Stockholders' Equity - Common Stock Subject to Repurchase (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Common stock subject to repurchase related to stock options (in shares)	18,665	55,537
Liability related to early exercises of stock options	$ 0.2	$ 0.4

Aggregate carrying value as of the balance sheet date of the liabilities for stock option plans and other equity-based compensation arrangements.

No definition available.

Name:	us-gaap_DeferredCompensationSharebasedArrangementsLiabilityCurrentAndNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant