ended
Jun. 30, 2019	Dec. 31, 2018
Maximum
Cash And Cash Equivalents [Line Items]
Short term investments contractual maturity term	1 year	1 year

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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