Stock-Based Compensation - Early Exercise Of Stock Options (Details)	9 Months Ended
Sep. 30, 2019 shares
Stock-Based Compensation
Unvested balance at beginning of period	912
Early exercised	471
Vested	(508)
Unvested balance at end of period	875

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration